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Full-Text Articles in Medical Molecular Biology
Ca2+ Efflux Facilitated By Co-Transport Of Inorganic Phosphate Anion In The H+/Ca2+ Antiporter Yfke, Wei Niu, Wenchang Zhou, Shuo Lu, Trung Vu, Vasanthi Jayaraman, José D Faraldo-Gómez, Lei Zheng
Ca2+ Efflux Facilitated By Co-Transport Of Inorganic Phosphate Anion In The H+/Ca2+ Antiporter Yfke, Wei Niu, Wenchang Zhou, Shuo Lu, Trung Vu, Vasanthi Jayaraman, José D Faraldo-Gómez, Lei Zheng
Journal Articles
Ca2+ is an important signaling messenger. In microorganisms, fungi, and plants, H+/Ca2+ antiporters (CAX) are known to play key roles in the homeostasis of intracellular Ca2+ by catalyzing its efflux across the cell membrane. Here, we reveal that the bacterial CAX homolog YfkE transports Ca2+ in two distinct modes: a low-flux H+/Ca2+ exchange mode and a high-flux mode in which Ca2+ and phosphate ions are co-transported (1:1) in exchange for H+. Coupling with phosphate greatly accelerates the Ca2+ efflux activity of YfkE. Our studies reveal that Ca2+ and phosphate bind to adjacent sites in a central translocation pathway and lead …