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Engineered Reversal of Function in Glycolytic Yeast Promoters
journal contribution
posted on 2019-05-03, 00:00 authored by Arun S. Rajkumar, Emre Özdemir, Alicia V. Lis, Konstantin Schneider, Jiufu Qin, Michael K. Jensen, Jay D. KeaslingPromoters are key components of cell
factory design, allowing precise
expression of genes in a heterologous pathway. Several commonly used
promoters in yeast cell factories belong to glycolytic genes, highly
expressed in actively growing yeast when glucose is used as a carbon
source. However, their expression can be suboptimal when alternate
carbon sources are used, or if there is a need to decouple growth
from production. Hence, there is a need for alternate promoters for
different carbon sources and production schemes. In this work, we
demonstrate a reversal of regulatory function in two glycolytic yeast
promoters by replacing glycolytic regulatory elements with ones induced
by the diauxic shift. We observe a shift in induction from glucose-rich
to glucose-poor medium without loss of regulatory activity, and strong
ethanol induction. Applications of these promoters were validated
for expression of the vanillin biosynthetic pathway, reaching production
of vanillin comparable to pathway designs using strong constitutive
promoters.