Cytoskeletal calmodulin-dependent protein kinase. Characterization, solubilization, and purification from rat brain.
Brain calmodulin-dependent protein kinase was isolated as the major cytoskeletal component of the post-synaptosomal fraction, accounting for about 50% of the total protein. The alpha- and beta-subunits of the enzyme were present in a ratio of about 6:1. The cytoskeletal preparation was also distinguished by the regular presence of tubulin and actin in approximately equimolar amounts to the beta-subunit. Electron microscopic morphology suggested that the enzyme formed a hierarchy of cytoskeletal complexes with an average diameter of 85 nm. These results indicate that cytoskeletal calmodulin-dependent protein kinase may have a structural as well as a catalytic role in neurons. The cytoskeletal enzyme could be solubilized in 8 M urea, displaying similar properties to its cytosolic counterpart. The postsynaptosomal cytoskeleton provides a simplified and well-defined model for the study of the protein-protein interactions involving calmodulin-dependent protein kinase.
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002147:Calmodulin / Q000378:metabolism*; D002499:Centrifugation, Density Gradient; D003599:Cytoskeleton / Q000201:enzymology; D046911:Macromolecular Substances; D008297:Male; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012995:Solubility; D014357:Trypsin / Q000378:metabolism
D002147:Calmodulin; D046911:Macromolecular Substances; D011494:Protein Kinases; D014357:Trypsin