title: Energy-linked potassium uptake by mitochondria from wild-type and poky strains of Neurospora crassa.
abstract: Mitochondria from Neurospora crassa, like mammalian mitochondria, carry out rapid, energy-linked K+ uptake and H+ release in the presence of valinomycin. The maximal rate of K+ uptake was about 1.0 mumol/mg of mitochondrial protein per min and was seen at valinomycin concentrations in the range of 100 to 200 mug per mg of mitochondrial protein and at K+ concentrations of 4 mM or above. Uptake could be supported either by substrate oxidation or by adenosine 5'-triphosphate (ATP), and was inhibited in the former case by antimycin or cyanide, in the latter case by oligomycin, and in both cases by 2,4-dinitrophenol. Mitochondria from the cytochrome-deficient mutant poky carried out substrate-driven K+ uptake at reduced rates, but oligomycin-sensitive, ATP-driven K+ uptake at rates about 60% greater than those shown by wild-type mitochondria. This result is consistent with the recent finding (Mainzer and Slayman 1976) that poky contains elevated amounts of oligomycin-sensitive mitochondrial adenosine 5'-triphosphatase activity.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000968:Antimycin A / Q000494:pharmacology; D003486:Cyanides / Q000494:pharmacology; D003580:Cytochromes / Q000096:biosynthesis; D004140:Dinitrophenols / Q000494:pharmacology; D006859:Hydrogen / Q000378:metabolism; D008293:Malates / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009154:Mutation; D009491:Neurospora / Q000378:metabolism*; D009492:Neurospora crassa / Q000378:metabolism* / Q000648:ultrastructure; D009840:Oligomycins / Q000494:pharmacology; D010101:Oxygen Consumption; D011188:Potassium / Q000378:metabolism*; D011773:Pyruvates / Q000378:metabolism; D014634:Valinomycin / Q000494:pharmacology
chemical_list: D003486:Cyanides; D003580:Cytochromes; D004140:Dinitrophenols; D008293:Malates; D009840:Oligomycins; D011773:Pyruvates; D014634:Valinomycin; D000968:Antimycin A; D006859:Hydrogen; D000255:Adenosine Triphosphate; D011188:Potassium