Portal de Periódicos da CAPES

Activation of Gal4p by Galactose-Dependent Interaction of Galactokinase and Gal80p

1996; American Association for the Advancement of Science; Volume: 272; Issue: 5268 Linguagem: Inglês

10.1126/science.272.5268.1662

1095-9203

Frank T. Zenke, Reinhard Engels, V. Vollenbroich, Jutta Meyer, Cornelis P. Hollenberg, Karin D. Breunig,

Plant Molecular Biology Research

Yeast galactokinase (Gal1p) is an enzyme and a regulator of transcription. In addition to phosphorylating galactose, Gal1p activates Gal4p, the activator of GAL genes, but the mechanism of this regulation has been unclear. Here, biochemical and genetic evidence is presented to show that Gal1p activates Gal4p by direct interaction with the Gal4p inhibitor Gal80p. Interaction requires galactose, adenosine triphosphate, and the regulatory function of Gal1p. These data indicate that Gal1p-Gal80p complex formation results in the inactivation of Gal80p, thereby transmitting the galactose signal to Gal4p.