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Hu W, Jiang C, Kim M, Xiao Y, Richter HJ, Guan D, Zhu K, Krusen BM, Roberts AN, Miller J, Steger DJ, Lazar MA. Isoform-specific functions of PPARγ in gene regulation and metabolism. Genes Dev 2022; 36:300-312. [PMID: 35273075 PMCID: PMC8973844 DOI: 10.1101/gad.349232.121] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/15/2022] [Indexed: 12/12/2022]
Abstract
In this study, Hu et al. investigated the specific functions of the two main PPARγ isoforms by generating mouse lines in which endogenous PPARγ1 and PPARγ2 were epitope-tagged to interrogate isoform-specific genomic binding, and mice deficient in either PPARγ1 or PPARγ2 to assess isoform-specific gene regulation. They show that PPARγ isoforms have specific and separable metabolic functions that may be targeted to improve therapy for insulin resistance and diabetes. Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor that is a vital regulator of adipogenesis, insulin sensitivity, and lipid metabolism. Activation of PPARγ by antidiabetic thiazolidinediones (TZD) reverses insulin resistance but also leads to weight gain that limits the use of these drugs. There are two main PPARγ isoforms, but the specific functions of each are not established. Here we generated mouse lines in which endogenous PPARγ1 and PPARγ2 were epitope-tagged to interrogate isoform-specific genomic binding, and mice deficient in either PPARγ1 or PPARγ2 to assess isoform-specific gene regulation. Strikingly, although PPARγ1 and PPARγ2 contain identical DNA binding domains, we uncovered isoform-specific genomic binding sites in addition to shared sites. Moreover, PPARγ1 and PPARγ2 regulated a different set of genes in adipose tissue depots, suggesting distinct roles in adipocyte biology. Indeed, mice with selective deficiency of PPARγ1 maintained body temperature better than wild-type or PPARγ2-deficient mice. Most remarkably, although TZD treatment improved glucose tolerance in mice lacking either PPARγ1 or PPARγ2, the PPARγ1-deficient mice were protected from TZD-induced body weight gain compared with PPARγ2-deficient mice. Thus, PPARγ isoforms have specific and separable metabolic functions that may be targeted to improve therapy for insulin resistance and diabetes.
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Affiliation(s)
- Wenxiang Hu
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Chunjie Jiang
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.,Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Mindy Kim
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Yang Xiao
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Hannah J Richter
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Dongyin Guan
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.,Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Kun Zhu
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Brianna M Krusen
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Arielle N Roberts
- Philadelphia College of Osteopathic Medicine, Philadelphia, Pennsylvania 19131, USA
| | - Jessica Miller
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - David J Steger
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.,Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
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2
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Shen Y, Su Y, Silva FJ, Weller AH, Sostre-Colón J, Titchenell PM, Steger DJ, Seale P, Soccio RE. Shared PPARα/γ Target Genes Regulate Brown Adipocyte Thermogenic Function. Cell Rep 2021; 30:3079-3091.e5. [PMID: 32130908 DOI: 10.1016/j.celrep.2020.02.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/10/2020] [Accepted: 02/07/2020] [Indexed: 12/13/2022] Open
Abstract
Brown adipose tissue (BAT) generates heat to maintain body temperature and suppress obesity. Agonists for nuclear receptors PPARα and PPARγ both affect brown adipocyte function, yet the interplay between these factors in BAT is uncertain. Here, we report that PPARα shares most genomic binding sites with PPARγ, and these common binding sites are more related to BAT function than PPARγ-selective sites without PPARα. Integrating PPARα and PPARγ genomic occupancy with cold-responsive BAT transcriptomes identifies a subset of 16 genes with potential relevance to BAT function. Among these, we focused on the lysosomal protease cathepsin Z (CTSZ) and showed it is necessary for mitochondrial respiration in both mouse and human brown adipocytes. Thus, CTSZ is a shared PPARα/γ target gene in BAT and a regulator of brown adipocyte thermogenic function.
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Affiliation(s)
- Yachen Shen
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yvonne Su
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Francisco J Silva
- Research and Development BioRestorative Therapies, New York, NY 11747, USA
| | - Angela H Weller
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jaimarie Sostre-Colón
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Paul M Titchenell
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David J Steger
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Patrick Seale
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Raymond E Soccio
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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3
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Sanchez DJ, Missiaen R, Skuli N, Steger DJ, Simon MC. Cell-Intrinsic Tumorigenic Functions of PPARγ in Bladder Urothelial Carcinoma. Mol Cancer Res 2021; 19:598-611. [PMID: 33431608 DOI: 10.1158/1541-7786.mcr-20-0189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 10/21/2020] [Accepted: 01/07/2021] [Indexed: 11/16/2022]
Abstract
The role of PPAR gamma (PPARγ) has been well characterized in the developmental process of adipogenesis, yet its aberrant expression patterns and functions in cancer subtypes are less understood. Although PPARγ has been recently demonstrated to play non-cell-autonomous roles in promoting bladder urothelial carcinoma (UC) progression, underlying mechanisms of the cell-intrinsic oncogenic activity remain unknown. Here, we report robust expression and nuclear accumulation of PPARγ in 47% of samples of patients with UC, exceeding mRNA expression patterns published by The Cancer Genome Atlas. In vitro assays revealed for the first time that treatment of UC cells with PPARγ inverse agonist or PPARG knockout by CRISPR-Cas9 reduces proliferation, migration, and invasion of multiple established UC cell lines, most strongly in those characterized by PPARG genomic amplification or activating mutations of RXRA, the obligate heterodimer of PPARγ. Through genome-wide approaches including chromatin immunoprecipitation sequencing and RNA sequencing, we define a novel set of PPARγ-regulated genes in UC, including Sonic Hedgehog (SHH). Similar to PPARγ, genetic inhibition of SHH reduces proliferation and motility. Finally, we demonstrate the PPARγ dependency of UC tumors in vivo by genetic and pharmacologic PPARγ inhibition in subcutaneous xenografts. Collectively, our data indicate that PPARγ promotes UC progression in a subset of patients, at least in part, through cell-autonomous mechanisms linked to SHH signaling. IMPLICATIONS: Genome-wide analysis of DNA-binding sites for oncogenic factor PPARγ revealed SHH as a novel downstream target involved in UC progression, providing important insight into the tumorigenic nature and molecular mechanism of PPARγ signaling in UC.
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Affiliation(s)
- Danielle J Sanchez
- Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Rindert Missiaen
- Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Nicolas Skuli
- Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David J Steger
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - M Celeste Simon
- Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. .,Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania
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4
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Cohen DM, Lim HW, Won KJ, Steger DJ. Shared nucleotide flanks confer transcriptional competency to bZip core motifs. Nucleic Acids Res 2019; 46:8371-8384. [PMID: 30085281 PMCID: PMC6144830 DOI: 10.1093/nar/gky681] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/17/2018] [Indexed: 12/31/2022] Open
Abstract
Sequence-specific DNA binding recruits transcription factors (TFs) to the genome to regulate gene expression. Here, we perform high resolution mapping of CEBP proteins to determine how sequence dictates genomic occupancy. We demonstrate a fundamental difference between the sequence repertoire utilized by CEBPs in vivo versus the palindromic sequence preference reported by classical in vitro models, by identifying a palindromic motif at <1% of the genomic binding sites. On the native genome, CEBPs bind a diversity of related 10 bp sequences resulting from the fusion of degenerate and canonical half-sites. Altered DNA specificity of CEBPs in cells occurs through heterodimerization with other bZip TFs, and approximately 40% of CEBP-binding sites in primary human cells harbor motifs characteristic of CEBP heterodimers. In addition, we uncover an important role for sequence bias at core-motif-flanking bases for CEBPs and demonstrate that flanking bases regulate motif function across mammalian bZip TFs. Favorable flanking bases confer efficient TF occupancy and transcriptional activity, and DNA shape may explain how the flanks alter TF binding. Importantly, motif optimization within the 10-mer is strongly correlated with cell-type-independent recruitment of CEBPβ, providing key insight into how sequence sub-optimization affects genomic occupancy of widely expressed CEBPs across cell types.
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Affiliation(s)
- Daniel M Cohen
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hee-Woong Lim
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kyoung-Jae Won
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - David J Steger
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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5
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Hu W, Jiang C, Guan D, Dierickx P, Zhang R, Moscati A, Nadkarni GN, Steger DJ, Loos RJF, Hu C, Jia W, Soccio RE, Lazar MA. Patient Adipose Stem Cell-Derived Adipocytes Reveal Genetic Variation that Predicts Antidiabetic Drug Response. Cell Stem Cell 2019; 24:299-308.e6. [PMID: 30639037 PMCID: PMC6368460 DOI: 10.1016/j.stem.2018.11.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 10/04/2018] [Accepted: 11/14/2018] [Indexed: 01/11/2023]
Abstract
Thiazolidinedione drugs (TZDs) target the transcriptional activity of peroxisome proliferator activated receptor γ (PPARγ) to reverse insulin resistance in type 2 diabetes, but side effects limit their clinical use. Here, using human adipose stem cell-derived adipocytes, we demonstrate that SNPs were enriched at sites of patient-specific PPARγ binding, which correlated with the individual-specific effects of the TZD rosiglitazone (rosi) on gene expression. Rosi induction of ABCA1, which regulates cholesterol metabolism, was dependent upon SNP rs4743771, which modulated PPARγ binding by influencing the genomic occupancy of its cooperating factor, NFIA. Conversion of rs4743771 from the inactive SNP allele to the active one by clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-mediated editing rescued PPARγ binding and rosi induction of ABCA1 expression. Moreover, rs4743771 is a major determinant of undesired serum cholesterol increases in rosi-treated diabetics. These data highlight human genetic variation that impacts PPARγ genomic occupancy and patient responses to antidiabetic drugs, with implications for developing personalized therapies for metabolic disorders.
