title: Derepression of the high-affinity phosphate uptake in the yeast Saccharomyces cerevisiae.
abstract: Phosphate starvation derepresses a high-affinity phosphate uptake system in Saccharomyces cerevisiae strain A294, while in the same time the low-affinity phosphate uptake system disappears. The protein synthesis inhibitor cycloheximide prevents the derepression, but has no effect as soon as the high-affinity system is fully derepressed. Two other protein synthesis inhibitors, lomofungin and 8-hydroxyquinoline, were found to interfere also with the low-affinity system and with Rb+ uptake. After incubation of the yeast cells in the presence of phosphate the high-affinity system is not derepressed, but the Vmax of the low-affinity system has decreased from about 35%. Phosphate supplement after derepression causes the high-affinity system to disappear to a certain extent while in the meantime the low-affinity system reappears. The results are compared with those found in the yeast Candida tropicalis for phosphate uptake.
mesh_terms: D001692:Biological Transport; D002175:Candida / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D012413:Rubidium / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*
chemical_list: D010710:Phosphates; D003513:Cycloheximide; D005947:Glucose; D012413:Rubidium