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Nuclear receptors: Difference between revisions

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F: C-terminal domain
F: C-terminal domain


See also [[Receptor]]
See also:
*[[Receptor]]
*[[Steroid Hormones and their receptors]]
*[[Intracellular receptors]]


=Thyroid Hormone Receptor-like=
=Thyroid Hormone Receptor-like=
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==Estrogen receptor==
==Estrogen receptor==
*[[Estrogen receptor]]
*[[Estrogen receptor]]
<scene name='Estrogen_receptor/Cv/1'>Click here to see the difference between conformations</scene> of estrogen receptor α complexed with raloxifene and a corepressor peptide (morph was taken from [http://molmovdb.org/cgi-bin/movie.cgi Gallery of Morphs] of the [http://molmovdb.org Yale Morph Server]).
<scene name='Estrogen_receptor/Cv/1'>Click here to see the difference between conformations</scene> of estrogen receptor α complexed with [[raloxifene]] and a corepressor peptide (morph was taken from [http://molmovdb.org/cgi-bin/movie.cgi Gallery of Morphs] of the [http://molmovdb.org Yale Morph Server]).


Structure of estradiol metal chelate and  estrogen receptor complex: The basis for designing a new class of SERMs<ref>PMID: 21473635</ref>.
Structure of estradiol metal chelate and  estrogen receptor complex: The basis for designing a new class of SERMs<ref>PMID: 21473635</ref>.
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Similar differences may be observed between ER which has bound the partial agonist and complete antagonist ligands. <scene name='71/714947/Antagonist_tamoxifen_bound_er/5'>Antagonist tamoxifen bound ER</scene> The most drastic difference is noticeable between agonist and antagonist ligands. Compare the agonist scene to the <scene name='71/714947/Agonist_estradiol_bound_er/2'>Agonist estradiol bound er</scene>. Special attention should be given to the bottom right alpha helices and beta sheets that are pushed out more in the antagonist compared to the agonist bound ER.  
Similar differences may be observed between ER which has bound the partial agonist and complete antagonist ligands. <scene name='71/714947/Antagonist_tamoxifen_bound_er/5'>Antagonist tamoxifen bound ER</scene> The most drastic difference is noticeable between agonist and antagonist ligands. Compare the agonist scene to the <scene name='71/714947/Agonist_estradiol_bound_er/2'>Agonist estradiol bound er</scene>. Special attention should be given to the bottom right alpha helices and beta sheets that are pushed out more in the antagonist compared to the agonist bound ER.  


Tamoxifen (an ER antagonist) is a drug created to bind ER and inhibit the transcription factor activity of ER. Tamoxifen is larger than the normal hormone ER binds (estradiol); for this reason added with the conformation estrogen receptor takes on, the activation loop is pushed into an inactive conformation. The picture below shows structural differences between the (left/blue) antagonist tamoxifen bound ER and the (right/tan) agonist estradiol bound ER. This blocks ER from giving the signal to grow. Antagonists are generally larger and cause estrogen receptors to be too hindered sterically to be able to bind to the major groove of DNA, inhibiting the receptor. The antagonist bound estrogen receptor is noticeably larger than the agonist bound version. Further inhibition occurs when ER has bound an antagonist ligand. Antagonist bound ER is still brought to Euchromatin in the nucleus. The larger than agonist bound ER ligand chaperon complex is not capable of binding the major groove of DNA, but still occupies the space around specific palindromic sites which ER binds and modifies the transcription of local genes to these palindromic sequence areas. This blocks agonist bound ER from being able to reach these specific palindromic major groove target loci in DNA.
===Estrogen receptor α===
===Estrogen receptor alpha===
* [[Estrogen receptor#Structure of estradiol metal chelate and  estrogen receptor complex: The basis for designing a new class of SERMs]] <ref>PMID: 21473635</ref>
* [[Estrogen receptor#Estrogen receptor α complexed with raloxifene and a corepressor peptide]]
* [[Estrogen receptor#Estrogen receptor α complexed with raloxifene and a corepressor peptide]]
* [[Tamoxifen|Tamoxifen and the Estrogen receptor]]
 
