Premium
The interaction of the bisphosphorylated N‐terminal arm of cardiac troponin I‐A 31 P‐NMR study
Author(s) -
Schmidtmann Anja,
Lohmann Karin,
Jaquet Kornelia
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)02340-2
Subject(s) - troponin complex , troponin i , heterotrimeric g protein , phosphorylation , chemistry , troponin , protein subunit , biophysics , biochemistry , medicine , biology , g protein , signal transduction , myocardial infarction , gene
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.