BACE1 also interacts with γ-secretase but not with A10. (A) CHAPSO-solubilized mouse brain microsomes were immunoprecipitated for PS1 CTF or using control resin. Immunoprecipitates were probed for PS1 NTF and for the coIP of BACE1. (B) Mouse brain microsomes solubilized in 1% CHAPSO were immunoprecipitated for BACE1 or TFR and probed for the coIP of PS1 CTF. (C and D) Mouse brain microsomes were immunoprecipitated for A10 (C) or BACE1 (D) and probed for the coIP of BACE1 or A10, respectively. Con, control; im, immature; m, mature.