RNA recognition motif 1 (RRM1) found in Schizosaccharomyces pombe meiotically up-regulated gene 28 protein (Mug28) and similar proteins; Mug28 is a meiosis-specific protein that regulates spore wall formation. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the first RRM motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871  94 SFLVVGGNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTG-----LSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRV 168
Cdd:cd21620    1 ERSLYVGNLPQTCQSEDLIILFEPYGNVCGAHIASRKKVKvswvkPSKLFAFVEFETKEAATTAIVLLNGITYMGCQLKV 80

                 ....
gi 357482871 169 EWST 172
Cdd:cd21620   81 EWSH 84

RNA recognition motif 1 (RRM1) found in Schizosaccharomyces pombe meiotically up-regulated gene 28 protein (Mug28) and similar proteins; Mug28 is a meiosis-specific protein that regulates spore wall formation. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the first RRM motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871  94 SFLVVGGNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTG-----LSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRV 168
Cdd:cd21620    1 ERSLYVGNLPQTCQSEDLIILFEPYGNVCGAHIASRKKVKvswvkPSKLFAFVEFETKEAATTAIVLLNGITYMGCQLKV 80

                 ....
gi 357482871 169 EWST 172
Cdd:cd21620   81 EWSH 84

RNA recognition motif. (a.k.a. RRM, RBD, or RNP domain); The RRM motif is probably diagnostic of an RNA binding protein. RRMs are found in a variety of RNA binding proteins, including various hnRNP proteins, proteins implicated in regulation of alternative splicing, and protein components of snRNPs. The motif also appears in a few single stranded DNA binding proteins. The RRM structure consists of four strands and two helices arranged in an alpha/beta sandwich, with a third helix present during RNA binding in some cases The C-terminal beta strand (4th strand) and final helix are hard to align and have been omitted in the SEED alignment The LA proteins have an N terminal rrm which is included in the seed. There is a second region towards the C terminus that has some features characteriztic of a rrm but does not appear to have the important structural core of a rrm. The LA proteins are one of the main autoantigens in Systemic lupus erythematosus (SLE), an autoimmune disease.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 357482871  100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQhTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILR 167
Cdd:pfam00076   4 GNLPPDTTEEDLKDLFSKFGPIKSIRLVRDE-TGRSKGFAFVEFEDEEDAEKAIEALNGKELGGRELK 70

polyadenylate binding protein, human types 1, 2, 3, 4 family; These eukaryotic proteins recognize the poly-A of mRNA and consists of four tandem RNA recognition domains at the N-terminus (rrm: pfam00076) followed by a PABP-specific domain (pfam00658) at the C-terminus. The protein is involved in the transport of mRNA's from the nucleus to the cytoplasm. There are four paralogs in Homo sapiens which are expressed in testis, platelets, broadly expressed and of unknown tissue range.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871   70 FVPPYLKAFVKEMTtlsSDDKNKNSFLvvgGNLPPETRNHDLLQLFQPFGHVIGADIAIAQhTGLSGRFAFVNFATKEAA 149
Cdd:TIGR01628 160 YVGRFIKKHEREAA---PLKKFTNLYV---KNLDPSVNEDKLRELFAKFGEITSAAVMKDG-SGRSRGFAFVNFEKHEDA 232

                          90
                  ....*....|
gi 357482871  150 QSAIERLNGI 159
Cdd:TIGR01628 233 AKAVEEMNGK 242

RNA recognition motif 1 (RRM1) found in Schizosaccharomyces pombe meiotically up-regulated gene 28 protein (Mug28) and similar proteins; Mug28 is a meiosis-specific protein that regulates spore wall formation. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the first RRM motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871  94 SFLVVGGNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTG-----LSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRV 168
Cdd:cd21620    1 ERSLYVGNLPQTCQSEDLIILFEPYGNVCGAHIASRKKVKvswvkPSKLFAFVEFETKEAATTAIVLLNGITYMGCQLKV 80

                 ....
gi 357482871 169 EWST 172
Cdd:cd21620   81 EWSH 84

RNA recognition motif;

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 357482871   100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRV 168
Cdd:smart00360   5 GNLPPDTTEEELRELFSKFGKVESVRLVRDKETGKSKGFAFVEFESEEDAEKALEALNGKELDGRPLKV 73

RNA recognition motif (RRM) superfamily; RRM, also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), is a highly abundant domain in eukaryotes found in proteins involved in post-transcriptional gene expression processes including mRNA and rRNA processing, RNA export, and RNA stability. This domain is 90 amino acids in length and consists of a four-stranded beta-sheet packed against two alpha-helices. RRM usually interacts with ssRNA, but is also known to interact with ssDNA as well as proteins. RRM binds a variable number of nucleotides, ranging from two to eight. The active site includes three aromatic side-chains located within the conserved RNP1 and RNP2 motifs of the domain. The RRM domain is found in a variety heterogeneous nuclear ribonucleoproteins (hnRNPs), proteins implicated in regulation of alternative splicing, and protein components of small nuclear ribonucleoproteins (snRNPs).

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIaIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVE 169
Cdd:cd00590    4 GNLPPDTTEEDLRELFSKFGEVVSVRI-VRDRDGKSKGFAFVEFESPEDAEKALEALNGTELGGRPLKVS 72

RNA recognition motif 2 (RRM2) found in Nicotiana sylvestris chloroplastic 33 kDa ribonucleoprotein (NsCP33) and similar proteins; The family includes NsCP33, Arabidopsis thaliana chloroplastic 31 kDa ribonucleoprotein (CP31A) and mitochondrial glycine-rich RNA-binding protein 2 (AtGR-RBP2). NsCP33 may be involved in splicing and/or processing of chloroplast RNA's. AtCP31A, also called RNA-binding protein 1/2/3 (AtRBP33), or RNA-binding protein CP31A, or RNA-binding protein RNP-T, or RNA-binding protein cp31, is required for specific RNA editing events in chloroplasts and stabilizes specific chloroplast mRNAs, as well as for normal chloroplast development under cold stress conditions by stabilizing transcripts of numerous mRNAs under these conditions. CP31A may modulate telomere replication through RNA binding domains. AtGR-RBP2, also called AtRBG2, or glycine-rich protein 2 (AtGRP2), or mitochondrial RNA-binding protein 1a (At-mRBP1a), plays a role in RNA transcription or processing during stress. It binds RNAs and DNAs sequence with a preference to single-stranded nucleic acids. AtGR-RBP2 displays strong affinity to poly(U) sequence. It exerts cold and freezing tolerance, probably by exhibiting an RNA chaperone activity during the cold and freezing adaptation process. Some members in this family contain two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the second RRM motif.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDY 161
Cdd:cd21608    5 GNLSWDTTEDDLRDLFSEFGEVESAKVITDRETGRSRGFGFVTFSTAEAAEAAIDALNGKEL 66

