FIG. 2.

SH2-Bβ enhances intracellular actin-dependent Listeria motility. (A) COS-7 cells were transfected with cDNA encoding either GFP alone or the indicated forms of GFP-SH2-Bβ. The large arrows refer to the initial position of the bacterium, while small arrows indicate the moving bacterium. In the schematic of SH2-Bβ, the circles represent proline-rich regions, the rectangle represents the pleckstrin homology domain, and the triangles represent the SH2 domain. Bar, 4 μm. (B) The movement of bacteria versus time was measured, and the velocity was calculated. Bars represent means plus standard errors of the means (SEM) [n = 13, 13, 10, and 14 for cells expressing GFP, GFP-SH2-Bβ, GFP-SH2-Bβ(R555E), and GFP-SH2-Bβ(504-670), respectively]. *, P < 0.05 compared to cells expressing GFP.