FIG. 7.

Subcellular fractionation of the β-galactosidase fusion proteins. (A) LLP fusion proteins. Postnuclear fractions obtained from COS-1 expressing β-galactosidase fusion proteins as indicated were analyzed by iodixanol-based linear density gradient centrifugation. After fractionation, membranes in each fraction were pelleted by ultracentrifugation and then analyzed by immunoblotting using β-galactosidase MAb. Subcellular fractionation of untransfected COS-1 was also performed, and aliquots of fractionated samples were analyzed by immunoblotting using antibodies directed against calnexin (ER marker) or β-COP (Golgi marker). (B) 706-752 and 816-844 fusion proteins. Postnuclear supernatants obtained from COS-1 expressing 706-752 or 816-844 fusion proteins were analyzed by subcellular fractionation followed by Western blotting using β-galactosidase MAb.