1
|
Mutchie TR, Yu OB, Di Milo ES, Arnold LA. Alternative binding sites at the vitamin D receptor and their ligands. Mol Cell Endocrinol 2019; 485:1-8. [PMID: 30654005 PMCID: PMC6444937 DOI: 10.1016/j.mce.2019.01.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 01/04/2019] [Accepted: 01/11/2019] [Indexed: 01/02/2023]
Abstract
In recent decades, the majority of ligands developed for the vitamin D receptor (VDR) bind at its deeply buried genomic ligand binding pocket. Theses ligands can be categorized into agonists and partial agonists/antagonists. A limited number of ligands, most of them peptides, bind the VDR‒coactivator binding site that is formed in the presence of an agonist and inhibit coactivator recruitment, and therefore transcription. Another solvent exposed VDR‒ligand binding pocket was identified for lithocholic acid, improving the overall stability of the VDR complex. Additional proposed interactions with VDR are discussed herein that include the alternative VDR‒ligand binding pocket that may mediate both non-genomic cellular responses and binding function 3 that was identified for the androgen receptor. Many VDR ligands increase blood calcium levels at therapeutic concentrations in vivo, thus the identification of alternative VDR‒ligand binding pockets might be crucial to develop non-calcemic and potent ligands for VDR to treat cancer and inflammatory disease.
Collapse
Affiliation(s)
- Tania R Mutchie
- Department of Chemistry and Biochemistry and Milwaukee Institute for Drug Discovery (MIDD), University of Wisconsin, Milwaukee, WI, 53211, USA
| | - Olivia B Yu
- Department of Chemistry and Biochemistry and Milwaukee Institute for Drug Discovery (MIDD), University of Wisconsin, Milwaukee, WI, 53211, USA
| | - Elliot S Di Milo
- Department of Chemistry and Biochemistry and Milwaukee Institute for Drug Discovery (MIDD), University of Wisconsin, Milwaukee, WI, 53211, USA
| | - Leggy A Arnold
- Department of Chemistry and Biochemistry and Milwaukee Institute for Drug Discovery (MIDD), University of Wisconsin, Milwaukee, WI, 53211, USA.
| |
Collapse
|
2
|
Souza PCT, Textor LC, Melo DC, Nascimento AS, Skaf MS, Polikarpov I. An alternative conformation of ERβ bound to estradiol reveals H12 in a stable antagonist position. Sci Rep 2017; 7:3509. [PMID: 28615710 PMCID: PMC5471280 DOI: 10.1038/s41598-017-03774-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 04/12/2017] [Indexed: 02/04/2023] Open
Abstract
The natural ligand 17β-estradiol (E2) is so far believed to induce a unique agonist-bound active conformation in the ligand binding domain (LBD) of the estrogen receptors (ERs). Both subtypes, ERα and ERβ, are transcriptionally activated in the presence of E2 with ERβ being somewhat less active than ERα under similar conditions. The molecular bases for this intriguing behavior are mainly attributed to subtype differences in the amino-terminal domain of these receptors. However, structural details that confer differences in the molecular response of ER LBDs to E2 still remain elusive. In this study, we present a new crystallographic structure of the ERβ LBD bound to E2 in which H12 assumes an alternative conformation that resembles antagonist ERs structures. Structural observations and molecular dynamics simulations jointly provide evidence that alternative ERβ H12 position could correspond to a stable conformation of the receptor under physiological pH conditions. Our findings shed light on the unexpected role of LBD in the lower functional response of ERβ subtype.
