Regulates intracellular calcium levels and cell volume for survival in response to hypo-osmotic shock. Acts as a mechanosensitive calcium channel in response to membrane stretch. The conductance is about 0.25 nanosiemens (PubMed:22910366). Involved in maintaining vacuole integrity and protecting the nuclear envelope upon hypo-osmotic shock (PubMed:25041276). Perinuclear endoplasmic reticulum. By stress (PubMed:12529438). Up-regulated by both hyper- and hypo-osmotic shocks (PubMed:22910366). EF-hand domain is involved in the detection of calcium concentration. Upon hypo-osmotic shock, the viability of the cells is not significantly different from that of wild-type, but an increase in cell volume is accompanied by an abnormally high increase in intracellular calcium concentration compared to wild-type. Belongs to the MscS (TC 1.A.23) family.