D230N Mutation in Tropomyosin and R92L Mutation in Cardiac Troponin T have Strikingly Different Impact on Calcium-Regulated Activation of Cardiac Myofilaments

Abstract

in myofilament Ca 2þ sensitivity was abolished by the expression of b-Tm. Furthermore, the McTnT 45-74 deletion-induced reduction in cooperativity of force production was more pronounced under a b-Tm background. Thus, our data shows that changes in the isoform expression of Tm modify T1dependent cardiac function, indicating that T1-Tm interactions exert a modulatory role in regulating cardiac thin filament activation.