Fig. 3

Rab dynamics in endosomes. a Maturation of an isolated RabA endosome to a RabD endosome. b Same as a, but the initial Rab content was 55% RabA, 45% RabB. c Here, the initial Rab content was 45% RabA, 55% RabB. Notice that the endosome evolved into a pure RabB structure. d-g Several RabA, RabB, RabC and RabD endosomes were created and allowed to fuse and divide. A membrane marker was initially loaded in a RabA endosome. With time, the endosomes carrying the markers changed their membrane composition by means of RabA maturation and a combination of fusion and fission. The size (relative to the initial value) of the endosomes carrying the markers is plotted underneath each panel. h-j. A soluble and a membrane marker were loaded in a RabA endosome. The endosomes containing the markers were followed during 30 min. In h the membrane marker was initially in a RabA endosome; afterwards, it moved back and forward between RabB and RabC endosomes until it was recycled. i The soluble marker suffered the same fate than the membrane marker until it was transferred first to a RabB endosome and then to a RabD endosome by means of several fusion and fission events. j The size of the endosomes carrying the soluble and membrane markers is shown. The size is expressed as the radius of a sphere having the volume of the endosome