Category
Poster - Basic
Description
The yeast plasma membrane proteins Rgt2 and Snf3 are glucose sensing receptors (GSRs) that generate an intracellular signal for the induction of gene expression in response to extracellular glucose. The membrane-associated casein kinases Yck1 and Yck2 (Ycks) are involved in this glucose signal transduction pathway by transmitting the glucose signal from the plasma membrane to the nucleus. Here, we provide evidence that cell surface levels of Rgt2 are significantly decreased in a yck1Dyck2ts mutant by unknown mechanisms. We show that Rgt2 is phosphorylated on the putative Yck consensus phosphorylation sites in its C-terminal domain (CTD) in a Yck-dependent manner and that this glucose-induced modification is critical for its stability and function. Consistently, we demonstrate that the Ycks are not activated by glucose but constitutively active. Based on these results, we propose that Rgt2 may use glucose binding as a molecular switch not to activate the Ycks but to promote Yck-dependent interaction and phosphorylation of the CTD that increases its stability.
The role for Casein kinases in glucose sensing and signaling in yeast
Poster - Basic
The yeast plasma membrane proteins Rgt2 and Snf3 are glucose sensing receptors (GSRs) that generate an intracellular signal for the induction of gene expression in response to extracellular glucose. The membrane-associated casein kinases Yck1 and Yck2 (Ycks) are involved in this glucose signal transduction pathway by transmitting the glucose signal from the plasma membrane to the nucleus. Here, we provide evidence that cell surface levels of Rgt2 are significantly decreased in a yck1Dyck2ts mutant by unknown mechanisms. We show that Rgt2 is phosphorylated on the putative Yck consensus phosphorylation sites in its C-terminal domain (CTD) in a Yck-dependent manner and that this glucose-induced modification is critical for its stability and function. Consistently, we demonstrate that the Ycks are not activated by glucose but constitutively active. Based on these results, we propose that Rgt2 may use glucose binding as a molecular switch not to activate the Ycks but to promote Yck-dependent interaction and phosphorylation of the CTD that increases its stability.
Comments
Undergraduate