Matrix Gla protein (MGP)

Matrix Gla protein is a small (~11 kDa), secreted, vitamin K-dependent extracellular matrix protein highly expressed by vascular smooth muscle cells, chondrocytes, bone cells, heart, lung, kidney, and other mesenchymal tissues. It contains multiple γ-carboxyglutamate residues that enable high-affinity calcium binding. Its principal biological function is the inhibition of pathological mineralization—specifically preventing inappropriate deposition of calcium phosphate crystals within blood vessels and soft tissues while also playing roles in normal bone organization. The activity of Matrix Gla protein depends on post-translational modifications requiring vitamin K; uncarboxylated forms are inactive. Genetic mutations cause Keutel syndrome—a rare disorder characterized by abnormal cartilage/bone mineralization—and knockout mice die early from massive arterial calcifications. Circulating levels/forms serve as biomarkers for cardiovascular risk assessment related to vitamin K status. No direct therapeutic agents currently target this molecule specifically; however its biology underlies risks associated with long-term use of vitamin K antagonists like warfarin.

Other names

Cell growth-inhibiting gene 36 proteinMGLAPMGP

Vitamin K antagonists (e.g., warfarin) inhibit γ-carboxylation, leading to inactive forms of MGP that cannot prevent pathological calcification.