Identification of p130(cas) as a substrate for the cytosolic protein tyrosine phosphatase PTP-PEST

Garton, A. J., Flint, A. J., Tonks, N. K. (November 1996) Identification of p130(cas) as a substrate for the cytosolic protein tyrosine phosphatase PTP-PEST. Molecular and Cellular Biology, 16 (11). pp. 6408-6418. ISSN 0270-7306

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Abstract

PTP-PEST is a ubiquitously expressed, cytosolic, mammalian protein tyrosine phosphatase (PTP) which exhibits high specific activity in vitro, We have investigated the substrate specificity of PTP-PEST by a novel substrate-trapping approach in combination within vitro dephosphorylation experiments. We initially identified a prominent 130-kDa tyrosine-phosphorylated protein in pervanadate-treated HeLa cell lysates which was preferentially dephosphorylated by PTP-PEST in vitro, In order to identify this potential substrate, mutant (substrate-trapping) forms of PTP-PEST were generated which lack catalytic activity but retain the ability to bind substrates. These mutant proteins associated in stable complex-es exclusively with the same 130-kDa protein, which was identified as p130(cas) by immunoblotting. This exclusive association was observed in lysates from several cell lines and in transfected COS cells, but was not observed with other members of the PTP family, strongly suggesting that p130(cas) represents a major physiologically relevant substrate for PTP-PEST. Our studies suggest potential roles for PTP-PEST in regulation of p130(cas) function, These functions include mitogen- and cell adhesion-induced signalling events and probable roles in transformation by various oncogenes. These results provide the first demonstration of a PTP having an inherently restricted substrate a specificity in vitro and in vivo. The methods used to identify p130(cas) as a specific substrate for PTP-PEST are potentially applicable to any PTP and should therefore prove useful in determining the physiological substrates of other members of the PTP family.

Item Type:	Paper
Uncontrolled Keywords:	FOCAL ADHESION KINASE SWISS 3T3 CELLS GROWTH-FACTOR RECEPTOR V-CRK ONCOGENE STABLE ASSOCIATION TERMINAL SEQUENCE FISSION YEAST SH3 DOMAINS PHOSPHORYLATION PHOSPHOTYROSINE
Subjects:	bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein characterization bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > protein tyrosine phosphatase
CSHL Authors:	Flint, Andrew Garton, Andrew Tonks, Nicholas K.
Communities:	CSHL labs > Tonks lab
Depositing User:	Matt Covey
Date:	November 1996
Date Deposited:	17 Dec 2013 19:42
Last Modified:	17 Dec 2013 19:42
PMCID:	PMC231642
Related URLs:	Publisher
URI:	https://repository.cshl.edu/id/eprint/29054

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