Study of MAMs. Cells were treated for 24 h with increasing concentrations of efavirenz (EFV), vehicles (MeOH or DMSO), thapsigargin (TG) 2 μM, rotenone (Rot) 25 μM or CCCP 10 μM. (A, B) Analysis of contact between specific MAM protein partners by co‐immunoprecipitation using protein A sepharose beads. Representative Western blotting images and histograms expressing quantification of (A) VAP B/C after immunoprecipitation of PTPIP51 and (B) Grp75 after immunoprecipitation of porin. A negative control (without primary antibody) was used as a control for the immunoprecipitation. (C) Western blotting analysis of PTPIP51 expression in whole‐cell extracts. Data (mean ± SEM, n = 5) are expressed as % of control (untreated cells, considered 100%). Statistical analysis was performed by one‐way ANOVA (*P < 0.05 for efavirenz vs. MeOH).