MYL4
Description
The MYL4 (myosin light chain 4) is a protein-coding gene located on chromosome 17.
Atrial Light Chain-1 (ALC-1), also known as Essential Light Chain, Atrial, is a 21.6 kDa protein encoded by the MYL4 gene. It's expressed in fetal cardiac ventricular and fetal skeletal muscle, as well as fetal and adult cardiac atrial tissue. ALC-1 binds the neck region of muscle myosin in adult atria. ALC-1 expression is reactivated in human ventricular myocardium in various cardiac muscle diseases, including hypertrophic cardiomyopathy, dilated cardiomyopathy, ischemic cardiomyopathy and congenital heart diseases. ALC-1 has an additional ~40 amino-acid N-terminal region compared to ventricular essential light chain VLC-1. This region contains residues critical for binding actin and modulating myosin kinetics. ALC-1 is expressed very early in skeletal muscle and cardiac muscle development. Two E-boxes and CArG box in the MYL4 promoter region regulate its transcription. While its expression in cardiac ventricles decreases in early postnatal development, it remains highly expressed in atria throughout adulthood.
MYL4 is also known as ALC1, AMLC, GT1, PRO1957.
