FIG. 3.
p31 deletion causes apoptosis in MEFs. (A) Infection of p31flox/− MEFs with Ad-Cre (cKO) progressively decreased p31 expression. p31flox/+ MEFs (Ctrl) were infected with Ad-Cre as controls. (B) Association of syntaxin 18 complex components. Triton extracts of p31flox/+ (Ctrl) or p31flox/− (cKO) MEFs 2 days after infection with Ad-Cre were subjected to immunoprecipitation (IP) with an anti-syntaxin 18 antibody. The Triton X-100 extracts and the immunoprecipitated proteins were separated and analyzed by immunoblotting (IB) with the indicated antibodies. IgG, immunoglobulin G. (C) p31 forms a complex with two ER SNAREs, syntaxin 18 and BNIP1, and in this large syntaxin 18 complex, p31 forms a subcomplex with ZW10 and RINT-1. (D) p31flox/− MEFs infected with Ad-LacZ (Ctrl) or Ad-Cre (cKO) were fixed at 2, 4, and 6 days after adenovirus treatment, and the percentage of apoptotic cells was determined by the TUNEL method. The percentage of TUNEL-positive cells (mean ± standard error of the mean) was calculated from three independent samples. P values were determined by Student's t test.