title: Transcriptional expression of selected genes associated with excretion of carboxylic acids from aci mutants of Saccharomyces cerevisiae.
abstract: BACKGROUND
  Saccharomyces cerevisiae is an excellent model organism for studies of transcriptional regulation of metabolic processes in other eukaryotic cells including human cells. Cellular acid-base balance can be disturbed in pathologic situations such as renal acidosis or cancer. The extracellular pH of malignant solid tumors is acidic in the range of 6.5-6.9. EG07 and EG37 aci mutants of Saccharomyces cerevisiae excessively excrete carboxylic acids to glucose-containing media or distilled water. The excreted acids are Krebs and/or glyoxylate cycle intermediates. The genes restoring the wild-type phenotype have function that does not easily explain theAci+ phenotype.
  
  
  METHODS
  In this study, using real-time PCR we measured relative mRNA expression, in the mutants compared to the wild-type strain, of selected genes associated with both carboxylic acid cycles and two cell transporters, Pma1 and Pdr12, of organic acids.
  
  
  RESULTS
  Unexpectedly, we found that the relative expression of the selected Krebs cycle and glyoxylate cycle genes did not change significantly. However, the expression of the two transporter genes was strongly elevated in EG37 and moderately increased in EG07.
  
  
  CONCLUSIONS
  These results indicate that the induction of the two cell transporterg enes plays an important role in acid excretion by the aci mutants.
authors.affiliation: Department of Biotechnology and Molecular Biology, University of Opole, Poland. boniesia@uni.opole.pl
authors.forename: Ewa
authors.initials: E
authors.lastname: Boniewska-Bernacka
authors.forename: Maciej
authors.initials: M
authors.lastname: Wieczorek
authors.forename: Anna
authors.initials: A
authors.lastname: Sadakierska-Chudy
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Dobosz
authors.forename: Anna
authors.initials: A
authors.lastname: Krop-Watorek
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D001692:Biological Transport; D002264:Carboxylic Acids / Q000378:metabolism*; D002952:Citric Acid Cycle / Q000235:genetics*; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism; D006038:Glyoxylates / Q000378:metabolism; D006801:Humans; D026901:Membrane Transport Proteins / Q000378:metabolism; D009154:Mutation; D006180:Proton-Translocating ATPases / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D013045:Species Specificity; D015533:Transcriptional Activation / Q000502:physiology*
chemical_list: D018528:ATP-Binding Cassette Transporters; D002264:Carboxylic Acids; D006038:Glyoxylates; D026901:Membrane Transport Proteins; C472673:Pdr12 protein, S cerevisiae; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; C092477:PMA1 protein, S cerevisiae; D006180:Proton-Translocating ATPases; D005947:Glucose; C031150:glyoxylic acid