Regulation of Phosphorylation Level and Distribution of PTP36, a Putative Protein Tyrosine Phosphatase, by Cell-Substrate Adhesion

doi:10.1074/jbc.274.29.20717

Regulation of Phosphorylation Level and Distribution of PTP36, a Putative Protein Tyrosine Phosphatase, by Cell-Substrate Adhesion*

From the Department of Oncology, Biomedical Research Center and^§Department of Urology, Osaka University Medical School, Suita, Osaka 565-0871, Japan and the ^¶School of Allied Health Science, Faculty of Medicine, Osaka University, Suita, Osaka 565-0871, Japan

Abstract

Recently we have cloned a putative protein tyrosine phosphatase, PTP36/PTPD2/pez, which possesses a domain homologous to the N-terminal half of band 4.1 protein. In mouse fibroblasts adhered to substrates, PTP36 was phosphorylated on serine residues. PTP36 was found to make complexes with serine/threonine kinase(s), which phosphorylated PTP36 in vitro. PTP36 was dephosphorylated rapidly when the cell-substrate adhesion was disrupted and it was phosphorylated again along with the reattachment of the cells to fibronectin. Rephosphorylation of PTP36 seemed to depend on actin polymerization since it was inhibited by cytochalasin D. The cell detachment also induced the translocation of PTP36 into the membrane-associated cytoskeletal fraction. Staurosporine and ML-9, which inhibited the phosphorylation of PTP36 in vivo, induced the translocation of PTP36 too. On the contrary, when the dephosphorylation of PTP36 was inhibited by okadaic acid, no translocation of PTP36 was induced by the cell detachment. These results demonstrate that the cell-substrate adhesion and cell spreading regulates the intracellular localization of PTP36 most likely through its phosphorylation and therefore, PTP36 may play important roles in the signal transduction pathway of cell-adhesion.

Footnotes

↵* This work was supported in part by a grant-in-aid from Ministry of Education for Science and Culture and Sapporo Bioscience Foundation.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.
↵‡ To whom correspondence should be addressed: Biomedical Research Center, Osaka University Medical School C6, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan. Tel.: 81-6-6879-3982; Fax: 81-6-6879–3989; E-mail: mogata@ongene.med.osaka-u.ac.jp.
↵2 M. Ogata and T. Hamaoka, unpublished observation.
Abbreviations:

PTP

protein tyrosine phosphatase

SH3

Src homology 3

MLCK

myosin light chain kinase

DMEM

Dulbecco’s modified Eagle’s medium

PAGE

polyacrylamide gel electophoresis

PBS

phosphate-buffered saline

BSA

bovine serum albumin

PMSF

phenylmethylsulfonyl fluoride

TPCK

l-1-tosylamido-2-phenylethyl chloromethyl ketone

PIPES

1,4-piperazinediethanesulfonic acid

mAb

monoclonal antibody
- Received September 23, 1998.
- Revision received March 18, 1999.
The American Society for Biochemistry and Molecular Biology, Inc.