Phosphatidylinositol 4,5-bisphosphate specifically stimulates PP60(c-src) catalyzed phosphorylation of gelsolin and related actin-binding proteins.
Gelsolin is a widely distributed Ca2+-dependent regulator of the cortical actin network. We demonstrate that gelsolin is phosphorylated by pp60(c-src) and that this phosphorylation is dramatically enhanced by phosphatidylinositol 4,5-bisphosphate (PIP2), known to specifically interact with gelsolin. Other phospholipids display only a marginal effect. pp56(lck), a tyrosine kinase of the same family, does not phosphorylate gelsolin. Other mammalian actin-binding proteins such as profilin and CapG but also fragmin from Physarum polycephalum are similar targets for PIP2-stimulated pp60(c-src) phosphorylation.
De Corte
V
V
Flanders Interuniversity Institute of Biotechnology, Department of Biochemistry, Faculty of Medicine, Universiteit Gent, Belgium.
Gettemans
J
J
Vandekerckhove
J
J
D000199:Actins / Q000378:metabolism; D000818:Animals; D002384:Catalysis; D018260:Gelsolin / Q000378:metabolism*; D006801:Humans; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D008840:Microfilament Proteins / Q000378:metabolism*; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D010766:Phosphorylation; D010804:Physarum / Q000378:metabolism; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism*; D019061:src-Family Kinases / Q000378:metabolism
D000199:Actins; D018260:Gelsolin; D008840:Microfilament Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; D010743:Phospholipids; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D016392:Proto-Oncogene Proteins pp60(c-src); D019061:src-Family Kinases