first ubiquitin-like (Ubl) domain located at the N-terminus of coronavirus SARS-CoV non-structural protein 3 (Nsp3) and related proteins; This ubiquitin-like (Ubl) domain (Ubl1) is found at the N-terminus of coronavirus Nsp3, a large multi-functional multi-domain protein which is an essential component of the replication/transcription complex (RTC). The functions of Ubl1 in CoVs are related to single-stranded RNA (ssRNA) binding and to interacting with the nucleocapsid (N) protein. SARS-CoV Ubl1 has been shown to bind ssRNA having AUA patterns, and since the 5'-UTR of the SARS-CoV genome has a number of AUA repeats, it may bind there. In mouse hepatitis virus (MHV), this Ubl1 domain binds the cognate N protein. Adjacent to Ubl1 is a Glu-rich acidic region (also referred to as hypervariable region, HVR); Ubl1 together with HVR has been called Nsp3a. Currently, the function of HVR in CoVs is unknown. This model corresponds to one of two Ubl domains in Nsp3; the other is located N-terminal to the papain-like protease (PLpro) and is not represented by this model.

                        10
                ....*....|...
gi 62088516   1 GIHDGLTVHLVIK 13
Cdd:cd01808  61 GIKDGLTVHLVIK 73

ubiquitin-like (Ubl) domain found in eukaryotic protein linking integrin-associated protein (IAP, also known as CD47) with cytoskeleton (PLIC) proteins; The PLIC proteins (or ubiquilins) family contains human homologs of the yeast ubiquitin-like (Ubl) Dsk2 protein, PLIC-1 (also termed ubiquilin-1), PLIC-2 (also termed ubiquilin-2, or Chap1), PLIC-3 (also termed ubiquilin-3) and PLIC-4 (also termed ubiquilin-4, ataxin-1 interacting ubiquitin-like protein, A1Up, connexin43-interacting protein of 75 kDa, or CIP75), and mouse PLIC proteins. They are ubiquitin (Ub)-binding adaptor proteins involved in all protein degradation pathways through delivering ubiquitinated substrates to proteasomes. They also promote autophagy-dependent cell survival during nutrient starvation. PLIC-1 regulates the function of the thrombospondin receptor CD47 and G protein signaling. It plays a role in TLR4-mediated signaling through interacting with the Toll/interleukin-1 receptor (TIR) domain of TLR4. It also inhibits the TLR3-Trif antiviral pathway by reducing the abundance of Trif. Moreover, PLIC-1 binds to gamma-aminobutyric acid receptors (GABAARs) and modulates the Ub-dependent, proteasomal degradation of GABAARs. Furthermore, PLIC-1 acts as a molecular chaperone regulating amyloid precursor protein (APP) biosynthesis, trafficking, and degradation by stimulating K63-linked polyubiquitination of lysine 688 in the APP intracellular domain. In addition, PLIC-1 is involved in the protein aggregation-stress pathway via associating with the Ub-interacting motif (UIM) proteins ataxin 3, HSJ1a, and epidermal growth factor substrate 15 (EPS15). PLIC-2 is a protein that binds the ATPase domain of the HSP70-like Stch protein. It functions as a negative regulator of G protein-coupled receptor (GPCR) endocytosis. It also involved in amyotrophic lateral sclerosis (ALS)-related dementia. PLIC-3 is encoded by UbiquilinN3, a testis-specific gene. It shows high sequence similarity with the Xenopus protein XDRP1, a nuclear phosphoprotein that binds to the N-terminus of cyclin A and inhibits Ca2+-induced degradation of cyclin A, but not cyclin B. PLIC-4 is an ubiquitin-like (Ubl) nuclear protein that interacts with ataxin-1 and further links ataxin-1 with the chaperone and Ub-proteasome pathways. It also binds to the non-ubiquitinated gap junction protein connexin43 (Cx43) and regulates the turnover of Cx43 through the proteasomal pathway. PLIC proteins contain an N-terminal Ubl domain that is responsible for the binding of Ub-interacting motifs (UIMs) expressed by proteasomes and endocytic adaptors, and C-terminal Ub-associated (UBA) domain that interacts with Ub chains present on proteins destined for proteasomal degradation. In addition, mammalian PLIC2 proteins have an extra collagen-like motif region, which is absent in other PLIC proteins and the yeast Dsk2 protein.

                        10
                ....*....|...
gi 62088516   1 GIHDGLTVHLVIK 13
Cdd:cd01808  61 GIKDGLTVHLVIK 73

ubiquitin-like (Ubl) domain found in eukaryotic protein linking integrin-associated protein (IAP, also known as CD47) with cytoskeleton (PLIC) proteins; The PLIC proteins (or ubiquilins) family contains human homologs of the yeast ubiquitin-like (Ubl) Dsk2 protein, PLIC-1 (also termed ubiquilin-1), PLIC-2 (also termed ubiquilin-2, or Chap1), PLIC-3 (also termed ubiquilin-3) and PLIC-4 (also termed ubiquilin-4, ataxin-1 interacting ubiquitin-like protein, A1Up, connexin43-interacting protein of 75 kDa, or CIP75), and mouse PLIC proteins. They are ubiquitin (Ub)-binding adaptor proteins involved in all protein degradation pathways through delivering ubiquitinated substrates to proteasomes. They also promote autophagy-dependent cell survival during nutrient starvation. PLIC-1 regulates the function of the thrombospondin receptor CD47 and G protein signaling. It plays a role in TLR4-mediated signaling through interacting with the Toll/interleukin-1 receptor (TIR) domain of TLR4. It also inhibits the TLR3-Trif antiviral pathway by reducing the abundance of Trif. Moreover, PLIC-1 binds to gamma-aminobutyric acid receptors (GABAARs) and modulates the Ub-dependent, proteasomal degradation of GABAARs. Furthermore, PLIC-1 acts as a molecular chaperone regulating amyloid precursor protein (APP) biosynthesis, trafficking, and degradation by stimulating K63-linked polyubiquitination of lysine 688 in the APP intracellular domain. In addition, PLIC-1 is involved in the protein aggregation-stress pathway via associating with the Ub-interacting motif (UIM) proteins ataxin 3, HSJ1a, and epidermal growth factor substrate 15 (EPS15). PLIC-2 is a protein that binds the ATPase domain of the HSP70-like Stch protein. It functions as a negative regulator of G protein-coupled receptor (GPCR) endocytosis. It also involved in amyotrophic lateral sclerosis (ALS)-related dementia. PLIC-3 is encoded by UbiquilinN3, a testis-specific gene. It shows high sequence similarity with the Xenopus protein XDRP1, a nuclear phosphoprotein that binds to the N-terminus of cyclin A and inhibits Ca2+-induced degradation of cyclin A, but not cyclin B. PLIC-4 is an ubiquitin-like (Ubl) nuclear protein that interacts with ataxin-1 and further links ataxin-1 with the chaperone and Ub-proteasome pathways. It also binds to the non-ubiquitinated gap junction protein connexin43 (Cx43) and regulates the turnover of Cx43 through the proteasomal pathway. PLIC proteins contain an N-terminal Ubl domain that is responsible for the binding of Ub-interacting motifs (UIMs) expressed by proteasomes and endocytic adaptors, and C-terminal Ub-associated (UBA) domain that interacts with Ub chains present on proteins destined for proteasomal degradation. In addition, mammalian PLIC2 proteins have an extra collagen-like motif region, which is absent in other PLIC proteins and the yeast Dsk2 protein.

                        10
                ....*....|...
gi 62088516   1 GIHDGLTVHLVIK 13
Cdd:cd01808  61 GIKDGLTVHLVIK 73