FIG. 1.

Human KB epithelial cells expressing crBAP31. (A) Control (parental) KB cells were stimulated with 0.5 μg of anti-Fas (α Fas) antibody per ml in the presence of 10 μg of CHX per ml for the indicated times, and whole-cell lysates were subjected to SDS-PAGE, immunoblotted with chicken anti-BAP31 (αBAP31) antibody, and visualized by enhanced chemiluminescence (30). The positions of full-length BAP31 and the BAP31 caspase cleavage products, p27 and p20, are indicated. (B) KB cells stably expressing wt BAP31-Flag or crBAP31-Flag were analyzed under the same conditions, but with mouse anti-Flag antibody. (C) Schematic of crBAP31-Flag in the ER (30), in which the caspase recognition aspartate residues (asterisks) at positions 164 and 238 have been mutated to alanine residues. The Flag epitope tag was inserted immediately upstream of the COOH-terminal tetrapeptide ER retrieval signal, KKEE. aa, amino acid.