High impact information on RGT2

• Recent studies of Saccharomyces cerevisiae revealed sensors that detect extracellular amino acids (Ssy1p) or glucose (Snf3p and Rgt2p) and are evolutionarily related to the transporters of these nutrients [1].
• Glucose sensing and signaling in Saccharomyces cerevisiae through the Rgt2 glucose sensor and casein kinase I [2].
• A two-hybrid screen for Std1-interacting proteins identified the hydrophilic C-terminal domains of the glucose sensors, Snf3 and Rgt2 [3].
• Rgt2p, a glucose transporter that functions as a high-glucose sensor, is required for conversion of Rgt1p into an activator by high levels of glucose [4].
• RGT2 and GRR1 also play a role in regulating the expression of the HXT genes, which appear to be the upstream components of the glucose-transport-dependent pathway regulating maltose permease inactivation [5].

Biological context of RGT2

• Mutations in other genes known to regulate gene expression in response to changes in glucose concentration, including SNF3, RGT2, and SNF5, also affect cell growth under ion stress conditions [6].
• The RGT2 locus was mapped 38 cM from SNF3 on chromosome IV [7].
• Furthermore, the ability of the low glucose signal to trigger accelerated gluconeogenic mRNA degradation depends upon the low glucose sensor, Snf3p, but not on the high glucose sensor, Rgt2p [8].

Anatomical context of RGT2

• Snf3 and Rgt2 are integral plasma membrane proteins with unique carboxy-terminal domains that are predicted to be localized in the cytoplasm [9].

Associations of RGT2 with chemical compounds

• We identified a dominant mutation in RGT2 that causes constitutive expression of several HXT genes, even in the absence of the inducer glucose [10].
• Pathway 1 uses Rgt2p as a sensor of extracellular glucose and causes degradation of maltose permease protein [11].

Physical interactions of RGT2

• Kinetic analysis of glucose uptake showed that the rgt1 and RGT2 suppressors restore glucose-repressible high-affinity glucose transport in a snf3 mutant [7].

Other interactions of RGT2

• Rgt2p, which along with Snf3p monitors extracellular glucose levels, appears to be the glucose sensor for the glucose-transport-independent pathway [5].
• The mutant forms block the transduction of the Snf3- and Rgt2-mediated glucose signals upstream of the Rgt1 transcriptional regulator [12].
• This N-terminal PEST-like sequence is the target of both the Rgt2p-dependent and the Glc7p-Reg1p-dependent glucose signaling pathways [13].
• Strikingly, the transmembrane components of several of these sensors, Ssylp, Mep2p, Snf3p. and Rgt2p, are unique members of nutrient-transport protein families [14].

References