IMMUNOCHEMICAL CHARACTERIZATION AND CELLULAR-DISTRIBUTION OF PROTEIN-KINASE-C ISOZYMES IN THE BOVINE CORPUS-LUTEUM

Research was conducted to determine the nature of the isoforms of prot ein kinase C (PKC) present in the bovine (Bos taurus) corpus luteum (C L) and their subcellular distribution. Western blot analysis was perfo rmed using isozyme-specific polyclonal antibodies and revealed that th e bovine corpus luteum contains the alpha and epsilon isozymes of PKC, but not the beta, gamma, delta or zeta isozymes. Subcellular fraction ation demonstrated that the alpha and epsilon isozymes of PKC were pre sent in both the cytosolic and plasma membrane fractions. Densitometri c measurements of Western blots of the subcellular luteal PKC fraction s indicated that PKC alpha was found predominantly in the cytosolic fr action, whereas the majority of PKC epsilon was associated with the pl asma membrane.