期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：6
页码：1540-1545
DOI：10.1073/pnas.1522423113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Most metazoan E3 ligases contain a signature RING domain that promotes the transfer of ubiquitin from the active site of E2 conjugating enzymes to lysine residues in substrates. Although these RING-E3s depend on E2 enzymes for catalysis, how they turn on their E2s at the right time and place remains poorly understood. Here we report a phosphorylation-dependent mechanism that ensures timely activation of the E2 Ube2S by its RING-E3, the anaphase-promoting complex (APC/C); while phosphorylation of a specific serine residue in the APC/C coactivator Cdc20 prevents delivery of Ube2S to the APC/C, removal of this mark by PP2AB56 allows Ube2S to bind the APC/C and catalyze ubiquitin chain elongation. PP2AB56 also stabilizes kinetochore–microtubule attachments to shut off the spindle checkpoint, suggesting that cells regulate the E2–E3 interplay to coordinate ubiquitination with critical events during cell division.
