The noncatalytic domain of protein-tyrosine phosphatase-PEST targets paxillin for dephosphorylation in vivo

J Biol Chem. 2000 Jan 14;275(2):1405-13. doi: 10.1074/jbc.275.2.1405.

Abstract

The noncatalytic domain of protein-tyrosine phosphatase (PTP)-PEST contains a binding site for the focal adhesion-associated protein paxillin. This binding site has been narrowed to a 52-residue sequence that is composed of two nonoverlapping, weak paxillin binding sites. The PTP-PEST binding site on paxillin has been mapped to the two carboxyl-terminal LIM (lin11, isl-1, and mec-3) domains. Transient expression of PTP-PEST reduced tyrosine phosphorylation of p130(cas), as anticipated. A PTP-PEST mutant defective for binding p130(cas) does not cause a reduction in its tyrosine phosphorylation in vivo. Expression of PTP-PEST also caused a reduction of phosphotyrosine on paxillin. Expression of mutants of PTP-PEST with deletions in the paxillin-binding site did not associate with paxillin in vivo and failed to cause a reduction in the phosphotyrosine content of paxillin. These results demonstrate that paxillin can serve as a PTP-PEST substrate in vivo and support the model that a noncatalytic domain interaction recruits paxillin to PTP-PEST to facilitate its dephosphorylation.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • Cell Line
  • Cells, Cultured
  • Chick Embryo
  • Cytoskeletal Proteins / chemistry*
  • Cytoskeletal Proteins / metabolism*
  • Glutathione Transferase / metabolism
  • Humans
  • Paxillin
  • Phosphoproteins / chemistry*
  • Phosphoproteins / metabolism*
  • Protein Tyrosine Phosphatase, Non-Receptor Type 12
  • Protein Tyrosine Phosphatases / chemistry*
  • Protein Tyrosine Phosphatases / isolation & purification
  • Protein Tyrosine Phosphatases / metabolism*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / isolation & purification
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae / metabolism
  • Substrate Specificity
  • Transfection

Substances

  • Cytoskeletal Proteins
  • PXN protein, human
  • Paxillin
  • Phosphoproteins
  • Recombinant Fusion Proteins
  • Glutathione Transferase
  • PTPN12 protein, human
  • Protein Tyrosine Phosphatase, Non-Receptor Type 12
  • Protein Tyrosine Phosphatases