RNA recognition motif 1 (RRM1) and 2 (RRM2) found in RRM-containing coactivator activator/modulator (CoAA) and similar proteins; This subfamily corresponds to the RRM in CoAA (also known as RBM14 or PSP2) and RNA-binding protein 4 (RBM4). CoAA is a heterogeneous nuclear ribonucleoprotein (hnRNP)-like protein identified as a nuclear receptor coactivator. It mediates transcriptional coactivation and RNA splicing effects in a promoter-preferential manner, and is enhanced by thyroid hormone receptor-binding protein (TRBP). CoAA contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a TRBP-interacting domain. RBM4 is a ubiquitously expressed splicing factor with two isoforms, RBM4A (also known as Lark homolog) and RBM4B (also known as RBM30), which are very similar in structure and sequence. RBM4 may also function as a translational regulator of stress-associated mRNAs as well as play a role in micro-RNA-mediated gene regulation. RBM4 contains two N-terminal RRMs, a CCHC-type zinc finger, and three alanine-rich regions within their C-terminal regions. This family also includes Drosophila RNA-binding protein lark (Dlark), a homolog of human RBM4. It plays an important role in embryonic development and in the circadian regulation of adult eclosion. Dlark shares high sequence similarity with RBM4 at the N-terminal region. However, Dlark has three proline-rich segments instead of three alanine-rich segments within the C-terminal region.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAiaqhtglsGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVE 169
Cdd:cd12343    5 GNLPDAATSEELRALFEKYGKVTECDIV--------KNYAFVHMEKEEDAEDAIKALNGYEFMGSRINVE 66

RNA recognition motif 3 (RRM3) found in CUGBP Elav-like family member CELF-1, CELF-2 and similar proteins; This subgroup corresponds to the RRM3 of CELF-1 (also termed BRUNOL-2, or CUG-BP1, or EDEN-BP) and CELF-2 (also termed BRUNOL-3, or ETR-3, or CUG-BP2, or NAPOR), both of which belong to the CUGBP1 and ETR-3-like factors (CELF) or BRUNOL (Bruno-like) family of RNA-binding proteins that have been implicated in the regulation of pre-mRNA splicing and in the control of mRNA translation and deadenylation. CELF-1 is strongly expressed in all adult and fetal tissues tested. Human CELF-1 is a nuclear and cytoplasmic RNA-binding protein that regulates multiple aspects of nuclear and cytoplasmic mRNA processing, with implications for onset of type 1 myotonic dystrophy (DM1), a neuromuscular disease associated with an unstable CUG triplet expansion in the 3'-UTR (3'-untranslated region) of the DMPK (myotonic dystrophy protein kinase) gene; it preferentially targets UGU-rich mRNA elements. It has been shown to bind to a Bruno response element, a cis-element involved in translational control of oskar mRNA in Drosophila, and share sequence similarity to Bruno, the Drosophila protein that mediates this process. The Xenopus homolog embryo deadenylation element-binding protein (EDEN-BP) mediates sequence-specific deadenylation of Eg5 mRNA. It specifically binds to the EDEN motif in the 3'-untranslated regions of maternal mRNAs and targets these mRNAs for deadenylation and translational repression. CELF-1 contain three highly conserved RNA recognition motifs (RRMs), also known as RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains): two consecutive RRMs (RRM1 and RRM2) situated in the N-terminal region followed by a linker region and the third RRM (RRM3) close to the C-terminus of the protein. The two N-terminal RRMs of EDEN-BP are necessary for the interaction with EDEN as well as a part of the linker region (between RRM2 and RRM3). Oligomerization of EDEN-BP is required for specific mRNA deadenylation and binding. CELF-2 is expressed in all tissues at some level, but highest in brain, heart, and thymus. It has been implicated in the regulation of nuclear and cytoplasmic RNA processing events, including alternative splicing, RNA editing, stability and translation. CELF-2 shares high sequence identity with CELF-1, but shows different binding specificity; it binds preferentially to sequences with UG repeats and UGUU motifs. It has been shown to bind to a Bruno response element, a cis-element involved in translational control of oskar mRNA in Drosophila, and share sequence similarity to Bruno, the Drosophila protein that mediates this process. It also binds to the 3'-UTR of cyclooxygenase-2 messages, affecting both translation and mRNA stability, and binds to apoB mRNA, regulating its C to U editing. CELF-2 also contain three highly conserved RRMs. It binds to RNA via the first two RRMs, which are important for localization in the cytoplasm. The splicing activation or repression activity of CELF-2 on some specific substrates is mediated by RRM1/RRM2. Both, RRM1 and RRM2 of CELF-2, can activate cardiac troponin T (cTNT) exon 5 inclusion. In addition, CELF-2 possesses a typical arginine and lysine-rich nuclear localization signal (NLS) in the C-terminus, within RRM3.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 357482871 101 NLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVEWSTP 173
Cdd:cd12638   14 HLPQEFGDQDILQMFMPFGNVVSAKVFIDKQTNLSKCFGFVSYDNPVSAQAAIQAMNGFQIGMKRLKVQLKRS 86

RNA recognition motif (RRM) found in cleavage stimulation factor subunit 2 (CSTF2), yeast ortholog mRNA 3'-end-processing protein RNA15 and similar proteins; This subfamily corresponds to the RRM domain of CSTF2, its tau variant and eukaryotic homologs. CSTF2, also termed cleavage stimulation factor 64 kDa subunit (CstF64), is the vertebrate conterpart of yeast mRNA 3'-end-processing protein RNA15. It is expressed in all somatic tissues and is one of three cleavage stimulatory factor (CstF) subunits required for polyadenylation. CstF64 contains an N-terminal RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), a CstF77-binding domain, a repeated MEARA helical region and a conserved C-terminal domain reported to bind the transcription factor PC-4. During polyadenylation, CstF interacts with the pre-mRNA through the RRM of CstF64 at U- or GU-rich sequences within 10 to 30 nucleotides downstream of the cleavage site. CSTF2T, also termed tauCstF64, is a paralog of the X-linked cleavage stimulation factor CstF64 protein that supports polyadenylation in most somatic cells. It is expressed during meiosis and subsequent haploid differentiation in a more limited set of tissues and cell types, largely in meiotic and postmeiotic male germ cells, and to a lesser extent in brain. The loss of CSTF2T will cause male infertility, as it is necessary for spermatogenesis and fertilization. Moreover, CSTF2T is required for expression of genes involved in morphological differentiation of spermatids, as well as for genes having products that function during interaction of motile spermatozoa with eggs. It promotes germ cell-specific patterns of polyadenylation by using its RRM to bind to different sequence elements downstream of polyadenylation sites than does CstF64. The family also includes yeast ortholog mRNA 3'-end-processing protein RNA15 and similar proteins. RNA15 is a core subunit of cleavage factor IA (CFIA), an essential transcriptional 3'-end processing factor from Saccharomyces cerevisiae. RNA recognition by CFIA is mediated by an N-terminal RRM, which is contained in the RNA15 subunit of the complex. The RRM of RNA15 has a strong preference for GU-rich RNAs, mediated by a binding pocket that is entirely conserved in both yeast and vertebrate RNA15 orthologs.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVEWS 171
Cdd:cd12398    6 GNIPYDATEEQLKEIFSEVGPVVSFRLVTDRETGKPKGYGFCEFRDAETALSAVRNLNGYELNGRPLRVDFA 77

