Stimulation of globin synthesis by 11-amino acid peptide.

We have used synthetic peptide to study a conserved RNA binding motif in eukaryotic poly(A) binding protein (PABP) as well as its functions. We synthesized an 11 amino-acid peptide based on the consensus sequence (GKSKGFGFV), which is found in all the sequenced eukaryotic PABPs. The synthetic peptide was found to be preferentially bound to the poly(A) alone or the poly(A) attached to the 3'-end of mRNA and not the deadenylated mRNA. Additionally, the 11-mer had strong affinity to bind to ATP. In vitro translation of rabbit globin mRNA poly(A) in the presence of the 11-mer resulted in stimulation of globin synthesis by two-fold as compared to translation in the presence of either deadenylated globin mRNA or globin mRNA poly(A) but in the absence of the 11-mer.