Collapse
Affiliation(s)
- Paulo C T Souza
- Institute of Chemistry, University of Campinas - UNICAMP, P. O. Box, 6154, Campinas, SP, Brazil.,Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands.,Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Larissa C Textor
- São Carlos Institute of Physics, University of São Paulo - USP, P.O. Box 396, São Carlos, SP, Brazil
| | - Denise C Melo
- Institute of Chemistry, University of Campinas - UNICAMP, P. O. Box, 6154, Campinas, SP, Brazil
| | - Alessandro S Nascimento
- São Carlos Institute of Physics, University of São Paulo - USP, P.O. Box 396, São Carlos, SP, Brazil
| | - Munir S Skaf
- Institute of Chemistry, University of Campinas - UNICAMP, P. O. Box, 6154, Campinas, SP, Brazil.
| | - Igor Polikarpov
- São Carlos Institute of Physics, University of São Paulo - USP, P.O. Box 396, São Carlos, SP, Brazil.
| |
Collapse
|
3
|
Teske KA, Yu O, Arnold LA. Inhibitors for the Vitamin D Receptor-Coregulator Interaction. VITAMINS AND HORMONES 2015; 100:45-82. [PMID: 26827948 DOI: 10.1016/bs.vh.2015.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The vitamin D receptor (VDR) belongs to the superfamily of nuclear receptors and is activated by the endogenous ligand 1,25-dihydroxyvitamin D3. The genomic effects mediated by VDR consist of the activation and repression of gene transcription, which includes the formation of multiprotein complexes with coregulator proteins. Coregulators bind many nuclear receptors and can be categorized according to their role as coactivators (gene activation) or corepressors (gene repression). Herein, different approaches to develop compounds that modulate the interaction between VDR and coregulators are summarized. This includes coregulator peptides that were identified by creating phage display libraries. Subsequent modification of these peptides including the introduction of a tether or nonhydrolyzable bonds resulted in the first direct VDR-coregulator inhibitors. Later, small molecules that inhibit VDR-coregulator inhibitors were identified using rational drug design and high-throughput screening. Early on, allosteric inhibition of VDR-coregulator interactions was achieved with VDR antagonists that change the conformation of VDR and modulate the interactions with coregulators. A detailed discussion of their dual agonist/antagonist effects is given as well as a summary of their biological effects in cell-based assays and in vivo studies.
Collapse
Affiliation(s)
- Kelly A Teske
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery (MIDD), University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Olivia Yu
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery (MIDD), University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Leggy A Arnold
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery (MIDD), University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA.
| |
Collapse
|
4
|
Yang J, Fuller PJ, Morgan J, Shibata H, McDonnell DP, Clyne CD, Young MJ. Use of phage display to identify novel mineralocorticoid receptor-interacting proteins. Mol Endocrinol 2014; 28:1571-84. [PMID: 25000480 DOI: 10.1210/me.2014-1101] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The mineralocorticoid receptor (MR) plays a central role in salt and water homeostasis via the kidney; however, inappropriate activation of the MR in the heart can lead to heart failure. A selective MR modulator that antagonizes MR signaling in the heart but not the kidney would provide the cardiovascular protection of current MR antagonists but allow for normal electrolyte balance. The development of such a pharmaceutical requires an understanding of coregulators and their tissue-selective interactions with the MR, which is currently limited by the small repertoire of MR coregulators described in the literature. To identify potential novel MR coregulators, we used T7 phage display to screen tissue-selective cDNA libraries for MR-interacting proteins. Thirty MR binding peptides were identified, from which three were chosen for further characterization based on their nuclear localization and their interaction with other MR-interacting proteins or, in the case of x-ray repair cross-complementing protein 6, its known status as an androgen receptor coregulator. Eukaryotic elongation factor 1A1, structure-specific recognition protein 1, and x-ray repair cross-complementing protein 6 modulated MR-mediated transcription in a ligand-, cell- and/or promoter-specific manner and colocalized with the MR upon agonist treatment when imaged using immunofluorescence microscopy. These results highlight the utility of phage display for rapid and sensitive screening of MR binding proteins and suggest that eukaryotic elongation factor 1A1, structure-specific recognition protein 1, and x-ray repair cross-complementing protein 6 may be potential MR coactivators whose activity is dependent on the ligand, cellular context, and target gene promoter.
