FIGURE 5.

The H component of CUTA interacts with BACE1. A, CUTA with an HA tag at the C terminus (CUTA-HA) was co-transfected with APP, BACE1, or NCT, all of which were Myc-tagged at the C terminus into HEK 293T cells. Cells co-transfected with pcDNA, and the indicated vectors were used as controls. Equal protein amounts of cell lysates were used for immunoprecipitation (IP) with an HA antibody and Western blot (WB) with the Myc antibody 9E10 to detect CUTA-interacting proteins. Ten percent of cell lysates were used as input to detect the expression of transfected proteins. B, pcDNA, BACE1-HA, and CUTA-Myc (left panel) or Myc-CUTA (right panel) were pairwise co-transfected into HEK 293T cells. Equal protein amounts of cell lysates were immunoprecipitated with an HA antibody and Western-blotted with a Myc antibody (left panels) or immunoprecipitated with the Myc antibody and Western-blotted with the HA antibody (right panels). Ten percent of cell lysates were used as input. *, nonspecific bands. C, the lysates of human brain tissues were immunoprecipitated with normal rabbit IgG, the R-CUTA antibody, or the BACE1 antibody 689. Immunoprecipitated proteins and input (5% of cell lysates) were subjected to SDS-PAGE and Western blot using another anti-BACE1 antibody (3D5) or R-CUTA.