A region of the cellobiohydrolase I promoter from the filamentous fungus Trichoderma reesei mediates glucose repression in Saccharomyces cerevisiae, dependent on mitochondrial activity

The upstream activating region that controls cellulose-induced expression o f the glucose-repressible cellobiohydrolase I gene (UARcb1) of the filament ous fungus Trichoderma reesei is shown to mediate transcription and glucose repression of a reporter gene in Saccharomyces cerevisiae, a unicellular m icroorganism that lacks the genes required for the utilization of cellulose . Glucose-controlled transcription mediated by UARcb1 requires the products of the genes SNF1 and SSN6, a protein kinase and a repressor, respectively , that regulate glucose-repressible yeast genes. Previously, it has been sh own that mitochondrial function is implicated in cellobiohydrolase I gene e xpression in T. reesei and this sensitivity to the metabolic state of the m itochondria was shown to be transcriptionally controlled by the 5'-flanking sequence of the cbh1 gene [Abrahao-Neto et al. (1995) Biochemistry 34 1045 6-10462]. Remarkably, transcription of the reporter gene controlled by UARc b1 in S. cerevisiae also showed a requirement for active mitochondria, sugg esting that a common mechanism involving mitochondrial activity controls gl ucose-repressible genes in both microorganisms. (C) 1998 Academic Press.