GBF-1 is required for secretion and endocytosis.

<p>(A) GBF-1 and AGEF-1 are required for caveolin secretion in oocytes. In both <i>agef-1(RNAi)</i> and <i>gbf-1(RNAi)</i> oocytes less CAV-1::GFP vesicles were observed throughout the cell when compared to mock treated animals. Single confocal planes are shown. (B) Endocytosis of yolk protein is impaired in <i>gbf-1(RNAi)</i> worms. In mock-treated and <i>agef-1(RNAi)</i> worms, YP170::GFP (VIT-2::GFP) accumulated in the maturing oocytes and in the developing embryos. In <i>gbf-1(RNAi)</i> worms a strong accumulation of YP170::GFP in the body cavity was observed in approximately 70% of the worms. (C) AGEF-1 and GBF-1 are required for efficient secretion of yolk protein. Both <i>agef-1(RNAi)</i> and <i>gbf-1(RNAi)</i> caused a buildup of yolk (YP170::GFP) in the intestine (indicated by black arrows). A DIC with GFP overlay is shown. (A–C) All experiments have been performed at least three times using similar experimental conditions using different RNAi feeding batches. The selected images are representative for the observed phenotype.