Identification and characterisation of lamprey protein kinase C delta-like gene

Protein kinase C-delta (PKC-delta), a member of the lipid-regulated serine/threonine PKC family, has been implicated in a wide range of important cellular processes, such as cell growth, differentiation, and apoptosis. Lampreys belong to the most primitive class of vertebrates, and there is little information on PKC-delta in these animals. In this study, a PKC-delta-like cDNA sequence and deduced PKC-delta-like amino acid sequence were identified in the Japanese lamprey (Lampetra japonica). The PKC-delta-like gene shared approximately 60% sequence identity with its homologs in jawed vertebrates. The anti-PKC-delta-like polyclonal antibodies were well prepared, and experiments showed that PKC-delta-like was primarily distributed in the supraneural body of the lamprey. Both mRNA and protein levels of PKC-delta-like in supraneural body cells were increased after incubation with cis-diaminedichloroplatinum (CDDP). Moreover, PKC-delta-like protein induced the apoptosis of HEK-293T cells. In addition, the activation of PKC-delta-like resulted in apoptosis. Conversely, the inhibition of PKC-delta-like activity disrupted the CDDP-mediated induction of cellular apoptosis. These results indicate that PKC-delta-like identified in lampreys might play an important role in apoptosis in jawless vertebrates.