Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
36
pubmed:dateCreated
2002-9-2
pubmed:abstractText
Nur77/NR4A1 is an "orphan member" of the nuclear hormone receptor superfamily. Nur77 and its close relatives Nurr1 and NOR-1 bind as monomers to a consensus binding site, the nerve growth factor induced protein I-B (NGFI-B)-binding response element (NBRE). The Nur77/NURR1/NOR1 nuclear receptors are classified as immediate early response genes which are induced through multiple signal transduction pathways. They have been implicated in cell proliferation, differentiation, and apoptosis. However, the mechanism of coactivation and ligand independent trans-activation remains unclear. Hence we examined the molecular basis of Nur77-mediated cofactor recruitment and activation. We observed that Nur77 trans-activates gene expression in a cell-specific manner, and operates in an activation function-1 (AF-1)-dependent manner. The AB region encodes an uncommonly potent N-terminal AF-1 domain delimited to between amino acids 50 and 160 and is essential for the ligand-independent activation of gene expression. Steroid receptor coactivator-2 (SRC-2) modulates the activity of the N-terminal AF-1 domain. Moreover, SRC-2 dramatically potentiates the retinoid induced RXR-dependent activation of the Nur77 ligand binding domain (LBD). Interestingly, the N-terminal AB region (not the LBD) facilitates coactivator recruitment and directly interacts with SRC, p300, PCAF, and DRIP-205. Consistent with this, homology modeling indicated that the Nur77 LBD coactivator binding cleft was substantially different from that of retinoic acid receptor gamma, a closely related AF-2-dependent receptor. In particular, the hydrophobic cleft characteristic of nuclear receptors was replaced with a much more hydrophilic surface with a distinct topology. This observation accounts for the inability of this nuclear receptor LBD to directly mediate cofactor recruitment. Furthermore, the AF-1 domain physically associates with the Nur77 C-terminal LBD and synergizes with the retinoid X receptor LBD. Thus, the AF-1 domain plays a major role in Nur77-mediated transcriptional activation, cofactor recruitment, and intra- and intermolecular interactions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
33001-11
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:12082103-Animals, pubmed-meshheading:12082103-COS Cells, pubmed-meshheading:12082103-Cell Differentiation, pubmed-meshheading:12082103-Cell Division, pubmed-meshheading:12082103-Cell Line, pubmed-meshheading:12082103-Cell Nucleus, pubmed-meshheading:12082103-DNA-Binding Proteins, pubmed-meshheading:12082103-Glutathione Transferase, pubmed-meshheading:12082103-Ligands, pubmed-meshheading:12082103-Luciferases, pubmed-meshheading:12082103-Mice, pubmed-meshheading:12082103-Models, Molecular, pubmed-meshheading:12082103-Nuclear Receptor Subfamily 4, Group A, Member 1, pubmed-meshheading:12082103-Plasmids, pubmed-meshheading:12082103-Protein Binding, pubmed-meshheading:12082103-Protein Structure, Tertiary, pubmed-meshheading:12082103-Protein Transport, pubmed-meshheading:12082103-Receptors, Cytoplasmic and Nuclear, pubmed-meshheading:12082103-Receptors, Steroid, pubmed-meshheading:12082103-Signal Transduction, pubmed-meshheading:12082103-Transcription Factors, pubmed-meshheading:12082103-Transcriptional Activation, pubmed-meshheading:12082103-Transfection
pubmed:year
2002
pubmed:articleTitle
The activation function-1 domain of Nur77/NR4A1 mediates trans-activation, cell specificity, and coactivator recruitment.
pubmed:affiliation
University of Queensland Centre for Molecular and Cellular Biology Institute for Molecular Bioscience, St. Lucia, Queensland 4072, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't