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Mitotic progression becomes irreversible in prometaphase and collapses when Wee1 and Cdc25 are inhibited

Mitosis requires precise coordination of multiple global reorganizations of the nucleus and cytoplasm. Cyclin-dependent kinase 1 (Cdk1) is the primary upstream kinase that directs mitotic progression by phosphorylation of a large number of substrate proteins. Cdk1 activation reaches the peak level d...

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Autores principales: Potapova, Tamara A., Sivakumar, Sushama, Flynn, Jennifer N., Li, Rong, Gorbsky, Gary J.
Formato: Texto
Lenguaje:English
Publicado: The American Society for Cell Biology 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3078080/
https://www.ncbi.nlm.nih.gov/pubmed/21325631
http://dx.doi.org/10.1091/mbc.E10-07-0599
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author Potapova, Tamara A.
Sivakumar, Sushama
Flynn, Jennifer N.
Li, Rong
Gorbsky, Gary J.
author_facet Potapova, Tamara A.
Sivakumar, Sushama
Flynn, Jennifer N.
Li, Rong
Gorbsky, Gary J.
author_sort Potapova, Tamara A.
collection PubMed
description Mitosis requires precise coordination of multiple global reorganizations of the nucleus and cytoplasm. Cyclin-dependent kinase 1 (Cdk1) is the primary upstream kinase that directs mitotic progression by phosphorylation of a large number of substrate proteins. Cdk1 activation reaches the peak level due to positive feedback mechanisms. By inhibiting Cdk chemically, we showed that, in prometaphase, when Cdk1 substrates approach the peak of their phosphorylation, cells become capable of proper M-to-G1 transition. We interfered with the molecular components of the Cdk1-activating feedback system through use of chemical inhibitors of Wee1 and Myt1 kinases and Cdc25 phosphatases. Inhibition of Wee1 and Myt1 at the end of the S phase led to rapid Cdk1 activation and morphologically normal mitotic entry, even in the absence of G2. Dampening Cdc25 phosphatases simultaneously with Wee1 and Myt1 inhibition prevented Cdk1/cyclin B kinase activation and full substrate phosphorylation and induced a mitotic “collapse,” a terminal state characterized by the dephosphorylation of mitotic substrates without cyclin B proteolysis. This was blocked by the PP1/PP2A phosphatase inhibitor, okadaic acid. These findings suggest that the positive feedback in Cdk activation serves to overcome the activity of Cdk-opposing phosphatases and thus sustains forward progression in mitosis.
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spelling pubmed-30780802011-06-30 Mitotic progression becomes irreversible in prometaphase and collapses when Wee1 and Cdc25 are inhibited Potapova, Tamara A. Sivakumar, Sushama Flynn, Jennifer N. Li, Rong Gorbsky, Gary J. Mol Biol Cell Articles Mitosis requires precise coordination of multiple global reorganizations of the nucleus and cytoplasm. Cyclin-dependent kinase 1 (Cdk1) is the primary upstream kinase that directs mitotic progression by phosphorylation of a large number of substrate proteins. Cdk1 activation reaches the peak level due to positive feedback mechanisms. By inhibiting Cdk chemically, we showed that, in prometaphase, when Cdk1 substrates approach the peak of their phosphorylation, cells become capable of proper M-to-G1 transition. We interfered with the molecular components of the Cdk1-activating feedback system through use of chemical inhibitors of Wee1 and Myt1 kinases and Cdc25 phosphatases. Inhibition of Wee1 and Myt1 at the end of the S phase led to rapid Cdk1 activation and morphologically normal mitotic entry, even in the absence of G2. Dampening Cdc25 phosphatases simultaneously with Wee1 and Myt1 inhibition prevented Cdk1/cyclin B kinase activation and full substrate phosphorylation and induced a mitotic “collapse,” a terminal state characterized by the dephosphorylation of mitotic substrates without cyclin B proteolysis. This was blocked by the PP1/PP2A phosphatase inhibitor, okadaic acid. These findings suggest that the positive feedback in Cdk activation serves to overcome the activity of Cdk-opposing phosphatases and thus sustains forward progression in mitosis. The American Society for Cell Biology 2011-04-15 /pmc/articles/PMC3078080/ /pubmed/21325631 http://dx.doi.org/10.1091/mbc.E10-07-0599 Text en © 2011 Potapova et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). “ASCB®,“ “The American Society for Cell Biology®,” and “Molecular Biology of the Cell®” are registered trademarks of The American Society of Cell Biology.
spellingShingle Articles
Potapova, Tamara A.
Sivakumar, Sushama
Flynn, Jennifer N.
Li, Rong
Gorbsky, Gary J.
Mitotic progression becomes irreversible in prometaphase and collapses when Wee1 and Cdc25 are inhibited
title Mitotic progression becomes irreversible in prometaphase and collapses when Wee1 and Cdc25 are inhibited
title_full Mitotic progression becomes irreversible in prometaphase and collapses when Wee1 and Cdc25 are inhibited
title_fullStr Mitotic progression becomes irreversible in prometaphase and collapses when Wee1 and Cdc25 are inhibited
title_full_unstemmed Mitotic progression becomes irreversible in prometaphase and collapses when Wee1 and Cdc25 are inhibited
title_short Mitotic progression becomes irreversible in prometaphase and collapses when Wee1 and Cdc25 are inhibited
title_sort mitotic progression becomes irreversible in prometaphase and collapses when wee1 and cdc25 are inhibited
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3078080/
https://www.ncbi.nlm.nih.gov/pubmed/21325631
http://dx.doi.org/10.1091/mbc.E10-07-0599
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