MYL7

Atrial Light Chain-2 (ALC-2) also known as Myosin regulatory light chain 2, atrial isoform (MLC2a) is a protein that in humans is encoded by the MYL7 gene. ALC-2 expression is restricted to cardiac muscle atria in healthy individuals, where it functions to modulate cardiac development and contractility. In human diseases, including hypertrophic cardiomyopathy, dilated cardiomyopathy, ischemic cardiomyopathy and others, ALC-2 expression is altered. Human ALC-2 is phosphorylated at its N-terminus at Serine-15 by a cardiac-specific myosin light chain kinase; interestingly, ALC-2 has a Serine at position 14, which is an Asparagine in the ventricular isoform that is shown to be deamidated (thus producing a negative charge similar to phosphorylation). Whether Serine-14 of human ALC-2 is also phosphorylated remains to be determined. Endogenous phosphorylation level is around 30% of the total ALC-2.