Phosphate transport processes in eukaryotic cells

Much more work has been done on P_i transport processes, even in the last five years, than we have been able to mention in the space available. We have restricted our discussion to studies on mechanisms of transport or transport regulation, identification of transport proteins and their essential amino acids, and isolation, purification, and reconstitution of P_i transport systems. Many valuable studies on the physiology of P_i transport and its regulation and P_i transport in nonepithelial cells have also been conducted. Transport of P_i into and out of organelles other than the mitochondrion is gaining well-deserved attention, as are transport processes in fungi and plants. It is hoped that in another five years many P_i transport processes will be understood in true molecular terms and that this will increase our knowledge of cellular bioenergetics and metabolism.