The novel co-activator CRABPII binds to RAR alpha and RXR alpha via two nuclear receptor interacting domains and does not require the AF-2 'core'

We identify the RAR alpha, RXR alpha and CRABPII domains required for the p hysical interaction of these proteins. On RAR alpha and RXR alpha, the sequ ences correspond to the DEF and DE domains, respectively, but the interacti on with CRABPII does not require the AF-2AD 'core'. On CRABPII, two interac ting domains are identified (NRID1 and NRID2), one of which contains the on ly enhancement transactivation domain of CRABPII. The interaction is ligand -independent and does not require the ligand-binding domain of CRABPII. The se results further stress that interaction of CRABPII with the nuclear rece ptors defines a novel level of transcriptional control. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.