Differential increase in cytoplasmic pH at bud and germ tube formation in Candida albicans: studies of a nongerminative variant

Abstract

The changes in cytoplasmic pH (pHi) accompanying the morphological transition of Candida albicans were studied using a nongerminative variant. A transient cytoplasmic alkalinization at the time of evagination was observed in both the variant and its parent. Under zinc-deficient conditions the wild-type cells that formed buds at pH 4.5 and mycelia at pH 6.5 showed an increase in pHi of 0.58 and 0.12 pH units, respectively. Under similar conditions the pHi of the nongerminative variant that formed buds at both pH 4.5 and 6.5 increased by 0.66 and 0.40 pH units, respectively, suggesting that a greater magnitude of increase in pHi at the time of evagination is probably needed for bud formation. These results provide evidence for a correlation between intracellular alkalinization and time of cell differentiation in C. albicans.

Functional specialization and differential regulation of short‐chain carboxylic acid transporters in the pathogen Candida albicans

“…Furthermore, the activities of plasma membrane proton transport systems are important in controlling internal pH and these are also associated with the regulation of dimorphism (Stewart et al. , 1988; 1989; Kaur and Mishra, 1994). The yeast form is favoured at low ambient pHs, for example around pH 4.0 when undissociated forms of carboxylic acids predominate and the simple diffusion of these acids into the cell is favoured.…”

Confocal ratio imaging of cytoplasmic pH during germ tube growth and appressorium induction by Magnaporthe grisea

“…Roncal et al (1993) presented results indicating a role for changes in pH c during conidiation of Penicillium cyclopium. In C. albicans, a yeast that can switch from yeast-like to hypha-like growth, pH c changes have been clearly correlated with the outgrowth of germ tubes from yeast-like cells (Stewart et al, 1988 ;Kaur & Mishra, 1994). On the basis of these results, Gadd (1995) discusses the role of intracellular pH as a second messenger in the dimorphic regulation of this fungus.…”

The Candida albicans antiporter gene CNH1 has a role in Na+ and H+ transport, salt tolerance, and morphogenesis The GenBank accession number for the sequence reported in this work is AF128238.

“…filamentous growth (Kaur & Mishra, 1994). Inactivation of plasma-membrane H + -extruding ATPase inhibited both cytoplasmic alkalinization and germ-tube formation (Monk et al, 1991(Monk et al, , 1993.…”