The ArfGEF GBF-1 Is Required for ER Structure, Secretion and Endocytic Transport in C. elegans
Figure 5
Recycling and internalization is not affected in gbf-1(RNAi) worms.
(A) Yolk protein uptake is strongly reduced in gbf-1(RNAi) oocytes. A Single confocal plane through the center of the cells is shown. The spermatheca and the most mature oocyte are oriented toward the top. (B) Localization and intensity of the yolk receptor RME-2::GFP in gbf-1(RNAi) oocytes is undistinguishable from that in control worms. An intensity plot is shown below their corresponding images. The peaks represent the fluorescence at the plasma membrane between cell boundaries. Gray values are given in arbitrary units. (C) Recycling to the plasma membrane is unaffected in gbf-1(RNAi) oocytes. RAB11.1::GFP labeled recycling endosomes reached the plasma membrane normally in gbf-1(RNAi) oocytes compared to control oocytes. A single confocal plane is shown. (D) Knockdown of GBF-1 does not alter endocytosis or degradation of caveolin. Internalization of CAV-1::GFP in gbf-1(RNAi) oocytes was indistinguishable from that in mock RNAi worms. Spermatheca is located to the left. (E) RME-2 is endocytosed and degraded in gbf-1(RNAi) one-cell embryos. The time required for internalization of RME-2 in gbf-1(RNAi) oocytes seems not to be different from that observed in mock RNAi control worms. Anterior of the embryo is oriented towards the top. Corresponding fluorescence and DIC images are shown. (A–E) All experiments have been performed at least three times with comparable experimental conditions using different RNAi feeding batches. The selected images are representative for the observed phenotype.