Fig. 9.

BACE1-dependent cleavage of IRA and IRB. a HEK 293 cells were transfected with an empty vector (Cont) or with IRA or IRB expression vector, then IR and endogenous GAPDH expression were detected by immunoblot. b IRsol was measured in conditioned media of cell expressing IRA or IRB by ELISA (left) and by immunobloting of the conditioned media untreated or treated with PGNaseF. c Cells were transfected with the indicated combinations of IRA, IRB and BACE1, and inactive BACE1 (BACE1i) expression vectors; then IRsol was measured by ELISA in conditioned media. d BACE1 overexpressing cells were transfected with IRA or IRB expression vector and IR was detected by immunoblot (left) or at the cell surface by flow cytometry (right). LE indicates a long exposure of the immunoblot. e Inactive BACE1 was co-immunoprecipitated with IRA or IRB as described in Fig. 2g. Immature (imm) and mature (mat) BACE1 are indicated. Data are means ± s.d. Statistical analyses were made using unpaired t-test. *p < 0.05; ***p < 0.001