Protein tyrosine phosphatase phi regulates paxillin tyrosine phosphorylation and mediates colony-stimulating factor 1-induced morphological changes in macrophages.

ABSTRACT: Removal of colony-stimulating factor 1 (CSF-1) causes macrophages to round up and to increase their expression of protein tyrosine phosphatase phi (PTP phi). This is accompanied by the disruption of focal complexes and the formation of ruffles. Here we have overexpressed wild-type (WT) PTP phi and a phosphatase-inactive (C325S) mutant in a macrophage cell line in the presence and absence of CSF-1. In the presence of CSF-1, WT PTP phi induces cell rounding and ruffle formation, while C325S PTP phi has no effect. In contrast, in CSF-1-starved cells, C325S PTP phi behaves in a dominant negative fashion, preventing rounding and ruffling. Furthermore, C325S PTP phi increases adhesion in cycling cells, while WT PTP phi enhances motility. In WT PTP phi-overexpressing cells, the focal contact prot

SUBMITTER: Pixley FJ 

PROVIDER: S-EPMC86738 | biostudies-literature | 2001 Mar

REPOSITORIES: biostudies-literature