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Affiliation(s)
- Wenxiang Hu
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Chunjie Jiang
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Dongyin Guan
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Pieterjan Dierickx
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Rong Zhang
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Arden Moscati
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Girish N Nadkarni
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - David J Steger
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ruth J F Loos
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Cheng Hu
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China; Institute for Metabolic Disease, Fengxian Central Hospital Affiliated to Southern Medical University, Shanghai 201499, China
| | - Weiping Jia
- Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Raymond E Soccio
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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6
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Sanchez DJ, Steger DJ, Skuli N, Bansal A, Simon MC. PPARγ is dispensable for clear cell renal cell carcinoma progression. Mol Metab 2018; 14:139-149. [PMID: 29866440 PMCID: PMC6034040 DOI: 10.1016/j.molmet.2018.05.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 05/11/2018] [Accepted: 05/17/2018] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE Clear cell renal cell carcinoma (ccRCC) is a subtype of kidney cancer defined by robust lipid accumulation, which prior studies have indicated plays an important role in tumor progression. We hypothesized that the peroxisome proliferator-activated receptor gamma (PPARγ), detected in both ccRCC tumors and cell lines, promotes lipid storage in ccRCC and contributes to tumorigenesis in this setting. PPARγ transcriptionally regulates a number of genes involved in lipid and glucose metabolism in adipocytes, yet its role in ccRCC has not been described. The objective of this study was to elucidate endogenous PPARγ function in ccRCC cells. METHODS AND RESULTS Using chromatin immunoprecipitation followed by deep sequencing (ChIP-seq), we found that PPARγ and its heterodimer RXR occupy the canonical DR1 PPAR binding motif at approximately 1000 locations throughout the genome that can be subdivided into adipose-shared and ccRCC-specific sites. CRISPR-Cas9 mediated, loss-of-function studies determined that PPARγ is dispensable for viability, proliferation, and migration of ccRCC cells in vitro and in vivo. Also, surprisingly, PPARγ deletion had little effect on the robust lipid accumulation that typifies the "clear cell" phenotype of kidney cancer. CONCLUSION Our results suggest that PPARγ plays neither a tumor suppressive nor oncogenic role in advanced ccRCC, and thus single-agent therapeutics targeting PPARγ are unlikely to be effective for the treatment of this disease. The unique cistrome of PPARγ in ccRCC cells demonstrates the importance of cell type in determining the functions of PPARγ.
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Affiliation(s)
- Danielle J Sanchez
- Abramson Family Cancer Research Institute, USA; Department of Cell and Developmental Biology, USA
| | | | - Nicolas Skuli
- Abramson Family Cancer Research Institute, USA; Department of Cancer Biology, USA
| | - Ankita Bansal
- Abramson Family Cancer Research Institute, USA; Department of Cancer Biology, USA
| | - M Celeste Simon
- Abramson Family Cancer Research Institute, USA; Department of Cell and Developmental Biology, USA.
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7
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Kim YH, Marhon SA, Zhang Y, Steger DJ, Won KJ, Lazar MA. Rev-erbα dynamically modulates chromatin looping to control circadian gene transcription. Science 2018; 359:1274-1277. [PMID: 29439026 DOI: 10.1126/science.aao6891] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 01/17/2018] [Indexed: 12/12/2022]
Abstract
Mammalian physiology exhibits 24-hour cyclicity due to circadian rhythms of gene expression controlled by transcription factors that constitute molecular clocks. Core clock transcription factors bind to the genome at enhancer sequences to regulate circadian gene expression, but not all binding sites are equally functional. We found that in mice, circadian gene expression in the liver is controlled by rhythmic chromatin interactions between enhancers and promoters. Rev-erbα, a core repressive transcription factor of the clock, opposes functional loop formation between Rev-erbα-regulated enhancers and circadian target gene promoters by recruitment of the NCoR-HDAC3 co-repressor complex, histone deacetylation, and eviction of the elongation factor BRD4 and the looping factor MED1. Thus, a repressive arm of the molecular clock operates by rhythmically modulating chromatin loops to control circadian gene transcription.
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Affiliation(s)
- Yong Hoon Kim
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.,Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.,Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Sajid A Marhon
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.,Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.,Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Yuxiang Zhang
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.,Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - David J Steger
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.,Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Kyoung-Jae Won
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA. .,Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.,Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA. .,Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.,Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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8
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Cohen DM, Steger DJ. Nuclear Receptor Function through Genomics: Lessons from the Glucocorticoid Receptor. Trends Endocrinol Metab 2017; 28:531-540. [PMID: 28495406 PMCID: PMC5505657 DOI: 10.1016/j.tem.2017.04.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/14/2017] [Accepted: 04/18/2017] [Indexed: 12/20/2022]
Abstract
Unlocking the therapeutic potential of the glucocorticoid receptor (GR) has motivated a search for small molecules that selectively modulate its ability to activate or repress gene transcription. Recently, breakthrough studies in the field of genomics have reinvigorated debate over longstanding transcriptional models explaining how GR controls tissue-specific gene expression. Here, we highlight these genomic studies with the dual goals of advancing understanding of nuclear receptor-mediated transcription and stimulating thought on the development of anti-inflammatory and immunosuppressive ligands for GR that have reduced harmful effects on metabolism.
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Affiliation(s)
- Daniel M Cohen
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David J Steger
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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9
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Emmett MJ, Lim HW, Jager J, Richter HJ, Adlanmerini M, Peed LC, Briggs ER, Steger DJ, Ma T, Sims CA, Baur JA, Pei L, Won KJ, Seale P, Gerhart-Hines Z, Lazar MA. Histone deacetylase 3 prepares brown adipose tissue for acute thermogenic challenge. Nature 2017; 546:544-548. [PMID: 28614293 PMCID: PMC5826652 DOI: 10.1038/nature22819] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 05/03/2017] [Indexed: 12/18/2022]
Abstract
Brown adipose tissue is a thermogenic organ that dissipates chemical energy as heat to protect animals against hypothermia and to counteract metabolic disease. However, the transcriptional mechanisms that determine the thermogenic capacity of brown adipose tissue before environmental cold are unknown. Here we show that histone deacetylase 3 (HDAC3) is required to activate brown adipose tissue enhancers to ensure thermogenic aptitude. Mice with brown adipose tissue-specific genetic ablation of HDAC3 become severely hypothermic and succumb to acute cold exposure. Uncoupling protein 1 (UCP1) is nearly absent in brown adipose tissue lacking HDAC3, and there is also marked downregulation of mitochondrial oxidative phosphorylation genes resulting in diminished mitochondrial respiration. Remarkably, although HDAC3 acts canonically as a transcriptional corepressor, it functions as a coactivator of oestrogen-related receptor α (ERRα) in brown adipose tissue. HDAC3 coactivation of ERRα is mediated by deacetylation of PGC-1α and is required for the transcription of Ucp1, Ppargc1a (encoding PGC-1α), and oxidative phosphorylation genes. Importantly, HDAC3 promotes the basal transcription of these genes independently of adrenergic stimulation. Thus, HDAC3 uniquely primes Ucp1 and the thermogenic transcriptional program to maintain a critical capacity for thermogenesis in brown adipose tissue that can be rapidly engaged upon exposure to dangerously cold temperature.
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Affiliation(s)
- Matthew J. Emmett
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hee-Woong Lim
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jennifer Jager
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hannah J. Richter
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marine Adlanmerini
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lindsey C. Peed
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Erika R. Briggs
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David J. Steger
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tao Ma
- Section for Metabolic Receptology at the Novo Nordisk Foundation Center for Basic Metabolic Research, and Institute for Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, 2200, DK
| | - Carrie A. Sims
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- The Trauma Center at Penn, Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104
| | - Joseph A. Baur
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Physiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Liming Pei
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Mitochondrial and Epigenomic Medicine, Children’s Hospital of Philadelphia, and Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kyoung-Jae Won
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Patrick Seale
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zachary Gerhart-Hines
- Section for Metabolic Receptology at the Novo Nordisk Foundation Center for Basic Metabolic Research, and Institute for Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, 2200, DK
| | - Mitchell A. Lazar
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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10
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Soccio RE, Li Z, Chen ER, Foong YH, Benson KK, Dispirito JR, Mullican SE, Emmett MJ, Briggs ER, Peed LC, Dzeng RK, Medina CJ, Jolivert JF, Kissig M, Rajapurkar SR, Damle M, Lim HW, Won KJ, Seale P, Steger DJ, Lazar MA. Targeting PPARγ in the epigenome rescues genetic metabolic defects in mice. J Clin Invest 2017; 127:1451-1462. [PMID: 28240605 DOI: 10.1172/jci91211] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 12/30/2016] [Indexed: 01/08/2023] Open
Abstract
Obesity causes insulin resistance, and PPARγ ligands such as rosiglitazone are insulin sensitizing, yet the mechanisms remain unclear. In C57BL/6 (B6) mice, obesity induced by a high-fat diet (HFD) has major effects on visceral epididymal adipose tissue (eWAT). Here, we report that HFD-induced obesity in B6 mice also altered the activity of gene regulatory elements and genome-wide occupancy of PPARγ. Rosiglitazone treatment restored insulin sensitivity in obese B6 mice, yet, surprisingly, had little effect on gene expression in eWAT. However, in subcutaneous inguinal fat (iWAT), rosiglitazone markedly induced molecular signatures of brown fat, including the key thermogenic gene Ucp1. Obesity-resistant 129S1/SvImJ mice (129 mice) displayed iWAT browning, even in the absence of rosiglitazone. The 129 Ucp1 locus had increased PPARγ binding and gene expression that were preserved in the iWAT of B6x129 F1-intercrossed mice, with an imbalance favoring the 129-derived alleles, demonstrating a cis-acting genetic difference. Thus, B6 mice have genetically defective Ucp1 expression in iWAT. However, when Ucp1 was activated by rosiglitazone, or by iWAT browning in cold-exposed or young mice, expression of the B6 version of Ucp1 was no longer defective relative to the 129 version, indicating epigenomic rescue. These results provide a framework for understanding how environmental influences like drugs can affect the epigenome and potentially rescue genetically determined disease phenotypes.
