Effects of cholesterol depletion on microdomain association of APP and segregation between syntaxin 1 and BACE1 in N2a cells. Mild reduction of cellular cholesterol levels (0.4 μM lovastatin and 1 mM MβCD) caused a switching of APP's microdomain association without changing segregation between BACE1 and syntaxin 1. Further reduction (0.4 μM lovastatin and 1.5 mM MβCD) induced a loss of BACE1 segregation from syntaxin 1, which is consistent with the requirement of intact cholesterol-dependent microdomains for BACE1 exclusion. Data are means + SD based on three independent experiments (n = 31–39). **, P < 0.01.