Collapse
Affiliation(s)
- Jun Yang
- MIMR-PHI Medical Research Institute (J.Y., P.J.F., J.M., C.D.C., M.J.Y.), Department of Medicine (J.Y., P.J.F., M.J.Y.), Monash University, Clayton, Victoria 3168, Australia; Department of Endocrinology, Metabolism, Rheumatology, and Nephrology (H.S.), Oita University, Yufu 879-5593, Japan; and Department of Pharmacology and Cancer Biology (D.P.M.), Duke University Medical Center, Durham, North Carolina 27710
| | | | | | | | | | | | | |
Collapse
|
5
|
Yu Z, Gao W, Jiang E, Lu F, Zhang L, Shi Z, Wang X, Chen L, Lv T. Interaction between IGF-IR and ER induced by E2 and IGF-I. PLoS One 2013; 8:e62642. [PMID: 23704881 PMCID: PMC3660452 DOI: 10.1371/journal.pone.0062642] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 03/24/2013] [Indexed: 12/30/2022] Open
Abstract
Estrogen receptor (ER) is a nuclear receptor and the insulin-like growth factor-I (IGF-I) receptor (IGF-IR) is a transmembrane tyrosine kinase receptor. Estrogen and IGF-I are known to have synergistic effects on the growth of breast cancer cells. Recently, non-nuclear effects of ER have been under investigation. To study the mechanism involved in this process, we have used MCF-7 breast cancer cell lines transfected with IGF-IR anti-sense cDNA (SX13, MCF-7(SX13)) that resulted in 50% reduction of IGF-IR. In MCF-7 cells, estradiol (E2) and IGF-I induced the rapid association of ER to IGF-IR, however, the interaction was abrogated in MCF-7(SX13) cells. In addition, NWTB3 cells (NIH3T3 cells overexpressing IGF-IR) were transiently transfected with ERα, the ER-IGF-IR interaction was induced by both E2 and IGF-I. Moreover, ERα regulated the IGF-I signaling pathways through phosphorylation of ERK1/2 and Akt and the interaction of ER-IGF-IR potentiated the cell growth. Finally, E2 and IGF-I stimulated translocation of ER from the nucleus to the cytoplasm. Taken together, these findings reveal that the interaction of the ER and IGF-IR is important for the non-genomic effects of ER.
Collapse
Affiliation(s)
- Zhenghong Yu
- Department of Medical Oncology, Jinling Hospital, Nanjing, China
- * E-mail: (ZY); (TL)
| | - Weimin Gao
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas, United States of America
| | - Enze Jiang
- Nanjing University School of Medicine, Nanjing, China
| | - Fang Lu
- Nanjing Foreign Language School, Nanjing, China
| | - Luo Zhang
- Department of Medical Oncology, Jinling Hospital, Nanjing, China
| | - Zhaorong Shi
- Hospital office, Jinling Hospital, Nanjing, China
| | - Xinxing Wang
- Department of Medical Oncology, Jinling Hospital, Nanjing, China
| | - Longbang Chen
- Department of Medical Oncology, Jinling Hospital, Nanjing, China
| | - Tangfeng Lv
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas, United States of America
- Department of Respiratory Medicine, Jinling Hospital, Nanjing, China
- * E-mail: (ZY); (TL)
| |
Collapse
|
6
|
Yang J, Chang CY, Safi R, Morgan J, McDonnell DP, Fuller PJ, Clyne CD, Young MJ. Identification of ligand-selective peptide antagonists of the mineralocorticoid receptor using phage display. Mol Endocrinol 2010; 25:32-43. [PMID: 21106883 DOI: 10.1210/me.2010-0193] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The mineralocorticoid receptor (MR) is a member of the nuclear receptor superfamily. Pathological activation of the MR causes cardiac fibrosis and heart failure, but clinical use of MR antagonists is limited by the renal side effect of hyperkalemia. The glucocorticoid cortisol binds the MR with equivalent affinity to that of the mineralocorticoids aldosterone and deoxycorticosterone. In nonepithelial tissues, including the myocardium, which do not express the cortisol-inactivating enzyme 11β hydroxysteroid dehydrogenase 2, cortisol has been implicated in the activation of MR. The mechanisms for ligand- and tissue-specific actions of the MR are undefined. Over the past decade, it has become clear that coregulator proteins are critical for nuclear receptor-mediated gene expression. A subset of these coregulators may confer specificity to MR-mediated responses. To evaluate whether different physiological ligands can induce distinct MR conformations that underlie differential coregulator recruitment and ligand-specific gene regulation, we utilized phage display technology to screen 10(8) 19mer peptides for their interaction with the MR in the presence of agonist ligands. We identified ligand-selective MR-interacting peptides that acted as potent antagonists of MR-mediated transactivation. This represents a novel mechanism of MR antagonism that may be manipulated in the rational design of a ligand- or tissue-selective MR modulator to treat diseases like heart failure without side effects such as hyperkalemia.
