Journal article
Intracellular pH distribution as a cell health indicator in Saccharomyces cerevisiae
Internal pH regulation is vital for many cell functions, including transport mechanisms and metabolic enzyme activity. More specifically, transport mechanisms are to a wide degree governed by internal pH distributions. We introduce the term standard deviation of the intracellular pH (s.d.(pHint)) to describe the internal pH distributions.
The cellular pH distributional response to external stress such as heat has not previously been determined. In this study, the intracellular pH (pHi) and the s.d.(pHint) of Saccharomyces cerevisiae cells exposed to supralethal temperatures were measured using fluorescence ratio imaging microscopy (FRIM).
An exponential decline in pHi was observed after an initial small decline. For the first time, we report the use of FRIM for determining in vivo plasma membrane proton permeability coefficients in yeast. Furthermore, the exponential decay of pHi and the rupture of the cell plasma membrane, as measured by propidium iodide staining, at 70°C were not simultaneous but were separated by a significant temporal difference.
Finally, a nonlinear relationship between the pHi and s.d.(pHint) was found; i.e. the s.d.(pHint) was significantly more sensitive to supralethal temperatures than pHi. s.d.(pHint) is therefore proposed as an early health/vitality indicator in S. cerevisiae cells exposed to heat stress.
Language: | English |
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Publisher: | The Royal Society |
Year: | 2011 |
Pages: | 1635-1643 |
ISSN: | 17425662 and 17425689 |
Types: | Journal article |
DOI: | 10.1098/rsif.2011.0148 |
ORCIDs: | 0000-0003-2718-9280 and 0000-0002-4323-5446 |
5-(6)-carboxyfluorescein diacetate succinimidyl ester Acid-Base Equilibrium Cell Membrane Permeability Fluoresceins Health Status Hydrogen-Ion Concentration Intracellular Fluid Microscopy, Fluorescence Propidium Saccharomyces cerevisiae Succinimides Temperature Time Factors heat stress intracellular pH membrane permeability yeast