FIG. 6.

Flotation gradient analysis of GP64 and FasI association with lipid raft microdomains. Sf9 cells infected with a virus expressing wild-type (w.t.) GP64 and the FasI protein (top two panels) were subjected to Triton X-100 extraction at 4°C. Insoluble membranes were isolated by flotation gradient fractionation. Proteins from each sucrose gradient fraction were examined by Western blot analysis with either an anti-FasI MAb (top panel) or an anti-GP64 MAb (lower three panels). Fractions 2 to 4 represent the more buoyant insoluble membranes associated with lipid rafts, and fractions 7 and 8 represent soluble non-raft portions of the membrane. Sf9 cells infected with viruses expressing palmitoylation-minus forms of GP64 (C503A and C503S) were treated as described above and probed with anti-GP64 MAb AcV5 (lower two panels).