Isolation and Characterization of PNUTS, a Putative Protein Phosphatase 1 Nuclear Targeting Subunit*
- From the ‡Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, New York 10021 and the ‖Institute of Environmental and Life Science, The Hallym Academy of Science, Hallym University, 1 Okcheon-dong, Chuncheon, Kangwon-do 200-703, Korea
Abstract
Protein phosphatase 1 (PP1) is found in the cell nucleus and has been implicated in several aspects of nuclear function. We report here the cloning and initial characterization of a novel protein ∼ named phosphatase 1 nucleartargeting subunit (PNUTS). This protein interacts with PP1 in a yeast two-hybrid assay, is found in a stable complex with PP1 in mammalian cell lysates, and exhibits a potent modulation of PP1 catalytic activity toward exogenous substratein vitro. PNUTS is a ubiquitously expressed protein that exhibits a discreet nuclear compartmentalization and is colocalized with chromatin at distinct phases during mitosis. The subcellular localization of PP1 and the activity toward substrates involved in many aspects of cell physiology have previously been shown to be regulated by association with noncatalytic targeting subunits. The properties of PNUTS are consistent with its role as a targeting subunit for the regulation of nuclear PP1 function.
Footnotes
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↵* This work was supported by National Institutes of Health Grant MH 40899.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) AF040954.
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↵§ These authors contributed equally to this work.
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↵¶ To whom correspondence should be addressed: Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, 1230 York Ave., New York, NY 10021. E-mail: allenp{at}rockvax.rockefeller.edu.
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↵1 The abbreviations used are: PP1, protein phosphatase 1; PAGE, polyacrylamide gel electrophoresis; PBS, phosphate-buffered saline; GST, glutathione S-transferase; PNUTS, phosphatase 1 nucleartargeting subunit.; DAPI, 41,6-diamidino-2-phenylindole.
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↵2 P. B. Allen, Y.-G. Kwon, A. C. Nairn, and P. Greengard, unpublished data.
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- Received August 14, 1997.
- Revision received November 5, 1997.
- The American Society for Biochemistry and Molecular Biology, Inc.
