Fig. 8. Endogenous Arl8 is present on lysosomes in Drosophila cells. (A) Protein blot of total cellular proteins from D.Mel-2 cells probed with a rabbit antiserum raised against Drosophila Arl8 (Dm Arl8, CG7891). The cells were treated with dsRNA from GFP (con) or Drosophila Arl8. (B) Confocal micrographs of D.Mel-2 cells treated as in (A) with dsRNA from GFP (control) or Drosophila Arl8. After fixation and permeabilisation, cells were labelled with anti-Drosophila Arl8, and imaged with identical settings. (C) Confocal micrographs of S2 cells expressing a GFP fusion to the C-terminus of Drosophila LAMP1 (CG3305) and labelled with anti-Drosophila Arl8. (D-E) Confocal projection stacks of mitotic D.Mel-2 cells labelled with antibodies against Drosophila Arl8 and tubulin. Arl8 does not detectably concentrate in the spindle mid-zone in late anaphase (D), or in the midbodies (E) during late telophase. (F) Confocal micrographs of COS cells transfected with a plasmid expressing a native (i.e. un-tagged) form of Drosophila Arl8, and labelled with antibodies to Drosophila Arl8 and CD63. The Drosophila protein is localised to lysosomes, and alters the perinuclear distribution of lysosomes seen in the adjacent untransfected cell. Bars, 5 µm.