Ral (Ras-like) family containing highly homologous RalA and RalB; The Ral (Ras-like) subfamily consists of the highly homologous RalA and RalB. Ral proteins are believed to play a crucial role in tumorigenesis, metastasis, endocytosis, and actin cytoskeleton dynamics. Despite their high sequence similarity (>80% sequence identity), nonoverlapping and opposing functions have been assigned to RalA and RalBs in tumor migration. In human bladder and prostate cancer cells, RalB promotes migration while RalA inhibits it. A Ral-specific set of GEFs has been identified that are activated by Ras binding. This RalGEF activity is enhanced by Ras binding to another of its target proteins, phosphatidylinositol 3-kinase (PI3K). Ral effectors include RLIP76/RalBP1, a Rac/cdc42 GAP, and the exocyst (Sec6/8) complex, a heterooctomeric protein complex that is involved in tethering vesicles to specific sites on the plasma membrane prior to exocytosis. In rat kidney cells, RalB is required for functional assembly of the exocyst and for localizing the exocyst to the leading edge of migrating cells. In human cancer cells, RalA is required to support anchorage-independent proliferation and RalB is required to suppress apoptosis. RalA has been shown to localize to the plasma membrane while RalB is localized to the intracellular vesicles. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  15 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:cd04139    1 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQLNILDTAGQEDYAAIRDNYFRSGEGFLLVFS 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  95 ITEHESFTATGEFREQILRVKaEEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:cd04139   81 ITDMESFTALAEFREQILRVK-EDDNVPLLLVGNKCDLEDKRQVSVEEAANLAEQWGVNYVETSAKTRANVDKVFFDLVR 159

                 ....
gi 884941707 175 EIRT 178
Cdd:cd04139  160 EIRQ 163

Ral (Ras-like) family containing highly homologous RalA and RalB; The Ral (Ras-like) subfamily consists of the highly homologous RalA and RalB. Ral proteins are believed to play a crucial role in tumorigenesis, metastasis, endocytosis, and actin cytoskeleton dynamics. Despite their high sequence similarity (>80% sequence identity), nonoverlapping and opposing functions have been assigned to RalA and RalBs in tumor migration. In human bladder and prostate cancer cells, RalB promotes migration while RalA inhibits it. A Ral-specific set of GEFs has been identified that are activated by Ras binding. This RalGEF activity is enhanced by Ras binding to another of its target proteins, phosphatidylinositol 3-kinase (PI3K). Ral effectors include RLIP76/RalBP1, a Rac/cdc42 GAP, and the exocyst (Sec6/8) complex, a heterooctomeric protein complex that is involved in tethering vesicles to specific sites on the plasma membrane prior to exocytosis. In rat kidney cells, RalB is required for functional assembly of the exocyst and for localizing the exocyst to the leading edge of migrating cells. In human cancer cells, RalA is required to support anchorage-independent proliferation and RalB is required to suppress apoptosis. RalA has been shown to localize to the plasma membrane while RalB is localized to the intracellular vesicles. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  15 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:cd04139    1 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQLNILDTAGQEDYAAIRDNYFRSGEGFLLVFS 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  95 ITEHESFTATGEFREQILRVKaEEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:cd04139   81 ITDMESFTALAEFREQILRVK-EDDNVPLLLVGNKCDLEDKRQVSVEEAANLAEQWGVNYVETSAKTRANVDKVFFDLVR 159

                 ....
gi 884941707 175 EIRT 178
Cdd:cd04139  160 EIRQ 163

Ras family; Includes sub-families Ras, Rab, Rac, Ral, Ran, Rap Ypt1 and more. Shares P-loop motif with GTP_EFTU, arf and myosin_head. See pfam00009 pfam00025, pfam00063. As regards Rab GTPases, these are important regulators of vesicle formation, motility and fusion. They share a fold in common with all Ras GTPases: this is a six-stranded beta-sheet surrounded by five alpha-helices.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707   16 KVIMVGSGGVGKSALTLQFMYDEFVEDYEPT-KADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:pfam00071   1 KLVLVGDGGVGKSSLLIRFTQNKFPEEYIPTiGVDFYTKTIEVDGKTVKLQIWDTAGQERFRALRPLYYRGADGFLLVYD 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707   95 ITEHESFTATGEFREQILRVKaeEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:pfam00071  81 ITSRDSFENVKKWVEEILRHA--DENVPIVLVGNKCDLEDQRVVSTEEGEALAKELGLPFMETSAKTNENVEEAFEELAR 158

