Immunocharacterization of delta- and zeta-isoenzymes of protein kinase C in rat renal mesangial cells.

The isoforms of protein kinase C (PKC) present in rat mesangial cells were identified by immunoblot analysis with antibody raised against isotype-specific peptides. In addition to the previously observed alpha- and epsilon-subspecies, mesangial cells also express the delta- and zeta-isoenzymes of PKC. On exposure to phorbol 12,13-dibutyrate (PDB) a complete depletion of PKC-delta is observed within 8 h. Removal of PDB results in a recovery of PKC-delta. In contrast, PKC-zeta is unaffected by addition or removal of PDB.