Additional PKA phosphorylation sites in human cardiac troponin I
نویسندگان
چکیده
منابع مشابه
The influence of trout cardiac troponin I and PKA phosphorylation on the Ca2+ affinity of the cardiac troponin complex.
The trout heart is 10-fold more sensitive to Ca(2+) than the mammalian heart. This difference is due, in part, to cardiac troponin C (cTnC) from trout having a greater Ca(2+) affinity than human cTnC. To determine what other proteins are involved, we cloned cardiac troponin I (cTnI) from the trout heart and determined how it alters the Ca(2+) affinity of a cTn complex containing all mammalian c...
متن کاملPKA phosphorylation of cardiac troponin I modulates activation and relaxation kinetics of ventricular myofibrils.
Protein kinase A (PKA) phosphorylation of myofibril proteins constitutes an important pathway for β-adrenergic modulation of cardiac contractility and relaxation. PKA targets the N-terminus (Ser-23/24) of cardiac troponin I (cTnI), cardiac myosin-binding protein C (cMyBP-C) and titin. The effect of PKA-mediated phosphorylation on the magnitude of contraction has been studied in some detail, but...
متن کاملStructural consequences of cardiac troponin I phosphorylation.
beta-Adrenergic stimulation of the heart results in bisphosphorylation of the N-terminal extension of cardiac troponin I (TnI). Bisphosphorylation of TnI reduces the affinity of the regulatory site on troponin C (TnC) for Ca(2+) by increasing the rate of Ca(2+) dissociation. What remains unclear is how the phosphorylation signal is transmitted from one subunit of troponin to another. We have pr...
متن کاملProtein kinase A (PKA)-dependent troponin-I phosphorylation and PKA regulatory subunits are decreased in human dilated cardiomyopathy.
BACKGROUND Most studies indicate that failing human hearts have greater baseline myofibrillar Ca2+ sensitivity of tension development than nonfailing hearts. Phosphorylation of cardiac troponin I (TnI) by cAMP-dependent protein kinase (PKA) decreases the affinity of the troponin complex for Ca2+, thus altering the Ca2+ sensitivity of force production. We tested the hypothesis that PKA-dependent...
متن کاملImpact of site-specific phosphorylation of protein kinase A sites Ser23 and Ser24 of cardiac troponin I in human cardiomyocytes.
PKA-mediated phosphorylation of contractile proteins upon β-adrenergic stimulation plays an important role in the regulation of cardiac performance. Phosphorylation of the PKA sites (Ser(23)/Ser(24)) of cardiac troponin (cTn)I results in a decrease in myofilament Ca(2+) sensitivity and an increase in the rate of relaxation. However, the relation between the level of phosphorylation of the sites...
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ژورنال
عنوان ژورنال: European Journal of Biochemistry
سال: 2001
ISSN: 0014-2956
DOI: 10.1046/j.1432-1327.2001.01871.x