A direct interaction between the nuclear receptor TR2 and histone deacetylases (HDACs) 3 and 4 is mediated by the DNA binding domain (DBD) of TR2. To test if this interaction is common to members of the nuclear receptor family, the Cys2-Cys2 type zinc finger (ZF) DBDs were subcloned from several nuclear receptors (mRARα, mRXRβ, mTR2, mTR4, RAR, mPPARδ, and mPPARγ2). Using GST pull-downs, both HDACs 3 and 4 were found to interact directly with the core DBD from each receptor. The three-dimensional structure of the ZF domains was essential for this interaction as disruption by zinc chelation precluded interaction with HDACs. The results suggest that the ZFs of nuclear receptors provide a general interaction interface for HDACs 3 and 4. Functional significance of this interaction was demonstrated using ChIP assays where a truncated TR2 protein (lacking the LBD) recruited HDACs 3 and 4 to the target DNA causing demonstrable histone deacetylation. GST pull-downs and mammalian two-hybrid interaction tests were then used to define the interaction domains of HDAC3 with TR2. Both the N- and C-terminal portions of HDAC3 showed interaction with the TR2 DBD. Thus, multiple domains of HDAC3 form the interaction surface for the DBD of nuclear receptors.
Bibliographical noteFunding Information:
We thank Dr Catherine Boulter (Department of Genetics, University of Cambridge, Cambridge, England) for the generous donation of the Kid1 cDNA clone. This work was supported by NIH grants DK54733, DK60521, DA11190, DA11806 and DA13926 to LNW.
- Histone deacetylase
- Nuclear receptor
- Zinc finger