Cdc20 is required for the post-anaphase, KEN-dependent degradation of centromere protein F.
Progression through mitosis and cytokinesis requires the sequential proteolysis of several cell-cycle regulators. This proteolysis is mediated by the ubiquitin-proteasome system, with the E3 ligase being the anaphase-promoting complex, also known as the cyclosome (APC/C). The APC/C is regulated by two activators, namely Cdc20 and Cdh1. The current view is that prior to anaphase, the APC/C is activated by Cdc20, but that following anaphase, APC/C switches to Cdh1-dependent activation. However, here we present an analysis of the kinetochore protein Cenp-F that is inconsistent with this notion. Although it has long been appreciated that Cenp-F is degraded sometime during or after mitosis, exactly when and how has not been clear. Here we show that degradation of Cenp-F initiates about six minutes after anaphase, and that this is dependent on a C-terminal KEN-box. Although these two observations are consistent with Cenp-F being a substrate of Cdh1-activated APC/C, Cenp-F is degraded normally in Cdh1-null cells. By contrast, RNAi-mediated repression of APC/C subunits or Cdc20 does inhibit Cenp-F degradation. These findings therefore suggest that the APC/C does not simply 'switch' upon anaphase onset; rather, our observations indicate that Cdc20 also contributes to post-anaphase activation of the APC/C. We also show that the post-anaphase, KEN-box-dependent degradation of Cenp-F requires it to be farnesylated, a post-translational modification usually linked to membrane association. Because so many of the behaviours of Cenp-F are farnesylation-dependent, we suggest that this modification plays a more global role in Cenp-F function.
Gurden
Mark D J
MD
Faculty of Life Sciences, Michael Smith Building, University of Manchester, Manchester M13 9PT, UK.
Holland
Andrew J
AJ
van Zon
Wouter
W
Tighe
Anthony
A
Vergnolle
Mailys A
MA
Andres
Douglas A
DA
Spielmann
H Peter
HP
Malumbres
Marcos
M
Wolthuis
Rob M F
RM
Cleveland
Don W
DW
Taylor
Stephen S
SS
D064173:Anaphase-Promoting Complex-Cyclosome; D000818:Animals; D015703:Antigens, CD; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D064199:Cdc20 Proteins; D064200:Cdh1 Proteins; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D006801:Humans; D018386:Kinetochores / Q000378:metabolism; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism*; D008853:Microscopy; D054876:Prenylation; D034622:RNA Interference; D043743:Ubiquitin-Protein Ligase Complexes / Q000378:metabolism
D015703:Antigens, CD; C513384:CDH1 protein, human; D015820:Cadherins; D064199:Cdc20 Proteins; C577491:Cdc20 protein, mouse; D064200:Cdh1 Proteins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; C577585:Fzr1 protein, mouse; D008840:Microfilament Proteins; C068688:centromere protein E; C094772:centromere protein F; C577488:CDC20 protein, human; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome