Figure 2.

Schematic representation of possible sites of SOCE in skeletal muscle. (A) SOCE at the triad is well supported and the most described in the literature. STIM and Orai are expressed in the triad membranes and respective SOCE was confirmed. (B) SOCE at the CEU is well described as a newly formed structure that is induced by strenuous exercise. STIM and Orai are expressed at the CEUs but the respective SOCE Ca²⁺-flux has not yet been demonstrated to date. (C) STIM at the lSR moves to the triad upon activation or activates Orai at the PM. It was also reported to modulate the activity of the SERCA pump. (D) Localization at the NMJ remains speculative for the time being.