Matrix Gla Protein (MGP) in Axial Skeletal Formation of Lizard Tail
Matrix Gla protein (MGP) is a member of the mineral-binding Gla protein family with the molecular weight of 10-kD and known to be involved in cartilage mineralization during development. MGP is expressed in chondrocytes, endothelial cells and vascular smooth muscle cells (Dan et al., 2012; Yao et al., 2009). The five γ-carboxyglutamic acid (Gla) residues of this protein possess high affinity for ions such as calcium and phosphate (Newman et al., 2001; Beazley et al., 2013) which enable it to prevent extracellular matrix calcification by binding the minerals thus limiting the amount of free calcium ions available to initiate calcification (Yagami et al., 1999; Dan et al., 2012). It has been reported that MGP does not only inhibit cartilage mineralization, but it also blocks chondrocyte maturation and both types of ossification (Yagami et al., 1999). Mineralization begins in matrix vesicles which is associated with MGP and at sites with accumulated proteoglycan. MGP inhibits calcium infl...