Literature citations

Transformation suppression by protein tyrosine phosphatase 1B requires a functional SH3 ligand.

We have recently shown that protein tyrosine phosphatase 1B (PTP1B) associates with the docking protein p130Cas in 3Y1 rat fibroblasts. This interaction is mediated by a proline-rich sequence on PTP1B and the SH3 domain on p130Cas. Expression of wild-type PTP1B (WT-PTP1B), but not a catalytically competent, proline-to-alanine point mutant that cannot bind p130Cas (PA-PTP1B), causes substantial tyrosine dephosphorylation of p130Cas (F. Liu, D. E. Hill, and J. Chernoff, J. Biol. Chem. 271:31290-31295, 1996). Here we demonstrate that WT-, but not PA-PTP1B, inhibits transformation of rat 3Y1 fibroblasts by v-crk, -src, and -ras, but not by v-raf. These effects on transformation correlate with the phosphorylation status of p130Cas and two proteins that are associated with p130Cas, Paxillin and Fak. Expression of WT-PTP1B reduces formation of p130Cas- Crk complexes and inhibits mitogen-activated protein kinase activation by Src and Crk. These data show that transformation suppression by PTP1B requires a functional SH3 ligand and suggest that p130Cas may represent an important physiological target of PTP1B in cells.

Related UniProtKB entries

Browse all 25 entries
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
FeedbackHelp