Biochemical and NMR mapping of the interface between CREB-binding protein and ligand binding domains of nuclear receptor: beyond the LXXLL motif.
CBP, cAMP-response element-binding protein (CREB)-binding protein, plays an important role as a general cointegrator of various signaling pathways and interacts with a large number of transcription factors. Interactions of CBP with ligand binding domains (LBDs) of nuclear receptors are mediated by LXXLL motifs, as are those of p160 proteins, although the number, distribution, and precise sequences of the motifs differ. We used a large N-terminal fragment of murine CBP to map by biochemical methods and NMR spectroscopy the interaction domain of CBP with the LBDs of several nuclear receptors. We show that distinct zones of that fragment are involved in the interactions: a 20-residue segment containing the LXXLL motif (residues 61-80) is implicated in the interaction with all three domains tested (peroxisome proliferator-activated receptor gamma-LBD, retinoid X receptor alpha-LBD, and estrogen-related receptor gamma-LBD), whereas a second N-terminal well conserved block of around 25 residues centered on a consensus L(40)PDEL(44) motif constitutes a secondary motif of interaction with peroxisome proliferator-activated receptor gamma-LBD. Sequence analysis reveals that both zones are well conserved in all vertebrate p300/CBP proteins, suggesting their functional importance. Interactions of p300/CBP coactivators with the LBDs of nuclear receptors are not limited to the canonical LXXLL motifs, involving both a longer contiguous segment around the motif and, for certain domains, an additional zone.
Klein
Fabrice A C
FA
Département de Biologie et Génomique Structurales, UMR 7104, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP Strasbourg, 1 rue Laurent Fries Illkirch 67404, France.
Atkinson
R Andrew
RA
Potier
Noelle
N
Moras
Dino
D
Cavarelli
Jean
J
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D050882:CREB-Binding Protein; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism*; D047495:PPAR gamma / Q000737:chemistry / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000378:metabolism*; D015534:Trans-Activators / Q000737:chemistry* / Q000378:metabolism*; D015533:Transcriptional Activation
D008024:Ligands; D009687:Nuclear Proteins; D047495:PPAR gamma; D010446:Peptide Fragments; D018160:Receptors, Cytoplasmic and Nuclear; D015534:Trans-Activators; D050882:CREB-Binding Protein; C494364:Crebbp protein, mouse