Early mitotic degradation of Nek2A depends on Cdc20-independent interaction with the APC/C.
The temporal control of mitotic protein degradation remains incompletely understood. In particular, it is unclear why the mitotic checkpoint prevents the anaphase-promoting complex/cyclosome (APC/C)-mediated degradation of cyclin B and securin in early mitosis, but not cyclin A. Here, we show that another APC/C substrate, NIMA-related kinase 2A (Nek2A), is also destroyed in pro-metaphase in a checkpoint-independent manner and that this depends on an exposed carboxy-terminal methionine-arginine (MR) dipeptide tail. Truncation of the Nek2A C terminus delays its degradation until late mitosis, whereas Nek2A C-terminal peptides interfere with APC/C activity in an MR-dependent manner. Most importantly, we show that Nek2A binds directly to the APC/C, also in an MR-dependent manner, even in the absence of the adaptor protein Cdc20. As similar C-terminal dipeptide tails promote direct association of Cdc20, Cdh1 and Apc10-Doc1 with core APC/C subunits, we propose that this sequence also allows a substrate, Nek2A, to directly bind the APC/C. Thus, although Cdc20 is required for the degradation of Nek2A, it is not required for its recruitment and this renders its degradation insensitive to the mitotic checkpoint.
Hayes
Michelle J
MJ
Department of Biochemistry, University of Leicester, Leicester, Leics LE1 7RH, UK.
Kimata
Yuu
Y
Wattam
Samantha L
SL
Lindon
Catherine
C
Mao
Guojie
G
Yamano
Hiroyuki
H
Fry
Andrew M
AM
D064173:Anaphase-Promoting Complex-Cyclosome; D000818:Animals; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D043743:Ubiquitin-Protein Ligase Complexes / Q000378:metabolism*; D014981:Xenopus; D029867:Xenopus Proteins / Q000378:metabolism*
D064199:Cdc20 Proteins; C577501:Cdc20 protein, Xenopus; D018797:Cell Cycle Proteins; D029867:Xenopus Proteins; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; C490316:NEK2 protein, Xenopus; D017346:Protein Serine-Threonine Kinases