Isoforms of protein kinase C and their distribution in human adrenal cortex and tumors.

The cytosol and microsomal fractions of human adrenal cortex contain 3 isoforms of protein kinase C: alpha, zeta, and epsilon. The latter fraction is present in trace amounts. No isoforms beta1, beta2, gamma and delta were found in these cell fractions. The distribution of alpha-isoform between the cytosol and microsomal fraction is determined by tissue origin: in normal tissue its content differs by no more than 10%, while in most tumors this isoform is translocated into the microsomal fraction. The distribution of zeta-isoform did not depend on tissue origin.