An atypical PMR2 locus is responsible for hypersensitivity to sodium and lithium cations in the laboratory strain Saccharomyces cerevisiae CEN.PK113-7D.
Saccharomyces cerevisiae strains belonging to the CEN.PK family are widely used in fundamental and applied yeast research. These strains have been reported to be hypersensitive to sodium ions and a previous microarray-based genotyping study indicated an atypical organization of the PMR2 locus. In other S. cerevisiae strains, this locus harbours one to five ENA genes that encode plasma membrane sodium-pumping ATPases. Sequence analysis of the PMR2 locus in S. cerevisiae CEN.PK113-7D revealed the presence of a new ENA gene that showed substantial sequence differences, both at the nucleotide level and at the predicted amino acid sequence level, with previously described ENA genes. The presence of this single and atypical ENA gene correlated with hypersensitivity to sodium and, in particular, to lithium ions. The native ENA6 gene was transcriptionally induced by sodium and lithium ions, but, apparently, the capacity for sodium export upon full induction was insufficient to achieve the levels of sodium and lithium ion tolerance observed in other S. cerevisiae strains. The sodium and lithium hypersensitivity of CEN.PK strains, which is potentially detrimental during cultivation in sodium-rich media, could, however, be suppressed by overexpression of ENA6.
Daran-Lapujade
Pascale
P
Department of Biotechnology, Kluyver Centre for Genomics of Industrial Fermentation, Delft University of Technology, Julianalaan 67, Delft, The Netherlands. p.a.s.daran-lapujade@tudelft.nl
Daran
Jean-Marc
JM
Luttik
Marijke A H
MA
Almering
Marinka J H
MJ
Pronk
Jack T
JT
Kötter
Peter
P
D000935:Antifungal Agents; D002412:Cations / Q000494:pharmacology*; D004271:DNA, Fungal / Q000235:genetics; D008094:Lithium / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012964:Sodium / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics* / Q000378:metabolism
D000935:Antifungal Agents; D002412:Cations; D004271:DNA, Fungal; C086375:ENA1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D008094:Lithium; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase