S6-1

This peptide is derived from the sequence of a region that contains the major phosphorylation site for cAMP-dependent protein kinase in rat hepatic ribosomal protein S6. Fractions obtained from DEAE-cellulose chromatography of extracts of the hybrid cells have also been assayed for ability to phosphorylate the synthetic octapeptide Arg-Arg-Leu-Ser-Ser-Leu-Arg-Ala (S6-1), the structure of which is based on a phosphorylated region of the S6 protein.