Phosphorylation of contractile proteins in heart and skeletal muscle.


Contractile performance of cardiac and skeletal muscles may be regulated by cyclic AMP or Ca2+, two second messengers that stimulate the phosphorylation of specific myofibrillar proteins. Cyclic AMP-dependent protein kinase catalyzed the rapid phosphorylation of a single site in the inhibitory subunit of cardiac troponin in vitro and in perfused hearts… (More)