title: The role of ATP in the control of H+-galactoside symport in the yeast Kluyveromyces marxianus.
abstract: Transport of methyl beta-D-thiogalactoside and p-nitrophenyl beta-D-galactoside is shown to proceed through the H+-lactose symporter of Kluyveromyces marxianus. Uptake of these compounds is strongly reduced under anaerobic conditions or aerobically in the presence of antimycin. It is shown that antimycin treatment affects p-nitrophenyl beta-D-galactoside uptake in a similar way as it affects the cellular amount of ATP, suggesting regulation of p-nitrophenyl beta-D-galactoside transport by ATP. Also, manipulation of cellular ATP by antimycin treatment followed by glucose incubation, or by aerobic incubation of cells with 2-deoxy-D-glucose, showed a similar dependence of galactoside uptake on the ATP level. Transport of the lipophilic cation tetraphenylphosphonium is affected by ATP variations in a similar way as galactoside influx. It is concluded that ATP regulates H+-galactoside symport by its influence on charge translocation. It is discussed that a membrane ATPase probably plays a central role in the control of the activity of H+-sugar symport.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000693:Anaerobiosis; D000968:Antimycin A / Q000031:analogs & derivatives / Q000494:pharmacology; D001693:Biological Transport, Active / Q000187:drug effects; D005697:Galactosides / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology; D006027:Glycosides / Q000378:metabolism*; D007202:Indicators and Reagents / Q000378:metabolism; D007700:Kinetics; D007716:Kluyveromyces / Q000378:metabolism*; D009861:Onium Compounds / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000378:metabolism; D011522:Protons; D004718:Saccharomycetales / Q000378:metabolism*
chemical_list: D005697:Galactosides; D006027:Glycosides; D007202:Indicators and Reagents; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D011522:Protons; C032456:antimycin; D000968:Antimycin A; D000255:Adenosine Triphosphate; D005947:Glucose; C013289:tetraphenylphosphonium