RNA recognition motif (RRM) found in transformer-2 protein homolog TRA2-alpha, TRA2-beta and similar proteins; This subfamily corresponds to the RRM of two mammalian homologs of Drosophila transformer-2 (Tra2), TRA2-alpha, TRA2-beta (also termed SFRS10), and similar proteins found in eukaryotes. TRA2-alpha is a 40-kDa serine/arginine-rich (SR) protein that specifically binds to gonadotropin-releasing hormone (GnRH) exonic splicing enhancer on exon 4 (ESE4) and is necessary for enhanced GnRH pre-mRNA splicing. It strongly stimulates GnRH intron A excision in a dose-dependent manner. In addition, TRA2-alpha can interact with either 9G8 or SRp30c, which may also be crucial for ESE-dependent GnRH pre-mRNA splicing. TRA2-beta is a serine/arginine-rich (SR) protein that controls the pre-mRNA alternative splicing of the calcitonin/calcitonin gene-related peptide (CGRP), the survival motor neuron 1 (SMN1) protein and the tau protein. Both, TRA2-alpha and TRA2-beta, contains a well conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), flanked by the N- and C-terminal arginine/serine (RS)-rich regions.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 357482871 101 NLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVEWS 171
Cdd:cd12363    8 GLSLYTTERDLREVFSRYGPIEKVQVVYDQQTGRSRGFGFVYFESVEDAKEAKERLNGQEIDGRRIRVDYS 78

RNA recognition motif 3 (RRM3) found in the Hu proteins family; This subfamily corresponds to the RRM3 of the Hu proteins family which represent a group of RNA-binding proteins involved in diverse biological processes. Since the Hu proteins share high homology with the Drosophila embryonic lethal abnormal vision (ELAV) protein, the Hu family is sometimes referred to as the ELAV family. Drosophila ELAV is exclusively expressed in neurons and is required for the correct differentiation and survival of neurons in flies. The neuronal members of the Hu family include Hu-antigen B (HuB or ELAV-2 or Hel-N1), Hu-antigen C (HuC or ELAV-3 or PLE21), and Hu-antigen D (HuD or ELAV-4), which play important roles in neuronal differentiation, plasticity and memory. HuB is also expressed in gonads. Hu-antigen R (HuR or ELAV-1 or HuA) is the ubiquitously expressed Hu family member. It has a variety of biological functions mostly related to the regulation of cellular response to DNA damage and other types of stress. Hu proteins perform their cytoplasmic and nuclear molecular functions by coordinately regulating functionally related mRNAs. In the cytoplasm, Hu proteins recognize and bind to AU-rich RNA elements (AREs) in the 3' untranslated regions (UTRs) of certain target mRNAs, such as GAP-43, vascular epithelial growth factor (VEGF), the glucose transporter GLUT1, eotaxin and c-fos, and stabilize those ARE-containing mRNAs. They also bind and regulate the translation of some target mRNAs, such as neurofilament M, GLUT1, and p27. In the nucleus, Hu proteins function as regulators of polyadenylation and alternative splicing. Each Hu protein contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). RRM1 and RRM2 may cooperate in binding to an ARE. RRM3 may help to maintain the stability of the RNA-protein complex, and might also bind to poly(A) tails or be involved in protein-protein interactions.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 357482871 101 NLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRV 168
Cdd:cd12377    6 NLAPDADESLLWQLFGPFGAVQNVKIIRDFTTNKCKGYGFVTMTNYDEAAVAIASLNGYRLGGRVLQV 73

RNA recognition motif 2 (RRM2) found in granule-associated RNA binding proteins p40-TIA-1 and TIAR; This subfamily corresponds to the RRM2 of nucleolysin TIA-1 isoform p40 (p40-TIA-1 or TIA-1) and nucleolysin TIA-1-related protein (TIAR), both of which are granule-associated RNA binding proteins involved in inducing apoptosis in cytotoxic lymphocyte (CTL) target cells. TIA-1 and TIAR share high sequence similarity. They are expressed in a wide variety of cell types. TIA-1 can be phosphorylated by a serine/threonine kinase that is activated during Fas-mediated apoptosis. TIAR is mainly localized in the nucleus of hematopoietic and nonhematopoietic cells. It is translocated from the nucleus to the cytoplasm in response to exogenous triggers of apoptosis. Both, TIA-1 and TIAR, bind specifically to poly(A) but not to poly(C) homopolymers. They are composed of three N-terminal highly homologous RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glutamine-rich C-terminal auxiliary domain containing a lysosome-targeting motif. TIA-1 and TIAR interact with RNAs containing short stretches of uridylates and their RRM2 can mediate the specific binding to uridylate-rich RNAs. The C-terminal auxiliary domain may be responsible for interacting with other proteins. In addition, TIA-1 and TIAR share a potential serine protease-cleavage site (Phe-Val-Arg) localized at the junction between their RNA binding domains and their C-terminal auxiliary domains.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNG 158
Cdd:cd12353    5 GDLSPEIETEDLKEAFAPFGEISDARVVKDTQTGKSKGYGFVSFVKKEDAENAIQGMNG 63

RNA recognition motif 1 (RRM1) and 2 (RRM2) found in CELF/Bruno-like family of RNA binding proteins and plant flowering time control protein FCA; This subfamily corresponds to the RRM1 and RRM2 domains of the CUGBP1 and ETR-3-like factors (CELF) as well as plant flowering time control protein FCA. CELF, also termed BRUNOL (Bruno-like) proteins, is a family of structurally related RNA-binding proteins involved in regulation of pre-mRNA splicing in the nucleus, and control of mRNA translation and deadenylation in the cytoplasm. The family contains six members: CELF-1 (also known as BRUNOL-2, CUG-BP1, NAPOR, EDEN-BP), CELF-2 (also known as BRUNOL-3, ETR-3, CUG-BP2, NAPOR-2), CELF-3 (also known as BRUNOL-1, TNRC4, ETR-1, CAGH4, ER DA4), CELF-4 (BRUNOL-4), CELF-5 (BRUNOL-5) and CELF-6 (BRUNOL-6). They all contain three highly conserved RNA recognition motifs (RRMs), also known as RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains): two consecutive RRMs (RRM1 and RRM2) situated in the N-terminal region followed by a linker region and the third RRM (RRM3) close to the C-terminus of the protein. The low sequence conservation of the linker region is highly suggestive of a large variety in the co-factors that associate with the various CELF family members. Based on both, sequence similarity and function, the CELF family can be divided into two subfamilies, the first containing CELFs 1 and 2, and the second containing CELFs 3, 4, 5, and 6. The different CELF proteins may act through different sites on at least some substrates. Furthermore, CELF proteins may interact with each other in varying combinations to influence alternative splicing in different contexts. This subfamily also includes plant flowering time control protein FCA that functions in the posttranscriptional regulation of transcripts involved in the flowering process. FCA contains two RRMs, and a WW protein interaction domain.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGI 159
Cdd:cd12361    5 GMIPKTASEEDVRPLFEQFGNIEEVQILRDKQTGQSKGCAFVTFSTREEALRAIEALHNK 64

