Identification of the phosphoserine residue in histone H1 phosphorylated by protein kinase C.
The site-specific phosphorylation of bovine histone H1 by protein kinase C was investigated in order to further elucidate the substrate specificity of protein kinase C. Protein kinase C was found to phosphorylate histone H1 to 1 mol per mol. Using N-bromosuccinimide and thrombin digestions, the phosphorylation site was localized to the globular region of the protein, containing residues 71-122. A tryptic peptide containing the phosphorylation site was purified. Modification of the phosphoserine followed by amino acid sequence analysis demonstrated that protein kinase C phosphorylated histone H1 on serine 103. This sequence, Gly97-Thr-Gly-Ala-Ser-Gly-Ser(PO4)-Phe-Lys105, supports the contention that basic amino acid residues C-terminal to the phosphorylation site are sufficient determinants for phosphorylation by protein kinase C.
D000595:Amino Acid Sequence; D000818:Animals; D001974:Bromosuccinimide / Q000378:metabolism; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D006657:Histones / Q000378:metabolism*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D012694:Serine / Q000031:analogs & derivatives*; D013379:Substrate Specificity; D013917:Thrombin / Q000378:metabolism
D006657:Histones; D010768:Phosphoserine; D012694:Serine; D011493:Protein Kinase C; D013917:Thrombin; D001974:Bromosuccinimide