Figure 4.

[³H]MVA labeling improves in mGBP1 proteins with C15-type CaaX boxes. COS-1 cells were transfected with empty vector (V) or DNAs encoding wild-type mGBP1 (wt), hGBP1 (hG), or mGBP1 variants with C15-type CaaX motifs (CTIS and Chim). Cells were labeled with either 100 μCi/ml [³H]MVA plus 10 μM compactin or 50 μCi/ml [³H]GG-OH and no compactin, and immunoprecipitates (top panels) or cell lysates (bottom panels) were prepared and analyzed by SDS-PAGE. Incorporation of radiolabel was detected by fluorographic exposure for 22 d ([³H]MVA) or 28w ([³H]GG-OH), and then GBPs on the membranes were visualized by immunoblotting.