RNA recognition motif 2 (RRM2) found in Saccharomyces cerevisiae protein HRB1, G-strand-binding protein 2 (GBP2) and similar proteins; The family includes Saccharomyces cerevisiae protein HRB1 (also called protein TOM34) and GBP2, both of which are SR-like mRNA-binding proteins which shuttle from the nucleus to the cytoplasm when bound to the mature mRNA molecules. They act as quality control factors for spliced mRNAs. GBP2, also called RAP1 localization factor 6, is a single-strand telomeric DNA-binding protein that binds single-stranded telomeric sequences of the type (TG[1-3])n in vitro. It also binds to RNA. GBP2 influences the localization of RAP1 in the nuclei and plays a role in modulating telomere length. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the second RRM motif.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 357482871 101 NLPPETRNHDLLQLFQPFGHVIGADIAIaQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRV 168
Cdd:cd21606    8 NLPYSINWQALKDMFKECGDVLRADVEL-DYNGRSRGFGTVIYATEEEMHRAIDTFNGYELEGRVLEV 74

RNA recognition motif (RRM) found in eukaryotic RNA-binding protein 18 and similar proteins; This subfamily corresponds to the RRM of RBM18, a putative RNA-binding protein containing a well-conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). The biological role of RBM18 remains unclear.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADI---AIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVEW 170
Cdd:cd12355    5 GNLDPRLTEYHLLKLLSKYGKIKKFDFlfhKTGPLKGQPRGYCFVTFETKEEAEKAIECLNGKLALGKKLVVRW 78

polyadenylate binding protein, human types 1, 2, 3, 4 family; These eukaryotic proteins recognize the poly-A of mRNA and consists of four tandem RNA recognition domains at the N-terminus (rrm: pfam00076) followed by a PABP-specific domain (pfam00658) at the C-terminus. The protein is involved in the transport of mRNA's from the nucleus to the cytoplasm. There are four paralogs in Homo sapiens which are expressed in testis, platelets, broadly expressed and of unknown tissue range.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871   70 FVPPYLKAFVKEMTtlsSDDKNKNSFLvvgGNLPPETRNHDLLQLFQPFGHVIGADIAIAQhTGLSGRFAFVNFATKEAA 149
Cdd:TIGR01628 160 YVGRFIKKHEREAA---PLKKFTNLYV---KNLDPSVNEDKLRELFAKFGEITSAAVMKDG-SGRSRGFAFVNFEKHEDA 232

                          90
                  ....*....|
gi 357482871  150 QSAIERLNGI 159
Cdd:TIGR01628 233 AKAVEEMNGK 242

RNA recognition motif 3 (RRM3) found in Schizosaccharomyces pombe mRNA export factor Crp79, meiotically up-regulated gene 28 protein (Mug28) and similar proteins; Crp79, also called meiotic expression up-regulated protein 5 (Mug5), or polyadenylate-binding protein crp79, or PABP, or poly(A)-binding protein, is an auxiliary mRNA export factor that binds the poly(A) tail of mRNA and is involved in the export of mRNA from the nucleus to the cytoplasm. Mug28 is a meiosis-specific protein that regulates spore wall formation. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the three RRM motif.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 357482871 110 DLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNG 158
Cdd:cd21622   21 DLEQLFSPFGQIVSSYLATYPGTGISKGFGFVAFSKPEDAAKAKETLNG 69

RNA recognition motif 2 (RRM2) found in the Hu proteins family; This subfamily corresponds to the RRM2 of Hu proteins family which represents a group of RNA-binding proteins involved in diverse biological processes. Since the Hu proteins share high homology with the Drosophila embryonic lethal abnormal vision (ELAV) protein, the Hu family is sometimes referred to as the ELAV family. Drosophila ELAV is exclusively expressed in neurons and is required for the correct differentiation and survival of neurons in flies. The neuronal members of the Hu family include Hu-antigen B (HuB or ELAV-2 or Hel-N1), Hu-antigen C (HuC or ELAV-3 or PLE21), and Hu-antigen D (HuD or ELAV-4), which play important roles in neuronal differentiation, plasticity and memory. HuB is also expressed in gonads. Hu-antigen R (HuR or ELAV-1 or HuA) is the ubiquitously expressed Hu family member. It has a variety of biological functions mostly related to the regulation of cellular response to DNA damage and other types of stress. Moreover, HuR has an anti-apoptotic function during early cell stress response. It binds to mRNAs and enhances the expression of several anti-apoptotic proteins, such as p21waf1, p53, and prothymosin alpha. HuR also has pro-apoptotic function by promoting apoptosis when cell death is unavoidable. Furthermore, HuR may be important in muscle differentiation, adipogenesis, suppression of inflammatory response and modulation of gene expression in response to chronic ethanol exposure and amino acid starvation. Hu proteins perform their cytoplasmic and nuclear molecular functions by coordinately regulating functionally related mRNAs. In the cytoplasm, Hu proteins recognize and bind to AU-rich RNA elements (AREs) in the 3' untranslated regions (UTRs) of certain target mRNAs, such as GAP-43, vascular epithelial growth factor (VEGF), the glucose transporter GLUT1, eotaxin and c-fos, and stabilize those ARE-containing mRNAs. They also bind and regulate the translation of some target mRNAs, such as neurofilament M, GLUT1, and p27. In the nucleus, Hu proteins function as regulators of polyadenylation and alternative splicing. Each Hu protein contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). RRM1 and RRM2 may cooperate in binding to an ARE. RRM3 may help to maintain the stability of the RNA-protein complex, and might also bind to poly(A) tails or be involved in protein-protein interactions.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 357482871  96 LVVGGnLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNG 158
Cdd:cd12652    3 LYVSG-LPKTMTQKELEQLFSQFGRIITSRILCDNVTGLSRGVGFIRFDKRVEAERAIKALNG 64

RNA recognition motif 1 (RRM1) found in serine/arginine-rich splicing factor 1 (SRSF1) and similar proteins; This subgroup corresponds to the RRM1 of SRSF1, also termed alternative-splicing factor 1 (ASF-1), or pre-mRNA-splicing factor SF2, P33 subunit. SRSF1 is a splicing regulatory serine/arginine (SR) protein involved in constitutive and alternative splicing, nonsense-mediated mRNA decay (NMD), mRNA export and translation. It also functions as a splicing-factor oncoprotein that regulates apoptosis and proliferation to promote mammary epithelial cell transformation. SRSF1 is a shuttling SR protein and contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), separated by a long glycine-rich spacer, and a C-terminal RS domains rich in serine-arginine dipeptides.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVigADIAIAQHTGLSGrFAFVNFATKEAAQSAIERLNGIDYHNFILRVEW 170
Cdd:cd12597   10 GNLPPDIRTKDIEDVFYKYGAI--RDIDLKNRRGGPP-FAFVEFEDPRDAEDAVYGRDGYDYDGYRLRVEF 77

RNA recognition motif 1 (RRM1) found in vertebrate RRM-containing coactivator activator/modulator (CoAA); This subgroup corresponds to the RRM1 of CoAA, also termed RNA-binding protein 14 (RBM14), or paraspeckle protein 2 (PSP2), or synaptotagmin-interacting protein (SYT-interacting protein), a heterogeneous nuclear ribonucleoprotein (hnRNP)-like protein identified as a nuclear receptor coactivator. It mediates transcriptional coactivation and RNA splicing effects in a promoter-preferential manner and is enhanced by thyroid hormone receptor-binding protein (TRBP). CoAA contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a TRBP-interacting domain. It stimulates transcription through its interactions with coactivators, such as TRBP and CREB-binding protein CBP/p300, via the TRBP-interacting domain and interaction with an RNA-containing complex, such as DNA-dependent protein kinase-poly(ADP-ribose) polymerase complexes, via the RRMs.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVigadiaiaQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVEWS 171
Cdd:cd12608    6 GNVDEDTSQEELSALFEPYGAV--------LSCAVMKQFAFVHMRGEAAADRAIRELNGRELHGRALVVEES 69

