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Fang Y, Yuan C, Li C, Lu C, Yu W, Wang G. The Mediator Med23 controls a transcriptional switch for muscle stem cell proliferation and differentiation in muscle regeneration. Cell Rep 2024; 43:114177. [PMID: 38691453 DOI: 10.1016/j.celrep.2024.114177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 03/14/2024] [Accepted: 04/16/2024] [Indexed: 05/03/2024] Open
Abstract
Muscle stem cells (MuSCs) contribute to a robust muscle regeneration process after injury, which is highly orchestrated by the sequential expression of multiple key transcription factors. However, it remains unclear how key transcription factors and cofactors such as the Mediator complex cooperate to regulate myogenesis. Here, we show that the Mediator Med23 is critically important for MuSC-mediated muscle regeneration. Med23 is increasingly expressed in activated/proliferating MuSCs on isolated myofibers or in response to muscle injury. Med23 deficiency reduced MuSC proliferation and enhanced its precocious differentiation, ultimately compromising muscle regeneration. Integrative analysis revealed that Med23 oppositely impacts Ternary complex factor (TCF)-targeted MuSC proliferation genes and myocardin-related transcription factor (MRTF)-targeted myogenic differentiation genes. Consistently, Med23 deficiency decreases the ETS-like transcription factor 1 (Elk1)/serum response factor (SRF) binding at proliferation gene promoters but promotes MRTF-A/SRF binding at myogenic gene promoters. Overall, our study reveals the important transcriptional control mechanism of Med23 in balancing MuSC proliferation and differentiation in muscle regeneration.
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Affiliation(s)
- Yi Fang
- State Key Laboratory of Genetic Engineering, School of Life Sciences and Zhongshan Hospital, Fudan University, Shanghai 200438, China; State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Chunlei Yuan
- State Key Laboratory of Genetic Engineering, School of Life Sciences and Zhongshan Hospital, Fudan University, Shanghai 200438, China
| | - Chonghui Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences and Zhongshan Hospital, Fudan University, Shanghai 200438, China; State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Chengjiang Lu
- State Key Laboratory of Genetic Engineering, School of Life Sciences and Zhongshan Hospital, Fudan University, Shanghai 200438, China; State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Wei Yu
- State Key Laboratory of Genetic Engineering, School of Life Sciences and Zhongshan Hospital, Fudan University, Shanghai 200438, China
| | - Gang Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences and Zhongshan Hospital, Fudan University, Shanghai 200438, China.
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2
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Malik S, Roeder RG. Regulation of the RNA polymerase II pre-initiation complex by its associated coactivators. Nat Rev Genet 2023; 24:767-782. [PMID: 37532915 PMCID: PMC11088444 DOI: 10.1038/s41576-023-00630-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2023] [Indexed: 08/04/2023]
Abstract
The RNA polymerase II (Pol II) pre-initiation complex (PIC) is a critical node in eukaryotic transcription regulation, and its formation is the major rate-limiting step in transcriptional activation. Diverse cellular signals borne by transcriptional activators converge on this large, multiprotein assembly and are transduced via intermediary factors termed coactivators. Cryogenic electron microscopy, multi-omics and single-molecule approaches have recently offered unprecedented insights into both the structure and cellular functions of the PIC and two key PIC-associated coactivators, Mediator and TFIID. Here, we review advances in our understanding of how Mediator and TFIID interact with activators and affect PIC formation and function. We also discuss how their functions are influenced by their chromatin environment and selected cofactors. We consider how, through its multifarious interactions and functionalities, a Mediator-containing and TFIID-containing PIC can yield an integrated signal processing system with the flexibility to determine the unique temporal and spatial expression pattern of a given gene.
