FOP Gene Switch Deciphered in Lab and in Life

A series of seminal collaborative experiments were
conducted in 2007 in Philadelphia, Tokyo, and Berlin and established
a central dogma of FOP research in the post gene discovery era: that
the FOP mutation activates the ACVR1 receptor in the absence of
bone morphogenetic protein (BMP) and leads to the promiscuous
stimulation of BMP signaling. Additionally, experiments performed
in Philadelphia confirmed that the mutated FOP receptor stimulates
leaky BMP signaling in cells from FOP patients and explosive
signaling when FOP cells are activated by BMPs.



Kevin Egan at the microscope in the FOP Lab.

These studies provide the first insight into a signaling pathway that
when damaged in a specific manner, orchestrates the promiscuous
differentiation of soft connective tissues into a disabling second
skeleton of heterotopic bone. Furthermore, they provide the
basis for developing model systems for testing drugs that might
block this renegade receptor.