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11
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Jager J, Wang F, Fang B, Lim HW, Peed LC, Steger DJ, Won KJ, Kharitonenkov A, Adams AC, Lazar MA. The Nuclear Receptor Rev-erbα Regulates Adipose Tissue-specific FGF21 Signaling. J Biol Chem 2016; 291:10867-75. [PMID: 27002153 DOI: 10.1074/jbc.m116.719120] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Indexed: 01/14/2023] Open
Abstract
FGF21 is an atypical member of the FGF family that functions as a hormone to regulate carbohydrate and lipid metabolism. Here we demonstrate that the actions of FGF21 in mouse adipose tissue, but not in liver, are modulated by the nuclear receptor Rev-erbα, a potent transcriptional repressor. Interrogation of genes induced in the absence of Rev-erbα for Rev-erbα-binding sites identified βKlotho, an essential coreceptor for FGF21, as a direct target gene of Rev-erbα in white adipose tissue but not liver. Rev-erbα ablation led to the robust elevated expression of βKlotho. Consequently, the effects of FGF21 were markedly enhanced in the white adipose tissue of mice lacking Rev-erbα. A major Rev-erbα-controlled enhancer at the Klb locus was also bound by the adipocytic transcription factor peroxisome proliferator-activated receptor (PPAR) γ, which regulates its activity in the opposite direction. These findings establish Rev-erbα as a specific modulator of FGF21 signaling in adipose tissue.
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Affiliation(s)
- Jennifer Jager
- From the Division of Endocrinology, Diabetes, and Metabolism, Departments of Medicine and Genetics, and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Fenfen Wang
- From the Division of Endocrinology, Diabetes, and Metabolism, Departments of Medicine and Genetics, and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Bin Fang
- From the Division of Endocrinology, Diabetes, and Metabolism, Departments of Medicine and Genetics, and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Hee-Woong Lim
- From the Division of Endocrinology, Diabetes, and Metabolism, Departments of Medicine and Genetics, and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Lindsey C Peed
- From the Division of Endocrinology, Diabetes, and Metabolism, Departments of Medicine and Genetics, and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - David J Steger
- From the Division of Endocrinology, Diabetes, and Metabolism, Departments of Medicine and Genetics, and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Kyoung-Jae Won
- From the Division of Endocrinology, Diabetes, and Metabolism, Departments of Medicine and Genetics, and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Alexei Kharitonenkov
- the Department of Chemistry, Indiana University Bloomington, Bloomington, Indiana 47405, and
| | - Andrew C Adams
- the Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, Indiana 46285
| | - Mitchell A Lazar
- From the Division of Endocrinology, Diabetes, and Metabolism, Departments of Medicine and Genetics, and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104,
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12
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Bauer RC, Sasaki M, Cohen DM, Cui J, Smith MA, Yenilmez BO, Steger DJ, Rader DJ. Tribbles-1 regulates hepatic lipogenesis through posttranscriptional regulation of C/EBPα. J Clin Invest 2015; 125:3809-18. [PMID: 26348894 DOI: 10.1172/jci77095] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 07/28/2015] [Indexed: 12/24/2022] Open
Abstract
Variants near the gene TRIB1 are significantly associated with several plasma lipid traits, circulating liver enzymes, and the development of coronary artery disease in humans; however, it is not clear how its protein product tribbles-1 regulates lipid metabolism. Here, we evaluated mice harboring a liver-specific deletion of Trib1 (Trib1_LSKO) to elucidate the role of tribbles-1 in mammalian hepatic lipid metabolism. These mice exhibited increased hepatic triglyceride (TG) content, lipogenic gene transcription, and de novo lipogenesis. Microarray analysis revealed altered transcription of genes that are downstream of the transcription factor C/EBPα, and Trib1_LSKO mice had increased hepatic C/EBPα protein. Hepatic overexpression of C/EBPα in WT mice phenocopied Trib1_LSKO livers, and hepatic knockout of Cebpa in Trib1_LSKO mice revealed that C/EBPα is required for the increased lipogenesis. Using ChIP-Seq, we found that Trib1_LSKO mice had increased DNA-bound C/EBPα near lipogenic genes and the Trib1 gene, which itself was transcriptionally upregulated by C/EBPα overexpression. Together, our results reveal that tribbles-1 regulates hepatic lipogenesis through posttranscriptional regulation of C/EBPα, which in turn transcriptionally upregulates Trib1. These data suggest an important role for C/EBPα in mediating the lipogenic effects of hepatic Trib1 deletion and provide insight into the association between TRIB1 and plasma lipids, and liver traits in humans.
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13
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Cohen DM, Won KJ, Nguyen N, Lazar MA, Chen CS, Steger DJ. ATF4 licenses C/EBPβ activity in human mesenchymal stem cells primed for adipogenesis. eLife 2015; 4:e06821. [PMID: 26111340 PMCID: PMC4501333 DOI: 10.7554/elife.06821] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 06/25/2015] [Indexed: 12/24/2022] Open
Abstract
A well-established cascade of transcription factor (TF) activity orchestrates adipogenesis in response to chemical cues, yet how cell-intrinsic determinants of differentiation such as cell shape and/or seeding density inform this transcriptional program remain enigmatic. Here, we uncover a novel mechanism licensing transcription in human mesenchymal stem cells (hMSCs) adipogenically primed by confluence. Prior to adipogenesis, confluency promotes heterodimer recruitment of the bZip TFs C/EBPβ and ATF4 to a non-canonical C/EBP DNA sequence. ATF4 depletion decreases both cell-density-dependent transcription and adipocyte differentiation. Global profiling in hMSCs and a novel cell-free assay reveals that ATF4 requires C/EBPβ for genomic binding at a motif distinct from that bound by the C/EBPβ homodimer. Our observations demonstrate that C/EBPβ bridges the transcriptional programs in naïve, confluent cells and early differentiating pre-adipocytes. Moreover, they suggest that homo- and heterodimer formation poise C/EBPβ to execute diverse and stage-specific transcriptional programs by exploiting an expanded motif repertoire.
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Affiliation(s)
- Daniel M Cohen
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Kyoung-Jae Won
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Nha Nguyen
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Mitchell A Lazar
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Christopher S Chen
- Department of Biomedical Engineering, Boston University, Boston, United States
| | - David J Steger
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
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14
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Zhang Y, Fang B, Emmett MJ, Damle M, Sun Z, Feng D, Armour SM, Remsberg JR, Jager J, Soccio RE, Steger DJ, Lazar MA. GENE REGULATION. Discrete functions of nuclear receptor Rev-erbα couple metabolism to the clock. Science 2015; 348:1488-92. [PMID: 26044300 DOI: 10.1126/science.aab3021] [Citation(s) in RCA: 228] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 05/22/2015] [Indexed: 12/21/2022]
Abstract
Circadian and metabolic physiology are intricately intertwined, as illustrated by Rev-erbα, a transcription factor (TF) that functions both as a core repressive component of the cell-autonomous clock and as a regulator of metabolic genes. Here, we show that Rev-erbα modulates the clock and metabolism by different genomic mechanisms. Clock control requires Rev-erbα to bind directly to the genome at its cognate sites, where it competes with activating ROR TFs. By contrast, Rev-erbα regulates metabolic genes primarily by recruiting the HDAC3 co-repressor to sites to which it is tethered by cell type-specific transcription factors. Thus, direct competition between Rev-erbα and ROR TFs provides a universal mechanism for self-sustained control of the molecular clock across all tissues, whereas Rev-erbα uses lineage-determining factors to convey a tissue-specific epigenomic rhythm that regulates metabolism tailored to the specific need of that tissue.
