Fig. 4.

The receptor-binding region is required to escape the secretory pathway, and the lipid-binding region mediates mitochondrial interaction. Cells transfected with apoE(171-272) without signal peptide (a) or apoE4(1-191) without signal peptide (c) were permeabilized with 0.5% Tween 20 and stained with anti-apoE (green). Cells cotransfected with DsRed2-Mito (red) and either of those two apoE4 constructs were permeabilized with 500 units of STP-O (b and d) and stained with anti-apoE (green). The cells were analyzed as in Fig. 3.