SHC1 is an interaction partner of Tarp D and L2. (A) Graphical representation of Tarp D and L2 and the respective GST–Tarp fusion proteins including all phospho-sites. Truncated versions of Tarp were used to avoid the actin-nucleating activity of the C terminus (Jewett et al., 2006) and any unknown binding regions. (B) Western blot showing pull-down of SHC1 and NCK2 from HeLa cell lysate using bead-coupled phospho-GST-Tarp. The fusion protein was phosphorylated in vitro with recombinant human SRC. Input shows Tarp loading (bead coupled, black arrowheads) and SHC1 and NCK2 loading in HeLa cell lysate (black arrowheads). Pulled-down SHC1 and NCK2 are indicated by open arrowheads. SHC1 was only pulled down in lanes where Tarp was phosphorylated (indicated as p-Tarp). NCK2 was only pulled down with p-Tarp L2. As a control, beads were phosphorylated in the absence of GST-Tarp and did not pull down SHC1. (C) Western blot showing coimmunoprecipitation of SHC1 (white arrowheads) and Tarp (black arrowhead) after infection of HeLa or End1/E6E7 cells (C. trachomatis L2, MOI 500) for 60 min.