Collapse
Affiliation(s)
- Jun Yang
- Prince Henry's Institute of Medical Research, Clayton, Victoria 3168, Australia
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Moore TW, Mayne CG, Katzenellenbogen JA. Minireview: Not picking pockets: nuclear receptor alternate-site modulators (NRAMs). Mol Endocrinol 2009; 24:683-95. [PMID: 19933380 DOI: 10.1210/me.2009-0362] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Because of their central importance in gene regulation and mediating the actions of many hormones, the nuclear receptors (NRs) have long been recognized as very important biological and pharmaceutical targets. Of all the surfaces available on a given NR, the singular site for regulation of receptor activity has almost invariably been the ligand-binding pocket of the receptor, the site where agonists, antagonists, and selective NR modulators interact. With our increasing understanding of the multiple molecular components involved in NR action, researchers have recently begun to look to additional interaction sites on NRs for regulating their activities by novel mechanisms. The alternate NR-associated interaction sites that have been targeted include the coactivator-binding groove and allosteric sites in the ligand-binding domain, the zinc fingers of the DNA-binding domain, and the NR response element in DNA. The studies thus far have been performed with the estrogen receptors, the androgen receptor (AR), the thyroid hormone receptors, and the pregnane X receptor. Phenotypic and conformation-based screens have also identified small molecule modulators that are believed to function through the NRs but have, as yet, unknown sites and mechanisms of action. The rewards from investigation of these NR alternate-site modulators should be the discovery of new therapeutic approaches and novel agents for regulating the activities of these important NR proteins.
Collapse
Affiliation(s)
- Terry W Moore
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | | | | |
Collapse
|
8
|
DuSell CD, Nelson ER, Wittmann BM, Fretz JA, Kazmin D, Thomas RS, Pike JW, McDonnell DP. Regulation of aryl hydrocarbon receptor function by selective estrogen receptor modulators. Mol Endocrinol 2009; 24:33-46. [PMID: 19901195 DOI: 10.1210/me.2009-0339] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Selective estrogen receptor modulators (SERMs), such as tamoxifen (TAM), have been used extensively for the treatment and prevention of breast cancer and other pathologies associated with aberrant estrogen receptor (ER) signaling. These compounds exhibit cell-selective agonist/antagonist activities as a consequence of their ability to induce different conformational changes in ER, thereby enabling it to recruit functionally distinct transcriptional coregulators. However, the observation that SERMs can also regulate aspects of calcium signaling and apoptosis in an ER-independent manner in some systems suggests that some of the activity of drugs within this class may also arise as a consequence of their ability to interact with targets other than ER. In this study, we demonstrate that 4-hydroxy-TAM (4OHT), an active metabolite of TAM, directly binds to and modulates the transcriptional activity of the aryl hydrocarbon receptor (AHR). Of specific interest was the observation, that in the absence of ER, 4OHT can induce the expression of AHR target genes involved in estradiol metabolism, cellular proliferation, and metastasis in cellular models of breast cancer. The potential role for AHR in SERM pharmacology was further underscored by the ability of 4OHT to suppress osteoclast differentiation in vitro in part through AHR. Cumulatively, these findings provide evidence that it is necessary to reevaluate the relative roles of ER and AHR in manifesting the pharmacological actions and therapeutic efficacy of TAM and other SERMs.
