Function

The phosphorylation of glucose at the sixth carbon position is the first step in glycolysis. The reaction is catalyzed by a family of enzymes called hexokinases, types I (MIM.142600) through IV (glucokinase) (MIM.138079).

Glucokinase is a structurally and functionally unique member of this family. Glucokinase is expressed only in mammalian liver and pancreatic islet beta cells. Because of its unique functional characteristics, the enzyme plays an important regulatory role in glucose metabolism. The rate of glucose metabolism in liver and pancreas is a function of the activity of the enzyme.

Pathology

 inactivating mutations in noninsulin-dependent diabetes mellitus (NIDDM) (MIM.125853)
 inactivating mutations in maturity-onset diabetes of the young MODY type II(MIM.125851)
 inactivating mutations in neonatal onset diabetes mellitus (MIM.606176)

 rare activating mutations in autosomal dominant congenital hyperinsulinism (MIM.602485) (V455M, A456V)