Fig. 5. Mutant GM130 and GRASP65 do not bind to Golgi membranes in vitro. (A) Wild-type (Wt) or1 mutant forms (C983 and M984A) of GM130 were synthesized in vitro and used for Golgi membrane binding assay as described in Fig. 4 (top). Amounts of membrane-bound GM130 were quantified as described in Materials and Methods (bottom). (B) Same as (A) except that wild-type (Wt) or mutant (G2A and G196A) forms of GRASP65 were used for the experiments.