G3PP is a 533 amino acid protein belonging to the major facilitator superfamily. G3PP is a multi-pass membrane protein that acts as a transporter of or glycerol-3-phoshphate between cellular compartments. Glycerol-3-phosphate is produced from glycerol and is an important factor in many biochemical pathways, including glycolysis. G3PP contains 12 putative transmembrane domains and N- and C-terminal Endoplasmic Reticulum (ER) retention signals. G3PP is expressed at highest levels in liver, kidney, small intestine, bone marrow and fetal tissues.