Enolase and glycolytic flux play a role in the regulation of the glucose permease gene RAG1 of Kluyveromyces lactis.
We isolated a mutant, rag17, which is impaired in glucose induction of expression of the major glucose transporter gene RAG1. The RAG17 gene encodes a protein 87% identical to S. cerevisiae enolases (Eno1 and Eno2). The Kleno null mutant showed no detectable enolase enzymatic activity and has severe growth defects on glucose and gluconeogenic carbon sources, indicating that K. lactis has a single enolase gene. In addition to RAG1, the transcription of several glycolytic genes was also strongly reduced in the DeltaKleno mutant. Moreover, the defect in RAG1 expression was observed in other mutants of the glycolytic pathway (hexokinase and phosphoglycerate kinase). Therefore, it seems that the enolase and a functional glycolytic flux are necessary for induction of expression of the Rag1 glucose permease in K. lactis.
Lemaire
Marc
M
UMR 5122 Microbiologie et Génétique, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France. mlemaire@uni-lyon1.fr
Wésolowski-Louvel
Micheline
M
D015966:Gene Expression Regulation, Fungal / Q000235:genetics*; D016654:Genes, RAG-1 / Q000235:genetics*; D005943:Gluconeogenesis / Q000502:physiology; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis / Q000502:physiology*; D006593:Hexokinase / Q000235:genetics; D007716:Kluyveromyces / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D008969:Molecular Sequence Data; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000737:chemistry*; D010735:Phosphoglycerate Kinase / Q000235:genetics; D010751:Phosphopyruvate Hydratase / Q000378:metabolism*
D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C031629:phosphoenolpyruvate-glucose phosphotransferase; D006593:Hexokinase; D010735:Phosphoglycerate Kinase; D010751:Phosphopyruvate Hydratase; D005947:Glucose