FIG. 6.

Palmitoylation is not required for LMP2A protein association, tyrosine phosphorylation, and ubiquitination. Wild-type LMP2A or mutant LMP2A was transiently transfected into BJAB cells. Fifteen hours after transfection, the cells were lysed. Lysates were immunoprecipitated (IP) for LMP2A, and immunoprecipitates were analyzed by SDS-PAGE, transferred to Immobilon membrane, and probed for either LMP2A (A and B; LMP2A), phosphorylated tyrosine residues (B; APT), or AIP-4 coassociation (B; AIP-4). Lyn immunoprecipitates were analyzed by Western blotting for Lyn and for LMP2A coassociation (A; Lyn and LMP2A). BJAB cells were also cotransfected with HA-Ub (C). Lysates were immunoprecipitated for LMP2A, and membranes were probed with an antibody for the HA tag to detect higher-molecular-weight LMP2A species representing ubiquitinated LMP2A (C, arrows). Empty vector was included as a control. Representative immunoblots of two independent experiments are shown.