| Using yeast two hybrid screening , beta galactosidase assays , and pull down assays , we show that RNF 8 , a RING finger protein recently isolated as a protein binding to a ubiquitin conjugating enzyme , binds to RXR alpha through the N terminal regions of both proteins . 1.2900546^^^ In COS 7 cells , overexpressed RNF 8 colocalized and interacted with RXR alpha in the nucleus , as shown by fluorescence resonance energy transfer . 0.79589522^^^ |