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Role for regulated phosphatase activity in generating mitotic oscillations in Xenopus cell-free extracts.

ABSTRACT: Although current textbook explanations of cell-cycle control in eukaryotes emphasize the periodic activation of cyclin-dependent protein kinases (CDKs), recent experimental observations suggest a significant role for the periodic activation and inactivation of a CDK-counteracting protein phosphatase 2A with a B55? subunit (PP2A:B55?), during mitotic cycles in frog-egg extracts and early embryos. In this paper, we extend an earlier mathematical model of embryonic cell cycles to include experimentally motivated roles for PP2A:B55? and its regulation by Greatwall kinase. Our model is consistent with what is already known about the regulation of CDK and PP2A:B55? in frog eggs, and it suggests a previously undescribed role for the Greatwall-PP2A:B55? interaction in creating a toggle switch for activation of the anaphase-promoting complex as embryonic cells exit mitosis and return to interphase.

SUBMITTER: Zhang T

PROVIDER: S-EPMC3870745 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature

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Role for regulated phosphatase activity in generating mitotic oscillations in Xenopus cell-free extracts.

Zhang Tongli T Tyson John J JJ Novák Béla B

Proceedings of the National Academy of Sciences of the United States of America 20131202 51

Although current textbook explanations of cell-cycle control in eukaryotes emphasize the periodic activation of cyclin-dependent protein kinases (CDKs), recent experimental observations suggest a significant role for the periodic activation and inactivation of a CDK-counteracting protein phosphatase 2A with a B55δ subunit (PP2A:B55δ), during mitotic cycles in frog-egg extracts and early embryos. In this paper, we extend an earlier mathematical model of embryonic cell cycles to include experiment ...[more]

PMID: 24297885

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