Fig. 3.

Interaction of PS1 with CTFβ requires the presence of both NCT and Aph-1. PS1/2-KO, NCT-KO, Ahp-1-KO, and Pen-2-KD cells were cultured for 12 h in the presence of both γ-secretase inhibitor compound E and proteasome inhibitor MG132. Cell lysates were subjected to co-immunoprecipitation using antibodies against each γ-secretase component, and the blots were probed with 6E10. As controls, 6E10 and C15 were employed. Since 6E10 was used for both immunoprecipitation and probing, both heavy chain and light chain IgG was detected in 6E10 immunoprecipitate, and the heavy chains of other polyclonal antibodies used were also detected throughout the immunoprecipitates. The band under the putative fAPP band detected in wild type cells and indicated with * is apparently nonspecific because it appears in all immunoprecipitates, including those from knockout cells.