Supplementary Figure 2: Expression of proteins in various cell lines.

(a) Histogram of flow cytometry data showing expression of cell surface TCR in cell lines indicated in the panel using a fluorescently conjugated anti-TCRβ antibody. (b) Histogram of flow cytometry data showing expression of endogenous CD45 phosphatase in HEK293T and Jurkat T cells using a fluorescently conjugated anti-CD45 antibody. (c) Normalized cytoplasmic densities of CSK, SHP-1 and SHP-2 expressed endogenously in cell lines indicated in the panels. Protein expression was detected by western blot using monoclonal antibodies specific to the proteins and data are normalized relative to the protein expression in CD4⁺ T cells. Quantification of the western blot is described in the Methods section. (d-f) Histograms of flow cytometry data showing cell surface expression of TCR (d), CD8 (e) and CD4 (f) in various HEK-derived cell lines using fluorescently conjugated antibodies against TCRβ, CD8β or CD4, respectively.