Low-oxygen signaling in the yeast Kluyveromyces lactis

Gruppo di Ricerca: 
Daniela Ottaviano, Michele M. Bianchi
Attach English: 

In the respiratory yeast Kluyveromyces lactis, little is known about the factors regulating the metabolic response to oxygen shortage. After searching for homologs of characterizedSaccharomyces cerevisiae regulators of the hypoxic response, we identified a gene that we named KlMGA2, homologous to MGA2. The deletion of KlMGA2 strongly reduced both fermentative and respiratory growth rate and altered fatty acid composition and unsaturation index of membranes. The reciprocal heterologous expression of MGA2 and KlMGA2 in the corresponding deletion mutant strains suggested that Mga2 and KlMga2 are functional homologs. KlMGA2 transcription was induced by hypoxia and the glucose sensor Rag4 mediated the hypoxic induction of KlMGA2. Transcription of lipid biosynthetic genes KlOLE1,KlERG1, KlFAS1 and KlATF1 was induced by hypoxia and was dependent on KlMga2, except for KlOLE1.  Rag4 was required for hypoxic induction of transcription for both KlMga2 dependent (KlERG1) and KlMga2 independent (KlOLE1) structural genes.

Anno del Convegno: 
2012

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