title: Ubiquitination site preferences in anaphase promoting complex/cyclosome (APC/C) substrates.
abstract: Ordered progression of mitosis requires precise control in abundance of mitotic regulators. The anaphase promoting complex/cyclosome (APC/C) ubiquitin ligase plays a key role by directing ubiquitin-mediated destruction of targets in a temporally and spatially defined manner. Specificity in APC/C targeting is conferred through recognition of substrate D-box and KEN degrons, while the specificity of ubiquitination sites, as another possible regulated dimension, has not yet been explored. Here, we present the first analysis of ubiquitination sites in the APC/C substrate ubiquitome. We show that KEN is a preferred ubiquitin acceptor in APC/C substrates and that acceptor sites are enriched in predicted disordered regions and flanked by serine residues. Our experimental data confirm a role for the KEN lysine as an ubiquitin acceptor contributing to substrate destruction during mitotic progression. Using Aurora A and Nek2 kinases as examples, we show that phosphorylation on the flanking serine residue could directly regulate ubiquitination and subsequent degradation of substrates. We propose a novel layer of regulation in substrate ubiquitination, via phosphorylation adjacent to the KEN motif, in APC/C-mediated targeting.
authors.affiliation: Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
authors.forename: Mingwei
authors.initials: M
authors.lastname: Min
authors.forename: Ugo
authors.initials: U
authors.lastname: Mayor
authors.forename: Catherine
authors.initials: C
authors.lastname: Lindon
mesh_terms: D020816:Amino Acid Motifs; D064173:Anaphase-Promoting Complex-Cyclosome / Q000378:metabolism*; D064096:Aurora Kinase A / Q000378:metabolism; D002460:Cell Line; D006801:Humans; D008938:Mitosis; D011485:Protein Binding; D013379:Substrate Specificity; D054875:Ubiquitination
chemical_list: D064173:Anaphase-Promoting Complex-Cyclosome; D064096:Aurora Kinase A
keywords: (APC/C); Aurora A; KEN; degron; ubiquitin acceptor; ubiquitination