The rate and extent of uptake of the fluorescent probe diS-C3(3) reporting on membrane potential in S. cerevisiae is affected by the strain under study, cell-growth phase, starvation and by the concentration of glucose both in the growth medium and in the monitored cell suspension under non-growth conditions. Killer toxin K1 brings about changes in membrane potential. In all types of cells tested, viz. in glucose-supplied stationary or exponential cells of the killer-sensitive strain S6/1 or a conventional strain RXII, or in glucose-free exponential cells of both strains, both active and heat-inactivated toxin slow down the potential-dependent uptake of diS-C3(3) into the cells. This may reflect "clogging" of pores in the cell wall that hinders, but does not prevent, probe passage to the plasma membrane and its equilibration. The clogging effect of heat-inactivated toxin is stronger than that exerted by active toxin. In susceptible cells, i.e. in exponential-phase glucose-supplied cells of the sensitive strain S6/1, this phase of probe uptake retardation is followed by an irreversible red shift in probe fluorescence maximum lambda max indicating damage to membrane integrity and cell permeabilization. A similar fast red shift in lambda max signifying lethal cell damage was found in heat-killed or nystatin-treated cells.

• MeSH
• Fluorescent Dyes metabolism   MeSH
• Fungal Proteins pharmacology   MeSH
• Carbocyanines metabolism   MeSH
• Killer Factors, Yeast MeSH
• Membrane Potentials drug effects   MeSH
• Mycotoxins pharmacology   MeSH
• Nystatin pharmacology   MeSH
• Saccharomyces cerevisiae physiology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• 3,3'-dipropylthiacarbocyanine MeSH Browser
• Fluorescent Dyes MeSH
• Fungal Proteins MeSH
• K1 killer toxin MeSH Browser
• Carbocyanines MeSH
• Killer Factors, Yeast MeSH
• Mycotoxins MeSH
• Nystatin MeSH

Changes in the membrane potential of Saccharomyces cerevisiae were monitored by the electrochromic probe 3-(4-(2-(6-(dibutylamino)-2-naphthyl)-trans- ethenyl)pyridinium)propanesulfonate (di-4-ANEPPS) that should incorporate into the plasma membrane. The probe had suitable spectral characteristics and exhibited an electrochromic shift upon a change in membrane potential but the magnitude of the response increased with time. The presence and properties of the cell wall affected the extent of cell staining. The time dependence of the fluorescent response indicated that the probe was not incorporated solely into the plasma membrane but spread gradually into the whole cell; this was confirmed by confocal microscopy. The probe is therefore suitable for assessing membrane potential changes only over time intervals up to 30 min. Longer monitoring will require either a modified staining protocol or a derivatization of the probe molecule. As found by using the dioctyl derivative di-8-ANEPPS, extending the aliphatic chains of the di-4-ANEPPS molecule does not prevent the dye from penetrating into the cell or liposome interior and, in addition, impairs staining.

• MeSH
• Staining and Labeling MeSH
• Cell Membrane metabolism   physiology   MeSH
• Cell Wall metabolism   MeSH
• Time Factors MeSH
• Fluorescence MeSH
• Microscopy, Confocal MeSH
• Liposomes metabolism   MeSH
• Membrane Potentials * MeSH
• Pyridinium Compounds metabolism   MeSH
• Saccharomyces cerevisiae metabolism   physiology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• 1-(3-sulfonatopropyl)-4-(beta-(2-(di-n-octylamino)-6-naphthyl)vinyl)pyridinium betaine MeSH Browser
• 1-(3-sulfonatopropyl)-4-(beta)(2-(di-n-butylamino)-6-naphthylvinyl)pyridinium betaine MeSH Browser
• Liposomes MeSH
• Pyridinium Compounds MeSH

• MeSH
• Genetic Techniques MeSH
• Hybridization, Genetic MeSH
• Killer Factors, Yeast MeSH
• Mutation MeSH
• Mycotoxins biosynthesis   genetics   pharmacology   MeSH
• Industry MeSH
• Saccharomyces cerevisiae Proteins MeSH
• Saccharomyces cerevisiae drug effects   genetics   metabolism   MeSH
• Transformation, Genetic MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• KHR1 protein, S cerevisiae MeSH Browser
• Killer Factors, Yeast MeSH
• Mycotoxins MeSH
• Saccharomyces cerevisiae Proteins MeSH