Expression of a transmembrane phosphotyrosine phosphatase inhibits cellular response to platelet-derived growth factor and insulin-like growth factor-1

R. A. Mooney, G. G. Freund, B. A. Way, K. L. Bordwell

Research output: Contribution to journalArticle

Abstract

Tyrosine phosphorylation is a mechanism of signal transduction shared by many growth factor receptors and oncogene products. Phosphotyrosine phosphatases (PTPases) potentially modulate or counter-regulate these signaling pathways. To test this hypothesis, the transmembrane PTPase CD45 (leukocyte common antigen) was expressed in the murine cell line C127. Hormone-dependent autophosphorylation of the platelet-derived growth factor (PDGF) and insulin-like growth factor-1 (IGF-1) receptors was markedly reduced in cells expressing the transmembrane PTPase. Tyrosine phosphorylation of other PDGF-dependent phosphoproteins (160, 140, and 55 kDa) and IGF-1-dependent phosphoproteins (145 kDa) was similarly decreased. Interestingly, the pattern of growth factor-independent tyrosine phosphorylations was comparable in cells expressing the PTPase and control cells. This suggests a selectivity or accessibility of the PTPase limited to a subset of cellular phosphotyrosyl proteins. The maximum mitogenic response to PDGF and IGF-1 in cells expressing the PTPase was decreased by 67 and 71%, respectively. These results demonstrate that a transmembrane PTPase can both affect the tyrosine phosphorylation state of growth factor receptors and modulate proximal and distal cellular responses to the growth factors.

Original languageEnglish (US)
Pages (from-to)23443-23446
Number of pages4
JournalJournal of Biological Chemistry
Volume267
Issue number33
StatePublished - Dec 1 1992
Externally publishedYes

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ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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