Cytochalasin D stimulation of tyrosine phosphorylation and phosphotyrosine-associated kinase activity in vascular smooth muscle cells.
The actin filament-disrupting agent cytochalasin D strikingly increased tyrosine phosphorylation of a 75 kDa protein (p75) in rabbit aortic vascular smooth muscle cells. The microtubule-disrupting agent, colchicine had no effect on p75 tyrosine phosphorylation. Cytochalasin D also stimulated p75-directed kinase activity as determined by kinase assays of anti-Tyr(P) immunoprecipitates. Cytochalasin D stimulated tyrosine phosphorylation of the F-actin-binding protein, p80/85 cortactin, but p75 was not immunologically related either to cortactin, the phosphatidylinositol 3'-kinase p85 alpha subunit, or the 80 kDa isoform of caldesmon. These results suggest that p75 may represent a cytochalasin D-inducible kinase or kinase-associated component and provide evidence for the existence of a potentially novel kinase pathway regulated by disruption of the actin cytoskeleton.
Abedi
H
H
Department of Medicine, University College London, United Kingdom.
Zachary
I
I
D000199:Actins / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D003078:Colchicine / Q000494:pharmacology; D051356:Cortactin; D015638:Cytochalasin D / Q000378:metabolism*; D008840:Microfilament Proteins / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D011817:Rabbits; D014443:Tyrosine / Q000378:metabolism*
D000199:Actins; D051356:Cortactin; D008840:Microfilament Proteins; D019000:Phosphotyrosine; D015638:Cytochalasin D; D014443:Tyrosine; D011494:Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D003078:Colchicine