Leucine Rich Repeat Containing Protein 39 (LRRC39)

LRRC39, a Heart- and Muscle-Specific Protein, Is a Novel Component of the Sarcomeric M-Band and Is Involved in Stretch Sensing.Mechanistically, knockdown of myomasp in NRVCM led to a dose-dependent suppression of serum response factor–dependent gene expression, consistent with earlier observations linking the M-band to serum response factor–mediated signaling. Finally, downregulation of myomasp/LRRC39 in spontaneously beating engineered heart tissue constructs resulted in significantly lower force generation and reduced fractional shortening. Likewise, knockdown of the myomasp/LRRC39 ortholog in zebrafish resulted in severely impaired heart function and cardiomyopathy in vivo.