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Affiliation(s)
- Yuxiang Zhang
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bin Fang
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew J Emmett
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Manashree Damle
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zheng Sun
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. Department of Molecular and Cellular Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Dan Feng
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sean M Armour
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jarrett R Remsberg
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jennifer Jager
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Raymond E Soccio
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David J Steger
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitchell A Lazar
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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15
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Lim HW, Uhlenhaut NH, Rauch A, Weiner J, Hübner S, Hübner N, Won KJ, Lazar MA, Tuckermann J, Steger DJ. Genomic redistribution of GR monomers and dimers mediates transcriptional response to exogenous glucocorticoid in vivo. Genome Res 2015; 25:836-44. [PMID: 25957148 PMCID: PMC4448680 DOI: 10.1101/gr.188581.114] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/13/2015] [Indexed: 01/04/2023]
Abstract
Glucocorticoids (GCs) are commonly prescribed drugs, but their anti-inflammatory benefits are mitigated by metabolic side effects. Their transcriptional effects, including tissue-specific gene activation and repression, are mediated by the glucocorticoid receptor (GR), which is known to bind as a homodimer to a palindromic DNA sequence. Using ChIP-exo in mouse liver under endogenous corticosterone exposure, we report here that monomeric GR interaction with a half-site motif is more prevalent than homodimer binding. Monomers colocalize with lineage-determining transcription factors in both liver and primary macrophages, and the GR half-site motif drives transcription, suggesting that monomeric binding is fundamental to GR's tissue-specific functions. In response to exogenous GC in vivo, GR dimers assemble on chromatin near ligand-activated genes, concomitant with monomer evacuation of sites near repressed genes. Thus, pharmacological GCs mediate gene expression by favoring GR homodimer occupancy at classic palindromic sites at the expense of monomeric binding. The findings have important implications for improving therapies that target GR.
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Affiliation(s)
- Hee-Woong Lim
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - N Henriette Uhlenhaut
- Max Delbrück Center for Molecular Medicine (MDC), 13125 Berlin, Germany; Institute for Diabetes and Obesity, Helmholtz Zentrum München, 85748 Garching, Germany
| | - Alexander Rauch
- Leibniz Institute for Age Research - Fritz Lipmann Institute Jena, D-07745 Jena, Germany
| | - Juliane Weiner
- Leibniz Institute for Age Research - Fritz Lipmann Institute Jena, D-07745 Jena, Germany
| | - Sabine Hübner
- Leibniz Institute for Age Research - Fritz Lipmann Institute Jena, D-07745 Jena, Germany; Institute for Comparative Molecular Endocrinology, University of Ulm, D-89081 Ulm, Germany
| | - Norbert Hübner
- Max Delbrück Center for Molecular Medicine (MDC), 13125 Berlin, Germany
| | - Kyoung-Jae Won
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Mitchell A Lazar
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; Department of Pharmacology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Jan Tuckermann
- Leibniz Institute for Age Research - Fritz Lipmann Institute Jena, D-07745 Jena, Germany; Institute for Comparative Molecular Endocrinology, University of Ulm, D-89081 Ulm, Germany
| | - David J Steger
- The Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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16
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Bauer RC, Sasaki M, Cohen DM, Cui J, Smith MA, Steger DJ, Rader DJ. Abstract 16: Tribbles1 Regulates Hepatic Lipogenesis in Mice through Post-Translational Regulation of C/EBPα. Arterioscler Thromb Vasc Biol 2015. [DOI: 10.1161/atvb.35.suppl_1.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tribbles1 (TRIB1) was recently identified in genome-wide association studies as being associated with plasma levels of VLDL, HDL, LDL, and TG as well as coronary artery disease in humans. Here we report studies in a Trib1 liver-specific knockout mouse (Trib1_LSKO) created via AAV-mediated delivery of Cre recombinase into mice with a floxed allele of Trib1. Four weeks after infection, Trib1_LSKO mice exhibit a 25% increase in liver weight (p<0.01) as compared to controls given null virus, and examination of hepatic lipids reveals a 78% increase in TG content (p<0.001) of Trib1_LSKO livers. Hepatic transcription of lipogenic genes (i.e. Scd1, Fasn, and Acaca) was increased greater than 2-fold in Trib1_LSKO mice, and when in vivo lipogenesis was measured, Trib1_LSKO animals exhibited significantly increased hepatic production of fatty acids (2.2-fold, p=0.02), diacylglycerol (1.8-fold, p<0.01), and TG (3.6-fold, p<0.001). Microarray and subsequent pathway analysis of Trib1_LSKO livers revealed altered transcription of genes downstream of the transcription factor C/EBPα, and western blot analysis of liver extracts showed increased protein levels of C/EBPα in Trib1_LSKO mice compared to controls. C57Bl/6 mice overexpressing C/EBPα via AAV (AAV_Cebpa) exhibit increases in hepatic production of TG (3.6-fold, p<0.001), fatty acids (2.5-fold, p<0.001), and diacylglycerol (2.1-fold, p<0.005) that mirror those observed in Trib1_LSKO mice. Interestingly, while Trib1_LSKO mice have altered plasma lipids, AAV_Cebpa animals do not, suggesting that Trib1 modulates plasma lipids via a mechanism separate from C/EBPα-mediated lipogenesis. Finally, ChIP-Seq analysis of C/EBPα DNA occupancy in Trib1_LSKO and AAV_Cebpa mice showed increased binding near lipogenic genes as well as upstream of Trib1 itself. Trib1 does show increased gene expression in response to C/EBPα overexpression, suggesting that Trib1 and C/EBPα participate in a feedback loop. In summary, we demonstrate here that Trib1 regulates de novo lipogenesis through modulation of hepatic protein levels of C/EBPα, which in turn regulates Trib1 expression. These data assign novel roles for both Trib1 and C/EBPα in the regulation of hepatic lipid metabolism.
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Affiliation(s)
- Robert C Bauer
- Div of Translational Medicine and Human Genetics, Univ of Pennsylvania, Philadelphia, PA
| | - Makoto Sasaki
- Dept of Medicine, Univ of Pennsylvania, Philadelphia, PA
| | - Daniel M Cohen
- Div of Translational Medicine and Human Genetics, Univ of Pennsylvania, Philadelphia, PA
| | - Jian Cui
- Div of Translational Medicine and Human Genetics, Univ of Pennsylvania, Philadelphia, PA
| | - Mikhaila A Smith
- Div of Translational Medicine and Human Genetics, Univ of Pennsylvania, Philadelphia, PA
| | - David J Steger
- Div of Translational Medicine and Human Genetics, Univ of Pennsylvania, Philadelphia, PA
| | - Daniel J Rader
- Div of Translational Medicine and Human Genetics, Univ of Pennsylvania, Philadelphia, PA
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17
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Harms MJ, Lim HW, Ho Y, Shapira SN, Ishibashi J, Rajakumari S, Steger DJ, Lazar MA, Won KJ, Seale P. PRDM16 binds MED1 and controls chromatin architecture to determine a brown fat transcriptional program. Genes Dev 2015; 29:298-307. [PMID: 25644604 PMCID: PMC4318146 DOI: 10.1101/gad.252734.114] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PR (PRD1-BF1-RIZ1 homologous) domain-containing 16 (PRDM16) drives a brown fat differentiation program, but the mechanisms by which PRDM16 activates brown fat-selective genes have been unclear. Through chromatin immunoprecipitation (ChIP) followed by deep sequencing (ChIP-seq) analyses in brown adipose tissue (BAT), we reveal that PRDM16 binding is highly enriched at a broad set of brown fat-selective genes. Importantly, we found that PRDM16 physically binds to MED1, a component of the Mediator complex, and recruits it to superenhancers at brown fat-selective genes. PRDM16 deficiency in BAT reduces MED1 binding at PRDM16 target sites and causes a fundamental change in chromatin architecture at key brown fat-selective genes. Together, these data indicate that PRDM16 controls chromatin architecture and superenhancer activity in BAT.
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Affiliation(s)
- Matthew J Harms
- Institute for Diabetes, Obesity, and Metabolism, Department of Cell and Developmental Biology
| | - Hee-Woong Lim
- Institute for Diabetes, Obesity, and Metabolism, Genetics Department, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Yugong Ho
- Genetics Department, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Suzanne N Shapira
- Institute for Diabetes, Obesity, and Metabolism, Department of Cell and Developmental Biology
| | - Jeff Ishibashi
- Institute for Diabetes, Obesity, and Metabolism, Department of Cell and Developmental Biology
| | - Sona Rajakumari
- Institute for Diabetes, Obesity, and Metabolism, Department of Cell and Developmental Biology
| | | | | | - Kyoung-Jae Won
- Institute for Diabetes, Obesity, and Metabolism, Genetics Department, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Patrick Seale
- Institute for Diabetes, Obesity, and Metabolism, Department of Cell and Developmental Biology,
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18
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Step SE, Lim HW, Marinis JM, Prokesch A, Steger DJ, You SH, Won KJ, Lazar MA. Anti-diabetic rosiglitazone remodels the adipocyte transcriptome by redistributing transcription to PPARγ-driven enhancers. Genes Dev 2014; 28:1018-28. [PMID: 24788520 PMCID: PMC4018489 DOI: 10.1101/gad.237628.114] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Rosiglitazone (rosi) is a powerful insulin sensitizer, but serious toxicities have curtailed its widespread clinical use. Rosi functions as a high-affinity ligand for PPARγ, the adipocyte-predominant nuclear receptor. Here, Lazar and colleagues investigate the direct effects of rosi on gene transcription. The authors delineate a novel mechanism by which rosi represses adipocyte gene transcription at endogenous levels of PPARγ and other transcription factors on a genome-wide scale. This study suggests that rosi activates and represses transcription by fundamentally different mechanisms that could inform anti-diabetic drug development. Rosiglitazone (rosi) is a powerful insulin sensitizer, but serious toxicities have curtailed its widespread clinical use. Rosi functions as a high-affinity ligand for peroxisome proliferator-activated receptor γ (PPARγ), the adipocyte-predominant nuclear receptor (NR). The classic model, involving binding of ligand to the NR on DNA, explains positive regulation of gene expression, but ligand-dependent repression is not well understood. We addressed this issue by studying the direct effects of rosi on gene transcription using global run-on sequencing (GRO-seq). Rosi-induced changes in gene body transcription were pronounced after 10 min and correlated with steady-state mRNA levels as well as with transcription at nearby enhancers (enhancer RNAs [eRNAs]). Up-regulated eRNAs occurred almost exclusively at PPARγ-binding sites, to which rosi treatment recruited coactivators, including MED1, p300, and CBP. In contrast, transcriptional repression by rosi involved a loss of coactivators from eRNA sites devoid of PPARγ and enriched for other transcription factors, including AP-1 factors and C/EBPs. Thus, rosi activates and represses transcription by fundamentally different mechanisms that could inform the future development of anti-diabetic drugs.
