Fracture Callus Protein 1 (FXC1)

FXC1 belongs to a family of evolutionarily conserved proteins that are organized in heterooligomeric complexes in the mitochondrial intermembrane space. These proteins mediate the import and insertion of hydrophobic membrane proteins into the mitochondrial inner membrane.The protein has a series of glutamine residues at its N terminus. Northern blot analysis detected ubiquitous, barely detectable expression of a 3.2-kb FXC1 transcript in adult human tissues. Fxc1 expression decreased dramatically during the proliferative stages, but increased 3- to 4-fold during the phase when these cells exhibit osteoblastic functions, such as production and deposition of matrix molecules. The results suggested that FXC1 may play a role during the production and deposition of matrix molecules in osteoblasts.