Collapse
Affiliation(s)
- Carolyn D DuSell
- Duke University Medical Center, Department of Pharmacology and Cancer Biology, Durham, North Carolina 27710, USA
| | | | | | | | | | | | | | | |
Collapse
|
9
|
van de Wijngaart DJ, Dubbink HJ, Molier M, de Vos C, Trapman J, Jenster G. Functional screening of FxxLF-like peptide motifs identifies SMARCD1/BAF60a as an androgen receptor cofactor that modulates TMPRSS2 expression. Mol Endocrinol 2009; 23:1776-86. [PMID: 19762545 DOI: 10.1210/me.2008-0280] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Androgen receptor (AR) transcriptional activity is tightly regulated by interacting cofactors and cofactor complexes. The best described cofactor interaction site in the AR is the hormone-induced coactivator binding groove in the ligand-binding domain, which serves as a high-affinity docking site for FxxLF-like motifs. This study aimed at identifying novel AR cofactors by in silico selection and functional screening of FxxLF-like peptide motifs. Candidate interacting motifs were selected from a proteome-wide screening and from a supervised screening focusing on components of protein complexes involved in transcriptional regulation. Of the 104 peptides tested, 12 displayed moderate to strong in vivo hormone-dependent interactions with AR. For three of these, ZBTB16/PLZF, SMARCA4/BRG1, and SMARCD1/BAF60a, the full-length protein was tested for interaction with AR. Of these, BAF60a, a subunit of the SWI/SNF chromatin remodeling complex, displayed hormone-dependent interactions with AR through its FxxFF motif. Vice versa, recruitment of BAF60a by the AR required an intact coactivator groove. BAF60a depletion by small interfering RNA in LNCaP cells demonstrated differential effects on expression of endogenous AR target genes. AR-driven expression of TMPRSS2 was almost completely blocked by BAF60a small interfering RNA. In summary, our data demonstrate that BAF60a directly interacts with the coactivator groove in the AR ligand-binding domain via its FxxFF motif, thereby selectively activating specific AR-driven promoters.
Collapse
Affiliation(s)
- Dennis J van de Wijngaart
- Department of Urology, Josephine Nefkens Institute, Erasmus Medical College, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
10
|
Di X, Yu L, Moore AB, Castro L, Zheng X, Hermon T, Dixon D. A low concentration of genistein induces estrogen receptor-alpha and insulin-like growth factor-I receptor interactions and proliferation in uterine leiomyoma cells. Hum Reprod 2008; 23:1873-83. [PMID: 18492705 DOI: 10.1093/humrep/den087] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Previously, we found that genistein at low concentrations stimulates the growth of human uterine leiomyoma (LM) cells, but not uterine smooth muscle (myometrial) cells (SMC). The aim of this study was to understand the molecular mechanism whereby genistein causes hyperproliferation of LM cells. METHODS The effects of genistein at 1 microg/ml on LM cells and SMC were evaluated using estrogen response element gene reporter, real-time RT-PCR, western blot, immunoprecipitation and cell proliferation assays. RESULTS Elevated estrogen receptor (ER) transactivation, increased mRNA expression of early estrogen-responsive genes, progesterone receptor and insulin-like growth factor-I (IGF-I), and decreased protein levels of ER-alpha (ER alpha) were found in genistein-treated LM cells, but not SMC. Additionally, extracellular regulated kinase (ERK), Src homology/collagen (Shc) and ER alpha were transiently activated, and interactions between ER alpha and IGF-I receptor (IGF-IR) were rapidly induced by genistein in LM cells. Using ER antagonist ICI 182,780 and MAPK/ERK kinase (MEK) inhibitor PD98059, we found that these early events were inhibited and the proliferative effect of genistein on LM cells was abrogated. CONCLUSIONS ER alpha is involved in the transient activation of ERK/mitogen activated protein kinase (MAPK) by genistein via its early association with IGF-IR, leading to hyper-responsiveness of LM cells and confirming that ER signaling is enhanced by activation of ERK/MAPK in LM cells.
