Calcium/calmodulin-dependent phosphorylation of vimentin in rat sertoli cells.
Ca2+-dependent protein phosphorylation and the role of calmodulin in this process was investigated in subcellular fractions of primary cultures of rat Sertoli cells. Significant Ca2+/calmodulin-dependent protein phosphorylation in Sertoli cells was restricted to the cytosol fraction. The calmodulin dependence of these effects was confirmed by using the calmodulin inhibitor trifluoperazine. One of the Ca2+/calmodulin-dependent phosphoproteins was identified as the intermediate filament protein vimentin, based on the following criteria: (i) migration pattern in two-dimensional polyacrylamide gels, (ii) Ca2+/calmodulin-dependent phosphorylation of a 58-kilodalton protein present in detergent-insoluble intermediate filament protein extract of Sertoli cells, and (iii) peptide mapping of the phosphoprotein. These data support a role for Ca2+/calmodulin-dependent protein phosphorylation in the modulation of Sertoli cell cytoskeletal components.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism*; D002478:Cells, Cultured; D007381:Intermediate Filament Proteins / Q000378:metabolism*; D007526:Isoelectric Point; D008297:Male; D008970:Molecular Weight; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D012708:Sertoli Cells / Q000378:metabolism*; D014268:Trifluoperazine / Q000494:pharmacology; D014746:Vimentin
D002135:Calcium-Binding Proteins; D002147:Calmodulin; D007381:Intermediate Filament Proteins; D010750:Phosphoproteins; D014746:Vimentin; D014268:Trifluoperazine; D011494:Protein Kinases; D002118:Calcium