Role of Calcium/Calcineurin Signalling in Regulating Intracellular Reactive Oxygen Species Homeostasis in .

The calcium/calcineurin signalling pathway is required for cell survival under various environmental stresses. Using , we explored the mechanism underlying calcium-regulated homeostasis of intracellular reactive oxygen species (ROS). We found that deletion of acyltransferase Akr1 and C-5 sterol desaturase Erg3 increased the intracellular ROS levels and cell death, and this could be inhibited by the addition of calcium. The hexose transporter Hxt1 and the amino acid permease Agp1 play crucial roles in maintaining intracellular ROS levels, and calcium induced the expression of the and genes. The cytosolic calcium concentration was decreased in both the and mutants relative to wild-type cells, potentially lowering basal expression of and . Moreover, the calcium/calcineurin signalling pathway also induced the expression of and , indicating that Akr1 and Erg3 might perform functions that help yeast cells to survive under high calcium concentrations. Our results provided mechanistic insight into how calcium regulated intracellular ROS levels in yeast.