May hydrolyze glucose-6-phosphate to glucose in the endoplasmic reticulum. May be responsible for glucose production through glycogenolysis and gluconeogenesis (By similarity). D-glucose 6-phosphate + H2O = D-glucose + phosphate Carbohydrate biosynthesis; gluconeogenesis. Specifically expressed in pancreatic islet cells, in particular those of beta-cell origin. Not detected in testis, kidney, muscle, liver, lung, spleen, brain, pituitary, gastric fundus or heart. Initial onset of expression in the pancreas is at 12 dpc and prominent expression is detected at 14 dpc. Up-regulated in islet cells cultured in hyperglycemic concentrations of glucose. N-glycosylated; the non-glycosylated form is more unstable and is degraded through the proteasome. Mice are no overt anatomical or behavioral phenotype but display a mild metabolic phenotype. Upon fasting those mice exhibit a significant decrease in blood glucose and triacylglycerol compared to wild-type mice. G6pc2 is an autoantigen which is the natural target of a prevalent T-cell population causing insulin-dependent diabetes mellitus through destruction of pancreatic beta cells. Belongs to the glucose-6-phosphatase family. Wrong choice of CDS.