===Estrogen receptor beta===
===Estrogen receptor β===
* [[Student Project 10 for UMass Chemistry 423 Spring 2015]]
* [[Student Project 10 for UMass Chemistry 423 Spring 2015]]
<scene name='48/483891/Initial_view/1'>Estrogen receptor β</scene> (ER-β) is 1 of the 2 isoforms of the estrogen receptor, a ligand-activated transcription factor which regulates the biological effects of the steroid hormone 17 β-estradiol, or estrogen, in both males and females. The complex is a hetero-tetrameric assembly consisting of 4 molecules and a ligand: 2 copies of <scene name='48/483891/Erbeta/1'>estrogen receptor β</scene>, 2 copies of <scene name='48/483891/Steroid_receptor/3'>steroid receptor coactivator-1</scene>, and the ligand, <scene name='48/483891/Ligand/3'>Genistein</scene>. Once the ligand is bound, the complex recruits the steroid receptor coactivators, which recruit other proteins to form the transcriptional complex for initiation of transcription. This activates expression of reporter genes containing estrogen response elements. Genistein is a phytoestrogen with structural similarity to estrogen which competes for estrogen receptors.  
<scene name='48/483891/Initial_view/1'>Estrogen receptor β</scene> (ER-β) is 1 of the 2 isoforms of the estrogen receptor, a ligand-activated transcription factor which regulates the biological effects of the steroid hormone 17 β-estradiol, or estrogen, in both males and females. The complex is a hetero-tetrameric assembly consisting of 4 molecules and a ligand: 2 copies of <scene name='48/483891/Erbeta/1'>estrogen receptor β</scene>, 2 copies of <scene name='48/483891/Steroid_receptor/3'>steroid receptor coactivator-1</scene>, and the ligand, <scene name='48/483891/Ligand/3'>Genistein</scene>. Once the ligand is bound, the complex recruits the steroid receptor coactivators, which recruit other proteins to form the transcriptional complex for initiation of transcription. This activates expression of reporter genes containing estrogen response elements. Genistein is a phytoestrogen with structural similarity to estrogen which competes for estrogen receptors.  
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Upon visualizing the estrogen receptor in an <scene name='48/483891/Arrow_view/1'>arrow representation</scene>, the structure can be classified as parallel or anti-parallel. Here is the zoomed <scene name='48/483891/Hydrophobic_pocket/3'>primarily hydrophobic pocket</scene>.
Upon visualizing the estrogen receptor in an <scene name='48/483891/Arrow_view/1'>arrow representation</scene>, the structure can be classified as parallel or anti-parallel. Here is the zoomed <scene name='48/483891/Hydrophobic_pocket/3'>primarily hydrophobic pocket</scene>.
== [[Estrogen-related receptor]]==
== [[Estrogen-related receptor]]==
**[[Tamoxifen|Tamoxifen and the Estrogen Receptor/Tamoxifen and the Estrogen-related receptor]]
<scene name='50/501401/Cv/4'>Binding of nuclear receptor corepressor 2 peptide and 4-hydroxytamoxifen</scene> to human estrogen-related receptor γ. The chemotherapeutic drugs bisphenol and <scene name='50/501401/Cv/5'>tamoxifen</scene> are nestled between 4 alpha helices in the ERR active site.
<scene name='50/501401/Cv/4'>Binding of nuclear receptor corepressor 2 peptide and 4-hydroxytamoxifen</scene> to human estrogen-related receptor γ. The chemotherapeutic drugs bisphenol and <scene name='50/501401/Cv/5'>tamoxifen</scene> are nestled between 4 alpha helices in the ERR active site.
== 3-Ketosteroid receptors==
== 3-Ketosteroid receptors==

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Alexander Berchansky, Michal Harel
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