Open AccessCatabolite inactivation of the sugar transporters in Saccharomyces cerevisiae is inhibited by the presence of a nitrogen source
Author(s) -
Lucero Pilar,
Moreno Eulalia,
Lagunas Rosario
Publication year - 2002
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/j.1567-1364.2002.tb00049.x
Subject(s) - catabolite repression , saccharomyces cerevisiae , biochemistry , sugar , biology , yeast , glucose transporter , transporter , snf3 , enzyme , gene , insulin , mutant , microbiology and biotechnology
Saccharomyces cerevisiae uses glucose preferentially to any other carbon source and this preferential use is ensured by control mechanisms triggered by glucose. The consensus is that inactivation of sugar transporters other than glucose transporters is one of these mechanisms. This inactivation is called catabolite inactivation because of its apparent analogy with the catabolite inactivation of gluconeogenic enzymes. Recently, doubt has been cast on the role of the inactivation of the sugar transporters in controlling the use of glucose because this inactivation neither is specifically triggered by glucose nor specifically affects non‐glucose sugar transporters. Based on the fact that this inactivation has been almost exclusively investigated using nitrogen‐starved cells, it has been proposed that it might be due to the stimulation of the protein turnover that follows nitrogen starvation. The results obtained in this work support this possibility since they show that the presence of a nitrogen source in the medium strongly inhibited the inactivation. It is concluded that, in growing yeast cells, the contribution of the inactivation by glucose of the non‐glucose sugar transporters to the preferential use of glucose is much lower than generally believed.