FIG. 1.

16E6 interacts with the transcriptional coactivator CBP/p300. (A) Equal amounts of partially purified full-length (FL) CBP/p300 from HeLa nuclear extract were passed over GST, GST-16E6, GST-P/CAF, and GST-YY1 micro-affinity columns. After SDS-PAGE and transfer to PVDF membranes, Western blot analysis detected the presence of CBP/p300. The positions of the molecular weight markers are also indicated. (B) GST micro-affinity columns were used to detect the interaction of IVT radiolabelled 16E6 with GST-CBP II (residues 1621 to 1877). No interaction was detected for the control GST column or the GST-CBP I (residues 461 to 662) column. The lower panel shows the Coomassie blue-stained SDS-gel of GST and GST fusion proteins eluted from the micro-affinity columns and also shows the molecular weight marker ladder. (C) Comparison of the 16E6-CBP II interaction with known E1A-CBP II and 16E6-E6AP interactions in GST micro-affinity column assays. (D) Demonstration of a direct interaction between 16E6 and CBP using two recombinant bacterially expressed proteins. GST or GST-E6 was passed over a column containing MBP-CBP (residues 1808 to 1852) fusion protein. Bound GST-fusion protein was detected by Western blot analysis using an anti-GST antibody. The MBP-CBP fusion protein was also passed over a GST or GST-E6 column, and the interaction detected with an anti-MBP antibody.