A: A431 cells loaded with C16:1-GM1 and incubated with or without 40 nM CTB (Right and Left panels respectively). Scale bars = 10 μm.
B: Same as in panel (A) using A431 cells loaded with Alexa C16:0-GM1.
C–E: Histograms quantitating the colocalization (Mx) of the C16:1- and C16:0-GM1 molecular species with Rab11a, Rab7 and Golgin97 compartments in cells treated with CTB (filled triangles) or with no toxin (open circles).
F: C16:1-GM1 Alexa568 loaded MEF-GM1−/− cells transiently expressing Rab11a (upper panels) and Golgin97-EGFP (lower panels) treated with 40 nM CTB or without toxin.
G: C16:0-GM1 loaded MEF-GM1−/− cells and treated as in (F).
H and I: Histograms quantitating the colocalization of the C16:1- and C16:0-GM1 isoforms with Rab11a and Golgin97 compartments as indicated. Open circles (no toxin) and filled triangles (plus CTB) as in Panels (C & D). N = 2 independent experiments. Scale bars = 10 μm.