RNA recognition motif 2 (RRM2) found in vertebrate RNA-binding protein RBM23, RBM39 and similar proteins; This subfamily corresponds to the RRM2 of RBM39 (also termed HCC1), a nuclear autoantigen that contains an N-terminal arginine/serine rich (RS) motif and three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). An octapeptide sequence called the RS-ERK motif is repeated six times in the RS region of RBM39. Although the cellular function of RBM23 remains unclear, it shows high sequence homology to RBM39 and contains two RRMs. It may possibly function as a pre-mRNA splicing factor.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGID 160
Cdd:cd12284    4 GSLHFNITEDMLRGIFEPFGKIEFVQLQKDPETGRSKGYGFIQFRDAEDAKKALEQLNGFE 64

RNA recognition motif 2 (RRM2) found in granule-associated RNA binding proteins (p40-TIA-1 and TIAR), and yeast nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1; This subfamily corresponds to the RRM3 of TIA-1, TIAR, and PUB1. Nucleolysin TIA-1 isoform p40 (p40-TIA-1 or TIA-1) and nucleolysin TIA-1-related protein (TIAR) are granule-associated RNA binding proteins involved in inducing apoptosis in cytotoxic lymphocyte (CTL) target cells. They share high sequence similarity and are expressed in a wide variety of cell types. TIA-1 can be phosphorylated by a serine/threonine kinase that is activated during Fas-mediated apoptosis.TIAR is mainly localized in the nucleus of hematopoietic and nonhematopoietic cells. It is translocated from the nucleus to the cytoplasm in response to exogenous triggers of apoptosis. Both TIA-1 and TIAR bind specifically to poly(A) but not to poly(C) homopolymers. They are composed of three N-terminal highly homologous RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glutamine-rich C-terminal auxiliary domain containing a lysosome-targeting motif. TIA-1 and TIAR interact with RNAs containing short stretches of uridylates and their RRM2 can mediate the specific binding to uridylate-rich RNAs. The C-terminal auxiliary domain may be responsible for interacting with other proteins. In addition, TIA-1 and TIAR share a potential serine protease-cleavage site (Phe-Val-Arg) localized at the junction between their RNA binding domains and their C-terminal auxiliary domains. This subfamily also includes a yeast nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1, termed ARS consensus-binding protein ACBP-60, or poly uridylate-binding protein, or poly(U)-binding protein, which has been identified as both a heterogeneous nuclear RNA-binding protein (hnRNP) and a cytoplasmic mRNA-binding protein (mRNP). It may be stably bound to a translationally inactive subpopulation of mRNAs within the cytoplasm. PUB1 is distributed in both, the nucleus and the cytoplasm, and binds to poly(A)+ RNA (mRNA or pre-mRNA). Although it is one of the major cellular proteins cross-linked by UV light to polyadenylated RNAs in vivo, PUB1 is nonessential for cell growth in yeast. PUB1 also binds to T-rich single stranded DNA (ssDNA); however, there is no strong evidence implicating PUB1 in the mechanism of DNA replication. PUB1 contains three RRMs, and a GAR motif (glycine and arginine rich stretch) that is located between RRM2 and RRM3.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVigADIAIAQHTGlsgrFAFVNFATKEAAQSAIERLNGIDYHNFILRVEW 170
Cdd:cd12354    6 GNITKGLTEALLQQTFSPFGQI--LEVRVFPDKG----YAFIRFDSHEAATHAIVSVNGTIINGQAVKCSW 70

RNA recognition motif 2 (RRM2) found in yeast nuclear and cytoplasmic polyadenylated RNA-binding protein PUB1 and similar proteins; This subgroup corresponds to the RRM2 of yeast protein PUB1, also termed ARS consensus-binding protein ACBP-60, or poly uridylate-binding protein, or poly(U)-binding protein. PUB1 has been identified as both, a heterogeneous nuclear RNA-binding protein (hnRNP) and a cytoplasmic mRNA-binding protein (mRNP), which may be stably bound to a translationally inactive subpopulation of mRNAs within the cytoplasm. It is distributed in both, the nucleus and the cytoplasm, and binds to poly(A)+ RNA (mRNA or pre-mRNA). Although it is one of the major cellular proteins cross-linked by UV light to polyadenylated RNAs in vivo, PUB1 is nonessential for cell growth in yeast. PUB1 also binds to T-rich single stranded DNA (ssDNA). However, there is no strong evidence implicating PUB1 in the mechanism of DNA replication. PUB1 contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a GAR motif (glycine and arginine rich stretch) that is located between RRM2 and RRM3.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVEWST 172
Cdd:cd12619    7 GDLSPEVTDAALFNAFSDFPSCSDARVMWDQKTGRSRGYGFVSFRSQQDAQNAINSMNGKWLGSRPIRCNWAT 79

RNA recognition motif 2 in fungal pre-messenger RNA splicing protein 24 (Prp24) and similar proteins; This subfamily corresponds to the RRM2 of Prp24, also termed U4/U6 snRNA-associated-splicing factor PRP24 (U4/U6 snRNP), an RNA-binding protein with four well conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). It facilitates U6 RNA base-pairing with U4 RNA during spliceosome assembly. Prp24 specifically binds free U6 RNA primarily with RRMs 1 and 2 and facilitates pairing of U6 RNA bases with U4 RNA bases. Additionally, it may also be involved in dissociation of the U4/U6 complex during spliceosome activation.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 357482871 101 NLPPETRNHDLLQLFQPFGHVIGADI-AIAQHTglSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVEWSTP 173
Cdd:cd12297    7 NFPPSYDERSIRDLFGDYGVILSVRLpSLRYNT--SRRFCYIDFTSPESARAAVELLNGLLEEGYTLVVKISDP 78

RNA recognition motif 1 (RRM1) found in RNA-binding protein 28 (RBM28) and similar proteins; This subfamily corresponds to the RRM1 of RBM28 and Nop4p. RBM28 is a specific nucleolar component of the spliceosomal small nuclear ribonucleoproteins (snRNPs), possibly coordinating their transition through the nucleolus. It specifically associates with U1, U2, U4, U5, and U6 small nuclear RNAs (snRNAs), and may play a role in the maturation of both small nuclear and ribosomal RNAs. RBM28 has four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an extremely acidic region between RRM2 and RRM3. The family also includes nucleolar protein 4 (Nop4p or Nop77p) encoded by YPL043W from Saccharomyces cerevisiae. It is an essential nucleolar protein involved in processing and maturation of 27S pre-rRNA and biogenesis of 60S ribosomal subunits. Nop4p also contains four RRMs.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 357482871 101 NLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVE 169
Cdd:cd12413    6 NLPYDTTDEQLEELFSDVGPVKRCFVVKDKGKDKCRGFGYVTFALAEDAQRALEEVKGKKFGGRKIKVE 74

