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

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.
Mesh Terms:
Animals, Binding Sites, Cell Line, Cells, Cultured, Chick Embryo, Cytoskeletal Proteins, Glutathione Transferase, Humans, Paxillin, Phosphoproteins, Protein Tyrosine Phosphatase, Non-Receptor Type 12, Protein Tyrosine Phosphatases, Recombinant Fusion Proteins, Saccharomyces cerevisiae, Substrate Specificity, Transfection
J. Biol. Chem.
Date: Jan. 14, 2000
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