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Dephosphorylation of human cyclin-dependent kinases by protein phosphatase type 2Cα and β2 isoforms

Cheng, Aiyang ; Kaldis, Philipp LU orcid and Solomon, Mark J. (2000) In Journal of Biological Chemistry 275(44). p.34744-34749
Abstract

We previously reported that the activating phosphorylation on cyclin-dependent kinases in yeast (Cdc28p) and in humans (Cdk2) is removed by type 2C protein phosphatases. In this study, we characterize this PP2C-like activity ha HeLa cell extract and determine that it is due to PP2Cβ2, a novel PP2Cβ isoform, and to PP2Cα. PP2Cα and PP2Cβ2 co-purified with Mg2+-dependent Cdk2/Cdk6 phosphatase activity in DEAE-Sepharose, Superdex-200, and Mono Q chromatographies. Moreover, purified recombinant PP2Cα and PP2Cβ2 proteins efficiently dephosphorylated monomeric Cdk2/Cdk6 in vitro. The dephosphorylation of Cdk2 and Cdk6 by PP2C isoforms was inhibited by the binding of cyclins. We found that the PP2C-like activity in HeLa cell... (More)

We previously reported that the activating phosphorylation on cyclin-dependent kinases in yeast (Cdc28p) and in humans (Cdk2) is removed by type 2C protein phosphatases. In this study, we characterize this PP2C-like activity ha HeLa cell extract and determine that it is due to PP2Cβ2, a novel PP2Cβ isoform, and to PP2Cα. PP2Cα and PP2Cβ2 co-purified with Mg2+-dependent Cdk2/Cdk6 phosphatase activity in DEAE-Sepharose, Superdex-200, and Mono Q chromatographies. Moreover, purified recombinant PP2Cα and PP2Cβ2 proteins efficiently dephosphorylated monomeric Cdk2/Cdk6 in vitro. The dephosphorylation of Cdk2 and Cdk6 by PP2C isoforms was inhibited by the binding of cyclins. We found that the PP2C-like activity in HeLa cell extract, partially purified HeLa PP2Cα and PP2Cβ2 isoforms, and the recombinant PP2Cs exhibited a comparable substrate preference for a phosphothreonine containing substrate, consistent with the conservation of threonine residues at the site of activating phosphorylation in CDKs.

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author
; and
publishing date
type
Contribution to journal
publication status
published
in
Journal of Biological Chemistry
volume
275
issue
44
pages
34744 - 34749
publisher
American Society for Biochemistry and Molecular Biology
external identifiers
  • pmid:10934208
  • scopus:0034602268
ISSN
0021-9258
DOI
10.1074/jbc.M006210200
language
English
LU publication?
no
id
ddd34f4c-ecb3-4bfe-96d4-3eb5b7515870
date added to LUP
2019-09-18 14:31:47
date last changed
2024-01-01 20:46:34
@article{ddd34f4c-ecb3-4bfe-96d4-3eb5b7515870,
  abstract     = {{<p>We previously reported that the activating phosphorylation on cyclin-dependent kinases in yeast (Cdc28p) and in humans (Cdk2) is removed by type 2C protein phosphatases. In this study, we characterize this PP2C-like activity ha HeLa cell extract and determine that it is due to PP2Cβ2, a novel PP2Cβ isoform, and to PP2Cα. PP2Cα and PP2Cβ2 co-purified with Mg<sup>2+</sup>-dependent Cdk2/Cdk6 phosphatase activity in DEAE-Sepharose, Superdex-200, and Mono Q chromatographies. Moreover, purified recombinant PP2Cα and PP2Cβ2 proteins efficiently dephosphorylated monomeric Cdk2/Cdk6 in vitro. The dephosphorylation of Cdk2 and Cdk6 by PP2C isoforms was inhibited by the binding of cyclins. We found that the PP2C-like activity in HeLa cell extract, partially purified HeLa PP2Cα and PP2Cβ2 isoforms, and the recombinant PP2Cs exhibited a comparable substrate preference for a phosphothreonine containing substrate, consistent with the conservation of threonine residues at the site of activating phosphorylation in CDKs.</p>}},
  author       = {{Cheng, Aiyang and Kaldis, Philipp and Solomon, Mark J.}},
  issn         = {{0021-9258}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{44}},
  pages        = {{34744--34749}},
  publisher    = {{American Society for Biochemistry and Molecular Biology}},
  series       = {{Journal of Biological Chemistry}},
  title        = {{Dephosphorylation of human cyclin-dependent kinases by protein phosphatase type 2Cα and β2 isoforms}},
  url          = {{http://dx.doi.org/10.1074/jbc.M006210200}},
  doi          = {{10.1074/jbc.M006210200}},
  volume       = {{275}},
  year         = {{2000}},
}