Calcium-permeable, cation-selective stretch-activated channel (SAC). Required for calcium influx and for vitality of MATa cells in a late, pheromone-induced event of the mating process requiring calcium induced signaling. Functions together with CCH1 to ensure that adequate levels of Ca(2+) are supplied to PMR1 to sustain secretion and growth. Required for growth in low-calcium environments. Together with CCH1, essential for tolerance to iron stress, which leads to an increased oxidative poise, and to cold stress. Interacts with CCH1 to form a Ca(2+) influx channel. Forms an oligomer with a molecular mass of 200 kDa by disulfide bonds. Trafficking to the plasma membrane is dependent on the N-glycosylation and the transporter protein SEC12. N-glycosylated. Present with 3210 molecules/cell in log phase SD medium. Truncation mutant consisting of amino acids 1-360 is fully functional. Truncation mutants consisting of amino acids 1-400 and 1-22 are partially functional. Truncation mutants consisting of amino acids 1-455, 1-133, and a mutant in which amino acids 3-22 are deleted, are not functional in Ca(2+) uptake.