RNA recognition motif 2 (RRM2) found in yeast meiotic activator RIM4 and similar proteins; This subfamily corresponds to the RRM2 of RIM4, also termed regulator of IME2 protein 4, a putative RNA binding protein that is expressed at elevated levels early in meiosis. It functions as a meiotic activator required for both the IME1- and IME2-dependent pathways of meiotic gene expression, as well as early events of meiosis, such as meiotic division and recombination, in Saccharomyces cerevisiae. RIM4 contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The family also includes a putative RNA-binding protein termed multicopy suppressor of sporulation protein Msa1. It is a putative RNA-binding protein encoded by a novel gene, msa1, from the fission yeast Schizosaccharomyces pombe. Msa1 may be involved in the inhibition of sexual differentiation by controlling the expression of Ste11-regulated genes, possibly through the pheromone-signaling pathway. Like RIM4, Msa1 also contains two RRMs, both of which are essential for the function of Msa1.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIgaDIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVE 169
Cdd:cd12454    9 GQLDPKTTDSELFRRFSKYGKIV--DCKLIKRPEPVNAFAFLRFESEEAAEAAVEEENHSEFLNKQIRVQ 76

RNA recognition motif 1 (RRM1) found in vertebrate RNA-binding motif, single-stranded-interacting protein 3 (RBMS3); This subgroup corresponds to the RRM1 of RBMS3, a new member of the c-myc gene single-strand binding proteins (MSSP) family of DNA regulators. Unlike other MSSP proteins, RBMS3 is not a transcriptional regulator. It binds with high affinity to A/U-rich stretches of RNA, and to A/T-rich DNA sequences, and functions as a regulator of cytoplasmic activity. RBMS3 contains two N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and its C-terminal region is acidic and enriched in prolines, glutamines and threonines.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871 102 LPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERL--NGI 159
Cdd:cd12472   12 LPPGTTDQDLIKLCQPYGKIVSTKAILDKNTNQCKGYGFVDFDSPAAAQKAVASLkaSGV 71

RNA recognition motif 1 (RRM1) found in yeast protein gar2 and similar proteins; This subfamily corresponds to the RRM1 of yeast protein gar2, a novel nucleolar protein required for 18S rRNA and 40S ribosomal subunit accumulation. It shares similar domain architecture with nucleolin from vertebrates and NSR1 from Saccharomyces cerevisiae. The highly phosphorylated N-terminal domain of gar2 is made up of highly acidic regions separated from each other by basic sequences, and contains multiple phosphorylation sites. The central domain of gar2 contains two closely adjacent N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The C-terminal RGG (or GAR) domain of gar2 is rich in glycine, arginine and phenylalanine residues.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVEWS 171
Cdd:cd12447    5 GGLSWNVDDPWLKKEFEKYGGVISARVITDRGSGRSKGYGYVDFATPEAAQKALAAMSGKEIDGRQINVDFS 76

RNA recognition motif 3 (RRM3) found in Saccharomyces cerevisiae protein HRB1, G-strand-binding protein 2 (GBP2) and similar proteins; The family includes Saccharomyces cerevisiae protein HRB1 (also called protein TOM34) and GBP2, both of which are SR-like mRNA-binding proteins which shuttle from the nucleus to the cytoplasm when bound to the mature mRNA molecules. They act as quality control factors for spliced mRNAs. GBP2, also called RAP1 localization factor 6, is a single-strand telomeric DNA-binding protein that binds single-stranded telomeric sequences of the type (TG[1-3])n in vitro. It also binds to RNA. GBP2 influences the localization of RAP1 in the nuclei and plays a role in modulating telomere length. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The model corresponds to the third RRM motif.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871  92 KNSFLVVGgNLPPETRNHDLLQLFQPFGHVIGADIaIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDY 161
Cdd:cd21607    1 RNNTIYCS-NLPLSTAESDLYDLFETIGKVNNAEL-KYDETGDPTGSAVVEYENLDDADVCISKLNNYNY 68

RNA recognition motif 1 (RRM1) found in the VICKZ family proteins; Thid subfamily corresponds to the RRM1 of IGF2BPs (or IMPs) found in the VICKZ family that have been implicated in the post-transcriptional regulation of several different RNAs and in subcytoplasmic localization of mRNAs during embryogenesis. IGF2BPs are composed of two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and four hnRNP K homology (KH) domains.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 357482871 100 GNLPPETRNHDLLQLFQPfghvigADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRVEWSTP 173
Cdd:cd12358    4 GNLSSDVNESDLRQLFEE------HKIPVSSVLVKKGGYAFVDCPDQSWADKAIEKLNGKILQGKVIEVEHSVP 71

sex-lethal family splicing factor; This model describes the sex-lethal family of splicing factors found in Dipteran insects. The sex-lethal phenotype, however, may be limited to the Melanogasters and closely related species. In Drosophila the protein acts as an inhibitor of splicing. This subfamily is most closely related to the ELAV/HUD subfamily of splicing factors (TIGR01661).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871   88 DDKNKNSFLVVGgNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILR 167
Cdd:TIGR01659 102 DTNNSGTNLIVN-YLPQDMTDRELYALFRTIGPINTCRIMRDYKTGYSFGYAFVDFGSEADSQRAIKNLNGITVRNKRLK 180

                  ....*.
gi 357482871  168 VEWSTP 173
Cdd:TIGR01659 181 VSYARP 186

RNA recognition motif 2 (RRM2) found in RNA-binding protein 34 (RBM34) and similar proteins; This subfamily corresponds to the RRM2 of RBM34, a putative RNA-binding protein containing two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). Although the function of RBM34 remains unclear currently, its RRM domains may participate in mRNA processing. RBM34 may act as an mRNA processing-related protein.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIeRLNGIDYHNFILRVE 169
Cdd:cd12395    5 GNLPFDIEEEELRKHFEDCGDVEAVRIVRDRETGIGKGFGYVLFKDKDSVDLAL-KLNGSKLRGRKLRVK 73