                  ...
gi 884941707  175 EIR 177
Cdd:pfam00071 159 EIL 161

small GTP-binding protein domain; Proteins with a small GTP-binding domain recognized by this model include Ras, RhoA, Rab11, translation elongation factor G, translation initiation factor IF-2, tetratcycline resistance protein TetM, CDC42, Era, ADP-ribosylation factors, tdhF, and many others. In some proteins the domain occurs more than once.This model recognizes a large number of small GTP-binding proteins and related domains in larger proteins. Note that the alpha chains of heterotrimeric G proteins are larger proteins in which the NKXD motif is separated from the GxxxxGK[ST] motif (P-loop) by a long insert and are not easily detected by this model. [Unknown function, General]

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707   16 KVIMVGSGGVGKSALTLQFMYDE-FVEDYEPTKADSYRKKVV-LDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVF 93
Cdd:TIGR00231   3 KIVIVGHPNVGKSTLLNSLLGNKgSITEYYPGTTRNYVTTVIeEDGKTYKFNLLDTAGQEDYDAIRRLYYPQVERSLRVF 82

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 884941707   94 SITEHESFTATG--EFREQILRVKaeEDKIPLLVVGNKSDLEERRQVPVEeaRSKAEEW-GVQYVETSAKTRANVDKVF 169
Cdd:TIGR00231  83 DIVILVLDVEEIleKQTKEIIHHA--DSGVPIILVGNKIDLKDADLKTHV--ASEFAKLnGEPIIPLSAETGKNIDSAF 157

Ral (Ras-like) family containing highly homologous RalA and RalB; The Ral (Ras-like) subfamily consists of the highly homologous RalA and RalB. Ral proteins are believed to play a crucial role in tumorigenesis, metastasis, endocytosis, and actin cytoskeleton dynamics. Despite their high sequence similarity (>80% sequence identity), nonoverlapping and opposing functions have been assigned to RalA and RalBs in tumor migration. In human bladder and prostate cancer cells, RalB promotes migration while RalA inhibits it. A Ral-specific set of GEFs has been identified that are activated by Ras binding. This RalGEF activity is enhanced by Ras binding to another of its target proteins, phosphatidylinositol 3-kinase (PI3K). Ral effectors include RLIP76/RalBP1, a Rac/cdc42 GAP, and the exocyst (Sec6/8) complex, a heterooctomeric protein complex that is involved in tethering vesicles to specific sites on the plasma membrane prior to exocytosis. In rat kidney cells, RalB is required for functional assembly of the exocyst and for localizing the exocyst to the leading edge of migrating cells. In human cancer cells, RalA is required to support anchorage-independent proliferation and RalB is required to suppress apoptosis. RalA has been shown to localize to the plasma membrane while RalB is localized to the intracellular vesicles. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  15 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:cd04139    1 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQLNILDTAGQEDYAAIRDNYFRSGEGFLLVFS 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  95 ITEHESFTATGEFREQILRVKaEEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:cd04139   81 ITDMESFTALAEFREQILRVK-EDDNVPLLLVGNKCDLEDKRQVSVEEAANLAEQWGVNYVETSAKTRANVDKVFFDLVR 159

                 ....
gi 884941707 175 EIRT 178
Cdd:cd04139  160 EIRQ 163

Ras subfamily of RAS small GTPases; Similar in fold and function to the bacterial EF-Tu GTPase. p21Ras couples receptor Tyr kinases and G protein receptors to protein kinase cascades

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707    15 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:smart00173   1 YKLVVLGSGGVGKSALTIQFIQGHFVDDYDPTIEDSYRKQIEIDGEVCLLDILDTAGQEEFSAMRDQYMRTGEGFLLVYS 80

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707    95 ITEHESFTATGEFREQILRVKaEEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:smart00173  81 ITDRQSFEEIKKFREQILRVK-DRDDVPIVLVGNKCDLESERVVSTEEGKELARQWGCPFLETSAKERVNVDEAFYDLVR 159

