FIGURE 4.

Actin assembly activity of Fhod3. A, HeLa cells were transfected with plasmids encoding the wild-type Fhod3-ΔN or mutant Fhod3-ΔN carrying the I1127A or K1273D substitution. Cells were fixed followed by visualization by GFP fluorescence (green) or phalloidin staining (red). Scale bar, 20 μm. B, quantitative analysis of stress fiber formation by expression of the wild-type Fhod3-ΔN or mutant Fhod3-ΔN protein carrying the I1127A or K1273D substitution. Cells showing parallel actin fibers aligned with the long axis throughout the cell (as in A) were counted, and the percentages are expressed as the mean ± S.D.