Plasma-membrane phospholipid unsaturation affects expression of the general amino-acid permease in Saccharomyces cerevisiae Y185.
Saccharomyces cerevisiae Y185, enriched in linoleyl residues and incubated for up to 4 h in derepression buffer, more rapidly acquired general amino-acid permease (GAP) activity, as measured by the rate of accumulation of L-alanine, compared with organisms enriched in oleyl residues. A GAP-less mutant incubated under the same conditions did not acquire further L-alanine-accumulating ability, irrespective of the nature of the fatty-acyl enrichment. During derepression, KT values for the GAP were virtually identical irrespective of the fatty-acyl enrichment, but Vmax values were greater for linoleyl residue-enriched organisms, particularly after 1 h in derepression buffer. During incubation in derepression buffer, organisms with either fatty-acyl enrichment did not differ in the size of the amino-N pool, the concentration of L-alanine in that pool, rates of protein synthesis and glucose fermentation, or rate and extent of incorporation of label from H2 32PO-4. Under conditions used to measure rates of L-alanine accumulation, organisms with either enrichment showed no evidence of metabolism of accumulated L-alanine.
D000409:Alanine / Q000378:metabolism; D026905:Amino Acid Transport Systems; D001692:Biological Transport; D002462:Cell Membrane; D007700:Kinetics; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000494:pharmacology; D026901:Membrane Transport Proteins / Q000378:metabolism*; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology; D010743:Phospholipids / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000648:ultrastructure
D026905:Amino Acid Transport Systems; D008041:Linoleic Acids; D026901:Membrane Transport Proteins; D009829:Oleic Acids; D010743:Phospholipids; D019301:Oleic Acid; D019787:Linoleic Acid; D000409:Alanine