FIG. 7.

The GABPα/GABPβ2 complex can bind to an Ets motif in the IL-7Rα promoter. (A) Formation of a protein/DNA complex in the presence and absence of GABPβ1L. Splenic T cells from WT or GABPβ1L^−/− mice were purified by negative selection and preactivated and expanded as described previously (38). Nuclear extracts were prepared and used in EMSAs. The probe contains an Ets motif in the IL-7Rα promoter with flanking sequences. The major protein/DNA complex, indicated by an arrow, contains GABPs as characterized in our previous studies (38). (B) GABPs bind to an Ets motif in the IL-7Rα promoter. The cDNAs of GABPα, GABPβ1L, and GABPβ2 were each separately cloned 3′ to the T7 promoter in plasmids and used in a reticulocyte lysate in vitro translation system to produce the respective proteins. The in vitro-translated (IVT) proteins were used in EMSAs as above (A) in the indicated combinations.