Repo-Man recruits PP1γ to chromatin and is essential for cell viability
Open Access
- 21 February 2006
- journal article
- research article
- Published by Rockefeller University Press in The Journal of cell biology
- Vol. 172 (5), 679-692
- https://doi.org/10.1083/jcb.200508154
Abstract
Protein phosphatase 1 (PP1) is a ubiquitous serine/threonine phosphatase regulating many cellular processes. PP1α and -γ are closely related isoforms with distinct localization patterns, shown here by time-lapse microscopy of stably expressed fluorescent protein fusions. A pool of PP1γ is selectively loaded onto chromatin at anaphase. Using stable isotope labeling and proteomics, we identified a novel PP1 binding protein, Repo-Man, which selectively recruits PP1γ onto mitotic chromatin at anaphase and into the following interphase. This approach revealed both novel and known PP1 binding proteins, quantitating their relative distribution between PP1α and -γ in vivo. When overexpressed, Repo-Man can also recruit PP1α to chromatin. Mutating Repo-Man's PP1 binding domain does not disrupt chromatin binding but abolishes recruitment of PP1 onto chromatin. RNA interference–induced knockdown of Repo-Man caused large-scale cell death by apoptosis, as did overexpression of this dominant-negative mutant. The data indicate that Repo-Man forms an essential complex with PP1γ and is required for the recruitment of PP1 to chromatin.Keywords
This publication has 28 references indexed in Scilit:
- Nucleolar proteome dynamicsNature, 2005
- Altered expression of cell cycle genes distinguishes aggressive neuroblastomaOncogene, 2004
- Proteomic Characterization of Protein Phosphatase Complexes of the Mammalian NucleusMolecular & Cellular Proteomics, 2004
- A Novel Transmembrane Ser/Thr Kinase Complexes with Protein Phosphatase-1 and Inhibitor-2Published by Elsevier BV ,2002
- Directed Proteomic Analysis of the Human NucleolusCurrent Biology, 2002
- Characterization of the Neuronal Targeting Protein Spinophilin and Its Interactions with Protein Phosphatase-1Biochemistry, 1999
- Differential Subcellular Localization of Protein Phosphatase-1 α, γ1, and δ Isoforms during Both Interphase and Mitosis in Mammalian CellsThe Journal of cell biology, 1998
- Structural basis for the recognition of regulatory subunits by the catalytic subunit of protein phosphatase 1The EMBO Journal, 1997
- Protein phosphatase 1 interacts with p53BP2, a protein which binds to the tumour suppressor p53FEBS Letters, 1995
- Purification of type 1 protein (serine/threonine) phosphatases by microcystin‐Sepharose affinity chromatographyFEBS Letters, 1994