TDA function in Saccharomyces cerevisiae during diauxic shift

S. cerevisiae undergoes a metabolic reprogramming during glucose deprivation, usually referred to as diauxic shift. Tda1/YMR291W encodes a kinase whose function is not completely understood. TDA1 is thought to interact with HXK2 by phosphorylation, HXK2 in turn regulates glucose-repressed genes. Additionally, after a revision was made on the regulatory model during diauxic shift (Coutant et al, 2019), the growth-curve differences during the ethanol-phase between pre- and post-revision in the EUROSCARF library, ?tda1 stood out as having the biggest change during the revision. Therefore, the assumption was made that the the gene is not only less understood than expected but also that the impact it has is also larger than previously expected. Thus, a "wildtype" strain (BY4741) and a tda1 deletant (YMR291W) from the EUROSCARF mat-alpha deletion library were cultivated in a YNB + amino acids (auxotrophic) + 2% glucose medium under standard flask cultivation conditions (37C, 220 rpm [ø = 5cm]) for 26 hours. Samples were taken at 10 hours after inoculation (glucose-phase) and 26 hours after inoculation (ethanol-phase). Extracellular metabolite analysis was performed using HPLC. The glucose levels were high and ethanol levels low for the "glucose-phase" samples and the reverse was true for the "ethanol-phase" samples. This indicates that A) the cells consumed glucose and produced ethanol, and B) glucose was depleted and it's implied that the cells were consuming ethanol (previous experiments performed using the same protocol showed lowered ethanol concentrations after 26h and onwards). RNA samples were extracted using an RNAseq extraction kit, and the samples were sent to NGI at SciLife where they were sequenced.