Galactose metabolic genes in yeast respond to a ratio of galactose and glucose.

ABSTRACT: Natural environments are filled with multiple, often competing, signals. In contrast, biological systems are often studied in "well-controlled" environments where only a single input is varied, potentially missing important interactions between signals. Catabolite repression of galactose by glucose is one of the best-studied eukaryotic signal integration systems. In this system, it is believed that galactose metabolic (GAL) genes are induced only when glucose levels drop below a threshold. In contrast, we show that GAL gene induction occurs at a constant external galactose:glucose ratio across a wide range of sugar concentrations. We systematically perturbed the components of the canonical galactose/glucose signaling pathways and found that these components do not account for ratio sensing

SUBMITTER: Escalante-Chong R 

PROVIDER: S-EPMC4321281 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature