Figure 2.

Acute cholesterol depletion alters intracellular localization of acylated GFP chimeras and GM₁. COS-7 cells, grown in lipoprotein-deficient serum for 18–20 h, were acutely depleted of cholesterol with the use of 20 mM MβCD for 1 h at 37°C. (A) GFP chimeras were detected with the use of rabbit anti-GFP and FITC-conjugated donkey anti-rabbit secondary antibody. Free cholesterol was detected with filipin. (B) Ganglioside GM₁ distribution detected with FITC-CTX. Arrowheads indicate areas of plasma membrane colocalization, and arrows indicate endosomal colocalization. Model descriptions of Figures 2–4 are as in Figure 1. (C) Viability of MβCD-treated COS-7 cells expressing YesGFP. Expressing cells were treated with vehicle, 20 mM MβCD for 1 h at 37°C, or 20 mM MβCD for 1 h followed by repletion with 30 μg/ml cholesterol:MβCD for 1 h at 37°C. Cellular viability was determined by MTT formazan production. Bar, 10 μm.