Expression of PEP-19 inhibits apoptosis in PC12 cells.

PEP-19 is a calmodulin-regulatory protein found specifically within neurons, though cellular functions of this protein have not been determined. In an effort to define potential effects of PEP-19, PC12 cell lines expressing this protein were generated and subjected to apoptotic stimuli. As measured by LDH release, cell death in PEP-19 expressing cells was 2- to 5-fold less following u.v. irradiation, and 2- to 4-fold less following staurosporine treatment than controls. Additionally, PEP-19-expressing cells displayed decreased DNA ladder formation, chromatin and condensation, caspase activation following staurosporine treatment. Overall, these results demonstrate that PEP-19 can inhibit apoptotic processes in PC12 cells, suggesting a potential regulatory mechanism for pathways leading to cell death.