Figure 5.

PS1 is coimmunoprecipitated with Notch1. (Upper) Diagram of the Notch1 construct HA-ΔEN. The N terminus (N), C terminus (C), TM domain, and the positions of the HA and myc epitopes are shown. The location of the CDC/ankyrin repeats is shaded. 293 cells were transfected with (+) or without (−) HA-ΔEN and PS1 as indicated. Cells were lysed in SDS buffer (crude lysate) or were lysed in coimmunoprecipitation (IP) lysis buffer and immunoprecipitated with α-HA or α-myc. Precipitating proteins were resolved by SDS/PAGE and immunoblotted with both α-PS1_CTF and α-PS1_NTF. Crude lysates equal 10% of the protein used in the coimmunoprecipitations. FL-PS1, NTF-PS1, and CTF-PS1 are indicated. Sizes of molecular weight markers in kDa are given on the right.