Phosphorylation of ribosomal protein S6 and a peptide analogue of S6 by a protease-activated kinase isolated from rat liver.
A trypsin-activated protein kinase has been isolated from rat liver using a peptide analogue of ribosomal protein S6 as a substrate in kinase assays. The structure of the peptide, Arg-Arg-Leu-Ser-Ser-Leu-Arg-Ala, was based on a region of S6 containing both an insulin- and cyclic AMP-regulated phosphorylation site. The trypsin-activated protein kinase phosphorylated a corresponding site in the peptide analogue and ribosomal protein S6 that was distinct from the preferred site for cyclic AMP-dependent protein kinase. Ribosomal S6 contained at least one other major site for the trypsin-activated protein kinase.
D000595:Amino Acid Sequence; D000818:Animals; D004789:Enzyme Activation; D008099:Liver / Q000201:enzymology*; D008297:Male; D009842:Oligopeptides / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D038601:Ribosomal Protein S6; D012269:Ribosomal Proteins / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D014357:Trypsin / Q000378:metabolism*
D009842:Oligopeptides; D010446:Peptide Fragments; D038601:Ribosomal Protein S6; D012269:Ribosomal Proteins; D011494:Protein Kinases; D014357:Trypsin