Mapping the interaction domains in TAF4 and Rta.

<p>(A) Plasmids that expressed deleted GFP-TAF4 were used to delineate the region in TAF4 that interacts with Rta. Numbers represent the positions of amino acids in TAF4. Q denotes the glutamine-rich regions. (B) 293T cells were cotransfected with pCMV-R and plasmids that expressed GFP fusion proteins including pEGFP-TAF4 (lanes 2, 7), pEGFP-TAF4-NM (lanes 3, 8), pEGFP-TAF4-C (lanes 4 and 9) or pEGFP-C1 (lanes 1, 6). Input lanes were loaded with 5% of the lysate (lanes 1–5). Proteins in the lysates were coimmunoprecipitated (IP) with anti-GFP antibody and analyzed by immunoblotting (IB) using anti-Rta antibody (lanes 6–9). (C) Deletion mutants of Rta were used to identify the region in Rta that interacts with TAF4. Numbers represent the positions of amino acids in Rta (D). Plasmids that expressed GFP-Rta (lanes 2, 7), GFP-N190 (lanes 3, 8), GFP-N191-415 (lanes 4, 9), GFP-Rev (lanes 5, 10) or GFP (lanes 1, 6) were transfected into 293T cells. The input lanes were loaded with 5% of the cell lysates and GFP-fusion proteins were detected using anti-GFP antibody (lanes 1–5). Proteins in the lysates were coimmunoprecipitated with anti-TAF4 antibody and analyzed by immunoblotting using anti-GFP antibody (lanes 6–10).