                   ...
gi 884941707   175 EIR 177
Cdd:smart00173 160 EIR 162

Ras family; Includes sub-families Ras, Rab, Rac, Ral, Ran, Rap Ypt1 and more. Shares P-loop motif with GTP_EFTU, arf and myosin_head. See pfam00009 pfam00025, pfam00063. As regards Rab GTPases, these are important regulators of vesicle formation, motility and fusion. They share a fold in common with all Ras GTPases: this is a six-stranded beta-sheet surrounded by five alpha-helices.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707   16 KVIMVGSGGVGKSALTLQFMYDEFVEDYEPT-KADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:pfam00071   1 KLVLVGDGGVGKSSLLIRFTQNKFPEEYIPTiGVDFYTKTIEVDGKTVKLQIWDTAGQERFRALRPLYYRGADGFLLVYD 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707   95 ITEHESFTATGEFREQILRVKaeEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:pfam00071  81 ITSRDSFENVKKWVEEILRHA--DENVPIVLVGNKCDLEDQRVVSTEEGEALAKELGLPFMETSAKTNENVEEAFEELAR 158

                  ...
gi 884941707  175 EIR 177
Cdd:pfam00071 159 EIL 161

R-Ras2/TC21, M-Ras/R-Ras3; The M-Ras/R-Ras-like subfamily contains R-Ras2/TC21, M-Ras/R-Ras3, and related members of the Ras family. M-Ras is expressed in lympho-hematopoetic cells. It interacts with some of the known Ras effectors, but appears to also have its own effectors. Expression of mutated M-Ras leads to transformation of several types of cell lines, including hematopoietic cells, mammary epithelial cells, and fibroblasts. Overexpression of M-Ras is observed in carcinomas from breast, uterus, thyroid, stomach, colon, kidney, lung, and rectum. In addition, expression of a constitutively active M-Ras mutant in murine bone marrow induces a malignant mast cell leukemia that is distinct from the monocytic leukemia induced by H-Ras. TC21, along with H-Ras, has been shown to regulate the branching morphogenesis of ureteric bud cell branching in mice. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  15 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:cd04145    3 YKLVVVGGGGVGKSALTIQFIQSYFVTDYDPTIEDSYTKQCEIDGQWARLDILDTAGQEEFSAMREQYMRTGEGFLLVFS 82

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  95 ITEHESFTATGEFREQILRVKaEEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:cd04145   83 VTDRGSFEEVDKFHTQILRVK-DRDEFPMILVGNKADLEHQRQVSREEGQELARQLKIPYIETSAKDRVNVDKAFHDLVR 161

                 ...
gi 884941707 175 EIR 177
Cdd:cd04145  162 VIR 164

Ras-like protein; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  15 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:PTZ00369   6 YKLVVVGGGGVGKSALTIQFIQNHFIDEYDPTIEDSYRKQCVIDEETCLLDILDTAGQEEYSAMRDQYMRTGQGFLCVYS 85

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  95 ITEHESFTATGEFREQILRVKaEEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:PTZ00369  86 ITSRSSFEEIASFREQILRVK-DKDRVPMILVGNKCDLDSERQVSTGEGQELAKSFGIPFLETSAKQRVNVDEAFYELVR 164

                 ...
gi 884941707 175 EIR 177
Cdd:PTZ00369 165 EIR 167

Rap1 family GTPase consists of Rap1a and Rap1b isoforms; The Rap1 subgroup is part of the Rap subfamily of the Ras family. It can be further divided into the Rap1a and Rap1b isoforms. In humans, Rap1a and Rap1b share 95% sequence homology, but are products of two different genes located on chromosomes 1 and 12, respectively. Rap1a is sometimes called smg p21 or Krev1 in the older literature. Rap1 proteins are believed to perform different cellular functions, depending on the isoform, its subcellular localization, and the effector proteins it binds. For example, in rat salivary gland, neutrophils, and platelets, Rap1 localizes to secretory granules and is believed to regulate exocytosis or the formation of secretory granules. Rap1 has also been shown to localize in the Golgi of rat fibroblasts, zymogen granules, plasma membrane, and the microsomal membrane of pancreatic acini, as well as in the endocytic compartment of skeletal muscle cells and fibroblasts. High expression of Rap1 has been observed in the nucleus of human oropharyngeal squamous cell carcinomas (SCCs) and cell lines; interestingly, in the SCCs, the active GTP-bound form localized to the nucleus, while the inactive GDP-bound form localized to the cytoplasm. Rap1 plays a role in phagocytosis by controlling the binding of adhesion receptors (typically integrins) to their ligands. In yeast, Rap1 has been implicated in multiple functions, including activation and silencing of transcription and maintenance of telomeres. Rap1a, which is stimulated by T-cell receptor (TCR) activation, is a positive regulator of T cells by directing integrin activation and augmenting lymphocyte responses. In murine hippocampal neurons, Rap1b determines which neurite will become the axon and directs the recruitment of Cdc42, which is required for formation of dendrites and axons. In murine platelets, Rap1b is required for normal homeostasis in vivo and is involved in integrin activation. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  15 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:cd04175    2 YKLVVLGSGGVGKSALTVQFVQGIFVEKYDPTIEDSYRKQVEVDGQQCMLEILDTAGTEQFTAMRDLYMKNGQGFVLVYS 81