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Affiliation(s)
- Sohail Malik
- Laboratory of Biochemistry & Molecular Biology, The Rockefeller University, New York, NY, USA.
| | - Robert G Roeder
- Laboratory of Biochemistry & Molecular Biology, The Rockefeller University, New York, NY, USA
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3
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Gao J, Bao M, Xing Y, Ding Y, Han T, Wen E, Liu J, Yue S, Wang R, Wang L, Liu J, Zhao S, Huang J, Liu E, Bai L. Mediator subunit MED1 deficiency prevents carbon tetrachloride-induced hepatic fibrosis in mice. Am J Physiol Gastrointest Liver Physiol 2023; 325:G418-G428. [PMID: 37668531 DOI: 10.1152/ajpgi.00076.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/17/2023] [Accepted: 08/22/2023] [Indexed: 09/06/2023]
Abstract
Mediator subunit mediator 1 (MED1) mediates ligand-dependent binding of the mediator coactivator complex to various nuclear receptors and plays a critical role in embryonic development, lipid and glucose metabolism, liver regeneration, and tumorigenesis. However, the precise role of MED1 in the development of liver fibrosis has been unclear. Here, we showed that MED1 expression was increased in livers from nonalcoholic steatohepatitis (NASH) patients and mice and positively correlated with transforming growth factor β (TGF-β) signaling and profibrotic factors. Upon treatment with carbon tetrachloride (CCl4), hepatic fibrosis was much less in liver-specific MED1 deletion (MED1ΔLiv) mice than in MED1fl/fl littermates. TGF-β/Smad2/3 signaling pathway was inhibited, and gene expression of fibrotic markers, including α-smooth muscle actin (α-SMA), collagen type 1 α 1 (Col1a1), matrix metalloproteinase-2 (Mmp2), and metallopeptidase inhibitor 1 (Timp1) were decreased in livers of MED1ΔLiv mice with CCl4 injection. Transcriptomic analysis revealed that the differentially expressed genes in livers of CCl4-administered MED1ΔLiv mice were enriched in the pathway of oxidoreductase activity, followed by robustly reduced oxidoreductase activity-related genes, such as Gm4756, Txnrd3, and Etfbkmt. More importantly, we found that the reduction of reactive oxygen species (ROS) in MED1 knockdown hepatocytes blocked the activation of TGF-β/Smad2/3 pathway and the expression of fibrotic genes in LX2 cells. These results indicate that MED1 is a positive regulator for hepatic fibrogenesis, and MED1 may be considered as a potential therapeutic target for the regression of liver fibrosis.NEW & NOTEWORTHY In this study, we present the first evidence that liver mediator 1 (MED1) deficiency attenuated carbon tetrachloride-induced hepatic fibrosis in mouse. The underlying mechanism is that MED1 deficiency reduces reactive oxygen species (ROS) production in hepatocytes, thus restricts the activation of TGF-β/Smad2/3 signaling pathway and fibrogenic genes expression in hepatic stellate cells (HSCs). These data suggest that MED1 is an essential regulator for hepatic fibrogenesis, and MED1 may be considered as a potential therapeutic target for liver fibrosis.
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Affiliation(s)
- Jie Gao
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
- School of Biological Science Technology and Engineering, Shaanxi University of Technology, Hanzhong, People's Republic of China
| | - Miaoye Bao
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Yuanming Xing
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Yiming Ding
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Tuo Han
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Ergang Wen
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Jun Liu
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Shaoyun Yue
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
| | - Rong Wang
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Ling Wang
- School of Biological Science Technology and Engineering, Shaanxi University of Technology, Hanzhong, People's Republic of China
| | - Junhui Liu
- Department of Clinical Laboratory, First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, People's Republic of China
| | - Sihai Zhao
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Jiansheng Huang
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Enqi Liu
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
| | - Liang Bai
- Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, People's Republic of China
- Cardiometabolic Innovation Center, Ministry of Education, Xi'an, People's Republic of China
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4
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Schiano C, Luongo L, Maione S, Napoli C. Mediator complex in neurological disease. Life Sci 2023; 329:121986. [PMID: 37516429 DOI: 10.1016/j.lfs.2023.121986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 07/18/2023] [Accepted: 07/26/2023] [Indexed: 07/31/2023]
Abstract
Neurological diseases, including traumatic brain injuries, stroke (haemorrhagic and ischemic), and inherent neurodegenerative diseases cause acquired disability in humans, representing a leading cause of death worldwide. The Mediator complex (MED) is a large, evolutionarily conserved multiprotein that facilities the interaction between transcription factors and RNA Polymerase II in eukaryotes. Some MED subunits have been found altered in the brain, although their specific functions in neurodegenerative diseases are not fully understood. Mutations in MED subunits were associated with a wide range of genetic diseases for MED12, MED13, MED13L, MED20, MED23, MED25, and CDK8 genes. In addition, MED12 and MED23 were deregulated in the Alzheimer's Disease. Interestingly, most of the genomic mutations have been found in the subunits of the kinase module. To date, there is only one evidence on MED1 involvement in post-stroke cognitive deficits. Although the underlying neurodegenerative disorders may be different, we are confident that the signal cascades of the biological-cognitive mechanisms of brain adaptation, which begin after brain deterioration, may also differ. Here, we analysed relevant studies in English published up to June 2023. They were identified through a search of electronic databases including PubMed, Medline, EMBASE and Scopus, including search terms such as "Mediator complex", "neurological disease", "brains". Thematic content analysis was conducted to collect and summarize all studies demonstrating MED alteration to understand the role of this central transcriptional regulatory complex in the brain. Improved and deeper knowledge of the regulatory mechanisms in neurological diseases can increase the ability of physicians to predict onset and progression, thereby improving diagnostic care and providing appropriate treatment decisions.
