Cardiac Myosin Filaments are Maintained by Stochastic Protein Replacement
Wood, N.B.; Kelly, C.M.; O’Leary, T.S.; et al.
Cardiac proteins are known to be intricately organized within filaments of muscle sarcomeres, but the mechanisms of protein turnover in these filaments remains a matter of debate. To examine the temporal and spatial dynamics of myosin replacement from the filament of mouse hearts, Previs and colleagues labeled proteins in vivo through metabolic incorporation of D3 L-leucine (via a mouse feed diet). A variety of analytical techniques, including MS-based bottom-up proteomics, were employed to quantify the mechanisms of newly synthesized protein synthesis in the heart. The results provide novel insights into protein turnover in cardiac muscle and the dynamic nature of their filamentous macromolecular assemblies.