Take our Survey

Reference: Moriya H and Johnston M (2004) Glucose sensing and signaling in Saccharomyces cerevisiae through the Rgt2 glucose sensor and casein kinase I. Proc Natl Acad Sci U S A 101(6):1572-7

Reference Help

Abstract


The yeast Saccharomyces cerevisiae senses glucose through two transmembrane glucose sensors, Snf3 and Rgt2. Extracellular glucose causes these sensors to generate an intracellular signal that induces expression of HXT genes encoding glucose transporters by inhibiting the function of Rgt1, a transcriptional repressor of HXT genes. We present the following evidence that suggests that the glucose sensors are coupled to the membrane-associated protein kinase casein kinase I (Yck1). (i) Overexpression of Yck1 leads to constitutive HXT1 expression; (ii) Yck1 (or its paralogue Yck2) is required for glucose induction of HXT1 expression; (iii) Yck1 interacts with the Rgt2 glucose sensor; and (iv) attaching the C-terminal cytoplasmic tail of Rgt2 to Yck1 results in a constitutive glucose signal. The likely targets of Yck1 in this signal transduction pathway are Mth1 and Std1, which bind to and regulate function of the Rgt1 transcription factor and bind to the C-terminal cytoplasmic domain of glucose sensors. Potential casein kinase I phosphorylation sites in Mth1 and Std1 are required for normal glucose regulation of HXT1 expression, and Yck1 catalyzes phosphorylation of Mth1 and Std1 in vitro. These results support a model of glucose signaling in which glucose binding to the glucose sensors causes them to activate Yck1 in the cell membrane, which then phosphorylates Mth1 and Std1 bound to the cytoplasmic face of the glucose sensors, triggering their degradation and leading to the derepression of HXT gene expression. Our results add nutrient sensing to the growing list of processes in which casein kinase I is involved.

Reference Type
Journal Article | Research Support, Non-U.S. Gov't | Research Support, U.S. Gov't, P.H.S.
Authors
Moriya H, Johnston M
Primary Lit For
Additional Lit For
Review For

Interaction Annotations


Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.

Interactor Interactor Type Assay Annotation Action Modification Phenotype Source Reference

Gene Ontology Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene Gene Ontology Term Qualifier Aspect Method Evidence Source Assigned On Annotation Extension Reference

Phenotype Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details.

Gene Phenotype Experiment Type Mutant Information Strain Background Chemical Details Reference

Regulation Annotations


Increase the total number of rows displayed on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; to filter the table by a specific experiment type, type a keyword into the Filter box (for example, “microarray”); download this table as a .txt file using the Download button or click Analyze to further view and analyze the list of target genes using GO Term Finder, GO Slim Mapper, SPELL, or YeastMine.

Regulator Target Experiment Assay Construct Conditions Strain Background Reference