Fig. 1.
Model of initiation of skeletal mineralization including the function of PHOSPHO1, TNAP, NPP1, and phosphate transporters. The first step of MV-mediated mineralization involves the convergence of two independent biochemical pathways: intravesicular Pi generation by the enzymatic action of PHOSPHO1 and influx of Pi, generated in the perivesicular space by the activities of TNAP and NPP1, via Pi transporters. PC phosphocholine, PEA phosphoethanolamine, MV matrix vesicle, PiT phosphate transporter 1, HA hydroxyapatite, ECM extracellular matrix, Pi inorganic phosphate, PPi inorganic pyrophosphate