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Affiliation(s)
- Concetta Schiano
- Department of Advanced Medical and Surgical Sciences (DAMSS), University of Campania "Luigi Vanvitelli", Italy.
| | - Livio Luongo
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Italy; IRCSS, Neuromed, Pozzilli, Italy
| | - Sabatino Maione
- Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", Italy; IRCSS, Neuromed, Pozzilli, Italy
| | - Claudio Napoli
- Department of Advanced Medical and Surgical Sciences (DAMSS), University of Campania "Luigi Vanvitelli", Italy; Clinical Department of Internal Medicine and Specialistic Units, Division of Clinical Immunology and Immunohematology, Transfusion Medicine, and Transplant Immunology (SIMT), Regional Reference Laboratory of Transplant Immunology (LIT), Azienda Universitaria Policlinico (AOU), Italy
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5
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Rengachari S, Schilbach S, Cramer P. Mediator structure and function in transcription initiation. Biol Chem 2023; 404:829-837. [PMID: 37078249 DOI: 10.1515/hsz-2023-0158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 04/06/2023] [Indexed: 04/21/2023]
Abstract
Recent advances in cryo-electron microscopy have led to multiple structures of Mediator in complex with the RNA polymerase II (Pol II) transcription initiation machinery. As a result we now hold in hands near-complete structures of both yeast and human Mediator complexes and have a better understanding of their interactions with the Pol II pre-initiation complex (PIC). Herein, we provide a summary of recent achievements and discuss their implications for future studies of Mediator and its role in gene regulation.
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Affiliation(s)
- Srinivasan Rengachari
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Sandra Schilbach
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077 Göttingen, Germany
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6
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Buyukcelebi K, Chen X, Abdula F, Elkafas H, Duval AJ, Ozturk H, Seker-Polat F, Jin Q, Yin P, Feng Y, Bulun SE, Wei JJ, Yue F, Adli M. Engineered MED12 mutations drive leiomyoma-like transcriptional and metabolic programs by altering the 3D genome compartmentalization. Nat Commun 2023; 14:4057. [PMID: 37429859 DOI: 10.1038/s41467-023-39684-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/26/2023] [Indexed: 07/12/2023] Open
Abstract
Nearly 70% of Uterine fibroid (UF) tumors are driven by recurrent MED12 hotspot mutations. Unfortunately, no cellular models could be generated because the mutant cells have lower fitness in 2D culture conditions. To address this, we employ CRISPR to precisely engineer MED12 Gly44 mutations in UF-relevant myometrial smooth muscle cells. The engineered mutant cells recapitulate several UF-like cellular, transcriptional, and metabolic alterations, including altered Tryptophan/kynurenine metabolism. The aberrant gene expression program in the mutant cells is, in part, driven by a substantial 3D genome compartmentalization switch. At the cellular level, the mutant cells gain enhanced proliferation rates in 3D spheres and form larger lesions in vivo with elevated production of collagen and extracellular matrix deposition. These findings indicate that the engineered cellular model faithfully models key features of UF tumors and provides a platform for the broader scientific community to characterize genomics of recurrent MED12 mutations.
