(B) Representative Western blot analysis of co-immunoprecipitations of myc-ACAP1 and Arf6-HA in the presence or absence of HA-BspF. HeLa cells were transfected to produce Arf6-HA and combinations of myc-ACAP1 and HA-BspF, or not, and myc-ACAP1 was immunoprecipitated using anti-myc-conjugated magnetic beads. Input lysates (6% of post-nuclear supernatants) and co-immunoprecipitates were separated by SDS-PAGE and probed for Arf6-HA, HA-BspF and myc-ACAP1 by Western blotting. Quantification of the Arf6/ACAP1 ratio was performed by densitometric analysis. Data are means ± SD of 3 independent experiments. The asterisk indicates a statistically significant difference (P = 0.0017, unpaired Student's t test) between BspF-producing and control conditions. 