ANKH


Progressive ankylosis protein homolog is a protein that in humans is encoded by the ANKH gene. ANKH is a multipass transmembrane protein that is expressed in joints and other tissues. It is involved in transport of pyrophosphate from cells into the extracellular space. It is expressed in osteoblasts. Deficiencies of ANKH are associated with excessive calcification of bone and with metastatic calcification.

Research

In a mouse model, mutation at the Ank locus causes a generalized, progressive form of arthritis accompanied by mineral deposition, formation of bony outgrowths, and joint destruction. The human homolog is virtually identical to the mouse protein and ANKH-mediated control of pyrophosphate levels has been suggested as a possible mechanism regulating tissue calcification and susceptibility to arthritis in higher animals.