Sch 9p kinase and the Gcn4p transcription factor regulate glycerol production during winemaking

Grape juice fermentation is a harsh environment with many stressful conditions, and Saccharomyces cerevisiae adapts its metabolism in response to those environmental challenges. Many nutrient-sensing pathways control this feature. The Tor/Sch9p pathway promotes growth and protein synthesis when nutrients are plenty, while the transcription factor Gcn4p is required for the activation of amino acid biosynthetic pathways. We previously showed that Sch9p impact on longevity depends on the nitrogen/carbon ratio. When nitrogen is limiting, SCH9 deletion shortens chronological life span, which is the case under winemaking conditions. Its deletion also increases glycerol during fermentation, so the…