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Affiliation(s)
- Sonia E Step
- Division of Endocrinology, Diabetes, and Metabolism
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Everett LJ, Lay JL, Lukovac S, Bernstein D, Steger DJ, Lazar MA, Kaestner KH. Integrative genomic analysis of CREB defines a critical role for transcription factor networks in mediating the fed/fasted switch in liver. BMC Genomics 2013; 14:337. [PMID: 23682854 PMCID: PMC3671974 DOI: 10.1186/1471-2164-14-337] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 05/13/2013] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Metabolic homeostasis in mammals critically depends on the regulation of fasting-induced genes by CREB in the liver. Previous genome-wide analysis has shown that only a small percentage of CREB target genes are induced in response to fasting-associated signaling pathways. The precise molecular mechanisms by which CREB specifically targets these genes in response to alternating hormonal cues remain to be elucidated. RESULTS We performed chromatin immunoprecipitation coupled to high-throughput sequencing of CREB in livers from both fasted and re-fed mice. In order to quantitatively compare the extent of CREB-DNA interactions genome-wide between these two physiological conditions we developed a novel, robust analysis method, termed the 'single sample independence' (SSI) test that greatly reduced the number of false-positive peaks. We found that CREB remains constitutively bound to its target genes in the liver regardless of the metabolic state. Integration of the CREB cistrome with expression microarrays of fasted and re-fed mouse livers and ChIP-seq data for additional transcription factors revealed that the gene expression switches between the two metabolic states are associated with co-localization of additional transcription factors at CREB sites. CONCLUSIONS Our results support a model in which CREB is constitutively bound to thousands of target genes, and combinatorial interactions between DNA-binding factors are necessary to achieve the specific transcriptional response of the liver to fasting. Furthermore, our genome-wide analysis identifies thousands of novel CREB target genes in liver, and suggests a previously unknown role for CREB in regulating ER stress genes in response to nutrient influx.
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Affiliation(s)
- Logan J Everett
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - John Le Lay
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Sabina Lukovac
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Diana Bernstein
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - David J Steger
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Klaus H Kaestner
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
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Mullican SE, Gaddis CA, Alenghat T, Nair MG, Giacomin PR, Everett LJ, Feng D, Steger DJ, Schug J, Artis D, Lazar MA. Histone deacetylase 3 is an epigenomic brake in macrophage alternative activation. Genes Dev 2012; 25:2480-8. [PMID: 22156208 DOI: 10.1101/gad.175950.111] [Citation(s) in RCA: 224] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Macrophages, a key cellular component of inflammation, become functionally polarized in a signal- and context-specific manner. Th2 cytokines such as interleukin 4 (IL-4) polarize macrophages to a state of alternative activation that limits inflammation and promotes wound healing. Alternative activation is mediated by a transcriptional program that is influenced by epigenomic modifications, including histone acetylation. Here we report that macrophages lacking histone deacetylase 3 (HDAC3) display a polarization phenotype similar to IL-4-induced alternative activation and, furthermore, are hyperresponsive to IL-4 stimulation. Throughout the macrophage genome, HDAC3 deacetylates histone tails at regulatory regions, leading to repression of many IL-4-regulated genes characteristic of alternative activation. Following exposure to Schistosoma mansoni eggs, a model of Th2 cytokine-mediated disease that is limited by alternative activation, pulmonary inflammation was ameliorated in mice lacking HDAC3 in macrophages. Thus, HDAC3 functions in alternative activation as a brake whose release could be of benefit in the treatment of multiple inflammatory diseases.
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Affiliation(s)
- Shannon E Mullican
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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21
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Steger DJ, Grant GR, Schupp M, Tomaru T, Lefterova MI, Schug J, Manduchi E, Stoeckert CJ, Lazar MA. Propagation of adipogenic signals through an epigenomic transition state. Genes Dev 2010; 24:1035-44. [PMID: 20478996 DOI: 10.1101/gad.1907110] [Citation(s) in RCA: 203] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The transcriptional mechanisms by which temporary exposure to developmental signals instigates adipocyte differentiation are unknown. During early adipogenesis, we find transient enrichment of the glucocorticoid receptor (GR), CCAAT/enhancer-binding protein beta (CEBPbeta), p300, mediator subunit 1, and histone H3 acetylation near genes involved in cell proliferation, development, and differentiation, including the gene encoding the master regulator of adipocyte differentiation, peroxisome proliferator-activated receptor gamma2 (PPARgamma2). Occupancy and enhancer function are triggered by adipogenic signals, and diminish upon their removal. GR, which is important for adipogenesis but need not be active in the mature adipocyte, functions transiently with other enhancer proteins to propagate a new program of gene expression that includes induction of PPARgamma2, thereby providing a memory of the earlier adipogenic signal. Thus, the conversion of preadipocyte to adipocyte involves the formation of an epigenomic transition state that is not observed in cells at the beginning or end of the differentiation process.
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Affiliation(s)
- David J Steger
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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22
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Lefterova MI, Zhang Y, Steger DJ, Schupp M, Schug J, Cristancho A, Feng D, Zhuo D, Stoeckert CJ, Liu XS, Lazar MA. PPARgamma and C/EBP factors orchestrate adipocyte biology via adjacent binding on a genome-wide scale. Genes Dev 2009; 22:2941-52. [PMID: 18981473 DOI: 10.1101/gad.1709008] [Citation(s) in RCA: 618] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Peroxisome proliferator-activated receptor gamma(PPARgamma), a nuclear receptor and the target of anti-diabetic thiazolinedione drugs, is known as the master regulator of adipocyte biology. Although it regulates hundreds of adipocyte genes, PPARgamma binding to endogenous genes has rarely been demonstrated. Here, utilizing chromatin immunoprecipitation (ChIP) coupled with whole genome tiling arrays, we identified 5299 genomic regions of PPARgamma binding in mouse 3T3-L1 adipocytes. The consensus PPARgamma/RXRalpha "DR-1"-binding motif was found at most of the sites, and ChIP for RXRalpha showed colocalization at nearly all locations tested. Bioinformatics analysis also revealed CCAAT/enhancer-binding protein (C/EBP)-binding motifs in the vicinity of most PPARgamma-binding sites, and genome-wide analysis of C/EBPalpha binding demonstrated that it localized to 3350 of the locations bound by PPARgamma. Importantly, most genes induced in adipogenesis were bound by both PPARgamma and C/EBPalpha, while very few were PPARgamma-specific. C/EBPbeta also plays a role at many of these genes, such that both C/EBPalpha and beta are required along with PPARgamma for robust adipocyte-specific gene expression. Thus, PPARgamma and C/EBP factors cooperatively orchestrate adipocyte biology by adjacent binding on an unanticipated scale.
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Affiliation(s)
- Martina I Lefterova
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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23
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Schupp M, Cristancho AG, Lefterova MI, Hanniman EA, Briggs ER, Steger DJ, Qatanani M, Curtin JC, Schug J, Ochsner SA, McKenna NJ, Lazar MA. Re-expression of GATA2 cooperates with peroxisome proliferator-activated receptor-gamma depletion to revert the adipocyte phenotype. J Biol Chem 2009; 284:9458-64. [PMID: 19136559 DOI: 10.1074/jbc.m809498200] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nuclear peroxisome proliferator-activated receptor-gamma (PPARgamma) is required for adipocyte differentiation, but its role in mature adipocytes is less clear. Here, we report that knockdown of PPARgamma expression in 3T3-L1 adipocytes returned the expression of most adipocyte genes to preadipocyte levels. Consistently, down-regulated but not up-regulated genes showed strong enrichment of PPARgamma binding. Surprisingly, not all adipocyte genes were reversed, and the adipocyte morphology was maintained for an extended period after PPARgamma depletion. To explain this, we focused on transcriptional regulators whose adipogenic regulation was not reversed upon PPARgamma depletion. We identified GATA2, a transcription factor whose down-regulation early in adipogenesis is required for preadipocyte differentiation and whose levels remain low after PPARgamma knockdown. Forced expression of GATA2 in mature adipocytes complemented PPARgamma depletion and impaired adipocyte functionality with a more preadipocyte-like gene expression profile. Ectopic expression of GATA2 in adipose tissue in vivo had a similar effect on adipogenic gene expression. These results suggest that PPARgamma-independent down-regulation of GATA2 prevents reversion of mature adipocytes after PPARgamma depletion.