RNA recognition motif 2 (RRM2) found found in type I polyadenylate-binding proteins; This subfamily corresponds to the RRM2 of type I poly(A)-binding proteins (PABPs), highly conserved proteins that bind to the poly(A) tail present at the 3' ends of most eukaryotic mRNAs. They have been implicated in the regulation of poly(A) tail length during the polyadenylation reaction, translation initiation, mRNA stabilization by influencing the rate of deadenylation and inhibition of mRNA decapping. The family represents type I polyadenylate-binding proteins (PABPs), including polyadenylate-binding protein 1 (PABP-1 or PABPC1), polyadenylate-binding protein 3 (PABP-3 or PABPC3), polyadenylate-binding protein 4 (PABP-4 or APP-1 or iPABP), polyadenylate-binding protein 5 (PABP-5 or PABPC5), polyadenylate-binding protein 1-like (PABP-1-like or PABPC1L), polyadenylate-binding protein 1-like 2 (PABPC1L2 or RBM32), polyadenylate-binding protein 4-like (PABP-4-like or PABPC4L), yeast polyadenylate-binding protein, cytoplasmic and nuclear (PABP or ACBP-67), and similar proteins. PABP-1 is a ubiquitously expressed multifunctional protein that may play a role in 3' end formation of mRNA, translation initiation, mRNA stabilization, protection of poly(A) from nuclease activity, mRNA deadenylation, inhibition of mRNA decapping, and mRNP maturation. Although PABP-1 is thought to be a cytoplasmic protein, it is also found in the nucleus. PABP-1 may be involved in nucleocytoplasmic trafficking and utilization of mRNP particles. PABP-1 contains four copies of RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), a less well conserved linker region, and a proline-rich C-terminal conserved domain (CTD). PABP-3 is a testis-specific poly(A)-binding protein specifically expressed in round spermatids. It is mainly found in mammalian and may play an important role in the testis-specific regulation of mRNA homeostasis. PABP-3 shows significant sequence similarity to PABP-1. However, it binds to poly(A) with a lower affinity than PABP-1. Moreover, PABP-1 possesses an A-rich sequence in its 5'-UTR and allows binding of PABP and blockage of translation of its own mRNA. In contrast, PABP-3 lacks the A-rich sequence in its 5'-UTR. PABP-4 is an inducible poly(A)-binding protein (iPABP) that is primarily localized to the cytoplasm. It shows significant sequence similarity to PABP-1 as well. The RNA binding properties of PABP-1 and PABP-4 appear to be identical. PABP-5 is encoded by PABPC5 gene within the X-specific subinterval, and expressed in fetal brain and in a range of adult tissues in mammalian, such as ovary and testis. It may play an important role in germ cell development. Unlike other PABPs, PABP-5 contains only four RRMs, but lacks both the linker region and the CTD. PABP-1-like and PABP-1-like 2 are the orthologs of PABP-1. PABP-4-like is the ortholog of PABP-5. Their cellular functions remain unclear. The family also includes the yeast PABP, a conserved poly(A) binding protein containing poly(A) tails that can be attached to the 3'-ends of mRNAs. The yeast PABP and its homologs may play important roles in the initiation of translation and in mRNA decay. Like vertebrate PABP-1, the yeast PABP contains four RRMs, a linker region, and a proline-rich CTD as well. The first two RRMs are mainly responsible for specific binding to poly(A). The proline-rich region may be involved in protein-protein interactions.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 357482871 101 NLPPETRNHDLLQLFQPFGHVIGADIAIaQHTGLSGRFAFVNFATKEAAQSAIERLNG 158
Cdd:cd12379    9 NLDKSIDNKALYDTFSAFGNILSCKVAT-DENGGSKGYGFVHFETEEAAERAIEKVNG 65

RNA recognition motif 1 (RRM1) found in (U)-binding-splicing factor PUF60 and similar proteins; This subfamily corresponds to the RRM1 of PUF60, also termed FUSE-binding protein-interacting repressor (FBP-interacting repressor or FIR), or Ro-binding protein 1 (RoBP1), or Siah-binding protein 1 (Siah-BP1). PUF60 is an essential splicing factor that functions as a poly-U RNA-binding protein required to reconstitute splicing in depleted nuclear extracts. Its function is enhanced through interaction with U2 auxiliary factor U2AF65. PUF60 also controls human c-myc gene expression by binding and inhibiting the transcription factor far upstream sequence element (FUSE)-binding-protein (FBP), an activator of c-myc promoters. PUF60 contains two central RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal U2AF (U2 auxiliary factor) homology motifs (UHM) that harbors another RRM and binds to tryptophan-containing linear peptide motifs (UHM ligand motifs, ULMs) in several nuclear proteins. Research indicates that PUF60 binds FUSE as a dimer, and only the first two RRM domains participate in the single-stranded DNA recognition.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGI 159
Cdd:cd12370    6 GSIYFELGEDTIRQAFAPFGPIKSIDMSWDPVTMKHKGFAFVEYEVPEAAQLALEQMNGV 65

RNA recognition motif 1 (RRM1) found in the Hu proteins family, Drosophila sex-lethal (SXL), and similar proteins; This subfamily corresponds to the RRM1 of Hu proteins and SXL. The Hu proteins family represents a group of RNA-binding proteins involved in diverse biological processes. Since the Hu proteins share high homology with the Drosophila embryonic lethal abnormal vision (ELAV) protein, the Hu family is sometimes referred to as the ELAV family. Drosophila ELAV is exclusively expressed in neurons and is required for the correct differentiation and survival of neurons in flies. The neuronal members of the Hu family include Hu-antigen B (HuB or ELAV-2 or Hel-N1), Hu-antigen C (HuC or ELAV-3 or PLE21), and Hu-antigen D (HuD or ELAV-4), which play important roles in neuronal differentiation, plasticity and memory. HuB is also expressed in gonads. Hu-antigen R (HuR or ELAV-1 or HuA) is ubiquitously expressed Hu family member. It has a variety of biological functions mostly related to the regulation of cellular response to DNA damage and other types of stress. Hu proteins perform their cytoplasmic and nuclear molecular functions by coordinately regulating functionally related mRNAs. In the cytoplasm, Hu proteins recognize and bind to AU-rich RNA elements (AREs) in the 3' untranslated regions (UTRs) of certain target mRNAs, such as GAP-43, vascular epithelial growth factor (VEGF), the glucose transporter GLUT1, eotaxin and c-fos, and stabilize those ARE-containing mRNAs. They also bind and regulate the translation of some target mRNAs, such as neurofilament M, GLUT1, and p27. In the nucleus, Hu proteins function as regulators of polyadenylation and alternative splicing. Each Hu protein contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). RRM1 and RRM2 may cooperate in binding to an ARE. RRM3 may help to maintain the stability of the RNA-protein complex, and might also bind to poly(A) tails or be involved in protein-protein interactions. This family also includes the sex-lethal protein (SXL) from Drosophila melanogaster. SXL governs sexual differentiation and X chromosome dosage compensation in flies. It induces female-specific alternative splicing of the transformer (tra) pre-mRNA by binding to the tra uridine-rich polypyrimidine tract at the non-sex-specific 3' splice site during the sex-determination process. SXL binds to its own pre-mRNA and promotes female-specific alternative splicing. It contains an N-terminal Gly/Asn-rich domain that may be responsible for the protein-protein interaction, and tandem RRMs that show high preference to bind single-stranded, uridine-rich target RNA transcripts.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 357482871 102 LPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRV 168
Cdd:cd12375    7 LPQSMTQEELRSLFGAIGPIESCKLVRDKITGQSLGYGFVNYRDPNDARKAINTLNGLDLENKRLKV 73

