| Structural highlights
Function
[SIA1A_MOUSE] E3 ubiquitin-protein ligase that mediates ubiquitination and subsequent proteasomal degradation of target proteins. E3 ubiquitin ligases accept ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfers the ubiquitin to targeted substrates. Mediates E3 ubiquitin ligase activity either through direct binding to substrates or by functioning as the essential RING domain subunit of larger E3 complexes. Triggers the ubiquitin-mediated degradation of many substrates, including proteins involved in transcription regulation (ELL2, MYB, POU2AF1, PML and RBBP8), a cell surface receptor (DCC), the cell-surface receptor-type tyrosine kinase FLT3, the cytoplasmic signal transduction molecules (KLF10/TIEG1 and NUMB), an antiapoptotic protein (BAG1), a microtubule motor protein (KIF22), a protein involved in synaptic vesicle function in neurons (SYP), a structural protein (CTNNB1) and SNCAIP. Confers constitutive instability to HIPK2 through proteasomal degradation. It is thereby involved in many cellular processes such as apoptosis, tumor suppression, cell cycle, axon guidance, transcription, spermatogenesis and TNF-alpha signaling. Has some overlapping function with SIAH2. Required for completion of meiosis I in males. Induces apoptosis in cooperation with PEG3. Upon nitric oxid (NO) generation that follows apoptotic stimulation, interacts with S-nitrosylated GAPDH, mediating the translocation of GAPDH to the nucleus. GAPDH acts as a stabilizer of SIAH1, facilitating the degradation of nuclear proteins.[1] [2] [3]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The Siah family of RING proteins function as ubiquitin ligase components, contributing to the degradation of multiple targets involved in cell growth, differentiation, angiogenesis, oncogenesis, and inflammation. Previously, a binding motif (degron) was recognized in many of the Siah degradation targets, suggesting that Siah itself may facilitate substrate recognition. We report the crystal structure of the Siah in complex with a peptide containing the degron motif. Binding is within a groove formed in part by the zinc fingers and the first two beta strands of the TRAF-C domain of Siah. We show that residues in the degron, previously described to facilitate binding to Siah, interact with the protein. Mutagenesis of Siah at sites of interaction also abrogates both in vitro peptide binding and destabilization of a known Siah target.
Elucidation of the substrate binding site of Siah ubiquitin ligase.,House CM, Hancock NC, Moller A, Cromer BA, Fedorov V, Bowtell DD, Parker MW, Polekhina G Structure. 2006 Apr;14(4):695-701. PMID:16615911[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Relaix F, Wei X, Li W, Pan J, Lin Y, Bowtell DD, Sassoon DA, Wu X. Pw1/Peg3 is a potential cell death mediator and cooperates with Siah1a in p53-mediated apoptosis. Proc Natl Acad Sci U S A. 2000 Feb 29;97(5):2105-10. PMID:10681424 doi:http://dx.doi.org/10.1073/pnas.040378897
- ↑ Dickins RA, Frew IJ, House CM, O'Bryan MK, Holloway AJ, Haviv I, Traficante N, de Kretser DM, Bowtell DD. The ubiquitin ligase component Siah1a is required for completion of meiosis I in male mice. Mol Cell Biol. 2002 Apr;22(7):2294-303. PMID:11884614
- ↑ House CM, Hancock NC, Moller A, Cromer BA, Fedorov V, Bowtell DD, Parker MW, Polekhina G. Elucidation of the substrate binding site of Siah ubiquitin ligase. Structure. 2006 Apr;14(4):695-701. PMID:16615911 doi:10.1016/j.str.2005.12.013
- ↑ House CM, Hancock NC, Moller A, Cromer BA, Fedorov V, Bowtell DD, Parker MW, Polekhina G. Elucidation of the substrate binding site of Siah ubiquitin ligase. Structure. 2006 Apr;14(4):695-701. PMID:16615911 doi:10.1016/j.str.2005.12.013
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