Gamma-glutamyl carboxylase

Gamma-glutamyl carboxylase is an enzyme that plays a crucial role in the blood clotting process. It is encoded by the GGCX gene in humans. This enzyme is primarily located in the endoplasmic reticulum of cells, where it catalyzes the carboxylation of glutamate residues on specific proteins to form gamma-carboxyglutamate (Gla).

Function

Gamma-glutamyl carboxylase is responsible for the post-translational modification of certain proteins in the body. This modification involves the addition of a carboxyl group to the gamma position of glutamate residues, a process known as gamma-carboxylation. The resulting gamma-carboxyglutamate residues are essential for the biological function of all known Gla-proteins.

Among the proteins known to undergo gamma-carboxylation are several involved in the blood clotting process, including prothrombin and factors VII, IX, and X. These proteins are known as vitamin K-dependent clotting factors because gamma-carboxylation is dependent on the presence of vitamin K.

Clinical significance

Mutations in the GGCX gene can lead to a rare disorder known as combined deficiency of vitamin K-dependent clotting factors (VKCFD). This condition is characterized by a bleeding tendency due to the impaired function of the vitamin K-dependent clotting factors.

See also

• Vitamin K
• Blood clotting
• Prothrombin
• Factor VII
• Factor IX
• Factor X