Mouse MEPE/OF45 Antibody

MEPE (matrix extracellular phosphoglycoprotein; also OF45) is a 56‑58 kDa member of the SIBLING protein family. It is expressed by osteocytes, osteoblasts, odontoblasts and chondrocytes. MEPE is found both intra- and extracellularly. Within the cell, it binds to CHK1. This protects CHK1 from degradation, and the cell from DNA damage. Extracellularly, it binds to Phex, which protects it from cathepsin B proteolysis. Undegraded, it promotes bone vascularization and blocks bone resorption. Following cleavage after Arg410 (in mouse), a 2 kDa ASARM fragment is generated that, when phosphorylated, blocks mineralization. Mature mouse MEPE is 417 amino acids (aa) in length. It contains an RGD motif and ASARM domain (aa 416‑433). In addition to its a 57 kDa form, 70 kDa, 42‑45 kDa and 30‑35 kDa forms of mouse MEPE have been reported. Whether they are cleavage forms or products of glycosylation is unclear. Over aa 147‑433, mouse MEPE shares 77% and 57% aa identity with rat and human MEPE, respectively.