TY - JOUR
T1 - Mechanistic insight into TRIP13-catalyzed Mad2 structural transition and spindle checkpoint silencing
AU - Brulotte, Melissa L.
AU - Jeong, Byung Cheon
AU - Li, Faxiang
AU - Li, Bing
AU - Yu, Eric B.
AU - Wu, Qiong
AU - Brautigam, Chad A.
AU - Yu, Hongtao
AU - Luo, Xuelian
N1 - Funding Information:
We thank Haydn Ball at the UTSW Protein Chemistry Technology Core for peptide synthesis, Shih-Chia Tso in the UTSW Macromolecular Biophysics Resource for assistance with analytical ultracentrifugation, and Michael Rape at the University of California at Berkeley for providing recombinant Ube2S. Use of Argonne National Laboratory Structural Biology Center beamlines at the Advanced Photon Source was supported by the US Department of Energy under contract DE-AC02-06CH11357. This study is supported by grants from the National Institutes of Health (GM107415 to X.L.), Cancer Prevention and Research Institute of Texas (RP160255 to X.L.) and the Welch Foundation (I-1932 to X.L. and I-1441 to H.Y.). H.Y. is an Investigator with the Howard Hughes Medical Institute.
Publisher Copyright:
© 2017 The Author(s).
PY - 2017/12/1
Y1 - 2017/12/1
N2 - The spindle checkpoint maintains genomic stability and prevents aneuploidy. Unattached kinetochores convert the latent open conformer of the checkpoint protein Mad2 (O-Mad2) to the active closed conformer (C-Mad2), bound to Cdc20. C-Mad2-Cdc20 is incorporated into the mitotic checkpoint complex (MCC), which inhibits the anaphase-promoting complex/cyclosome (APC/C). The C-Mad2-binding protein p31comet and the ATPase TRIP13 promote MCC disassembly and checkpoint silencing. Here, using nuclear magnetic resonance (NMR) spectroscopy, we show that TRIP13 and p31comet catalyze the conversion of C-Mad2 to O-Mad2, without disrupting its stably folded core. We determine the crystal structure of human TRIP13, and identify functional TRIP13 residues that mediate p31comet-Mad2 binding and couple ATP hydrolysis to local unfolding of Mad2. TRIP13 and p31comet prevent APC/C inhibition by MCC components, but cannot reactivate APC/C already bound to MCC. Therefore, TRIP13-p31comet intercepts and disassembles free MCC not bound to APC/C through mediating the local unfolding of the Mad2 C-terminal region.
AB - The spindle checkpoint maintains genomic stability and prevents aneuploidy. Unattached kinetochores convert the latent open conformer of the checkpoint protein Mad2 (O-Mad2) to the active closed conformer (C-Mad2), bound to Cdc20. C-Mad2-Cdc20 is incorporated into the mitotic checkpoint complex (MCC), which inhibits the anaphase-promoting complex/cyclosome (APC/C). The C-Mad2-binding protein p31comet and the ATPase TRIP13 promote MCC disassembly and checkpoint silencing. Here, using nuclear magnetic resonance (NMR) spectroscopy, we show that TRIP13 and p31comet catalyze the conversion of C-Mad2 to O-Mad2, without disrupting its stably folded core. We determine the crystal structure of human TRIP13, and identify functional TRIP13 residues that mediate p31comet-Mad2 binding and couple ATP hydrolysis to local unfolding of Mad2. TRIP13 and p31comet prevent APC/C inhibition by MCC components, but cannot reactivate APC/C already bound to MCC. Therefore, TRIP13-p31comet intercepts and disassembles free MCC not bound to APC/C through mediating the local unfolding of the Mad2 C-terminal region.
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U2 - 10.1038/s41467-017-02012-2
DO - 10.1038/s41467-017-02012-2
M3 - Article
C2 - 29208896
AN - SCOPUS:85037169216
SN - 2041-1723
VL - 8
JO - Nature communications
JF - Nature communications
IS - 1
M1 - 1956
ER -