Figure 2. Profilin interacts with γ-TuRC.

(A, B, C) Extracts of B16 cells were precipitated with immobilized Abs to profilin (A), γ-tubulin (B) or GCP2 (C), followed by Western blotting and probing with Abs against profilin (Pfn), γ-tubulin (γ-Tb), GCP2, GCP4, and calmodulin (negative control) as indicated (C). In each blot (A, B, C), the sample lanes denoted 1–4 show: total cell extract, gel load (1); no cell extract (2); precipitated proteins (3); and Ab-free carrier (4). Note reciprocal precipitation in all three cases. (D) Extracts of B16 control (1, 4, 6) and profilin knock-out KO27 (2, 5, 7) cells were precipitated with immobilized Abs to profilin, followed by Western blotting and probing with Abs against profilin (Pfn), γ-tubulin (γ-Tb), GCP2, GCP4, actin, and calmodulin (negative control) as indicated. The sample lanes denoted 1–7 show: total cell extract, gel load (1, 2); no cell extract (3); precipitated proteins (4–5); and Ab-free carrier (6–7). Note co-precipitation of γ-tubulin, GCP2, GCP4, and actin with profilin Ab occurs in B16 cells solely. (B, D) Asterisks (*) in panels (B) and (D), lanes 2 and 3, and 3–5, respectively, denote cut off bands reflecting precipitating Abs.