Seven in absentia protein family; The seven in absentia (sina) gene was first identified in Drosophila. The Drosophila Sina protein is essential for the determination of the R7 pathway in photoreceptor cell development: the loss of functional Sina results in the transformation of the R7 precursor cell to a non- neuronal cell type. The Sina protein contains an N-terminal RING finger domain pfam00097. Through this domain, Sina binds E2 ubiquitin-conjugating enzymes (UbcD1) Sina also interacts with Tramtrack (TTK88) via PHYL. Tramtrack is a transcriptional repressor that blocks photoreceptor determination, while PHYL down-regulates the activity of TTK88. In turn, the activity of PHYL requires the activation of the Sevenless receptor tyrosine kinase, a process essential for R7 determination. It is thought that thus Sina targets TTK88 for degradation, therefore promoting the R7 pathway. Murine and human homologs of Sina have also been identified. The human homolog Siah-1 also binds E2 enzymes (UbcH5) and through a series of physical interactions, targets beta-catenin for ubiquitin degradation. Siah-1 expression is enhanced by p53, itself promoted by DNA damage. Thus this pathway links DNA damage to beta-catenin degradation. Sina proteins, therefore, physically interact with a variety of proteins. The N-terminal RING finger domain that binds ubiquitin conjugating enzymes is described in pfam00097, and does not form part of the alignment for this family. The remainder C-terminal part is involved in interactions with other proteins, and is included in this alignment. In addition to the Drosophila protein and mammalian homologs, whose similarity was noted previously, this family also includes putative homologs from Caenorhabditis elegans, Arabidopsis thaliana.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 145326664  148 IRCRAMEKVIEASIVPCPNAKHGCKETTTYCNQSSHEKVCKF--VRCSCPVSNCNYVSSYSNLKSH 211
Cdd:pfam03145   1 IRNLALEKVAESLLFPCKYASSGCSETLPYTEKADHEERCEFrpYSCPCPGSSCTWQGSLDAVMPH 66

Seven in absentia protein family; The seven in absentia (sina) gene was first identified in Drosophila. The Drosophila Sina protein is essential for the determination of the R7 pathway in photoreceptor cell development: the loss of functional Sina results in the transformation of the R7 precursor cell to a non- neuronal cell type. The Sina protein contains an N-terminal RING finger domain pfam00097. Through this domain, Sina binds E2 ubiquitin-conjugating enzymes (UbcD1) Sina also interacts with Tramtrack (TTK88) via PHYL. Tramtrack is a transcriptional repressor that blocks photoreceptor determination, while PHYL down-regulates the activity of TTK88. In turn, the activity of PHYL requires the activation of the Sevenless receptor tyrosine kinase, a process essential for R7 determination. It is thought that thus Sina targets TTK88 for degradation, therefore promoting the R7 pathway. Murine and human homologs of Sina have also been identified. The human homolog Siah-1 also binds E2 enzymes (UbcH5) and through a series of physical interactions, targets beta-catenin for ubiquitin degradation. Siah-1 expression is enhanced by p53, itself promoted by DNA damage. Thus this pathway links DNA damage to beta-catenin degradation. Sina proteins, therefore, physically interact with a variety of proteins. The N-terminal RING finger domain that binds ubiquitin conjugating enzymes is described in pfam00097, and does not form part of the alignment for this family. The remainder C-terminal part is involved in interactions with other proteins, and is included in this alignment. In addition to the Drosophila protein and mammalian homologs, whose similarity was noted previously, this family also includes putative homologs from Caenorhabditis elegans, Arabidopsis thaliana.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 145326664  148 IRCRAMEKVIEASIVPCPNAKHGCKETTTYCNQSSHEKVCKF--VRCSCPVSNCNYVSSYSNLKSH 211
Cdd:pfam03145   1 IRNLALEKVAESLLFPCKYASSGCSETLPYTEKADHEERCEFrpYSCPCPGSSCTWQGSLDAVMPH 66

Seven in absentia protein family; The seven in absentia (sina) gene was first identified in Drosophila. The Drosophila Sina protein is essential for the determination of the R7 pathway in photoreceptor cell development: the loss of functional Sina results in the transformation of the R7 precursor cell to a non- neuronal cell type. The Sina protein contains an N-terminal RING finger domain pfam00097. Through this domain, Sina binds E2 ubiquitin-conjugating enzymes (UbcD1) Sina also interacts with Tramtrack (TTK88) via PHYL. Tramtrack is a transcriptional repressor that blocks photoreceptor determination, while PHYL down-regulates the activity of TTK88. In turn, the activity of PHYL requires the activation of the Sevenless receptor tyrosine kinase, a process essential for R7 determination. It is thought that thus Sina targets TTK88 for degradation, therefore promoting the R7 pathway. Murine and human homologs of Sina have also been identified. The human homolog Siah-1 also binds E2 enzymes (UbcH5) and through a series of physical interactions, targets beta-catenin for ubiquitin degradation. Siah-1 expression is enhanced by p53, itself promoted by DNA damage. Thus this pathway links DNA damage to beta-catenin degradation. Sina proteins, therefore, physically interact with a variety of proteins. The N-terminal RING finger domain that binds ubiquitin conjugating enzymes is described in pfam00097, and does not form part of the alignment for this family. The remainder C-terminal part is involved in interactions with other proteins, and is included in this alignment. In addition to the Drosophila protein and mammalian homologs, whose similarity was noted previously, this family also includes putative homologs from Caenorhabditis elegans, Arabidopsis thaliana.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 145326664  148 IRCRAMEKVIEASIVPCPNAKHGCKETTTYCNQSSHEKVCKF--VRCSCPVSNCNYVSSYSNLKSH 211
Cdd:pfam03145   1 IRNLALEKVAESLLFPCKYASSGCSETLPYTEKADHEERCEFrpYSCPCPGSSCTWQGSLDAVMPH 66

