Yeast Methylotrophy: Metabolism, Gene Regulation and Peroxisome Homeostasis
Figure 2
Molecular mechanism of methanol-inducible gene expression. (a) Relative expression levels of H. polymorpha MOX (encoding AOD), C. boidinii AOD1, and C. boidinii DAS1 during growth on various carbon sources. On glucose-containing media, expression is completely repressed. When glucose is completely consumed or cells are shifted to glycerol medium, a derepressed level of expression of the AOD genes is induced (derepression) and the extent of derepression of the AOD genes differs between H. polymorpha and C. boidinii. When cells are grown on methanol, the maximum level of expression of AOD genes is achieved not only by derepression but also by methanol-specific gene activation. The induction of DAS1 on methanol medium is achieved only by methanol-specific gene activation. (b) During growth on glucose, expression of methanol-inducible genes is repressed. When cells are shifted to methanol, initially, a Trm2p-related derepression event occurs followed by a Trm1p-related methanol-specific gene activation.