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Affiliation(s)
- Michael Schupp
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Univ. of Pennsylvania School of Medicine, 700 CRB, 415 Curie Blvd., Philadelphia, PA 19104-6149, USA
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24
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Tomaru T, Steger DJ, Lefterova MI, Schupp M, Lazar MA. Adipocyte-specific expression of murine resistin is mediated by synergism between peroxisome proliferator-activated receptor gamma and CCAAT/enhancer-binding proteins. J Biol Chem 2009; 284:6116-25. [PMID: 19126543 DOI: 10.1074/jbc.m808407200] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Resistin antagonizes insulin action in mouse, making it a potential therapeutic target for treating metabolic diseases such as diabetes. To better understand how mouse resistin gene (Retn) expression is restricted to fat tissue, we identified an adipocyte-specific enhancer located approximately 8.8-kb upstream of the transcription start site. This region contains a binding site for the master adipogenic regulator peroxisome proliferator-activated receptor gamma (PPARgamma), and binds endogenous PPARgamma together with its partner retinoid-X receptor alpha (RXRalpha). It also contains three binding sites for CCAAT/enhancer-binding protein (C/EBP), and is bound by endogenous C/EBPalpha and C/EBPbeta in adipocytes. Exogenous expression of PPARgamma/RXRalpha and C/EBPalpha in non-adipocyte cells synergistically drives robust expression from the enhancer. Although PPARgamma ligands repress Retn transcription in adipocytes, rosiglitazone paradoxically stimulates the enhancer activity, suggesting that the enhancer is not directly involved in negative regulation. Unlike expression of Retn in mouse, human resistin (RETN) is expressed primarily in macrophages. Interestingly, the region homologous to the mouse Retn enhancer in the human gene contains all three C/EBP elements, but is not conserved for the sequence bound by PPARgamma. Furthermore, it displays little or no binding by PPARgamma in vitro. Taken together, the data suggest that a composite enhancer binding both PPARgamma and C/EBP factors confers adipocyte-specific expression to Retn in mouse, and its absence from the human gene may explain the lack of adipocyte expression in humans.
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Affiliation(s)
- Takuya Tomaru
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6149, USA
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25
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Phelan CA, Weaver JM, Steger DJ, Joshi S, Maslany JT, Collins JL, Zuercher WJ, Willson TM, Walker M, Jaye M, Lazar MA. Selective partial agonism of liver X receptor alpha is related to differential corepressor recruitment. Mol Endocrinol 2008; 22:2241-9. [PMID: 18669643 DOI: 10.1210/me.2008-0041] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Classically, activated transcription by nuclear receptors (NRs) is due to a ligand-induced switch from corepressor- to coactivator-bound states. However, coactivators and corepressors recognize overlapping surfaces of liganded and unliganded NRs, respectively. Here we show that, at sufficiently high concentration, the NR corepressor (NCoR) influences the activity of the liver X receptor (LXR) even in the presence of a potent full agonist that destabilizes NCoR binding. Partial agonist ligands that less effectively dissociate NCoR from LXR are even more sensitive to NCoR levels, in a target gene-selective manner. Thus, differential recruitment of NCoR is a major determinant of partial agonism and selective LXR modulation of target genes.
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Affiliation(s)
- Caroline A Phelan
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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26
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Shearer BG, Steger DJ, Way JM, Stanley TB, Lobe DC, Grillot DA, Iannone MA, Lazar MA, Willson TM, Billin AN. Identification and characterization of a selective peroxisome proliferator-activated receptor beta/delta (NR1C2) antagonist. Mol Endocrinol 2007; 22:523-9. [PMID: 17975020 DOI: 10.1210/me.2007-0190] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The identification of small molecule ligands for the peroxisome proliferator-activated receptors (PPARs) has been instrumental in elucidating their biological roles. In particular, agonists have been the focus of much of the research in the field with relatively few antagonists being described and all of those being selective for PPARalpha or PPARgamma. The comparison of these agonist and antagonist ligands in cellular and animal systems has often led to surprising results and new insights into the biology of the PPARs. The PPARbeta/delta receptor is emerging as an important regulator of energy metabolism, inflammation, and cell growth and differentiation; however, only agonist ligands have been described for this receptor thus far. Here we describe the first report of a PPARbeta/delta small molecule antagonist ligand. This antagonist ligand will be a useful tool for elucidating the biological roles of PPARbeta/delta.
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Affiliation(s)
- Barry G Shearer
- Research and Development, GlaxoSmithKline, Research Triangle Park, NC 27709, USA
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27
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Abstract
Chromatin remodeling is required for efficient transcription of eukaryotic genes. In a genetic selection for budding yeast mutants that were defective in induction of the phosphate-responsive PHO5 gene, we identified mutations in ARG82/IPK2, which encodes a nuclear inositol polyphosphate kinase. In arg82 mutant strains, remodeling of PHO5 promoter chromatin is impaired, and the adenosine triphosphate-dependent chromatin-remodeling complexes SWI/SNF and INO80 are not efficiently recruited to phosphate-responsive promoters. These results suggest a role for the small molecule inositol polyphosphate in the regulation of chromatin remodeling and transcription.
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Affiliation(s)
- David J Steger
- Department of Biochemistry and Biophysics, Howard Hughes Medical Institute, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143-0448, USA
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Abstract
Novel discoveries result from genetic analyses of transcription and chromatin remodeling because these methods identify activities in an unbiased manner. By describing our genetic approaches to identify regulators of PHO5 transcription and chromatin remodeling, we hope to encourage others to apply similar strategies to their genes of interest.
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Affiliation(s)
- David J Steger
- Howard Hughes Medical Institute, University of California, San Francisco, Department of Biochemistry and Biophysics, San Francisco, California 94143-2240, USA
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29
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Owen-Hughes T, Utley RT, Steger DJ, West JM, John S, Côté J, Havas KM, Workman JL. Analysis of nucleosome disruption by ATP-driven chromatin remodeling complexes. Methods Mol Biol 2000; 119:319-31. [PMID: 10804522 DOI: 10.1385/1-59259-681-9:319] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- T Owen-Hughes
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, USA
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30
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Abstract
We analyzed the targeting of histone acetyltransferase (HAT) complexes by DNA-binding activators during transcriptional activation and the resulting distribution of acetylated histones. An in vitro competition assay was developed to acetylate and transcribe a nucleosomal array template in the presence of excess non-specific chromatin, which mimics in vivo conditions. Stimulation of transcription from the nucleosomal array template under competitive conditions by the SAGA and NuA4 HAT complexes depended on the presence of the Gal4-VP16 activator, which recognizes sites in the promoter and directly interacts with these HATs. Importantly, the stimulation of transcription by SAGA and NuA4 depended on the presence of Gal4-VP16 during histone acetylation, and Gal4-VP16-bound nucleosomal templates were acetylated preferentially by SAGA and NuA4 relative to the competitor chromatin. While targeting of the SAGA complex led to H3 acetylation of promoter-proximal nucleosomes, targeting of the NuA4 complex led to a broader domain of H4 acetylation of >3 kbp. Thus, either promoter-proximal H3 acetylation by SAGA or broadly distributed acetylation of H4 by NuA4 activated transcription from chromatin templates.
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Affiliation(s)
- M Vignali
- Howard Hughes Medical Institute and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, 306 Althouse Laboratory, University Park, PA 16802, USA
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31
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Abstract
CHD proteins are members of the chromo domain family, a class of proteins involved in transcription, DNA degradation and chromatin structure. In higher eukaryotes, there are two distinct subfamilies of CHD proteins: CHD1 and CHD3/4. Analyses carried out in vitro indicate that the CHD3/4 proteins may regulate transcription via alteration of chromatin structure. However, little is known about the role of CHD proteins in vivo, particularly the CHD1 subfamily. To understand better the cellular function of CHD proteins, we initiated a study on the Chd1p protein from budding yeast. Using genomic DNA arrays, we identified genes whose expression is affected by the absence of Chd1p. A synthetic-lethal screen uncovered genetic interactions between SWI/SNF genes and CHD1. Biochemical experiments using Chd1p purified from yeast showed that it reconfigures the structure of nucleosome core particles in a manner distinct from the SWI-SNF complex. Taken together, these results suggest that Chd1p functions as a nucleosome remodeling factor, and that Chd1p may share overlapping roles with the SWI-SNF complex to regulate transcription.
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Affiliation(s)
- H G Tran
- Department of Biochemistry and Biophysics and Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, USA
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LiCalsi C, Christophe S, Steger DJ, Buescher M, Fischer W, Mellon PL. AP-2 family members regulate basal and cAMP-induced expression of human chorionic gonadotropin. Nucleic Acids Res 2000; 28:1036-43. [PMID: 10648798 PMCID: PMC102581 DOI: 10.1093/nar/28.4.1036] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The AP-2 family of transcriptional regulator proteins has three members, alpha, beta and gamma. AP-2alpha and gamma are expressed in placenta and in the human trophoblast cell line JEG-3. AP-2 has been shown to regulate expression of the placental human chorionic gonado-tropin (hCG) alpha- and beta-subunit genes, however, previous work did not distinguish between the family members. Tryptic peptides of the AP-2 protein complexes purified from JEG-3 cells by oligo-affinity chromatography using the hCGalpha AP-2 site match the amino acid sequence of AP-2gamma. The fact that AP-2gamma is present at significant levels and binds the hCGalpha trophoblast-specific element suggests that AP-2gamma is at least part of the binding complex in vivo and plays a role in regulating hCG expression. We show that mutation of each of four AP-2 binding sites within the hCGbeta promoter decreases expression in transfection assays, demonstrating that all four sites are required for maximal expression in JEG-3 cells. Furthermore, we find differences in regulation of the family members: AP-2alpha mRNA levels increase in response to cAMP while AP-2gamma mRNA levels do not. The demonstrated importance of the AP-2 sites in controlling hCGalpha and beta expression and the likely involvement of more than one family member suggest that a balance in AP-2 proteins is involved in coordinate regulation of these genes. Moreover, many placenta-restricted genes are regulated by AP-2 proteins, thus members of this family may play an important overall role in placenta-specific expression.
