The RNA-Binding Protein KSRP Modulates Cytokine Expression of CD4⁺ T Cells

Figure 6

In vitro binding of KSRP to different 3-UTRs. In vitro-transcribed biotinylated IFN-γ, IL-5, IL-10, IL-9, and TNF-α 3-UTR or TNF-α 3-UTR without ARE (delARE) RNAs were incubated with whole cell extracts from murine EL4 T cells. After several washing steps, the bound proteins were eluted with high salt (2 M KCl). The eluted proteins were separated in SDS-PAGE. KSRP was identified by western blotting using a specific anti-KSRP antibody. In the eluate fraction (eluate), binding of KSRP to the different 3-UTRs is shown. The supernatant represents the amount of KSRP not bound to streptavidin-agarose in pull-down analyses. The blot is representative of three other blots showing similar results.