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Affiliation(s)
- Kadir Buyukcelebi
- Robert Lurie Comprehensive Cancer Center, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, IL, USA
| | - Xintong Chen
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine Northwestern University, Chicago, IL, USA
| | - Fatih Abdula
- Robert Lurie Comprehensive Cancer Center, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, IL, USA
| | - Hoda Elkafas
- Robert Lurie Comprehensive Cancer Center, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, IL, USA
| | - Alexander James Duval
- Robert Lurie Comprehensive Cancer Center, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, IL, USA
| | - Harun Ozturk
- Robert Lurie Comprehensive Cancer Center, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, IL, USA
| | - Fidan Seker-Polat
- Robert Lurie Comprehensive Cancer Center, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, IL, USA
| | - Qiushi Jin
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine Northwestern University, Chicago, IL, USA
| | - Ping Yin
- Robert Lurie Comprehensive Cancer Center, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, IL, USA
| | - Yue Feng
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Serdar E Bulun
- Robert Lurie Comprehensive Cancer Center, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, IL, USA
| | - Jian Jun Wei
- Robert Lurie Comprehensive Cancer Center, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, IL, USA
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Feng Yue
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine Northwestern University, Chicago, IL, USA
| | - Mazhar Adli
- Robert Lurie Comprehensive Cancer Center, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, IL, USA.
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7
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Abril-Garrido J, Dienemann C, Grabbe F, Velychko T, Lidschreiber M, Wang H, Cramer P. Structural basis of transcription reduction by a promoter-proximal +1 nucleosome. Mol Cell 2023:S1097-2765(23)00255-1. [PMID: 37148879 DOI: 10.1016/j.molcel.2023.04.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/16/2023] [Accepted: 04/11/2023] [Indexed: 05/08/2023]
Abstract
At active human genes, the +1 nucleosome is located downstream of the RNA polymerase II (RNA Pol II) pre-initiation complex (PIC). However, at inactive genes, the +1 nucleosome is found further upstream, at a promoter-proximal location. Here, we establish a model system to show that a promoter-proximal +1 nucleosome can reduce RNA synthesis in vivo and in vitro, and we analyze its structural basis. We find that the PIC assembles normally when the edge of the +1 nucleosome is located 18 base pairs (bp) downstream of the transcription start site (TSS). However, when the nucleosome edge is located further upstream, only 10 bp downstream of the TSS, the PIC adopts an inhibited state. The transcription factor IIH (TFIIH) shows a closed conformation and its subunit XPB contacts DNA with only one of its two ATPase lobes, inconsistent with DNA opening. These results provide a mechanism for nucleosome-dependent regulation of transcription initiation.
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Affiliation(s)
- Julio Abril-Garrido
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Christian Dienemann
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Frauke Grabbe
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Taras Velychko
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Michael Lidschreiber
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Haibo Wang
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
| | - Patrick Cramer
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
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8
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Gorbea Colón JJ, Palao L, Chen SF, Kim HJ, Snyder L, Chang YW, Tsai KL, Murakami K. Structural basis of a transcription pre-initiation complex on a divergent promoter. Mol Cell 2023; 83:574-588.e11. [PMID: 36731470 PMCID: PMC10162435 DOI: 10.1016/j.molcel.2023.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 11/28/2022] [Accepted: 01/06/2023] [Indexed: 02/04/2023]
Abstract
Most eukaryotic promoter regions are divergently transcribed. As the RNA polymerase II pre-initiation complex (PIC) is intrinsically asymmetric and responsible for transcription in a single direction, it is unknown how divergent transcription arises. Here, the Saccharomyces cerevisiae Mediator complexed with a PIC (Med-PIC) was assembled on a divergent promoter and analyzed by cryoelectron microscopy. The structure reveals two distinct Med-PICs forming a dimer through the Mediator tail module, induced by a homodimeric activator protein localized near the dimerization interface. The tail dimer is associated with ∼80-bp upstream DNA, such that two flanking core promoter regions are positioned and oriented in a suitable form for PIC assembly in opposite directions. Also, cryoelectron tomography visualized the progress of the PIC assembly on the two core promoter regions, providing direct evidence for the role of the Med-PIC dimer in divergent transcription.
