The APC/C recruits cyclin B1-Cdk1-Cks in prometaphase before D box recognition to control mitotic exit.
The ubiquitin ligase anaphase-promoting complex/cyclosome (APC/C) is activated at prometaphase by mitotic phosphorylation and binding of its activator, Cdc20. This initiates cyclin A degradation, whereas cyclin B1 is stabilized by the spindle checkpoint. Upon checkpoint release, the RXXL destruction box (D box) was proposed to direct cyclin B1 to core APC/C or Cdc20. In this study, we report that endogenous cyclin B1-Cdk1 is recruited to checkpoint-inhibited, phosphorylated APC/C in prometaphase independently of Cdc20 or the cyclin B1 D box. Like cyclin A, cyclin B1 binds the APC/C by the Cdk cofactor Cks and the APC3 subunit. Prior binding to APC/C(Cdc20) makes cyclin B1 a better APC/C substrate in metaphase, driving mitotic exit and cytokinesis. We conclude that in prometaphase, the phosphorylated APC/C can recruit both cyclin A and cyclin B1 in a Cks-dependent manner. This suggests that the spindle checkpoint blocks D box recognition of APC/C-bound cyclin B1, whereas distinctive complexes between the N terminus of cyclin A and Cdc20 evade checkpoint control.
van Zon
Wouter
W
Division of Molecular Biology and 2 Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, Netherlands.
Ogink
Janneke
J
ter Riet
Bas
B
Medema
René H
RH
te Riele
Hein
H
Wolthuis
Rob M F
RM
D064173:Anaphase-Promoting Complex-Cyclosome; D000818:Animals; D016203:CDC2 Protein Kinase / Q000235:genetics / Q000378:metabolism*; D042846:CDC2-CDC28 Kinases; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D019925:Cyclin A / Q000235:genetics / Q000378:metabolism; D056744:Cyclin B1 / Q000235:genetics / Q000378:metabolism*; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008938:Mitosis / Q000502:physiology*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D015739:Nocodazole / Q000378:metabolism; D010766:Phosphorylation; D049468:Prometaphase / Q000502:physiology*; D011485:Protein Binding; D047428:Protein Kinase Inhibitors / Q000378:metabolism; D011687:Purines / Q000378:metabolism; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D000077546:Roscovitine; D064249:Securin; D050257:Tubulin Modulators / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism; D043743:Ubiquitin-Protein Ligase Complexes / Q000235:genetics / Q000378:metabolism*
C093090:CKS1B protein, human; D002352:Carrier Proteins; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins; D019925:Cyclin A; D056744:Cyclin B1; D009363:Neoplasm Proteins; D047428:Protein Kinase Inhibitors; D011687:Purines; D011993:Recombinant Fusion Proteins; D064249:Securin; D050257:Tubulin Modulators; D025801:Ubiquitin; D000077546:Roscovitine; C577488:CDC20 protein, human; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; D016203:CDC2 Protein Kinase; D042846:CDC2-CDC28 Kinases; D018844:Cyclin-Dependent Kinases; D015739:Nocodazole