Amino acid uptake as a function of differentiation in Candida albicans: studies of a non-germinative variant

The transport of four amino acids (L-methionine, L-phenylalanine, L-lysine and L-alanine) was studied during pH-regulated dimorphism in Candida albicans and its stable, non-germinative variant. The permeases responsible for uptake responded differently to differentiation and the transport activities varied during the course of morphogenesis. An increase in uptake around the time of evagination was observed in all four amino acids in both the strains studied. The uptake rates of L-methionine and L-phenylalanine were greater in fully differentiated hyphae, while the rate of L-lysine was higher in fully differentiated buds. Uptake rates of L-alanine, however, did not show any morphotypic related variation. The possible implication of these transport activities in relation to differentiation is discussed.