Figures & data
Figure 1 Multiple Rabs cooperate to regulate phagosome acidification and phagolysosome formation for apoptotic cell degradation in C. elegans. (A) RAB-14 and UNC-108/RAB2 may act sequentially to deliver V-type ATPase to apoptotic cell-containing phagosomes. UNC-108 mainly associates with vesicles derived from the trans-Golgi network (TGN) and promotes the transport of V-type ATPase to early endosomes. RAB-14 functions in the following step to deliver V-type ATPase to phagosomes by mediating the tethering, docking and fusion of early endosomes to phagosomes through the recruitment of tethering effectors. The acquisition of V-type ATPase initiates phagosomal acidification. (B) RAB-14, UNC-108 and RAB-7 act in sequential steps to regulate phagolysosome formation. RAB-14 and UNC-108 recruit lysosome-targeting tethers as effectors to bring lysosomes in close contact with phagosomes. RAB-7 acts in the next step to mediate lysosome docking and fusion by promoting SNARE paring and complex formation. The HOPS complex may serve as the effector for both UNC-108 (RAB-14) and RAB-7 to coordinate the tethering and fusion of lysosomes to phagosomes.
