Fig. 8: Cells use an active, specific mechanism to implement galactose-palatinose diauxie. | Communications Biology

Fig. 8: Cells use an active, specific mechanism to implement galactose-palatinose diauxie.

From: The type of carbon source not the growth rate it supports can determine diauxie in Saccharomyces cerevisiae

Fig. 8

Initially they consume galactose (left). Active Gal4 indirectly represses MAL11. This repression together with the negative feedback through Ima1 and Ima5 reduces intracellular palatinose concentrations, weakening positive feedback in the MAL regulon (greyed out arrows). When galactose runs out (right), Gal80 inactivates Gal4. The repression on MAL11 lifts, and the higher levels of the Mal11 transporters increase intracellular palatinose, further activating MAL11. Positive feedback in the MAL regulon strengthens and becomes self-reinforcing, and cells consume palatinose.

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