Cardiac myosin regulatory light chain kinase modulates cardiac contractility by phosphorylating both myosin regulatory light chain and troponin I.

ABSTRACT: Heart muscle contractility and performance are controlled by posttranslational modifications of sarcomeric proteins. Although myosin regulatory light chain (RLC) phosphorylation has been studied extensively in vitro and in vivo, the precise role of cardiac myosin light chain kinase (cMLCK), the primary kinase acting upon RLC, in the regulation of cardiomyocyte contractility remains poorly understood. In this study, using recombinantly expressed and purified proteins, various analytical methods, in vitro and in situ kinase assays, and mechanical measurements in isolated ventricular trabeculae, we demonstrate that human cMLCK is not a dedicated kinase for RLC but can phosphorylate other sarcomeric proteins with well-characterized regulatory functions. We show that

SUBMITTER: Sevrieva IR 

PROVIDER: S-EPMC7135997 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature