5h9m

Structural highlights

Function

[SIAH2_HUMAN] 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 (POU2AF1, PML, NCOR1), a cell surface receptor (DCC), an antiapoptotic protein (BAG1), and a protein involved in synaptic vesicle function in neurons (SYP). Mediates ubiquitination and proteasomal degradation of DYRK2 in response to hypoxia. It is thereby involved in apoptosis, tumor suppression, cell cycle, transcription and signaling processes. Has some overlapping function with SIAH1. Triggers the ubiquitin-mediated degradation of TRAF2, whereas SIAH1 can not. Promotes monoubiquitination of SNCA.^{[1] [2] [3] [4] [5]}

See Also

• Ubiquitin protein ligase 3D structures

References

1. ↑ Boehm J, He Y, Greiner A, Staudt L, Wirth T. Regulation of BOB.1/OBF.1 stability by SIAH. EMBO J. 2001 Aug 1;20(15):4153-62. PMID:11483518 doi:10.1093/emboj/20.15.4153
2. ↑ Habelhah H, Frew IJ, Laine A, Janes PW, Relaix F, Sassoon D, Bowtell DD, Ronai Z. Stress-induced decrease in TRAF2 stability is mediated by Siah2. EMBO J. 2002 Nov 1;21(21):5756-65. PMID:12411493
3. ↑ Szargel R, Rott R, Eyal A, Haskin J, Shani V, Balan L, Wolosker H, Engelender S. Synphilin-1A inhibits seven in absentia homolog (SIAH) and modulates alpha-synuclein monoubiquitylation and inclusion formation. J Biol Chem. 2009 Apr 24;284(17):11706-16. doi: 10.1074/jbc.M805990200. Epub 2009, Feb 17. PMID:19224863 doi:10.1074/jbc.M805990200
4. ↑ Perez M, Garcia-Limones C, Zapico I, Marina A, Schmitz ML, Munoz E, Calzado MA. Mutual regulation between SIAH2 and DYRK2 controls hypoxic and genotoxic signaling pathways. J Mol Cell Biol. 2012 Oct;4(5):316-30. doi: 10.1093/jmcb/mjs047. Epub 2012 Aug 9. PMID:22878263 doi:10.1093/jmcb/mjs047
5. ↑ Hu G, Zhang S, Vidal M, Baer JL, Xu T, Fearon ER. Mammalian homologs of seven in absentia regulate DCC via the ubiquitin-proteasome pathway. Genes Dev. 1997 Oct 15;11(20):2701-14. PMID:9334332