In Vivo Indicators of Cytoplasmic, Vacuolar, and Extracellular pH Using pHluorin2 in Candida albicans.
Tournu, Heléne | 2019-09-24
Environmental or chemically induced stresses often trigger physiological
responses that regulate intracellular pH. As such, the capacity to detect pH changes
in real time and within live cells is of fundamental importance to essentially all aspects
of biology. In this respect, pHluorin, a pH-sensitive variant of green fluorescent
protein, has provided an invaluable tool to detect such responses. Here, we report
the adaptation of pHluorin2 (PHL2), a substantially brighter variant of pHluorin, for
use with the human fungal pathogen Candida albicans. As well as a cytoplasmic
PHL2 indicator, we describe a version that specifically localizes within the fungal
vacuole, an acidified subcellular compartment with important functions in nutrient
storage and pH homeostasis. In addition, by means of a glycophosphatidylinositolanchored
PHL2-fusion protein, we generated a cell surface pH sensor.