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Affiliation(s)
- Jose J Gorbea Colón
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Leon Palao
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shin-Fu Chen
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Hee Jong Kim
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Laura Snyder
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yi-Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Kuang-Lei Tsai
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| | - Kenji Murakami
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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9
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Buyukcelebi K, Chen X, Abdula F, Duval A, Ozturk H, Seker-Polat F, Jin Q, Yin P, Feng Y, Wei JJ, Bulun S, Yue F, Adli M. Engineered MED12 mutations drive uterine fibroid-like transcriptional and metabolic programs by altering the 3D genome compartmentalization. RESEARCH SQUARE 2023:rs.3.rs-2537075. [PMID: 36798375 PMCID: PMC9934745 DOI: 10.21203/rs.3.rs-2537075/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Uterine fibroid (UF) tumors originate from a mutated smooth muscle cell (SMC). Nearly 70% of these tumors are driven by hotspot recurrent somatic mutations in the MED12 gene; however, there are no tractable genetic models to study the biology of UF tumors because, under culture conditions, the non-mutant fibroblasts outgrow the mutant SMC cells, resulting in the conversion of the population to WT phenotype. The lack of faithful cellular models hampered our ability to delineate the molecular pathways downstream of MED12 mutations and identify therapeutics that may selectively target the mutant cells. To overcome this challenge, we employed CRISPR knock-in with a sensitive PCR-based screening strategy to precisely engineer cells with mutant MED12 Gly44, which constitutes 50% of MED12 exon two mutations. Critically, the engineered myometrial SMC cells recapitulate several UF-like cellular, transcriptional and metabolic alterations, including enhanced proliferation rates in 3D spheres and altered Tryptophan/kynurenine metabolism. Our transcriptomic analysis supported by DNA synthesis tracking reveals that MED12 mutant cells, like UF tumors, have heightened expression of DNA repair genes but reduced DNA synthesis rates. Consequently, these cells accumulate significantly higher rates of DNA damage and are selectively more sensitive to common DNA-damaging chemotherapy, indicating mutation-specific and therapeutically relevant vulnerabilities. Our high-resolution 3D chromatin interaction analysis demonstrates that the engineered MED12 mutations drive aberrant genomic activity due to a genome-wide chromatin compartmentalization switch. These findings indicate that the engineered cellular model faithfully models key features of UF tumors and provides a novel platform for the broader scientific community to characterize genomics of recurrent MED12 mutations and discover potential therapeutic targets.
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10
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Lambert É, Puwakdandawa K, Tao YF, Robert F. From structure to molecular condensates: emerging mechanisms for Mediator function. FEBS J 2023; 290:286-309. [PMID: 34698446 DOI: 10.1111/febs.16250] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/15/2021] [Accepted: 10/25/2021] [Indexed: 02/05/2023]
Abstract
Mediator is a large modular protein assembly whose function as a coactivator of transcription is conserved in all eukaryotes. The Mediator complex can integrate and relay signals from gene-specific activators bound at enhancers to activate the general transcription machinery located at promoters. It has thus been described as a bridge between these elements during initiation of transcription. Here, we review recent studies on Mediator relating to its structure, gene specificity and general requirement, roles in chromatin architecture as well as novel concepts involving phase separation and transcriptional bursting. We revisit the mechanism of action of Mediator and ultimately put forward models for its mode of action in gene activation.