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  95 ITEHESFTATGEFREQILRVKaEEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:cd04175   82 ITAQSTFNDLQDLREQILRVK-DTEDVPMILVGNKCDLEDERVVGKEQGQNLARQWGCAFLETSAKAKINVNEIFYDLVR 160

                 ..
gi 884941707 175 EI 176
Cdd:cd04175  161 QI 162

Rap2 family GTPase consists of Rap2a, Rap2b, and Rap2c; The Rap2 subgroup is part of the Rap subfamily of the Ras family. It consists of Rap2a, Rap2b, and Rap2c. Both isoform 3 of the human mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) and Traf2- and Nck-interacting kinase (TNIK) are putative effectors of Rap2 in mediating the activation of c-Jun N-terminal kinase (JNK) to regulate the actin cytoskeleton. In human platelets, Rap2 was shown to interact with the cytoskeleton by binding the actin filaments. In embryonic Xenopus development, Rap2 is necessary for the Wnt/beta-catenin signaling pathway. The Rap2 interacting protein 9 (RPIP9) is highly expressed in human breast carcinomas and correlates with a poor prognosis, suggesting a role for Rap2 in breast cancer oncogenesis. Rap2b, but not Rap2a, Rap2c, Rap1a, or Rap1b, is expressed in human red blood cells, where it is believed to be involved in vesiculation. A number of additional effector proteins for Rap2 have been identified, including the RalGEFs RalGDS, RGL, and Rlf, which also interact with Rap1 and Ras. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  15 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:cd04176    2 YKVVVLGSGGVGKSALTVQFVSGTFIEKYDPTIEDFYRKEIEVDSSPSVLEILDTAGTEQFASMRDLYIKNGQGFIVVYS 81

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  95 ITEHESFTATGEFREQILRVKAEEdKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:cd04176   82 LVNQQTFQDIKPMRDQIVRVKGYE-KVPIILVGNKVDLESEREVSSAEGRALAEEWGCPFMETSAKSKTMVNELFAEIVR 160

                 ..
gi 884941707 175 EI 176
Cdd:cd04176  161 QM 162

Ras-related in brain (Rab) family of small guanosine triphosphatases (GTPases); Rab GTPases form the largest family within the Ras superfamily. There are at least 60 Rab genes in the human genome, and a number of Rab GTPases are conserved from yeast to humans. Rab GTPases are small, monomeric proteins that function as molecular switches to regulate vesicle trafficking pathways. The different Rab GTPases are localized to the cytosolic face of specific intracellular membranes, where they regulate distinct steps in membrane traffic pathways. In the GTP-bound form, Rab GTPases recruit specific sets of effector proteins onto membranes. Through their effectors, Rab GTPases regulate vesicle formation, actin- and tubulin-dependent vesicle movement, and membrane fusion. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which mask C-terminal lipid binding and promote cytosolic localization. While most unicellular organisms possess 5-20 Rab members, several have been found to possess 60 or more Rabs; for many of these Rab isoforms, homologous proteins are not found in other organisms. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Since crystal structures often lack C-terminal residues, the lipid modification site is not available for annotation in many of the CDs in the hierarchy, but is included where possible.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  16 KVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYR-KKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:cd00154    2 KIVLIGDSGVGKTSLLLRFVDNKFSENYKSTIGVDFKsKTIEVDGKKVKLQIWDTAGQERFRSITSSYYRGAHGAILVYD 81

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 884941707  95 ITEHESFTATGEFREQILRVKaeEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDL 172
Cdd:cd00154   82 VTNRESFENLDKWLNELKEYA--PPNIPIILVGNKSDLEDERQVSTEEAQQFAKENGLLFFETSAKTGENVDEAFESL 157

