Figure 10. Rbsn-5 binds to Dor/Vps18 and is also required for early endosomal fusions.
(A) Rbsn-5 directly binds to Dor, based on prominent growth of yeast colonies on synthetic medium lacking Ade in yeast two hybrid experiments. (B) Rab7-positive late endosomes are fragmented in cells undergoing Rbsn-5 RNAi. Note the absence of Rbsn-5 signal in nephrocytes but not in the gut that is visible in the bottom part of this panel, indicating efficient knockdown. (C) Endosomes are fragmented in Rbsn-5 RNAi garland cells, based on the lack of large α-vacuoles in ultrastructural images. (D) In the absence of Rbsn-5, Rab5-positive early endosomes are fragmented and accumulate in the perinuclear region of garland nephrocytes, and the plot profile of the framed area is also shown. Note that Vps8-HA remains associated with these early endosomes. Bars: (B,D): 10 µm, (C,C’): 5 and 1 µm, respectively.