Fig. 4. The transmembrane domain of CD98 associates with ß1 integrin. (A) Equal amount of cell lysates (500 µg) from cell populations transfected with either control vector (Vector) or the constructs illustrated were immunoprecipitated with an anti-human CD98 (upper panel) or an anti-mouse ß1 integrin (middle panel) antibody. The immunoprecipitates were separated by 7% SDS-PAGE and transferred to nitrocellulose. Membranes were subsequently immunoblotted with an anti-mouse integrin ß1 (upper panel) or an anti-human CD98 (middle panel) antibody. The lower panel represents an immunoblot of total cell lysates for mouse ß1 integrin to confirm equal loading. (B) Cell lysates from cell populations prepared as described in A were immunoprecipitated with an anti-human CD69 (upper panel) and immunoblotted with an anti-mouse integrin ß1. The lower panel is an immunoblot of the cell lysates for mouse integrin ß1 to demonstrate equal loading.