Fig. 2: Glucose transport mechanism across the endoplasmic reticulum membrane.

Cytosolic glucose-6-phosphate (G6P) enters the ER via glucose-6-phosphate translocase (G6PT/SLC37A4), where glucose-6-phosphatase (G6PC) hydrolyzes it to glucose and inorganic phosphate (Pi). Glucose is recycled or exported. Associated disorders include GSD1b (G6PT/G6PC1 mutations), G6PC2 deficiency (pancreas-specific), and ubiquitously expressed G6PC3 defects.