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. Author manuscript; available in PMC: 2015 Jun 2.
Published in final edited form as: Curr Biol. 2014 May 15;24(11):1187–1198. doi: 10.1016/j.cub.2014.04.003

Figure 6. Arl1 links Rab4 to the Arf GEFS BIG1/2 at early endosomes.

Figure 6

(A) Arl1 associates with the Rab4 subdomain. The image shown is from Cos7 cells expressing mCherry-Rab4a and Arl1-GFP. Arrowhead depicts Rab4-enriched buds (red) positive for Arl1 (green). Scale bar = 1μm. (B) Arl1 knockdown (see also Figure S3A and B) causes loss of both BIG1 and AP-3 from early endosomes. Control Cos7 cells or Arl1-depleted cells were loaded with transferrin (green), fixed and stained for endogenous BIG1 (blue) and AP-3 (red). Arrowheads depict transferrin containing endosomes that are positive for AP-3 and BIG1 in control but negative in Arl1-depleted cells respectively. Scale bar on cell = 10μm and 1μm on enlarged endosome images. (C– F) Quantification of endogenous AP-3 (C), BIG1 (D), AP-1 (E) and GGA-3 (F) fluorescence on EEA1/transferrin containing endosomes. In (C) Control, N = 252 and Arl1 KD, N=154 endosomes. In (D), Control, N=324 and Arl1 KD, N=116 endosomes. In (E), Control, N=207 and Arl1 KD, N=214 endosomes. In (F), Control, N=164 and Arl1 KD, N=195 endosomes. Mann Whitney’s test was used to test for significance. Error bars represent mean±SEM. ‘*’ indicates significantly different at p < 0.0001. See also Figure S3A–B.