Immunocharacterization of δ- and ζ-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 - and -subspecies, mesangial cells also express the δ- and ζ-isoenzymes of PKC. On exposure to phorbol 12,13-dibutyrate (PDB) a complete depletion of PKC-δ is observed within 8 h. Removal of PDB results in a recovery of PKC-δ. In contrast, PKC-ζ is unaffected by addition or removal of PDB.