Facilitative glucose transporter that plays a role in glucose metabolism and regulation of longevity. May also play a role in lipid metabolism. Glucose transport activity of isoform a is competitively inhibited by mannose, galactose and fructose, suggesting ability to transport also other hexose sugars. Detected on the basolateral but not on the apicolateral membrane of intestinal cells. Isoform a is expressed in pharyngeal muscle and intestinal cells in both embryos and adults (at protein level). RNAi-mediated knockdown of the protein causes reduced 2-deoxy-D-glucose uptake, glucose oxidation and glucose conversion to triglyceride; simultaneous knockout of daf-2 or age-1 causes further reductions. The lifespan in low glucose environment is extended by 20-25% after knockdown, with 7% extension in daf-2 mutant background and no significant extension in age-1 mutant background. Fat accumulation in intestinal cells is increased. Brood size and dauer formation are not affected. Belongs to the major facilitator superfamily. Sugar transporter (TC 2.A.1.1) family. Glucose transporter subfamily.