4ppe
From Proteopedia
human RNF4 RING domain
Structural highlights
FunctionRNF4_HUMAN 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.[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedThe post-translational modification of DNA repair and checkpoint proteins by ubiquitin and small ubiquitin-like modifier (SUMO) critically orchestrates the DNA damage response (DDR). The ubiquitin ligase RNF4 integrates signaling by SUMO and ubiquitin, through its selective recognition and ubiquitination of SUMO-modified proteins. Here, we define a key new determinant for target discrimination by RNF4, in addition to interaction with SUMO. We identify a nucleosome-targeting motif within the RNF4 RING domain that can bind DNA and thereby enables RNF4 to selectively ubiquitinate nucleosomal histones. Furthermore, RNF4 nucleosome-targeting is crucially required for the repair of TRF2-depleted dysfunctional telomeres by 53BP1-mediated non-homologous end joining. RNF4 interacts with both SUMO and nucleosomes to promote the DNA damage response.,Groocock LM, Nie M, Prudden J, Moiani D, Wang T, Cheltsov A, Rambo RP, Arvai AS, Hitomi C, Tainer JA, Luger K, Perry JJ, Lazzerini-Denchi E, Boddy MN EMBO Rep. 2014 May;15(5):601-8. doi: 10.1002/embr.201338369. Epub 2014 Apr 8. PMID:24714598[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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