Ras Homolog Enriched in Brain (RheB) is a small GTPase; Rheb (Ras Homolog Enriched in Brain) subfamily. Rheb was initially identified in rat brain, where its expression is elevated by seizures or by long-term potentiation. It is expressed ubiquitously, with elevated levels in muscle and brain. Rheb functions as an important mediator between the tuberous sclerosis complex proteins, TSC1 and TSC2, and the mammalian target of rapamycin (TOR) kinase to stimulate cell growth. TOR kinase regulates cell growth by controlling nutrient availability, growth factors, and the energy status of the cell. TSC1 and TSC2 form a dimeric complex that has tumor suppressor activity, and TSC2 is a GTPase activating protein (GAP) for Rheb. The TSC1/TSC2 complex inhibits the activation of TOR kinase through Rheb. Rheb has also been shown to induce the formation of large cytoplasmic vacuoles in a process that is dependent on the GTPase cycle of Rheb, but independent of the TOR kinase, suggesting Rheb plays a role in endocytic trafficking that leads to cell growth and cell-cycle progression. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  16 KVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFSI 95
Cdd:cd04137    3 KIAVLGSRSVGKSSLTVQFVEGHFVESYYPTIENTFSKIITYKGQEYHLEIVDTAGQDEYSILPQKYSIGIHGYILVYSV 82

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  96 TEHESFTATGEFREQILRvKAEEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMRE 175
Cdd:cd04137   83 TSRKSFEVVKVIYDKILD-MLGKESVPIVLVGNKSDLHMERQVSAEEGKKLAESWGAAFLESSAKENENVEEAFELLIEE 161

                 .
gi 884941707 176 I 176
Cdd:cd04137  162 I 162

Rab GTPase family 11 (Rab11)-like includes Rab11a, Rab11b, and Rab25; Rab11a, Rab11b, and Rab25 are closely related, evolutionary conserved Rab proteins that are differentially expressed. Rab11a is ubiquitously synthesized, Rab11b is enriched in brain and heart and Rab25 is only found in epithelia. Rab11/25 proteins seem to regulate recycling pathways from endosomes to the plasma membrane and to the trans-Golgi network. Furthermore, Rab11a is thought to function in the histamine-induced fusion of tubulovesicles containing H+, K+ ATPase with the plasma membrane in gastric parietal cells and in insulin-stimulated insertion of GLUT4 in the plasma membrane of cardiomyocytes. Overexpression of Rab25 has recently been observed in ovarian cancer and breast cancer, and has been correlated with worsened outcomes in both diseases. In addition, Rab25 overexpression has also been observed in prostate cancer, transitional cell carcinoma of the bladder, and invasive breast tumor cells. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  14 LHKVIMVGSGGVGKSALTLQFMYDEFVEDYEPT-KADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLV 92
Cdd:cd01868    3 LFKIVLIGDSGVGKSNLLSRFTRNEFNLDSKSTiGVEFATRTIQIDGKTIKAQIWDTAGQERYRAITSAYYRGAVGALLV 82

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  93 FSITEHESFTATGEFREQiLRVKAEEDkIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDL 172
Cdd:cd01868   83 YDITKKSTFENVERWLKE-LRDHADSN-IVIMLVGNKSDLRHLRAVPTEEAKAFAEKNGLSFIETSALDGTNVEEAFKQL 160

                 ....
gi 884941707 173 MREI 176
Cdd:cd01868  161 LTEI 164

Rab GTPase families 8, 10, 13 (Rab8, Rab10, Rab13); Rab8/Sec4/Ypt2 are known or suspected to be involved in post-Golgi transport to the plasma membrane. It is likely that these Rabs have functions that are specific to the mammalian lineage and have no orthologs in plants. Rab8 modulates polarized membrane transport through reorganization of actin and microtubules, induces the formation of new surface extensions, and has an important role in directed membrane transport to cell surfaces. The Ypt2 gene of the fission yeast Schizosaccharomyces pombe encodes a member of the Ypt/Rab family of small GTP-binding proteins, related in sequence to Sec4p of Saccharomyces cerevisiae but closer to mammalian Rab8. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  13 ALHKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYR-KKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLL 91
Cdd:cd01867    2 YLFKLLLIGDSGVGKSCLLLRFSEDSFNPSFISTIGIDFKiRTIELDGKKIKLQIWDTAGQERFRTITTSYYRGAMGIIL 81