RNA recognition motif 2 (RRM2) found in the Hu proteins family, Drosophila sex-lethal (SXL), and similar proteins; This subfamily corresponds to the RRM2 of Hu proteins and SXL. The Hu proteins family represents a group of RNA-binding proteins involved in diverse biological processes. Since the Hu proteins share high homology with the Drosophila embryonic lethal abnormal vision (ELAV) protein, the Hu family is sometimes referred to as the ELAV family. Drosophila ELAV is exclusively expressed in neurons and is required for the correct differentiation and survival of neurons in flies. The neuronal members of the Hu family include Hu-antigen B (HuB or ELAV-2 or Hel-N1), Hu-antigen C (HuC or ELAV-3 or PLE21), and Hu-antigen D (HuD or ELAV-4), which play important roles in neuronal differentiation, plasticity and memory. HuB is also expressed in gonads. Hu-antigen R (HuR or ELAV-1 or HuA) is the ubiquitously expressed Hu family member. It has a variety of biological functions mostly related to the regulation of cellular response to DNA damage and other types of stress. Hu proteins perform their cytoplasmic and nuclear molecular functions by coordinately regulating functionally related mRNAs. In the cytoplasm, Hu proteins recognize and bind to AU-rich RNA elements (AREs) in the 3' untranslated regions (UTRs) of certain target mRNAs, such as GAP-43, vascular epithelial growth factor (VEGF), the glucose transporter GLUT1, eotaxin and c-fos, and stabilize those ARE-containing mRNAs. They also bind and regulate the translation of some target mRNAs, such as neurofilament M, GLUT1, and p27. In the nucleus, Hu proteins function as regulators of polyadenylation and alternative splicing. Each Hu protein contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). RRM1 and RRM2 may cooperate in binding to an ARE. RRM3 may help to maintain the stability of the RNA-protein complex, and might also bind to poly(A) tails or be involved in protein-protein interactions. Also included in this subfamily is the sex-lethal protein (SXL) from Drosophila melanogaster. SXL governs sexual differentiation and X chromosome dosage compensation in flies. It induces female-specific alternative splicing of the transformer (tra) pre-mRNA by binding to the tra uridine-rich polypyrimidine tract at the non-sex-specific 3' splice site during the sex-determination process. SXL binds also to its own pre-mRNA and promotes female-specific alternative splicing. SXL contains an N-terminal Gly/Asn-rich domain that may be responsible for the protein-protein interaction, and tandem RRMs that show high preference to bind single-stranded, uridine-rich target RNA transcripts.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 357482871 101 NLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGI 159
Cdd:cd12376    7 GLPKTMTQKELEQLFSQYGRIITSRILRDQLTGVSRGVGFIRFDKRIEAEEAIKGLNGQ 65

RNA recognition motif 2 (RRM2) found in U2 large nuclear ribonucleoprotein auxiliary factor U2AF 65 kDa subunit (U2AF65) and similar proteins; This subfamily corresponds to the RRM2 of U2AF65 and dU2AF50. U2AF65, also termed U2AF2, is the large subunit of U2 small nuclear ribonucleoprotein (snRNP) auxiliary factor (U2AF), which has been implicated in the recruitment of U2 snRNP to pre-mRNAs and is a highly conserved heterodimer composed of large and small subunits. U2AF65 specifically recognizes the intron polypyrimidine tract upstream of the 3' splice site and promotes binding of U2 snRNP to the pre-mRNA branchpoint. U2AF65 also plays an important role in the nuclear export of mRNA. It facilitates the formation of a messenger ribonucleoprotein export complex, containing both the NXF1 receptor and the RNA substrate. Moreover, U2AF65 interacts directly and specifically with expanded CAG RNA, and serves as an adaptor to link expanded CAG RNA to NXF1 for RNA export. U2AF65 contains an N-terminal RS domain rich in arginine and serine, followed by a proline-rich segment and three C-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The N-terminal RS domain stabilizes the interaction of U2 snRNP with the branch point (BP) by contacting the branch region, and further promotes base pair interactions between U2 snRNA and the BP. The proline-rich segment mediates protein-protein interactions with the RRM domain of the small U2AF subunit (U2AF35 or U2AF1). The RRM1 and RRM2 are sufficient for specific RNA binding, while RRM3 is responsible for protein-protein interactions. The family also includes Splicing factor U2AF 50 kDa subunit (dU2AF50), the Drosophila ortholog of U2AF65. dU2AF50 functions as an essential pre-mRNA splicing factor in flies. It associates with intronless mRNAs and plays a significant and unexpected role in the nuclear export of a large number of intronless mRNAs.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 357482871 100 GNLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRV 168
Cdd:cd12231    6 GGLPNYLNEDQVKELLQSFGKLKAFNLVKDSATGLSKGYAFCEYVDDNVTDQAIAGLNGMQLGDKKLLV 74

RNA recognition motif (RRM) found in serine/arginine-rich splicing factor SRSF2, SRSF8 and similar proteins; This subfamily corresponds to the RRM of SRSF2 and SRSF8. SRSF2, also termed protein PR264, or splicing component, 35 kDa (splicing factor SC35 or SC-35), is a prototypical SR protein that plays important roles in the alternative splicing of pre-mRNA. It is also involved in transcription elongation by directly or indirectly mediating the recruitment of elongation factors to the C-terminal domain of polymerase II. SRSF2 is exclusively localized in the nucleus and is restricted to nuclear processes. It contains a single N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), followed by a C-terminal RS domain rich in serine-arginine dipeptides. The RRM is responsible for the specific recognition of 5'-SSNG-3' (S=C/G) RNA. In the regulation of alternative splicing events, it specifically binds to cis-regulatory elements on the pre-mRNA. The RS domain modulates SRSF2 activity through phosphorylation, directly contacts RNA, and promotes protein-protein interactions with the spliceosome. SRSF8, also termed SRP46 or SFRS2B, is a novel mammalian SR splicing factor encoded by a PR264/SC35 functional retropseudogene. SRSF8 is localized in the nucleus and does not display the same activity as PR264/SC35. It functions as an essential splicing factor in complementing a HeLa cell S100 extract deficient in SR proteins. Like SRSF2, SRSF8 contains a single N-terminal RRM and a C-terminal RS domain.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 357482871 101 NLPPETRNHDLLQLFQPFGHVigADIAI--AQHTGLSGRFAFVNFATKEAAQSAIERLNGIDYHNFILRV 168
Cdd:cd12311    5 NLTYRTTPDDLRRVFEKYGEV--GDVYIprDRYTRESRGFAFVRFYDKRDAEDAIDAMDGAELDGRELRV 72

RNA recognition motif 3 (RRM3) found in RNA-binding protein 28 (RBM28) and similar proteins; This subfamily corresponds to the RRM3 of RBM28 and Nop4p. RBM28 is a specific nucleolar component of the spliceosomal small nuclear ribonucleoproteins (snRNPs), possibly coordinating their transition through the nucleolus. It specifically associates with U1, U2, U4, U5, and U6 small nuclear RNAs (snRNAs), and may play a role in the maturation of both small nuclear and ribosomal RNAs. RBM28 has four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an extremely acidic region between RRM2 and RRM3. The family also includes nucleolar protein 4 (Nop4p or Nop77p) encoded by YPL043W from Saccharomyces cerevisiae. It is an essential nucleolar protein involved in processing and maturation of 27S pre-rRNA and biogenesis of 60S ribosomal subunits. Nop4p also contains four RRMs.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 357482871 101 NLPPETRNHDLLQLFQPFGHVIGADIAIAQHTGLSGRFAFVNFATKEAAQSAIERLN------GIDYHNFILRV 168
Cdd:cd12415    7 NLSFDTTEEDLKEFFSKFGEVKYARIVLDKDTGHSKGTAFVQFKTKESADKCIEAANdesedgGLVLDGRKLIV 80