Fig. 6. Inhibition of actin cup formation by ActA repeats. Raw264.7 cells transiently transfected with GFP-tagged ActA repeats (A-aA'') or with the mutated form of the repeats (B-B'') were incubated with antibody-coated sheep RBC, fixed and stained with Texas Red-conjugated phalloidin. Cells expressing the active form of the ActA repeats were able to bind sheep RBC but did not form actin cups (arrows in A, A''). In contrast, the formation of actin cups was not affected in control (untransfected) cells and in cells that expressed the mutated form of the ActA repeats (arrows in B, B''). A, B: phalloidin lebelling; A', B': GFP signal; A'', B'': phase contrast. Scale bar: 10 µm.