DescriptionThe power of conservation is exemplified in the C. elegans intestinal epithelia. As a model to study endocytic recycling, molecular transport regulators have been characterized in this genetically tractable system. In this dissertation, I describe the molecular requirements for Syndpin/SDPN-1 in vivo. Proteoliposome assays confirm that full-length SDPN-1 is capable of tubulating acidic liposomes in vitro. As a likely accessory protein, SDPN-1 coordinates the exit of recycling cargo from the early endosome. I propose that Syndapin/SDPN-1 facilitates this transport step through the localized recruitment of actin to early endosomes. In addition, the worm intestine provides a lucid understanding of the endosomal determinates that coordinate TGFβ signaling. We report TGFβ signaling and internalization require Clathrin-Dependent Endocytosis (CDE). Furthermore, post internalization of the receptors result in the sorting of the type I and the type II receptors into distinct molecular sorting complexes. Mutants defective in retromer-dependent recycling missort their type I SMA-6 to the lysosome and impair signaling. Alternatively, the type II receptor, DAF-4 (dauer formation defective-4) is returned through the ARF-6 (ADP-ribosylation factor-6) dependent recycling pathway.