Signature of the oligomeric behaviour of nuclear receptors at the sequence and structural level.
Fiche publication
Date publication
avril 2004
Auteurs
Membres identifiés du Cancéropôle Est :
Dr MORAS Dino
Tous les auteurs :
Brelivet Y, Kammerer S, Rochel N, Poch O, Moras D
Lien Pubmed
Résumé
Nuclear receptors (NRs) are ligand-dependent transcription factors that control a large number of physiological events through the regulation of gene transcription. NRs function either as homodimers or as heterodimers with retinoid X receptor/ultraspiracle protein (RXR/USP). A structure-based sequence analysis aimed at discovering the molecular mechanism that controls the dimeric association of the ligand-binding domain reveals two sets of differentially conserved residues, which partition the entire NR superfamily into two classes related to their oligomeric behaviour. Site-directed mutagenesis confirms the functional importance of these residues for the dimerization process and/or transcriptional activity. All homodimers belong to class I, in which the related residues contribute a communication pathway of two salt bridges linking helix 1 on the cofactor-binding site to the dimer interface. A salt bridge involving a differentially conserved arginine residue in loop H8-H9 defines the signature motif of heterodimers. RXR/USP and all Caenorhabditis elegans NRs belong to class I, supporting the hypothesis of an earlier emergence of this class.
Référence
EMBO Rep. 2004 Apr;5(4):423-9.