Collapse
Affiliation(s)
- X Di
- Comparative Pathobiology Group, Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
DuSell CD, Umetani M, Shaul PW, Mangelsdorf DJ, McDonnell DP. 27-hydroxycholesterol is an endogenous selective estrogen receptor modulator. Mol Endocrinol 2007; 22:65-77. [PMID: 17872378 PMCID: PMC2194632 DOI: 10.1210/me.2007-0383] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Selective estrogen receptor (ER) modulators (SERMs) are ER ligands whose relative agonist/antagonist activities vary in a cell- and promoter-dependent manner. The molecular basis underlying this selectivity can be attributed to the ability of these ligands to induce distinct alterations in ER structure leading to differential recruitment of coactivators and corepressors. Whether SERM activity is restricted to synthetic ligands or whether molecules exist in vivo that function in an analogous manner remains unresolved. However, the recent observation that oxysterols bind ER and antagonize the actions of 17beta-estradiol (E2) on the vascular wall suggests that this class of ligands may possess SERM activity. We demonstrate here that 27-hydroxycholesterol (27HC), the most prevalent oxysterol in circulation, functions as a SERM, the efficacy of which varies when assessed on different endpoints. Importantly, 27HC positively regulates both gene transcription and cell proliferation in cellular models of breast cancer. Using combinatorial peptide phage display, we have determined that 27HC induces a unique conformational change in both ERalpha and ERbeta, distinguishing it from E2 and other SERMs. Thus, as with other ER ligands, it appears that the unique pharmacological activity of 27HC relates to its ability to impact ER structure and modulate cofactor recruitment. Cumulatively, these data indicate that 27HC is an endogenous SERM with partial agonist activity in breast cancer cells and suggest that it may influence the pathology of breast cancer. Moreover, given the product-precursor relationship between 27HC and cholesterol, our findings have implications with respect to breast cancer risk in obese/hypercholesteremic individuals.
Collapse
Affiliation(s)
- Carolyn D DuSell
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | | | | | | | | |
Collapse
|
12
|
Zella LA, Chang CY, McDonnell DP, Pike JW. The vitamin D receptor interacts preferentially with DRIP205-like LxxLL motifs. Arch Biochem Biophys 2007; 460:206-12. [PMID: 17254542 PMCID: PMC1924797 DOI: 10.1016/j.abb.2006.12.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 12/11/2006] [Accepted: 12/15/2006] [Indexed: 10/23/2022]
Abstract
The vitamin D receptor (VDR) mediates the biological actions of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) through its capacity to recruit coregulatory proteins. This interaction is mediated via a coregulatory LxxLL motif. We screened a combinatorial (x)7LxxLL(x)7 phage library with purified VDR to identify peptides that displayed high affinity and selectivity for VDR. These peptides contained the consensus sequence Lx E/H x H/F P L/M/I LxxLL and exhibited significant sequence similarity to the active LxxLL box found in DRIP205. Nearly all LxxLL peptides interacted in a ligand-dependent manner directly with human VDR. However, a pattern of selectivity of the peptides for other members of the nuclear receptor family was also observed. Interestingly, the interaction between the VDR and many of the peptides was differentially sensitive to a broad assortment of VDR ligands. Finally, several of these peptides were shown to inhibit activation of a 1,25(OH)2D3-sensitive reporter gene. These studies suggest that the LxxLL motif can interact directly with the VDR and that this interaction is regulated by chemically diverse vitamin D ligands.
