Identification of protein tyrosine phosphatases associating with the PDGF receptor.
Protein tyrosine phosphatase (PTP) in-gel assays were used to explore association of PTPs with the platelet-derived growth factor beta-receptor (PDGFbetaR). Five PTP activity bands of approximately 120, approximately 70, approximately 60, approximately 53, and approximately 45 kDa could be detected in PDGFbetaR immunoprecipitates and were identified by immunodepletion experiments as PTP-PEST, SHP-2, an active fragment of SHP-2, PTP-1B, and T-cell PTP, respectively. The PTP pattern that was obtained was similar in PDGFbetaR immunoprecipitates from HEK 293 cells overexpressing the human PDGFbetaR and from murine fibroblasts. Association of PTP-1B with the PDGFbetaR was stabilized by pretreatment of the cells with hydrogen peroxide. The epidermal growth factor receptor (EGFR) immunoprecipitated from fibroblasts, and c-Kit isolated from CHRF myeloid cells, were associated with partially overlapping but quantitatively different patterns of PTPs. PTP-PEST was the predominant PTP in EGFR immunoprecipitates, and SHP-1 appeared in c-Kit immunoprecipitates. We propose that the differential association of PTPs with different RTKs is related to their respective contributions to regulation of RTK signaling.
Markova
Boyka
B
Research Unit Molecular Cell Biology, Medical Faculty, Friedrich Schiller University, Drackendorfer Strasse 1, D-07747 Jena, Germany.
Herrlich
Peter
P
Rönnstrand
Lars
L
Böhmer
Frank-D
FD
D000818:Animals; D002458:Cell Fractionation; D002460:Cell Line; D002461:Cell Line, Transformed; D006801:Humans; D015151:Immunoblotting; D051379:Mice; D018345:Mice, Knockout; D010766:Phosphorylation; D011233:Precipitin Tests; D017027:Protein Tyrosine Phosphatases / Q000032:analysis* / Q000235:genetics / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000032:analysis* / Q000235:genetics / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014162:Transfection; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism
D014443:Tyrosine; D020794:Receptor Protein-Tyrosine Kinases; D020797:Receptor, Platelet-Derived Growth Factor beta; D017027:Protein Tyrosine Phosphatases