Sugar efflux transporter for intercellular exchange
This family includes proteins such as drosophila saliva, MtN3 involved in root nodule development and a protein involved in activation and expression of recombination activation genes (RAGs). Although the molecular function of these proteins is unknown, they are almost certainly transmembrane proteins. This family contains a region of two transmembrane helices that is found in two copies in most members of the family. This family also contains specific sugar efflux transporters that are essential for the maintenance of animal blood glucose levels, plant nectar production, and plant seed and pollen development. In many organisims it meditaes gluose transport; in Arabidopsis it is necessary for pollen viability; and two of the rice homologs are specifically exploited by bacterial pathogens for virulence by means of direct binding of a bacterial effector to the SWEET promoter.