Muscle-specific stress fibers give rise to sarcomeres in cardiomyocytes

• DOI: 10.7554/elife.42144
• Publication Date: 2018-12-12T13:01:35Z
• Authors: Aidan M Fenix; Abigail C Neininger; Nilay Taneja; Karren Hyde; Mike R Visetsouk; Ryan J Garde; Baohong Liu; Benjamin R Nixon; Annabelle E Manalo; Jason R Becker; Scott W Crawley; David M Bader; Matthew J Tyska; Qi Liu; Jennifer H Gutzman; Dylan T Burnette
• Keywords: Sarcomeres; 0301 basic medicine; QH301-705.5; Science; Muscle Fibers, Skeletal; Formins; cardiomyocytes; myosin; sarcomeres; Cell Line; 03 medical and health sciences; Cell Line, Tumor; Stress Fibers; Humans; Myocytes, Cardiac; Biology (General); Microscopy, Confocal; Nonmuscle Myosin Type IIB; Myosin Heavy Chains; Molecular Motor Proteins; Q; Microfilament Proteins; R; Cell Biology; Actins; formins; Actin Cytoskeleton; Medicine; RNA Interference; actin; HeLa Cells

The sarcomere is the contractile unit within cardiomyocytes driving heart muscle contraction. We sought to test mechanisms regulating actin and myosin filament assembly during formation. Therefore, we developed an assay using human monitor assembly. report a population of stress fibers, similar arcs in non-muscle cells, which are essential precursors. show sarcomeric filaments arise directly from fibers. This requires formins (e.g., FHOD3), IIA IIB. Furthermore, short cardiac II grow form ~1.5 μm long that then 'stitch' together stack at core (i.e., A-band). A-band dependent on proper organization and, as such, also FHOD3 use this experimental paradigm present evidence for unifying model