title: Phosphatase 1 nuclear targeting subunit is an essential regulator of M-phase entry, maintenance, and exit.
abstract: Mitotic progression is regulated largely through dynamic and reversible protein phosphorylation that is modulated by opposing actions of protein kinases and phosphatases. In this study, we show that phosphatase 1 nuclear targeting subunit (Pnuts) functions as a master regulator of mitosis by modulating protein phosphatase 1 (PP1). Overexpression of Pnuts in Xenopus egg extracts inhibited both mitotic and meiotic exit. Immunodepletion of Pnuts from egg extracts revealed its essential functions in mitotic entry and maintenance. The level of Pnuts oscillates during the cell cycle and peaks in mitosis. Pnuts destruction during M-phase exit is mediated by the anaphase-promoting complex/cyclosome (APC/C)-targeted ubiquitination and proteolysis, and conserved destruction motifs of Pnuts. Disruption of Pnuts degradation delayed M-phase exit, suggesting it as an important mechanism to permit M-phase exit.
authors.affiliation: From the Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska 68583.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Fisher
authors.affiliation: From the Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska 68583.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: From the Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska 68583.
authors.forename: Lan
authors.initials: L
authors.lastname: Wu
authors.affiliation: From the Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska 68583 Aimin.Peng@UNMC.edu.
authors.forename: Aimin
authors.initials: A
authors.lastname: Peng
mesh_terms: D000818:Animals; D001483:Base Sequence; D002455:Cell Division; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008540:Meiosis; D008938:Mitosis; D009687:Nuclear Proteins / Q000378:metabolism*; D059748:Proteolysis; D016601:RNA-Binding Proteins / Q000378:metabolism*; D054875:Ubiquitination; D014981:Xenopus
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C110225:PPP1R10 protein, human; D016601:RNA-Binding Proteins
keywords: APC/C; Cell Cycle; Mitosis; Phosphatase; Phosphoprotein Phosphatase 1 (PP1); Pnuts; Xenopus