2mp2

Structural highlights

Function

[SUMO3_HUMAN] Ubiquitin-like protein which can be covalently attached to target lysines either as a monomer or as a lysine-linked polymer. Does not seem to be involved in protein degradation and may function as an antagonist of ubiquitin in the degradation process. Plays a role in a number of cellular processes such as nuclear transport, DNA replication and repair, mitosis and signal transduction. Covalent attachment to its substrates requires prior activation by the E1 complex SAE1-SAE2 and linkage to the E2 enzyme UBE2I, and can be promoted by an E3 ligase such as PIAS1-4, RANBP2 or CBX4.^{[1] [2]} [RNF4_MOUSE] E3 ubiquitin-protein ligase which binds polysumoylated chains covalently attached to proteins and mediates 'Lys-6'-, 'Lys-11'-, 'Lys-48'- and 'Lys-63'-linked polyubiquitination of those substrates and their subsequent targeting to the proteasome for degradation. Regulates the degradation of several proteins including PML and the transcriptional activator PEA3. Involved in chromosome alignment and spindle assembly, it regulates the kinetochore CENPH-CENPI-CENPK complex by targeting polysumoylated CENPI to proteasomal degradation. Regulates the cellular responses to hypoxia and heat shock through degradation of respectively EPAS1 and PARP1. Alternatively, it may also bind DNA/nucleosomes and have a more direct role in the regulation of transcription for instance enhancing basal transcription and steroid receptor-mediated transcriptional activation.^[3]

See Also

• SUMO

References

1. ↑ Tatham MH, Jaffray E, Vaughan OA, Desterro JM, Botting CH, Naismith JH, Hay RT. Polymeric chains of SUMO-2 and SUMO-3 are conjugated to protein substrates by SAE1/SAE2 and Ubc9. J Biol Chem. 2001 Sep 21;276(38):35368-74. Epub 2001 Jul 12. PMID:11451954 doi:10.1074/jbc.M104214200
2. ↑ Meulmeester E, Kunze M, Hsiao HH, Urlaub H, Melchior F. Mechanism and consequences for paralog-specific sumoylation of ubiquitin-specific protease 25. Mol Cell. 2008 Jun 6;30(5):610-9. doi: 10.1016/j.molcel.2008.03.021. PMID:18538659 doi:10.1016/j.molcel.2008.03.021
3. ↑ Liew CW, Sun H, Hunter T, Day CL. RING domain dimerization is essential for RNF4 function. Biochem J. 2010 Oct 1;431(1):23-9. PMID:20681948 doi:10.1042/BJ20100957
4. ↑ Xu Y, Plechanovova A, Simpson P, Marchant J, Leidecker O, Kraatz S, Hay RT, Matthews SJ. Structural insight into SUMO chain recognition and manipulation by the ubiquitin ligase RNF4. Nat Commun. 2014 Jun 27;5:4217. doi: 10.1038/ncomms5217. PMID:24969970 doi:http://dx.doi.org/10.1038/ncomms5217