APC15 mediates CDC20 autoubiquitylation by APC/C(MCC) and disassembly of the mitotic checkpoint complex

Nat Struct Mol Biol. 2012 Nov;19(11):1116-23. doi: 10.1038/nsmb.2412. Epub 2012 Sep 24.

Abstract

The anaphase-promoting complex/cyclosome (APC/C) bound to CDC20 (APC/C(CDC20)) initiates anaphase by ubiquitylating B-type cyclins and securin. During chromosome bi-orientation, CDC20 assembles with MAD2, BUBR1 and BUB3 into a mitotic checkpoint complex (MCC) that inhibits substrate recruitment to the APC/C. APC/C activation depends on MCC disassembly, which was proposed to require CDC20 autoubiquitylation. Here we characterize APC15, a human APC/C subunit related to yeast Mnd2. APC15 is located near APC/C's MCC binding site; it is required for APC/C-bound MCC (APC/C(MCC))-dependent CDC20 autoubiquitylation and degradation and for timely anaphase initiation but is dispensable for substrate ubiquitylation by APC/C(CDC20) and APC/C(CDH1). Our results support the model wherein MCC is continuously assembled and disassembled to enable rapid activation of APC/C(CDC20) and CDC20 autoubiquitylation promotes MCC disassembly. We propose that APC15 and Mnd2 negatively regulate APC/C coactivators and report generation of recombinant human APC/C.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaphase-Promoting Complex-Cyclosome
  • Calcium-Binding Proteins / metabolism
  • Cdc20 Proteins
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • HeLa Cells
  • Humans
  • Immunoprecipitation
  • M Phase Cell Cycle Checkpoints / genetics
  • M Phase Cell Cycle Checkpoints / physiology*
  • Mad2 Proteins
  • Microscopy, Electron
  • Microscopy, Fluorescence
  • Models, Biological*
  • Poly-ADP-Ribose Binding Proteins
  • Protein-Serine-Threonine Kinases / metabolism
  • RNA Interference
  • RNA, Small Interfering / genetics
  • Repressor Proteins / metabolism
  • Time-Lapse Imaging
  • Ubiquitin-Protein Ligase Complexes / metabolism*
  • Ubiquitin-Protein Ligases
  • Ubiquitination

Substances

  • ANAPC15 protein, human
  • BUB3 protein, human
  • Calcium-Binding Proteins
  • Cdc20 Proteins
  • Cell Cycle Proteins
  • MAD2L1 protein, human
  • Mad2 Proteins
  • Poly-ADP-Ribose Binding Proteins
  • RNA, Small Interfering
  • Repressor Proteins
  • CDC20 protein, human
  • Ubiquitin-Protein Ligase Complexes
  • Anaphase-Promoting Complex-Cyclosome
  • Ubiquitin-Protein Ligases
  • BUB1 protein, human
  • Bub1 spindle checkpoint protein
  • Protein-Serine-Threonine Kinases