Dimorphism-associated changes in intracellular pH of Candida albicans

Levels of plasma membrane H+-ATPase do not change during growth and morphogenesis ofCandida albicans

“…The transient rise in the PMATPase activity suggests that the activity of this enzyme is probably required at the time of commitment to either phenotypic forms. This is consistent with the fact that in both yeast and mycelial forms of C. albicans, the rate of efflux of protons also increases around the time of evagination and addition of specific PM-ATPase inhibitors in the germ tube media leads to complete cessation of differentiation [5].…”

“…PM-ATPase during morphological transition of C. albicans has been implicated by the recognition that its activity is essential for the maintenance of pH i and for the translation of signal generated by transient alkalization of the internal milieu [5]. An analysis of PM-ATPase activity during the various stages of growth of C. albicans reveals that there is an increase in plasma membrane H+-ATPase activity during the late exponential phase and decreases thereafter (Fig.…”

“…The enzyme activity profile matches well with the overall growth and acidification of the external media of this organism (not shown). Our group has recently observed transient intracellular alkalinization and variations in the nutrient uptake during morphological transition of C. albicans [5,12]. Considering these findings and their relation to PM-ATPase activity, it became necessary to elucidate the role of this enzyme during growth and dimorphism of this yeast.…”

“…Zinc-depleted G 1 singlets of late log phase cells were related into fresh medium at 37 ° C, either at pH 4.5 or pH 6.5 for bud or hyphal formation, respectively (Fig. lc) [5].…”

“…A transient cytoplasmic alkalinization in C. albicans cells preceding differentiation to either a bud or hyphal form has been observed and linked to plasma membrane ATPase activity [5]. Thus, the physiological role played by PM-ATPase of C. albicans becomes very relevant.…”