Fig. 2. Dictyostelium DdRab11 is associated with contractile vacuole
membranes.(A,B) Post-nuclear extracts prepared from homogenized cells were
fractionated on Percoll gradients as described in Materials and Methods. After
fractionation, samples were subjected to SDS-PAGE followed by western blot
analysis using antibodies to DdRab11 and RabD. DdRab11 protein was confined to
the top fractions of the gradient that corresponded to non-lysosomal membranes
vesicles. Bottom fractions represent lysosomal membrane fraction that
contained lysosomal marker enzymes. (C,D) Protein samples (20 µg) from
post-nuclear supernatant (PNS), purified contractile vacuole (light membranes)
and purified lysosomes were subjected to SDS-PAGE and western blot analysis.
DdRab11 and RabD were both enriched in contractile vacuole membranes, but only
RabD was enriched in purified lysosomes.
