Matrix gla protein

Matrix gla protein (MGP) is a protein found in numerous body tissues that requires vitamin K for its optimum function. It is present in bone (together with the related vitamin K-dependent protein osteocalcin), as well as in heart, kidney and lung. In bone, its production is increased by vitamin D.

Genetics
The MGP was linked to the short arm of chromosome 12 in 1990.

Physiology
MGP and osteocalcin are both calcium-binding proteins that may participate in the organisation of bone tissue. Both have glutamate residues that are post-translationally carboxylated by the enzyme gamma-glutamyl carboxylase in a reaction that requires Vitamin K hydroquinone. This process also occurs with a number of proteins involved in coagulation: prothrombin, factor VII, factor IX and factor X, protein C, protein S and protein Z.

Role in disease
Abnormalities in the MGP gene have been linked with Keutel syndrome, a rare condition characterised by abnormal calcium deposition in cartilage, peripheral stenosis of the pulmonary artery, and midfacial hypoplasia.