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  92 VFSITEHESFTATGEFREQILRVKAEEdkIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFD 171
Cdd:cd01867   82 VYDITDEKSFENIKNWMRNIDEHASED--VERMLVGNKCDMEEKRVVSKEEGEALAREYGIKFLETSAKANINVEEAFLT 159

                 ....*...
gi 884941707 172 LMREIRTK 179
Cdd:cd01867  160 LAKDILKK 167

Rem, Rem2, Rad, Gem/Kir (RGK) subfamily of Ras GTPases; RGK subfamily. The RGK (Rem, Rem2, Rad, Gem/Kir) subfamily of Ras GTPases are expressed in a tissue-specific manner and are dynamically regulated by transcriptional and posttranscriptional mechanisms in response to environmental cues. RGK proteins bind to the beta subunit of L-type calcium channels, causing functional down-regulation of these voltage-dependent calcium channels, and either termination of calcium-dependent secretion or modulation of electrical conduction and contractile function. Inhibition of L-type calcium channels by Rem2 may provide a mechanism for modulating calcium-triggered exocytosis in hormone-secreting cells, and has been proposed to influence the secretion of insulin in pancreatic beta cells. RGK proteins also interact with and inhibit the Rho/Rho kinase pathway to modulate remodeling of the cytoskeleton. Two characteristics of RGK proteins cited in the literature are N-terminal and C-terminal extensions beyond the GTPase domain typical of Ras superfamily members. The N-terminal extension is not conserved among family members; the C-terminal extension is reported to be conserved among the family and lack the CaaX prenylation motif typical of membrane-associated Ras proteins. However, a putative CaaX motif has been identified in the alignment of the C-terminal residues of this CD.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  16 KVIMVGSGGVGKSALTLQFMYDEFVE-DYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:cd04148    2 RVVLLGDSGVGKSSLANIFTAGVYEDsAYEASGDDTYERTVSVDGEEATLVVYDHWEQEDGMWLEDSCMQVGDAYVIVYS 81

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  95 ITEHESFTATGEFREQILRVKAEEDkIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:cd04148   82 VTDRSSFEKASELRIQLRRARQAED-IPIILVGNKSDLVRSREVSVQEGRACAVVFDCKFIETSAALQHNVDELFEGIVR 160

                        170
                 ....*....|.
gi 884941707 175 EIRTKKMSENK 185
Cdd:cd04148  161 QVRLRRDSKEK 171

Ras - dorsal-ventral anterior localization (Ras-dva) family; Ras-dva subfamily. Ras-dva (Ras - dorsal-ventral anterior localization) subfamily consists of a set of proteins characterized only in Xenopus leavis, to date. In Xenopus Ras-dva expression is activated by the transcription factor Otx2 and begins during gastrulation throughout the anterior ectoderm. Ras-dva expression is inhibited in the anterior neural plate by factor Xanf1. Downregulation of Ras-dva results in head development abnormalities through the inhibition of several regulators of the anterior neural plate and folds patterning, including Otx2, BF-1, Xag2, Pax6, Slug, and Sox9. Downregulation of Ras-dva also interferes with the FGF-8a signaling within the anterior ectoderm. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  16 KVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFSI 95
Cdd:cd04147    1 RLVFMGAAGVGKTALIQRFLYDTFEPKHRRTVEELHSKEYEVAGVKVTIDILDTSGSYSFPAMRKLSIQNGDAFALVYSV 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  96 TEHESFTATGEFREQILRVKaeEDK-IPLLVVGNKSDLEERRQVPVEEARSKAE-EWGVQYVETSAKTRANVDKVFFDLM 173
Cdd:cd04147   81 DDPESFEEVKRLREEILEVK--EDKfVPIVVVGNKIDSLAERQVEAADALSTVElDWNNGFVEASAKDNENVTEVFKELL 158

