EC3.1.3.9
小胞体・膜に存在し、内腔で活性を示す。肝臓にあり、脳、骨格筋には存在しない。
細胞質中のグルコース6-リン酸は輸送体T1により小胞体内宮に入り加水分解されグルコースを生じる。グルコースとリン酸は各々輸送体T2、T3により細胞質に戻される。
Function
Hydrolyzes glucose-6-phosphate to glucose in the endoplasmic reticulum. Forms with the glucose-6-phosphate transporter (SLC37A4/G6PT) the complex responsible for glucose production through glycogenolysis and gluconeogenesis. Hence, it is the key enzyme in homeostatic regulation of blood glucose levels.
Catalytic activity
D-glucose 6-phosphate + H2O = D-glucose + phosphate.
Pathway
Carbohydrate biosynthesis; gluconeogenesis.
Subcellular location
Endoplasmic reticulum membrane; Multi-pass membrane protein.
Involvement in disease
Defects in G6PC are the cause of glycogen storage disease type 1A (GSD1A) [MIM:232200]. A metabolic disorder characterized by impairment of terminal steps of glycogenolysis and gluconeogenesis. Patients manifest a wide range of clinical symptoms and biochemical abnormalities, including hypoglycemia, severe hepatomegaly due to excessive accumulation of glycogen, kidney enlargement, growth retardation, lactic acidemia, hyperlipidemia, and hyperuricemia.
