Differential activities of protein tyrosine phosphatases in intact cells

Lammers, R., Bossenmaier, B., Cool, D. E., Tonks, N. K., Schlessinger, J., Fischer, E. H., Ullrich, A. (October 1993) Differential activities of protein tyrosine phosphatases in intact cells. Journal of Biological Chemistry, 268 (30). pp. 22456-22462. ISSN 0021-9258

Abstract

We have employed transient co-overexpression of protein tyrosine phosphatases (PTPs) with a panel of receptor tyrosine kinases (RTKs) to investigate molecular parameters that regulate dephosphorylation activity and specificity in intact cells. Our results demonstrate clear differences in susceptibility of various forms of different RTKs to the action of PTP 1B, T-cell phosphatase (TC-PTP), and CD45, which suggests cellular compartmentalization as a major factor defining activity and overall function. TC-M PTP, a nonlocalized cytosolic mutant, is deregulated and is therefore able to efficiently suppress v-erbB- and v-fms-induced cell transformation, which is not observed with the intact TC-PTP or PTP 1B. The transmembrane PTP CD45 displays more selectivity but appears to be already active during transport to the cell surface. Dephosphorylation activity is also dependent on relative RTK/PTP expression levels and can be modulated by the SH2 domain-containing noncatalytic subunit of phosphatidylinositol 3'-kinase, p85. Overexpression of high affinity binding proteins could therefore contribute to RTK-induced cell transformation and cancer.

Item Type: Paper
Uncontrolled Keywords: GROWTH-FACTOR RECEPTOR MOLECULAR CHARACTERIZATION ENDOPLASMIC-RETICULUM INSULIN-RECEPTOR GENE-TRANSFER NEU ONCOGENE CDNA CLONING EGF RECEPTOR SH2 DOMAINS EXPRESSION
Subjects: organs, tissues, organelles, cell types and functions > cell types and functions > cell types
organs, tissues, organelles, cell types and functions > cell types and functions > cell types
organs, tissues, organelles, cell types and functions > cell types and functions > cell types
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > protein tyrosine phosphatase
CSHL Authors:
Communities: CSHL labs > Tonks lab
Depositing User: Matt Covey
Date: October 1993
Date Deposited: 17 Dec 2013 17:37
Last Modified: 17 Dec 2013 17:37
Related URLs:
URI: https://repository.cshl.edu/id/eprint/29075

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