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Loss of the Greatwall Kinase Weakens the Spindle Assembly Checkpoint.
PLoS Genet. 2016 09; 12(9):e1006310.PG

Abstract

The Greatwall kinase/Mastl is an essential gene that indirectly inhibits the phosphatase activity toward mitotic Cdk1 substrates. Here we show that although Mastl knockout (MastlNULL) MEFs enter mitosis, they progress through mitosis without completing cytokinesis despite the presence of misaligned chromosomes, which causes chromosome segregation defects. Furthermore, we uncover the requirement of Mastl for robust spindle assembly checkpoint (SAC) maintenance since the duration of mitotic arrest caused by microtubule poisons in MastlNULL MEFs is shortened, which correlates with premature disappearance of the essential SAC protein Mad1 at the kinetochores. Notably, MastlNULL MEFs display reduced phosphorylation of a number of proteins in mitosis, which include the essential SAC kinase MPS1. We further demonstrate that Mastl is required for multi-site phosphorylation of MPS1 as well as robust MPS1 kinase activity in mitosis. In contrast, treatment of MastlNULL cells with the phosphatase inhibitor okadaic acid (OKA) rescues the defects in MPS1 kinase activity, mislocalization of phospho-MPS1 as well as Mad1 at the kinetochore, and premature SAC silencing. Moreover, using in vitro dephosphorylation assays, we demonstrate that Mastl promotes persistent MPS1 phosphorylation by inhibiting PP2A/B55-mediated MPS1 dephosphorylation rather than affecting Cdk1 kinase activity. Our findings establish a key regulatory function of the Greatwall kinase/Mastl->PP2A/B55 pathway in preventing premature SAC silencing.

Authors+Show Affiliations

Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore, Republic of Singapore.Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore, Republic of Singapore.Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore, Republic of Singapore.Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore, Republic of Singapore. Department of Biochemistry, National University of Singapore (NUS), Singapore, Republic of Singapore.Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore, Republic of Singapore.Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore, Republic of Singapore. Department of Anatomy, National University of Singapore (NUS), Singapore, Republic of Singapore.Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore, Republic of Singapore.Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore, Republic of Singapore. Department of Biochemistry, National University of Singapore (NUS), Singapore, Republic of Singapore.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

27631493

Citation

Diril, M Kasim, et al. "Loss of the Greatwall Kinase Weakens the Spindle Assembly Checkpoint." PLoS Genetics, vol. 12, no. 9, 2016, pp. e1006310.
Diril MK, Bisteau X, Kitagawa M, et al. Loss of the Greatwall Kinase Weakens the Spindle Assembly Checkpoint. PLoS Genet. 2016;12(9):e1006310.
Diril, M. K., Bisteau, X., Kitagawa, M., Caldez, M. J., Wee, S., Gunaratne, J., Lee, S. H., & Kaldis, P. (2016). Loss of the Greatwall Kinase Weakens the Spindle Assembly Checkpoint. PLoS Genetics, 12(9), e1006310. https://doi.org/10.1371/journal.pgen.1006310
Diril MK, et al. Loss of the Greatwall Kinase Weakens the Spindle Assembly Checkpoint. PLoS Genet. 2016;12(9):e1006310. PubMed PMID: 27631493.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Loss of the Greatwall Kinase Weakens the Spindle Assembly Checkpoint. AU - Diril,M Kasim, AU - Bisteau,Xavier, AU - Kitagawa,Mayumi, AU - Caldez,Matias J, AU - Wee,Sheena, AU - Gunaratne,Jayantha, AU - Lee,Sang Hyun, AU - Kaldis,Philipp, Y1 - 2016/09/15/ PY - 2015/10/28/received PY - 2016/08/19/accepted PY - 2016/9/16/entrez PY - 2016/9/16/pubmed PY - 2017/5/24/medline SP - e1006310 EP - e1006310 JF - PLoS genetics JO - PLoS Genet. VL - 12 IS - 9 N2 - The Greatwall kinase/Mastl is an essential gene that indirectly inhibits the phosphatase activity toward mitotic Cdk1 substrates. Here we show that although Mastl knockout (MastlNULL) MEFs enter mitosis, they progress through mitosis without completing cytokinesis despite the presence of misaligned chromosomes, which causes chromosome segregation defects. Furthermore, we uncover the requirement of Mastl for robust spindle assembly checkpoint (SAC) maintenance since the duration of mitotic arrest caused by microtubule poisons in MastlNULL MEFs is shortened, which correlates with premature disappearance of the essential SAC protein Mad1 at the kinetochores. Notably, MastlNULL MEFs display reduced phosphorylation of a number of proteins in mitosis, which include the essential SAC kinase MPS1. We further demonstrate that Mastl is required for multi-site phosphorylation of MPS1 as well as robust MPS1 kinase activity in mitosis. In contrast, treatment of MastlNULL cells with the phosphatase inhibitor okadaic acid (OKA) rescues the defects in MPS1 kinase activity, mislocalization of phospho-MPS1 as well as Mad1 at the kinetochore, and premature SAC silencing. Moreover, using in vitro dephosphorylation assays, we demonstrate that Mastl promotes persistent MPS1 phosphorylation by inhibiting PP2A/B55-mediated MPS1 dephosphorylation rather than affecting Cdk1 kinase activity. Our findings establish a key regulatory function of the Greatwall kinase/Mastl->PP2A/B55 pathway in preventing premature SAC silencing. SN - 1553-7404 UR - https://www.unboundmedicine.com/medline/citation/27631493/Loss_of_the_Greatwall_Kinase_Weakens_the_Spindle_Assembly_Checkpoint_ L2 - http://dx.plos.org/10.1371/journal.pgen.1006310 DB - PRIME DP - Unbound Medicine ER -