Fig. 6

Modeling endosome acidification. A proton pump with affinity for RabA and RabD domains was included in endosomes and the proton concentration was calculated using a set of ODE programmed in COPASI. a The endosomes were classified according to the prevailing Rab domain and the pH was calculated from the proton concentration in each structure. The histograms of the pH distribution for each Rab domain were obtained combining the population of endosomes of 5 independent 30 min-runs. b Membrane (light brown) and soluble (dark brown) markers were included in RabA endosomes at the beginning of the simulations and the pH sensed by the probes at each time was recorded. The panel shows the pH sensed by 10 markers in 5 independent runs. Three membrane markers recycled to the plasma membrane before the end of the simulations