Changes in PC12 cell morphology induced by transfection with 42C cDNA, coding for a member of the S-100 protein...

The cloned DNA coding for 42C protein (light chain of calpactin I), whose mRNA is induced in PC12 cells by treatment with nerve growth factor (NGF), was reintroduced into these cells. A cell line was obtained in which the outgrowth of processes in the absence of added NGF, similar to that induced in the parental PC12 cells by the factor, was accompanied by high levels of 42C RNA. The apparent reason for this constitutive overexpression of 42C is the stable integration of multiple copies of the 42C DNA into the cell genome. These results further support the notion that S-100 protein family, of which 42C is a member, may play an important role in development.