Matrix Gla protein associates with the organic matrix of bone and cartilage. It is thought to act as an inhibitor of calcification []. Defects in MGP are the cause of Keutel syndrome (KS). KS is an autosomal recessive disorder characterised by abnormal cartilage calcification, peripheral pulmonary stenosis neural hearing loss and midfacial hypoplasia [].
This entry includes a group of plant zinc finger proteins, including JACKDAW from Arabidopsis. They bind DNA via their zinc fingers []. JACKDAW (JKD) protein is a transcription factor that regulates tissue boundaries and asymmetric cell division by a rapid up-regulation of 'SCARECROW' (SCR), thus controlling the nuclear localization of 'SHORT-ROOT' (SHR) and restricting its action []. It controls epidermal patterning in the Arabidopsis root meristem []. It directly regulates SCR and MAGPIE (MGP) expression in cooperation with SHR, SCR and MGP [].
Bone gamma-carboxyglutamic acid protein (BGP), also known as osteocalcin, and matrix gamma-carboxyglutamic acid protein (MGP) are the only vitamin K-dependent proteins that have been isolated from bone. MGP is a small protein found in bone, dentin and cartilage. It contains five gamma-carboxyglutamic acid (Gla) residues (formed by post-translational modification of glutamic acid by vitamin K-dependent carboxylase) and a single disulphide bond. BGP is a 49 residue protein found in bone. It contains three Gla residues and a single disulphide bond. There is little similarity between these vitamin K-dependent bone proteins and the blood coagulation proteins, though they are believed to have diverged from a common ancestor [].
