Nutrient associated changes in plasma membrane H⁺-ATPase activity of permeabilized <i>Candida albicans </i>cells

Abstract

Nutrient stimulated H⁺ extrusion by cells and spheroplasts of <i>Candida albicans </i>and its underlying mechanism has been investigated. Glucose and glutamic acid stimulated extrusion by a factor of 6 and 1.4 respectively in cells, but had no effect on spheroplasts. Proline showed no H⁺ stimulation in cells, however, it stimulated spheroplasts 1.5 fold. ATPase activity of toluene-ethanoi-Triton-X-100 (TET) permeabilized cells decreased by 20% following exposure to glucose and proline and 30% following exposure to glutamic acid. Permeabilized spheroplasts of <i>Candida albicans </i>showed drastic reduction in ATPase activity by 40%, 70% and 85% following exposure to glucose, proline and glutamic acid respectively. Externally added F-actin fully restored activity in the case of permeabilized cells and partly with spheroplasts suggesting that ATPase interacts with other membrane proteins during nutrient stimulation of cells.