PKC ϵ is associated with myosin IIA and actin in fibroblasts

Proteins coimmunoprecipitating with protein kinase C (PKC) ϵ in fibroblasts were identified through matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI TOF m/s). This method identified myosin IIA in PKC ϵ immunoprecipitates, as well as known PKC ϵ binding proteins, actin, β''Cop and cytokeratin. Myosin is not a substrate for PKC ϵ. Immunofluorescence analysis showed that PKC ϵ is colocalised with actin and myosin in actomyosin stress fibers in fibroblasts. Inhibitors of PKC and myosin ATPase activity, as well as microfilament-disrupting drugs, all inhibited spreading of fibroblasts after passage, suggesting a role for a PKC ϵ–actin–myosin complex in cell spreading. [Copyright &y& Elsevier]