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Affiliation(s)
- C LiCalsi
- The Departments of Reproductive Medicine and Neurosciences and the Center for the Study of Reproductive Biology and Disease, University of California at San Diego, La Jolla, CA 92093-0674, USA
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Abstract
Acetylation of lysine residues within the amino-terminal tails of the core histone proteins is strongly correlated to the regulation of gene transcription in vivo. To directly study the effects of histone acetylation on transcription, we have developed a biochemical system examining the regulation of RNA polymerase II-directed transcription by native histone acetyltransferases (HATs). For the promoter sequences investigated, it has been demonstrated that HATs facilitate transcription from nucleosomal DNA templates in an acetyl-CoA-dependent fashion but do not affect transcription from histone-free templates. Here, protocols are presented describing the in vitro assembly of evenly spaced nucleosomal arrays on DNA fragments harboring gene regulatory sequences and the use of these templates with purified HAT complexes in transcription assays.
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Affiliation(s)
- D J Steger
- Department of Biochemistry and Biophysics, University of California at San Francisco, 513 Parnassus Avenue, San Francisco, California 94143-0448, USA
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Neely KE, Hassan AH, Wallberg AE, Steger DJ, Cairns BR, Wright AP, Workman JL. Activation domain-mediated targeting of the SWI/SNF complex to promoters stimulates transcription from nucleosome arrays. Mol Cell 1999; 4:649-55. [PMID: 10549297 DOI: 10.1016/s1097-2765(00)80216-6] [Citation(s) in RCA: 213] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The yeast SWI/SNF complex is required for the transcription of several yeast genes and has been shown to alter nucleosome structure in an ATP-dependent reaction. In this study, we show that the complex stimulated in vitro transcription from nucleosome templates in an activation domain-dependent manner. Transcription stimulation by SWI/SNF required an activation domain with which it directly interacts. The acidic activation domains of VP16, Gcn4, Swi5, and Hap4 interacted directly with the purified SWI/SNF complex and with the SWI/SNF complex in whole-cell extracts. The similarity of activation domain interactions and transcriptional stimulation between SWI/SNF and the SAGA histone acetyltransferase complex may account for their apparent overlapping functions in vivo.
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Affiliation(s)
- K E Neely
- Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802, USA
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Steger DJ, Utley RT, Grant PA, John S, Eberharter A, Côté J, Owen-Hughes T, Ikeda K, Workman JL. Regulation of transcription by multisubunit complexes that alter nucleosome structure. Cold Spring Harb Symp Quant Biol 1999; 63:483-91. [PMID: 10384312 DOI: 10.1101/sqb.1998.63.483] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- D J Steger
- Howard Hughes Medical Institute, Pennsylvania State University, University Park 16802, USA
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Ohba R, Steger DJ, Brownell JE, Mizzen CA, Cook RG, Côté J, Workman JL, Allis CD. A novel H2A/H4 nucleosomal histone acetyltransferase in Tetrahymena thermophila. Mol Cell Biol 1999; 19:2061-8. [PMID: 10022893 PMCID: PMC83999 DOI: 10.1128/mcb.19.3.2061] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recently, we reported the identification of a 55-kDa polypeptide (p55) from Tetrahymena macronuclei as a catalytic subunit of a transcription-associated histone acetyltransferase (HAT A). Extensive homology between p55 and Gcn5p, a component of the SAGA and ADA transcriptional coactivator complexes in budding yeast, suggests an immediate link between the regulation of chromatin structure and transcriptional output. Here we report the characterization of a second transcription-associated HAT activity from Tetrahymena macronuclei. This novel activity is distinct from complexes containing p55 and putative ciliate SAGA and ADA components and shares several characteristics with NuA4 (for nucleosomal H2A/H4), a 1.8-MDa, Gcn5p-independent HAT complex recently described in yeast. A key feature of both the NuA4 and Tetrahymena activities is their acetylation site specificity for lysines 5, 8, 12, and 16 of H4 and lysines 5 and 9 of H2A in nucleosomal substrates, patterns that are distinct from those of known Gcn5p family members. Moreover, like NuA4, the Tetrahymena activity is capable of activating transcription from nucleosomal templates in vitro in an acetyl coenzyme A-dependent fashion. Unlike NuA4, however, sucrose gradient analyses of the ciliate enzyme, following sequential denaturation and renaturation, estimate the molecular size of the catalytically active subunit to be approximately 80 kDa, consistent with the notion that a single polypeptide or a stable subcomplex is sufficient for this H2A/H4 nucleosomal HAT activity. Together, these data document the importance of this novel HAT activity for transcriptional activation from chromatin templates and suggest that a second catalytic HAT subunit, in addition to p55/Gcn5p, is conserved between yeast and Tetrahymena.
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Affiliation(s)
- R Ohba
- Department of Biochemistry and Molecular Genetics, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908, USA
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Ikeda K, Steger DJ, Eberharter A, Workman JL. Activation domain-specific and general transcription stimulation by native histone acetyltransferase complexes. Mol Cell Biol 1999; 19:855-63. [PMID: 9858608 PMCID: PMC83942 DOI: 10.1128/mcb.19.1.855] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/1998] [Accepted: 09/23/1998] [Indexed: 11/20/2022] Open
Abstract
Recent progress in identifying the catalytic subunits of histone acetyltransferase (HAT) complexes has implicated histone acetylation in the regulation of transcription. Here, we have analyzed the function of two native yeast HAT complexes, SAGA (Spt-Ada-Gcn5 Acetyltransferase) and NuA4 (nucleosome acetyltransferase of H4), in activating transcription from preassembled nucleosomal array templates in vitro. Each complex was tested for the ability to enhance transcription driven by GAL4 derivatives containing either acidic, glutamine-rich, or proline-rich activation domains. On nucleosomal array templates, the SAGA complex selectively stimulates transcription driven by the VP16 acidic activation domain in an acetyl coenzyme A-dependent manner. In contrast, the NuA4 complex facilitates transcription mediated by any of the activation domains tested if allowed to preacetylate the nucleosomal template, indicating a general stimulatory effect of histone H4 acetylation. However, when the extent of acetylation by NuA4 is limited, the complex also preferentially stimulates VP16-driven transcription. SAGA and NuA4 interact directly with the VP16 activation domain but not with a glutamine-rich or proline-rich activation domain. These data suggest that recruitment of the SAGA and NuA4 HAT complexes by the VP16 activation domain contributes to HAT-dependent activation. In addition, extensive H4/H2B acetylation by NuA4 leads to a general activation of transcription, which is independent of activator-NuA4 interactions.
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Affiliation(s)
- K Ikeda
- Howard Hughes Medical Institute and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802-4500, USA
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Steger DJ, Eberharter A, John S, Grant PA, Workman JL. Purified histone acetyltransferase complexes stimulate HIV-1 transcription from preassembled nucleosomal arrays. Proc Natl Acad Sci U S A 1998; 95:12924-9. [PMID: 9789016 PMCID: PMC23656 DOI: 10.1073/pnas.95.22.12924] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protein acetylation has been implicated in the regulation of HIV-1 gene transcription. Here, we have exploited the activities of four native histone acetyltransferase (HAT) complexes from yeast to directly test whether acetylation regulates HIV-1 transcription in vitro. HAT activities acetylating either histone H3 (SAGA, Ada, and NuA3) or H4 (NuA4) stimulate HIV-1 transcription from preassembled nucleosomal templates in an acetyl CoA-dependent manner. HIV-1 transcription from histone-free DNA is not affected by the HATs, indicating that these activities function in a chromatin-specific fashion. For Ada and NuA4, we demonstrate that acetylation of only histone proteins mediates enhanced transcription, suggesting that these complexes facilitate transcription at least in part by modifying histones. To address a potential mechanism by which HAT complexes stimulate transcription, we performed a restriction enzyme accessibility analysis. Each of the HATs increases the cutting efficiencies of restriction endonucleases targeting the HIV-1 chromatin templates in a manner not requiring transcription, suggesting that histone acetylation leads to nucleosome remodeling.
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Affiliation(s)
- D J Steger
- Howard Hughes Medical Institute and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
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Utley RT, Ikeda K, Grant PA, Côté J, Steger DJ, Eberharter A, John S, Workman JL. Transcriptional activators direct histone acetyltransferase complexes to nucleosomes. Nature 1998; 394:498-502. [PMID: 9697775 DOI: 10.1038/28886] [Citation(s) in RCA: 414] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Transcriptional co-activators were originally identified as proteins that act as intermediaries between upstream activators and the basal transcription machinery. The discovery that co-activators such as Tetrahymena and yeast Gcn5, as well as human p300/CBP, pCAF, Src-1, ACTR and TAFII250, can acetylate histones suggests that activators may be involved in targeting acetylation activity to promoters. Several histone deacetylases have been linked to transcriptional co-repressor proteins, suggesting that the action of both acetylases and deacetylases is important in the regulation of many genes. Here we demonstrate the binding of two native yeast histone acetyltransferase (HAT) complexes to the herpesvirus VP16 activation domain and the yeast transcriptional activator Gcn4, and show that it is their interaction with the VP16 activation domain that targets Gal4-VP16-bound nucleosomes for acetylation. We find that Gal4-VP16-driven transcription from chromatin templates is stimulated by both HAT complexes in an acetyl CoA-dependent reaction. Our results demonstrate the targeting of native HAT complexes by a transcription-activation domain to nucleosomes in order to activate transcription.
