Meta-Biol

• Pathways

Unique among FGFR1 fusion proteins, which generally give rise to an atypical myeloproliferative syndrome (EMS) (reviewed in Jackson, 2010), the BCR-FGFR1 fusion results in a more typical chronic myeloid leukemia (CML). Although both EMS and CML activate PLCgamma signaling, and mutation of the FGFR1 Y766 PLCgamma binding site attenuates both diseases, CML-specific signaling also appears to be mediated through the BCR portion of the fusion protein. BCR Y177 binds GRB2-GAB1 and induces CML-like leukemia in mice, while expression of a Y177F BCR-FGFR1 fusion induces EMS-like disease (Roumiantsev, 2004).