title: Substrate modification with lysine 63-linked ubiquitin chains through the UBC13-UEV1A ubiquitin-conjugating enzyme.
abstract: Protein modification with lysine 63-linked ubiquitin chains has been implicated in the non-proteolytic regulation of signaling pathways. To understand the molecular mechanisms underlying this process, we have developed an in vitro system to examine the activity of the ubiquitin-conjugating enzyme UBC13-UEV1A with TRAF6 in which TRAF6 serves as both a ubiquitin ligase and substrate for modification. Although TRAF6 potently stimulates the activity of UBC13-UEV1A to synthesize ubiquitin chains, it is not appreciably ubiquitinated. We have determined that the presentation of Lys(63) of ubiquitin by UEV1A suppresses TRAF6 modification. Based on our observations, we propose that the modification of proteins with Lys(63)-linked ubiquitin chains occurs through a UEV1A-independent substrate modification and UEV1A-dependent Lys(63)-linked ubiquitin chain synthesis mechanism.
authors: Rigel Pharmaceuticals, Inc., South San Francisco, California 94080, USA. matt.petroski@yahoo.com
authors: Matthew D
authors: MD
authors: Petroski
authors: Xiulan
authors: X
authors: Zhou
authors: Guoqiang
authors: G
authors: Dong
authors: Sarkiz
authors: S
authors: Daniel-Issakani
authors: Donald G
authors: DG
authors: Payan
authors: Jianing
authors: J
authors: Huang
mesh_terms: D000818:Animals; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D008239:Lysine / Q000737:chemistry*; D051379:Mice; D008958:Models, Molecular; D011485:Protein Binding; D013379:Substrate Specificity; D048029:TNF Receptor-Associated Factor 6 / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry / Q000502:physiology*; D025801:Ubiquitin / Q000737:chemistry; D044763:Ubiquitin-Conjugating Enzymes / Q000737:chemistry / Q000502:physiology*
chemical_list: D048029:TNF Receptor-Associated Factor 6; D014157:Transcription Factors; D025801:Ubiquitin; C097310:UBE2D3 protein, human; C471607:UBE2N protein, human; C471624:UBE2V1 protein, human; C524395:UBE2V1 protein, mouse; C514982:Ube2n protein, mouse; D044763:Ubiquitin-Conjugating Enzymes; D008239:Lysine