Phosphorylation of rabbit cardiac-muscle troponin I by phosphorylase kinase. The effect of adrenaline.
1. Incubation of rabbit cardiac-muscle troponin I with phosphorylase b kinase leads to the incorporation of .07-1.2 mol of Pi/mol. 2. The major site of phosphorylation is a serine residue at position 72. 3. Lesser amounts of phosphate are incorporated into threonine-138, threonine-162 and serine 20. 4. Serine-20 is the only site that contains a significant amount of phosphate before incubation with phosphorylase b kinase. 5. Unlike the situation with serine-20, the extent of phosphorylation of serine-72 and threonine-138 in the perfused rabbit heart does not change when the heart is exposed to adrenaline (4 microM).
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001665:Binding Sites; D002850:Chromatography, Gel; D004837:Epinephrine / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects; D009124:Muscle Proteins / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D010764:Phosphorylase Kinase / Q000378:metabolism*; D010766:Phosphorylation; D011817:Rabbits; D014336:Troponin / Q000378:metabolism*
D000596:Amino Acids; D009124:Muscle Proteins; D010446:Peptide Fragments; D014336:Troponin; D010764:Phosphorylase Kinase; D004837:Epinephrine