Gene Expression of the three glyceraldehyde-3-phosphate dehydrogenase isoforms in different genetic backgrounds of Saccharomyces cerevisiae during alcoholic fermentation

Identifier:  TFG:9017

Handle: https://hdl.handle.net/20.500.11797/TFG9017

Authors:  Díaz Bernabeu, Neus

Abstract:
In Saccharomyces cerevisiae, glyceraldehyde-3-phosphate dehydrogenase (GADPH or TDH) is encoded by three isoforms. Proteomic data indicates that melatonin binds Tdh2p, potentially influencing energy metabolism. This study mapped TDH transcription during alcoholic fermentation in Lalvin Clos wild type, Δtdh2, and Δtdh3 strains using RT-qPCR. In the wild type, TDH2 and TDH3 expression peaked at 8 h, consistent with high glycolytic flux, whereas TDH1 increased during the exponential and stationary phases. Deletion of TDH2 triggered early TDH3 expression followed by TDH1 induction, restoring growth and fermentation. In the Δtdh3 strain, TDH2 was upregulated only during the exponential phase and fermentations was delayed by 24 h, indicating that Tdh2p supports stationary-phase metabolism while Tdh3p contributes to redox homeostasis. Together with previous proteomic data, these results support a model in which melatonin may transiently interact with Tdh2p to modulate fermentative metabolism.