Collapse
Affiliation(s)
- Lee A Zella
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | | | | | | |
Collapse
|
13
|
Khan G, Penttinen P, Cabanes A, Foxworth A, Chezek A, Masterpole K, Yu B, Smeds A, Halttunen T, Good C, Mäkelä S, Hilakivi-Clarke L. Maternal flaxseed diet during pregnancy or lactation increases female rat offspring's susceptibility to carcinogen-induced mammary tumorigenesis. Reprod Toxicol 2007; 23:397-406. [PMID: 17398067 PMCID: PMC3615982 DOI: 10.1016/j.reprotox.2007.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Revised: 12/13/2006] [Accepted: 02/07/2007] [Indexed: 10/23/2022]
Abstract
Flaxseed contains several dietary components that have been linked to low breast cancer risk; i.e., n-3 polyunsaturated fatty acids (PUFAs), lignans and fiber, but it also contains detectable levels of cadmium, a heavy metal that activates the estrogen receptor (ER). Since estrogenic exposures early in life modify susceptibility to develop breast cancer, we wondered whether maternal dietary intake of 5% or 10% flaxseed during pregnancy or lactation (between postpartum days 5 and 25) might affect 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumorigenesis in the rat offspring. Our data indicated that both in utero and postnatal 5% and 10% flaxseed exposures shortened mammary tumor latency, and 10% flaxseed exposure increased tumor multiplicity, compared to the controls. Further, when assessed in 8-week-old rats, in utero 10% flaxseed exposure increased lobular ER-alpha protein levels, and both in utero and postnatal flaxseed exposures dose-dependently reduced ER-beta protein levels in the terminal end buds (TEBs) lobules and ducts. Exposures to flaxseed did not alter the number of TEBs or affect cell proliferation within the epithelial structures. In a separate group of immature rats that were fed 5% defatted flaxseed diet (flaxseed source different than in the diets fed to pregnant or lactating rats) for 7 days, cadmium exposure through the diet was six-fold higher than allowed for humans by World Health Organization, and cadmium significantly accumulated in the liver and kidneys of the rats. It remains to be determined whether the increased mammary cancer in rats exposed to flaxseed through a maternal diet in utero or lactation was caused by cadmium present in flaxseed, and whether the reduced mammary ER-beta content was causally linked to increased mammary cancer risk among the offspring.
Collapse
MESH Headings
- 4-Butyrolactone/analogs & derivatives
- 4-Butyrolactone/metabolism
- 9,10-Dimethyl-1,2-benzanthracene/administration & dosage
- 9,10-Dimethyl-1,2-benzanthracene/toxicity
- Adenocarcinoma/chemically induced
- Adenocarcinoma/metabolism
- Adenocarcinoma/pathology
- Animals
- Animals, Newborn
- Butylene Glycols/metabolism
- Cadmium/administration & dosage
- Cadmium/toxicity
- Dose-Response Relationship, Drug
- Drug Synergism
- Female
- Flax/chemistry
- Kidney/drug effects
- Kidney/metabolism
- Kidney/pathology
- Lactation
- Lignans/metabolism
- Liver/drug effects
- Liver/metabolism
- Liver/pathology
- Mammary Glands, Animal/drug effects
- Mammary Glands, Animal/metabolism
- Mammary Glands, Animal/pathology
- Mammary Neoplasms, Animal/chemically induced
- Mammary Neoplasms, Animal/metabolism
- Mammary Neoplasms, Animal/pathology
- Plant Preparations/administration & dosage
- Plant Preparations/chemistry
- Plant Preparations/toxicity
- Pregnancy
- Prenatal Exposure Delayed Effects
- Proliferating Cell Nuclear Antigen/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Estrogen/metabolism
Collapse
Affiliation(s)
- Galam Khan
