Synthesis of the brain-specific S-100 protein in a cell-free system from wheat embryo programmed with poly(A)-containing RNA from rabbit brain.

Polyadenylated polysomal RNA was prepared from rabbit cerebral hemispheres using phenol extraction and chromatography on oligo(dT)-cellulose. This RNA directed the synthesis of the brain-specific S-100 protein in cell-free extracts from wheat embryo. S-100 protein was absent from the products of endogenous incorporation and from a reaction programmed with kidney mRNA. These results suggest that S-100 protein mRNA contains a poly(adenylic acid) sequence and rule out the necessity of a brain-specific factor for translation of -S100 protein mRNA.