What is sarcalumenin?
Ans:- It is a low-affinity Ca+±binding protein. It is present in the skeletal muscle longitudinal tubule.
It is thought to be involved in the transfer of Ca++ from sites of Ca++ uptake in the longitudinal tubules (when muscle relaxes) to the sites of Ca++ release in the terminal cisternae (for the next contraction).
It has been observed that sarcalumenin increases the Ca++ uptake by SERCA, by buffering the luminal Ca++ near the SERCA.
[Ref: Best & Taylor’s Physiological basis of Medical Practice. 13th edi.]