Fig. 4. GM130 and GRASP65 are directly targeted to Golgi apparatus in vitro. (A) [³⁵S]-labeled GM130 were synthesized in vitro using reticulocyte lysate and incubated with increasing amount of purified Golgi, mitochondrial or microsomal membranes as indicated. Membranes were recovered by centrifugation, the bound material was analyzed by SDS-PAGE and autoradiography. The picture shown is a representative of three experiments with similar results (top gallery). Amounts of membrane-bound GM130 and GRASP65 were quantified as described in Materials and Methods and plotted against the amounts of final membrane concentrations. The results shown were the average of three experiments and the vertical bars indicate standard deviations (bottom). (B) Experiments were carried out for GRASP65 as described in (A).