title: Some characteristics of tetraphenylphosphonium uptake into Saccharomyces cerevisiae.
abstract: The characteristics of the uptake of the lipophilic cation tetraphenylphosphonium (TPP+) into Saccharomyces cerevisiae have been investigated in order to establish whether this compound can be used to monitor the membrane potential of his organism. Unlike dibenzyldimethylammonium, TPP+ is not translocated via the thiamine transport system, nor via another inducible translocation mechanism. On changing the experimental conditions the equilibrium potential of TPP+ varies according to expected changes of the membrane potential. TPP+ accumulation is higher in metabolizing cells than in non-metabolizing cells. In addition, decreasing the medium pH, addition of the proton conductor 2,4-dinitrophenol and addition of K+ all cause an apparent depolarization, whereas Ca2+ apparently hyperpolarizes the cell membrane. It is concluded that TPP+, if applied at low concentrations, can be used to measure the membrane potential of S. cerevisiae.
mesh_terms: D019297:2,4-Dinitrophenol; D001692:Biological Transport / Q000187:drug effects; D002122:Calcium Chloride / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004140:Dinitrophenols / Q000494:pharmacology; D007202:Indicators and Reagents / Q000378:metabolism*; D007461:Iodoacetates / Q000494:pharmacology; D019807:Iodoacetic Acid; D007700:Kinetics; D009861:Onium Compounds / Q000378:metabolism*; D009943:Organophosphorus Compounds; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D004140:Dinitrophenols; D007202:Indicators and Reagents; D007461:Iodoacetates; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D002122:Calcium Chloride; D019297:2,4-Dinitrophenol; C013289:tetraphenylphosphonium; D019807:Iodoacetic Acid