The JM-B region modulates Ron receptor activation by affecting the orientation of the JM-C region. A) Schematic of mutants. Deletions of different lengths in the JM-B region are indicated by arrows. Mutated residues are highlighted in bold. B) &D) 293 cells were transfected with HA-tagged wild-type or mutant Ron in the presence and absence of MSP. Lysates were immunoprecipitated with anti p-Y and blotted for HA, or directly blotted for p-Ron1238/9, p-Ron1360 and HA, p-Erk and Erk. C) &E) Relative luciferase activity in 293 cells co-transfected with wild-type or mutant Ron, and an AP-1 luciferase reporter in the presence and absence of MSP.