Cell free translation of rat epidermal calcium-binding protein (EP-12) messenger RNA

The primary step in the biosynthesis of 12 KDa rat epidermal calcium binding protein was studied by cell-free protein synthesis. Poly(A)+ rich RNA was extracted and purified from whole newborn rat skin and translated in a lysate system in the presence of labeled methionine. Immunoprecipitation of translation products with a monospecific antibody directed against this protein, which did not react with parvalbumin yielded a product migrating as a single band of molecular weight 12 KDa on polyacrylamide gel electrophoresis. Thus, a mRNA coding for this protein is present in rat skin. The presence of this messenger RNA opens the way for further studies on the regulation of epidermal expression during epidermal cell proliferation and differentiation.