View source for 4pxm


==The Estrogen Receptor Alpha Ligand Binding Domain D538G Mutant in Complex with Estradiol and a glucocorticoid receptor-interacting protein 1 NR box II peptide==
<StructureSection load='4pxm' size='340' side='right'caption='[[4pxm]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4pxm]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4PXM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4PXM FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EST:ESTRADIOL'>EST</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4pxm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4pxm OCA], [https://pdbe.org/4pxm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4pxm RCSB], [https://www.ebi.ac.uk/pdbsum/4pxm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4pxm ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ESR1_HUMAN ESR1_HUMAN] Nuclear hormone receptor. The steroid hormones and their receptors are involved in the regulation of eukaryotic gene expression and affect cellular proliferation and differentiation in target tissues. Ligand-dependent nuclear transactivation involves either direct homodimer binding to a palindromic estrogen response element (ERE) sequence or association with other DNA-binding transcription factors, such as AP-1/c-Jun, c-Fos, ATF-2, Sp1 and Sp3, to mediate ERE-independent signaling. Ligand binding induces a conformational change allowing subsequent or combinatorial association with multiprotein coactivator complexes through LXXLL motifs of their respective components. Mutual transrepression occurs between the estrogen receptor (ER) and NF-kappa-B in a cell-type specific manner. Decreases NF-kappa-B DNA-binding activity and inhibits NF-kappa-B-mediated transcription from the IL6 promoter and displace RELA/p65 and associated coregulators from the promoter. Recruited to the NF-kappa-B response element of the CCL2 and IL8 promoters and can displace CREBBP. Present with NF-kappa-B components RELA/p65 and NFKB1/p50 on ERE sequences. Can also act synergistically with NF-kappa-B to activate transcription involving respective recruitment adjacent response elements; the function involves CREBBP. Can activate the transcriptional activity of TFF1. Also mediates membrane-initiated estrogen signaling involving various kinase cascades. Isoform 3 is involved in activation of NOS3 and endothelial nitric oxide production. Isoforms lacking one or several functional domains are thought to modulate transcriptional activity by competitive ligand or DNA binding and/or heterodimerization with the full length receptor. Isoform 3 can bind to ERE and inhibit isoform 1.<ref>PMID:7651415</ref> <ref>PMID:10970861</ref> <ref>PMID:9328340</ref> <ref>PMID:10681512</ref> <ref>PMID:10816575</ref> <ref>PMID:11477071</ref> <ref>PMID:11682626</ref> <ref>PMID:15078875</ref> <ref>PMID:16043358</ref> <ref>PMID:15891768</ref> <ref>PMID:16684779</ref> <ref>PMID:18247370</ref> <ref>PMID:17932106</ref> <ref>PMID:19350539</ref> <ref>PMID:20705611</ref> <ref>PMID:21937726</ref> <ref>PMID:21330404</ref> <ref>PMID:22083956</ref> 
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== Publication Abstract from PubMed ==
Somatic mutations in the estrogen receptor alpha (ERalpha) gene (ESR1), especially Y537S and D538G, have been linked to acquired resistance to endocrine therapies. Cell based studies demonstrated that these mutants confer ERalpha constitutive activity and antiestrogen resistance and suggest that ligand-binding domain dysfunction leads to endocrine therapy resistance. Here, we integrate biophysical and structural biology data to reveal how these mutations lead to a constitutively active and antiestrogen resistant ERalpha. We show that these mutant ERs recruit coactivator in the absence of hormone while their affinities for estrogen agonist (estradiol) and antagonist (4-hydroxytamoxifen) are reduced. Further, they confer antiestrogen resistance by altering the conformational dynamics of the loop connecting Helix 11 and Helix 12 in the ligand-binding domain of ERalpha, which leads to a stabilized agonist state and an altered antagonist state that resists inhibition.

Estrogen receptor alpha somatic mutations Y537S and D538G confer breast cancer endocrine resistance by stabilizing the activating function-2 binding conformation.,Fanning SW, Mayne CG, Dharmarajan V, Carlson KE, Martin TA, Novick SJ, Toy W, Green B, Panchamukhi S, Katzenellenbogen BS, Tajkhorshid E, Griffin PR, Shen Y, Chandarlapaty S, Katzenellenbogen JA, Greene GL Elife. 2016 Feb 2;5. pii: e12792. doi: 10.7554/eLife.12792. PMID:26836308<ref>PMID:26836308</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 4pxm" style="background-color:#fffaf0;"></div>

==See Also==
*[[Estrogen receptor 3D structures|Estrogen receptor 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Fanning SW]]
[[Category: Greene GL]]
[[Category: Panchamukhi S]]