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Affiliation(s)
- R T Utley
- Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802-4500, USA
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Grant PA, Schieltz D, Pray-Grant MG, Steger DJ, Reese JC, Yates JR, Workman JL. A subset of TAF(II)s are integral components of the SAGA complex required for nucleosome acetylation and transcriptional stimulation. Cell 1998; 94:45-53. [PMID: 9674426 DOI: 10.1016/s0092-8674(00)81220-9] [Citation(s) in RCA: 349] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A number of transcriptional coactivator proteins have been identified as histone acetyltransferase (HAT) proteins, providing a direct molecular basis for the coupling of histone acetylation and transcriptional activation. The yeast Spt-Ada-Gcn5-acetyltransferase (SAGA) complex requires the coactivator protein Gcn5 for HAT activity. Identification of protein subunits by mass spectrometry and immunoblotting revealed that the TATA binding protein-associated factors (TAF(II)s) TAF(II)90, -68/61, -60, -25/23, and -20/17 are integral components of this complex. In addition, TAF(II)68 was required for both SAGA-dependent nucleosomal HAT activity and transcriptional activation from chromatin templates in vitro. These results illustrate a role for certain TAF(II) proteins in the regulation of gene expression at the level of chromatin modification that is distinct from the TFIID complex and TAF(II)145.
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Affiliation(s)
- P A Grant
- Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802-4500, USA
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Abstract
An early step in a pathway leading to transcriptional initiation involves the rearrangement of chromatin at gene regulatory sequences. To study this process, we have developed a biochemical system analyzing the interactions between chromatin templates composed of arrays of positioned nucleosomes and sequence-specific transcriptional activators. Here, a procedure is presented for the assembly of nucleosomal arrays on DNA fragments containing synthetic and natural gene sequences inserted within tandem repeats of sea urchin 5S rDNA. We also provide methods for the use of these templates in transcription factor-binding assays, as well as experimental data illustrating the efficacy of such analyses to uncover mechanisms directing factor-mediated nucleosome remodeling.
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Affiliation(s)
- D J Steger
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802-4500, USA
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Abstract
To investigate mechanisms yielding DNase I-hypersensitive sites (DHSs) at gene regulatory regions, we have initiated a biochemical analysis of transcription factor binding and nucleosome remodeling with a region of the human immunodeficiency virus 1 (HIV-1) 5' long terminal repeat (LTR) that harbors constitutive DHSs in vivo. In vitro reconstitution of an HIV-1 5' LTR fragment into nucleosome core particles demonstrates that Sp1, NF-kappaB1, LEF-1, ETS-1 and USF can gain access to their binding sites in HIV-1 nucleosomal DNA. The factor-bound mononucleosomes resist histone displacement from the DNA by the chromatin remodeling activity, SW1-SNF, or the histone chaperone, nucleoplasmin, suggesting that the binding of these factors to nucleosomal HIV-1 sequences forms a stable complex that includes the underlying histones. However, when the HIV-1 5' LTR fragment is incorporated into a nucleosomal array, Sp1 and NF-kappaB1 binding produce regions of enhanced DNase I sensitivity specifically at the HIV-1 nucleosome. These regions resemble the observed in vivo DHSs, yet the HIV-1 nucleosome remains intact even in the presence of nucleoplasmin. Thus, the constitutive DHSs identified at the HIV-1 enhancer in native chromatin may reflect the presence of a ternary complex composed of transcriptional activators, histones and DNA.
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Affiliation(s)
- D J Steger
- Department of Biochemistry and Molecular Biology, The Center for Gene Regulation, The Pennsylvania State University, University Park 16802-4500, USA
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Abstract
Activation of gene transcription in vivo is accompanied by an alteration of chromatin structure. The specific binding of transcriptional activators disrupts nucleosomal arrays, suggesting that the primary steps leading to transcriptional initiation involve interactions between activators and chromatin. The affinity of transcription factors for nucleosomal DNA is determined by the location of recognition sequences within nucleosomes, and by the cooperative interactions of multiple proteins targeting binding sites contained within the same nucleosomes. In addition, two distinct types of enzymatic complexes facilitate binding of transcription factors to nucleosomal DNA. These include type A histone acetyltransferases (e.g. GCN5/ADA transcriptional adaptor complex) and ATP-driven molecular machines that disrupt histone-DNA interactions (e.g. SWI/SNF and NURF complexes). These observations raise the important question of what happens to the histones during chromatin remodeling. We discuss evidence supporting the retention of histones at transcription factor-bound sequences as well as two alternative pathways of histone loss from gene control elements upon transcription factor binding: histone octamer sliding and histone dissociation.
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Affiliation(s)
- D J Steger
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802-4500, USA
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Abstract
The human glycoprotein hormone alpha-subunit gene is expressed in two quite dissimilar tissues, the placenta and anterior pituitary. Tissue-specific expression is determined by combinations of elements, some of which are common and others of which are specific to each tissue. In the placenta, a composite enhancer confers specific expression. It contains four protein-binding sites: two cyclic AMP (cAMP) response elements that bind CREB, a trophoblast-specific element that binds TSEB, and a sequence motif, AGATAA, that matches the consensus binding site for a family of transcription factors termed the GATA-binding proteins. In pituitary gonadotropes, the cAMP response elements remain important for expression, TSEB is absent, and elements further upstream participate in tissue-specific expression. Here we establish a regulatory role for the GATA element in both the placenta and pituitary by demonstrating that a mutation of this element decreases alpha-subunit gene expression 15-fold in JEG-3 human placental cells and 2.5-fold in alpha T3-1 mouse pituitary gonadotropes. In JEG-3 cells, human GATA-2 (hGATA-2) and hGATA-3 are highly expressed and both proteins bind to the alpha-subunit gene GATA element. In alpha T3-1 cells, the GATA motif is bound by mouse GATA-2 (mGATA-2) and an mGATA-4-related protein. Cotransfection of hGATA-2 or hGATA-3 into alpha T3-1 cells activates the alpha-subunit gene threefold. These studies establish a role for the GATA-binding proteins in placental and pituitary alpha-subunit gene expression, significantly expanding the known target genes of GATA-2, GATA-3, and perhaps GATA-4.
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Affiliation(s)
- D J Steger
- Department of Reproductive Medicine, University of California, San Diego, La Jolla 92093-0674
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Steger DJ, Büscher M, Hecht JH, Mellon PL. Coordinate control of the alpha- and beta-subunit genes of human chorionic gonadotropin by trophoblast-specific element-binding protein. Mol Endocrinol 1993; 7:1579-88. [PMID: 7511787 DOI: 10.1210/mend.7.12.7511787] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The alpha- and beta-subunit genes of hCG are coordinately regulated in the trophectoderm of the early embryo and placenta. Placenta-specific expression of the alpha-subunit gene is determined by a composite enhancer made of three clustered components: cAMP-responsive elements, a GATA site, and the trophoblast-specific element (TSE). We have investigated the basis of placenta-specific expression of the major hCG beta-subunit gene, hCG beta 5. Enhancement of expression localizes to the region from -305 to -279, whereas full cAMP regulation requires the region from -305 to -249. Four DNAse-I footprints are present, three of which can be competed by the TSE element from the alpha-subunit gene. Methylation interference establishes that binding to the element located in the key region for expression, from -301 to -275, requires contacts with a CCNNNGGG core sequence that matches the alpha-subunit gene TSE. Sequence-specific DNA affinity chromatography using the alpha-subunit gene TSE allows purification of TSE-binding protein. This purified protein binds specifically to the key element, -301 to -275, and to at least two additional TSE elements clustered in the regulatory region of the hCG beta 5 gene. We conclude that both the alpha- and beta-subunit genes of hCG require the placenta-specific factor TSE-binding protein for expression, providing a mechanism for their coordinate regulation in placental cells.
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Affiliation(s)
- D J Steger
- Department of Reproductive Medicine, University of California-San Diego, La Jolla 92093
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Steger DJ, Altschmied J, Büscher M, Mellon PL. Evolution of placenta-specific gene expression: comparison of the equine and human gonadotropin alpha-subunit genes. Mol Endocrinol 1991; 5:243-55. [PMID: 1710031 DOI: 10.1210/mend-5-2-243] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Primate and equine species are thought to be unique among mammals in synthesizing placental gonadotropin glycoprotein hormones. Human chorionic gonadotropin (CG) and equine pregnant mare's serum gonadotropin (PMSG) are produced in placenta by the specific activation of a glycoprotein hormone alpha-subunit gene and a corresponding beta-subunit gene. The evolutionary mechanisms for the apparently independent acquisition of tissue specificity were investigated by cloning the 5' flanking region of the equine alpha-subunit gene and comparing the DNA elements and trans-acting factors involved in placental expression. We find that though the equine gene is expressed and induced by cAMP, it does not contain the elements known to confer tissue-specific expression to the human gene, the cAMP response element (CRE) and the trophoblast-specific element (TSE), nor does it bind to the trans-acting factors CREB and TSEB. Instead, an additional factor (alpha-ACT) is found which binds to the equine and human, but not the murine, alpha-subunit genes in a region between the positions of the CRE and TSE and confers cAMP responsiveness.
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Affiliation(s)
- D J Steger
- Salk Institute, La Jolla, California 92037
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