                 ....
gi 884941707 174 REIR 177
Cdd:cd04147  159 QQAN 162

Rab GTPase family 6 (Rab6); Rab6 is involved in microtubule-dependent transport pathways through the Golgi and from endosomes to the Golgi. Rab6A of mammals is implicated in retrograde transport through the Golgi stack, and is also required for a slow, COPI-independent, retrograde transport pathway from the Golgi to the endoplasmic reticulum (ER). This pathway may allow Golgi residents to be recycled through the ER for scrutiny by ER quality-control systems. Yeast Ypt6p, the homolog of the mammalian Rab6 GTPase, is not essential for cell viability. Ypt6p acts in endosome-to-Golgi, in intra-Golgi retrograde transport, and possibly also in Golgi-to-ER trafficking. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  15 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKA-DSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVF 93
Cdd:cd01861    1 HKLVFLGDQSVGKTSIITRFMYDTFDNQYQATIGiDFLSKTMYVDDKTVRLQLWDTAGQERFRSLIPSYIRDSSVAVVVY 80

                         90       100       110       120       130       140       150
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 884941707  94 SITEHESFTATgefREQILRVKAEEDKIPLLV-VGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVF 169
Cdd:cd01861   81 DITNRQSFDNT---DKWIDDVRDERGNDVIIVlVGNKTDLSDKRQVSTEEGEKKAKENNAMFIETSAKAGHNVKQLF 154

A Ras homolog member I (ARHI); ARHI (A Ras homolog member I) is a member of the Ras family with several unique structural and functional properties. ARHI is expressed in normal human ovarian and breast tissue, but its expression is decreased or eliminated in breast and ovarian cancer. ARHI contains an N-terminal extension of 34 residues (human) that is required to retain its tumor suppressive activity. Unlike most other Ras family members, ARHI is maintained in the constitutively active (GTP-bound) state in resting cells and has modest GTPase activity. ARHI inhibits STAT3 (signal transducers and activators of transcription 3), a latent transcription factor whose abnormal activation plays a critical role in oncogenesis. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  15 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:cd04140    2 YRVVVFGAGGVGKSSLVLRFVKGTFRESYIPTIEDTYRQVISCSKSICTLQITDTTGSHQFPAMQRLSISKGHAFILVYS 81

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  95 ITEHESFTATGEFREQILRVK-AEEDKIPLLVVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLM 173
Cdd:cd04140   82 ITSKQSLEELKPIYELICEIKgNNLEKIPIMLVGNKCDESPSREVSSSEGAALARTWNCAFMETSAKTNHNVQELFQELL 161

Rab GTPase family 18 (Rab18); Rab18 subfamily. Mammalian Rab18 is implicated in endocytic transport and is expressed most highly in polarized epithelial cells. However, trypanosomal Rab, TbRAB18, is upregulated in the BSF (Blood Stream Form) stage and localized predominantly to elements of the Golgi complex. In human and mouse cells, Rab18 has been identified in lipid droplets, organelles that store neutral lipids. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  16 KVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYR-KKVVLDGEEVQIDILDTAGQEDYAAIRDNYFRSGEGFLLVFS 94
Cdd:cd01863    2 KILLIGDSGVGKSSLLLRFTDDTFDEDLSSTIGVDFKvKTVTVDGKKVKLAIWDTAGQERFRTLTSSYYRGAQGVILVYD 81

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  95 ITEHESFTATGEFREQILRVKAEEDKIPLLvVGNKSDLEErRQVPVEEARSKAEEWGVQYVETSAKTRANVDKVFFDLMR 174
Cdd:cd01863   82 VTRRDTFDNLDTWLNELDTYSTNPDAVKML-VGNKIDKEN-REVTREEGQKFARKHNMLFIETSAKTRIGVQQAFEELVE 159

                 ..
gi 884941707 175 EI 176
Cdd:cd01863  160 KI 161

Rab family protein; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707   6 SKGQSS---LALhKVIMVGSGGVGKSALTLQFMYDEfVEDYEPTKADSYR-KKVVLDGEEVQIDILDTAGQEDYAAIRDN 81
Cdd:PLN03118   4 SSGQSSgydLSF-KILLIGDSGVGKSSLLVSFISSS-VEDLAPTIGVDFKiKQLTVGGKRLKLTIWDTAGQERFRTLTSS 81

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 884941707  82 YFRSGEGFLLVFSITEHESFTATGE-FREQILRVKAEEDKIPLLvVGNKSDLEERRQVPVEEARSKAEEWGVQYVETSAK 160
Cdd:PLN03118  82 YYRNAQGIILVYDVTRRETFTNLSDvWGKEVELYSTNQDCVKML-VGNKVDRESERDVSREEGMALAKEHGCLFLECSAK 160