TY - JOUR

T1 - Escape from the checkpoint

T2 - Nek2A binds a unique conformation of the APC/C-MCC complex

AU - Nilsson, Jakob

PY - 2020

Y1 - 2020

N2 - Cell division depends on the timely degradation of numerous proteins by the anaphase-promoting complex/cyclosome (APC/C). The APC/C is a large E3 ubiquitin ligase that in complex with Cdc20 recognises degrons in its substrates. The ability of APC/C-Cdc20 to bind degrons is prevented by the binding of the mitotic checkpoint complex (MCC) which constitutes the "wait anaphase" signal. Curiously, the mitotic kinase Nek2A is insensitive to the presence of the MCC. How Nek2A avoids MCC inhibition has been unclear but now work from Alfieri and colleagues published in this issue of EMBO reports provides an explanation [1]. It shows that Nek2A is able to bind a specific open conformation of the APC/C-MCC complex that allows Nek2A ubiquitination. A dimer of Nek2A binds two distinct binding pockets on the APC/C through C-terminal MR motifs and thus independently of degrons. One of the MR binding pockets is only available for interaction in the open form of APC/C-MCC explaining Nek2A selectivity for this conformation. Whether other substrates bind the APC/C directly without using canonical degrons will be important to determine.

AB - Cell division depends on the timely degradation of numerous proteins by the anaphase-promoting complex/cyclosome (APC/C). The APC/C is a large E3 ubiquitin ligase that in complex with Cdc20 recognises degrons in its substrates. The ability of APC/C-Cdc20 to bind degrons is prevented by the binding of the mitotic checkpoint complex (MCC) which constitutes the "wait anaphase" signal. Curiously, the mitotic kinase Nek2A is insensitive to the presence of the MCC. How Nek2A avoids MCC inhibition has been unclear but now work from Alfieri and colleagues published in this issue of EMBO reports provides an explanation [1]. It shows that Nek2A is able to bind a specific open conformation of the APC/C-MCC complex that allows Nek2A ubiquitination. A dimer of Nek2A binds two distinct binding pockets on the APC/C through C-terminal MR motifs and thus independently of degrons. One of the MR binding pockets is only available for interaction in the open form of APC/C-MCC explaining Nek2A selectivity for this conformation. Whether other substrates bind the APC/C directly without using canonical degrons will be important to determine.

U2 - 10.15252/embr.202050494

DO - 10.15252/embr.202050494

M3 - Journal article

C2 - 32431068

VL - 21

JO - E M B O Reports

JF - E M B O Reports

SN - 1469-221X

IS - 6

M1 - e50494

ER -