Figure 4.

Btk and PI 3-kinase-γ synergize in fibroblast transformation. Rat-2 cells expressing SrcE378G were coinfected with the following combination of retroviruses: p101 and p110γ (A), Btk and p101 (B), Btk and p110γ (C), and Btk with p101 and p110γ (D); Rat-2 cells without SrcE378G were coinfected with p101 and p110γ (E) or Btk with p101 and p110γ (F) as controls. Forty-eight hours postinfection, 10,000 cells from each infection were plated in duplicate soft agar dishes (6 cm diameter). Colonies equal to or larger than 0.5 mm were counted and photographed after 12 days of incubation, and numbers are reflective of at least two different experiments.. Colonies are ∼0.5 mm, small (S); 0.5 to 1.0 mm, medium (M); or larger than 1.0 mm, large (L).