The interaction of the bisphosphorylated N-terminal arm of cardiac troponin I-A 31P-NMR study.
Cardiac troponin I, the inhibitory subunit of the heterotrimeric cardiac troponin (cTn) complex is phosphorylated by protein kinase A at two serine residues located in its heart-specific N-terminal extension. This flexible arm interacts at different sites within cTn dependent on its phosphorylation degree. Bisphosphorylation is known to induce conformational changes within cTnI which finally lead to a reduction of the calcium affinity of cTnC. However, as we show here, the bisphosphorylated cTnI arm does not interact with cTnC, but with cTnT and/or cTnI.
Schmidtmann
Anja
A
Physiologische Chemie, Abt. Biochemie Supramolekularer Systeme, Medizinische Fakultät, Ruhr-Universität Bochum, MA 2/39, 44780, Bochum, Germany.
Lohmann
Karin
K
Jaquet
Kornelia
K
D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009206:Myocardium / Q000378:metabolism*; D010759:Phosphorus Isotopes; D010766:Phosphorylation; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D019209:Troponin C / Q000378:metabolism; D019210:Troponin I / Q000737:chemistry / Q000378:metabolism*; D020107:Troponin T / Q000378:metabolism
D010759:Phosphorus Isotopes; D019209:Troponin C; D019210:Troponin I; D020107:Troponin T