Dana Gášková

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Membrane-potential-dependent accumulation of diS-C3(3) in intact yeast cells in suspension is accompanied by a red shift of the maximum of its fluorescence emission spectrum, lambda max, caused by a readily reversible probe binding to cell constituents. Membrane depolarization by external KCl (with or without valinomycin) or by ionophores causes a fast and(More)
No methods are currently available for fully reliable monitoring of membrane potential changes in suspensions of walled cells such as yeast. Our method using the Nernstian cyanine probe diS-C3(3) monitors even relatively fast changes in membrane potential delta psi by recording the shifts of probe fluorescence maximum lambda max consequent on delta(More)
The long-term action of recommended (RC) and near-recommended concentrations of several commercial biocides (Lonzabac 12.100, Genamin CS302D, benzalkonium chloride and 2-phenoxyethanol) on cells ofS. cerevisiae wild-type strain DTXII was described using plating tests while short-term effects were determined using the potentiometric fluorescent probe(More)
Attempt was made to measure the membrane potential in yeast cells by the electrochromic probe di-4-ANEPPS (dibutylaminonaphthylethylene pyridinium propyl sulfonate) which has previously been used for measuring action potentials in neurons [1, 2]. This probe is believed to provide fluorescent response to changes in transmembrane electric field in nanoseconds(More)
K+ is one of the cations (besides protons) whose transport across the plasma membrane is believed to contribute to the maintenance of membrane potential. To ensure K+ transport, Saccharomyces cerevisiae cells possess several types of active and passive transporters mediating the K+ influx and efflux, respectively. A diS-C3(3) assay was used to compare the(More)
The potentiometric fluorescence probe diS-C3(3) is expelled from S. cerevisiae by ABC pumps Pdr5 and Snq2 and can conveniently be used for studying their performance. The activity of these pumps in a strain with wild-type PDR1 allele was shown to drop sharply on glucose depletion from the medium and then again at the end of the diauxic shift when the cells(More)
Like other tested wild-type strains (DTXII and IL-125-2B), exponential glucose- and/or fructose-grown cells of Saccharomyces cerevisiae BY4742 exhibit the previously described high activity of Pdr5p and Snq2p pumps (measured as export of the potentiometric fluorescent probe diS-C3(3)). Upon saccharide depletion from the medium the pump activity in these(More)
Energy production via oxidative phosphorylation generates a mitochondrial membrane potential (DeltaPsi(m)) across the inner membrane. In this work, we show that a lower DeltaPsi(m) is associated with increased lifespan in Caenorhabditis elegans. The long-lived mutants daf-2(e1370), age-1(hx546), clk-1(qm30), isp-1(qm150) and eat-2(ad465) all have a lower(More)
The fluorescent dye 3,3'-dipropylthiadicarbocyanine, diS-C(3)(3), is a suitable probe to monitor real changes of plasma membrane potential in yeast cells which are too small for direct membrane potential measurements with microelectrodes. A method presented in this paper makes it possible to convert changes of equilibrium diS-C(3)(3) fluorescence spectra,(More)
We have developed a novel screening method that measures the kinetics and potencies of inhibitors of the yeast multidrug resistance pumps Pdr5p and Snq2p. The assay uses the potentiometric fluorescent probe diS-C(3)(3) (as a benchmark substrate of both pumps) to distinguish drugs with minimal effects on plasma membrane potential as a marker of side-effects(More)