Sarcolipin (SLN)

Sarcoplasmic reticulum Ca(2+)-ATPases are transmembrane proteins that catalyze the ATP-dependent transport of Ca(2+) from the cytosol into the lumen of the sarcoplasmic reticulum in muscle cells.

Sarcolipin is a small proteolipid that regulates several sarcoplasmic reticulum Ca(2+)-ATPases. The transmembrane protein interacts with Ca(2+)-ATPases and reduces the accumulation of Ca(2+) in the sarcoplasmic reticulum without affecting the rate of ATP hydrolysis.SLN is highly expressed in rabbit fast-twitch skeletal muscle, but it is expressed to a lower extent in slow-twitch muscle and to an even lower extent in cardiac muscle, where ATP2A2 and PLN are highly expressed. It is expressed in only trace amounts in pancreas and prostate.