FIGURE 3.

IFNAR1 is palmitoylated on cysteine 463. A, amino acid sequence of the 458–507 part of the carboxyl-terminal cytoplasmic tail of human IFNAR1. The two cytoplasmic cysteines in positions 463 and 502 are highlighted in boldface type. Cys-463 and Cys-502 were mutated into alanine individually or in combination, and the corresponding mutants are named AC, CA, and AA as indicated (mutations are underlined). B, L929R2 cells stably transfected with wild-type IFNAR1 (CC) or with the indicated mutants were incubated for 4 h with [³H]palmitate. IFNAR1 was immunoprecipitated from cell lysates, and immune complexes (treated or not with 1 m NH₂OH for 1 h) were separated by SDS-PAGE. The IFNAR1 immunoprecipitate was split in two before being analyzed either by Western blotting (WB) (lower panel) or by autoradiography (upper panel).