Matrix Extracellular Phosphoglycoprotein (MEPE)

The predicted 525-amino acid MEPE protein has a signal peptide, 2 N-glycosylation motifs, a glycosaminoglycan-attachment site, an RGD cell-attachment motif, and phosphorylation motifs. Rowe et al. (2000) noted that MEPE shares molecular similarities with several dentin-bone extracellular matrix RGD-containing phosphoglycoproteins, including dentin sialophosphoprotein (DSPP ), osteopontin (SPP1 ), and dentin matrix protein-1 (DMP1 ). RT-PCR detected MEPE expression in bone marrow and brain. High-level expression of a 2-kb MEPE transcript was detected in 4 OHO tumor samples. Rowe et al. (2000) concluded that MEPE is a candidate gene for an OHO tumor-secreted phosphaturic factor that may play a role in the pathophysiology of tumor-induced osteomalacia.