RING finger, HC subclass, found in seven in absentia homolog 1 (SIAH1) and similar proteins; SIAH1, also known as Siah-1a, is an inducible E3 ubiquitin-protein ligase that contributes to proteasome-mediated degradation of multiple targets in numerous cellular processes including apoptosis, tumor suppression, cell cycle, axon guidance, transcription regulation, and tumor necrosis factor signaling. SIAH1 functions as a scaffolding protein and interacts with a variety of different substrates for ubiquitination and subsequent degradation. It regulates the oncoprotein p34SEI-1 polyubiquitination and its subsequent degradation in a p53-dependent manner, which mediates p53 preferential vitamin C cytotoxicity. It targets the nonreceptor tyrosine kinase activated Cdc42-associated kinase 1 (ACK1), a valid target in cancer therapy, for ubiquitinylation and proteasomal degradation. It also interacts with KLF10 and targets it for degradation. The CDK2 phosphorylation-mediated KLF10 dissociation from SIAH1 is linked to cell cycle progression. Moreover, SIAH1 is downregulated and associated with apoptosis and invasion in human breast cancer. It targets TAp73, a homolog of the tumor suppressor p53, for degradation. It is suppressed by hypoxia-inducible factor 1-alpha (HIF-1alpha) under hypoxic conditions to regulate TAp73 levels. It also promotes the migration and invasion of human glioma cells by regulating HIF-1alpha signaling under hypoxia. Furthermore, SIAH1 forms a protein complex with glyceraldehyde-3-phosphate dehydrogenase (GAPDH). The apoptosis signal-regulating kinase 1 (ASK1) functions as an activator of the GAPDH-Siah1 stress-signaling cascade. It also plays an important role in ethanol-induced apoptosis in neural crest cells (NCCs). SIAH1 contains an N-terminal C3HC4-type RING-HC finger, two zinc-finger subdomains, and a C-terminal tumor necrosis factor (TNF) receptor associated factor (TRAF)-like substrate-binding domain (SBD) responsible for dimer formation.

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gi 145326664 103 VLDCPTCCEPLKRPIYQCSNGHLACSSCCQKLNkKCSFCR 142
Cdd:cd16751    5 LFECPVCFDYVLPPILQCQSGHLVCSNCRPKLT-CCPTCR 43

RING finger, HC subclass, found in mind bomb MIB1, MIB2, RGLG1, RGLG2, and similar proteins; MIBs are large, multi-domain E3 ubiquitin-protein ligases that promote ubiquitination of the cytoplasmic tails of Notch ligands. They are also responsible for TBK1 K63-linked ubiquitination and activation, promoting interferon production and controlling antiviral immunity. Moreover, MIBs selectively control responses to cytosolic RNA and regulate type I interferon transcription. Both MIB1 and MIB2 have similar domain architectures, which consist of two Mib-Herc2 domains flanking a ZZ zinc finger, a REP region including two tandem Mib repeats, an ANK region that spans ankyrin repeats, and a RNG region, where MIB1 and MIB2 contain three and two C3HC4-type RING-HC fingers, respectively. This model corresponds to the third RING-HC finger of MIB1, as well as the second RING-HC finger of MIB2. In addition to MIB1 and MIB2, the RING-HC fingers of RING domain ligase RGLG1, RGLG2 and similar proteins from plant are also included in this model. RGLG1 is a ubiquitously expressed E3 ubiquitin-protein ligase that interacts with UBC13 and, together with UBC13, catalyzes the formation of K63-linked polyubiquitin chains, which is involved in DNA damage repair. RGLG1 mediates the formation of canonical, K48-linked polyubiquitin chains that target proteins for degradation. It also regulates apical dominance by acting on the auxin transport proteins abundance. RGLG1 has overlapping functions with its closest sequelog, RGLG2. They both function as RING E3 ligases that interact with ethylene response factor 53 (ERF53) in the nucleus and negatively regulate the plant drought stress response. All RGLG proteins contain a Von Willebrand factor type A (vWA) domain and a C3HC4-type RING-HC finger.

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gi 145326664 106 CPTCCEPLKRPIYQCsnGHLACSSCCQKLnKKCSFCR 142
Cdd:cd16520    3 CPICMERKKNVVFLC--GHGTCQKCAEKL-KKCPICR 36