A 1779-bp complementary DNA (cDNA) that encodes protein kinase C-zeta (PKC-zeta) has been isolated from a human frontal cortex library using traditional plaque-screening methods and PCR screening. The deduced 592-amino-acid sequence of the human PKC-zeta clone has a 95-96% identity to those deduced from the previously described rat and mouse PKC-zeta clones.