- Lombardi Cancer Center and Department of Oncology, Georgetown University, 3970 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Pauliina Penttinen
- Functional Foods Forum, University of Turku, Itäinen Pitkäkatu 4A, FI-20520 Turku, Finland
| | - Anna Cabanes
- Lombardi Cancer Center and Department of Oncology, Georgetown University, 3970 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Aaron Foxworth
- Lombardi Cancer Center and Department of Oncology, Georgetown University, 3970 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Antonia Chezek
- Lombardi Cancer Center and Department of Oncology, Georgetown University, 3970 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Kristen Masterpole
- Lombardi Cancer Center and Department of Oncology, Georgetown University, 3970 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Bin Yu
- Lombardi Cancer Center and Department of Oncology, Georgetown University, 3970 Reservoir Rd, NW, Washington, DC 20057, USA
| | - Annika Smeds
- Department of Organic Chemistry, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku, Finland
| | - Teemu Halttunen
- Functional Foods Forum, University of Turku, Itäinen Pitkäkatu 4A, FI-20520 Turku, Finland
| | - Carolyn Good
- Bell Institute of Health and Nutrition, General Mills Inc., 9000 Plymouth Ave, N Minneapolis, MN 55427
| | - Sari Mäkelä
- Functional Foods Forum, University of Turku, Itäinen Pitkäkatu 4A, FI-20520 Turku, Finland
- Department of Biochemistry and Food Chemistry, University of Turku, Vatselankatu 2, FI-20500 Turku, Finland
| | - Leena Hilakivi-Clarke
- Lombardi Cancer Center and Department of Oncology, Georgetown University, 3970 Reservoir Rd, NW, Washington, DC 20057, USA
| |
Collapse
|
14
|
Affiliation(s)
- Yuan-Shan Zhu
- Associate Professor of Medicine, Department of Medicine/Endocrinology, Weill Medical College of Cornell University, 1300 York Avenue, Box 149, New York, New York 10021
| |
Collapse
|
15
|
Nakajima T, Fujino S, Nakanishi G, Kim YS, Jetten AM. TIP27: a novel repressor of the nuclear orphan receptor TAK1/TR4. Nucleic Acids Res 2004; 32:4194-204. [PMID: 15302918 PMCID: PMC514368 DOI: 10.1093/nar/gkh741] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The nuclear orphan receptor TAK1/TR4 functions as a positive as well as a negative regulator of transcription; however, little is known about the factors regulating or mediating its activity. Yeast two-hybrid analysis using the ligand-binding domain (LBD) of TAK1 as bait identified a novel TAK1-interacting protein, referred to as TIP27, which functions as a repressor of TAK1-mediated transactivation. TIP27 is a 27 kDa protein containing two zinc finger motifs. Mammalian two-hybrid analysis showed that TIP27 interacts specifically with TAK1 and not with several other nuclear receptors tested. The region between Asp39 and Lys79 of TIP27, referred to as TAK1-interaction domain (TID), is critical for its interaction with TAK1 while the TAK1-LBD from helix 3 until the C-terminus is required for the optimal interaction with TIP27. Pull-down assays demonstrated that the TIP27 physically interacts with TAK1 and supported the critical importance of the TID. Confocal microscopy showed that in the nucleus, TIP27 and TAK1 co-localize. TIP27 acts as a strong repressor of DR1-dependent transcriptional activation by TAK1. This repression does not involve the inhibition of TAK1 homodimerization or DR1 binding but may be due to an effect on co-activator recruitment by TAK1. Our results indicate that TIP27 functions as a TAK1-selective repressor.
Collapse
Affiliation(s)
- Takeshi Nakajima
- Cell Biology Section, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | | | | | | | | |
Collapse
|