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Affiliation(s)
- Élie Lambert
- Institut de recherches cliniques de Montréal, Canada
| | | | - Yi Fei Tao
- Institut de recherches cliniques de Montréal, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal, Canada.,Département de Médecine, Faculté de Médecine, Université de Montréal, Canada
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11
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Bajracharya A, Xi J, Grace KF, Bayer EE, Grant CA, Clutton CH, Baerson SR, Agarwal AK, Qiu Y. PHYTOCHROME-INTERACTING FACTOR 4/HEMERA-mediated thermosensory growth requires the Mediator subunit MED14. PLANT PHYSIOLOGY 2022; 190:2706-2721. [PMID: 36063057 PMCID: PMC9706435 DOI: 10.1093/plphys/kiac412] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/12/2022] [Indexed: 05/19/2023]
Abstract
While moderately elevated ambient temperatures do not trigger stress responses in plants, they do substantially stimulate the growth of specific organs through a process known as thermomorphogenesis. The basic helix-loop-helix transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) plays a central role in regulating thermomorphogenetic hypocotyl elongation in various plant species, including Arabidopsis (Arabidopsis thaliana). Although it is well known that PIF4 and its co-activator HEMERA (HMR) promote plant thermosensory growth by activating genes involved in the biosynthesis and signaling of the phytohormone auxin, the detailed molecular mechanism of such transcriptional activation is not clear. In this report, we investigated the role of the Mediator complex in the PIF4/HMR-mediated thermoresponsive gene expression. Through the characterization of various mutants of the Mediator complex, a tail subunit named MED14 was identified as an essential factor for thermomorphogenetic hypocotyl growth. MED14 was required for the thermal induction of PIF4 target genes but had a marginal effect on the levels of PIF4 and HMR. Further transcriptomic analyses confirmed that the expression of numerous PIF4/HMR-dependent, auxin-related genes required MED14 at warm temperatures. Moreover, PIF4 and HMR physically interacted with MED14 and both were indispensable for the association of MED14 with the promoters of these thermoresponsive genes. While PIF4 did not regulate MED14 levels, HMR was required for the transcript abundance of MED14. Taken together, these results unveil an important thermomorphogenetic mechanism, in which PIF4 and HMR recruit the Mediator complex to activate auxin-related growth-promoting genes when plants sense moderate increases in ambient temperature.
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Affiliation(s)
| | - Jing Xi
- Natural Products Utilization Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Oxford, Mississippi, USA
| | - Karlie F Grace
- Department of Biology, University of Mississippi, Oxford, Mississippi 38677, USA
| | - Eden E Bayer
- Department of Biology, University of Mississippi, Oxford, Mississippi 38677, USA
| | - Chloe A Grant
- Department of Biology, University of Mississippi, Oxford, Mississippi 38677, USA
| | - Caroline H Clutton
- Department of Biology, University of Mississippi, Oxford, Mississippi 38677, USA
| | - Scott R Baerson
- Natural Products Utilization Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Oxford, Mississippi, USA
| | - Ameeta K Agarwal
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Oxford, Mississippi, USA
- Division of Pharmacology, Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, Mississippi, USA
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12
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Warfield L, Donczew R, Mahendrawada L, Hahn S. Yeast Mediator facilitates transcription initiation at most promoters via a Tail-independent mechanism. Mol Cell 2022; 82:4033-4048.e7. [PMID: 36208626 PMCID: PMC9637718 DOI: 10.1016/j.molcel.2022.09.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 05/12/2022] [Accepted: 09/13/2022] [Indexed: 11/06/2022]
Abstract
Mediator (MED) is a conserved factor with important roles in basal and activated transcription. Here, we investigate the genome-wide roles of yeast MED by rapid depletion of its activator-binding domain (Tail) and monitoring changes in nascent transcription. Rapid Tail depletion surprisingly reduces transcription from only a small subset of genes. At most of these Tail-dependent genes, in unperturbed conditions, MED is detected at both the UASs and promoters. In contrast, at most Tail-independent genes, we find MED primarily at promoters but not at the UASs. These results suggest that MED Tail and activator-mediated MED recruitment regulates only a small subset of genes. Furthermore, we define three classes of genes that differ in PIC assembly pathways and the requirements for MED Tail, SAGA, TFIID, and BET factors Bdf1/2. Our combined results have broad implications for the roles of MED, other coactivators, and mechanisms of transcriptional regulation at different gene classes.
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Affiliation(s)
- Linda Warfield
- Fred Hutchinson Cancer Center, 1100 Fairview Ave N, Mailstop A1-162, Seattle, WA 98109, USA
| | - Rafal Donczew
- Fred Hutchinson Cancer Center, 1100 Fairview Ave N, Mailstop A1-162, Seattle, WA 98109, USA
| | - Lakshmi Mahendrawada
- Fred Hutchinson Cancer Center, 1100 Fairview Ave N, Mailstop A1-162, Seattle, WA 98109, USA
| | - Steven Hahn
- Fred Hutchinson Cancer Center, 1100 Fairview Ave N, Mailstop A1-162, Seattle, WA 98109, USA.
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13
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Richter WF, Nayak S, Iwasa J, Taatjes DJ. The Mediator complex as a master regulator of transcription by RNA polymerase II. Nat Rev Mol Cell Biol 2022; 23:732-749. [PMID: 35725906 PMCID: PMC9207880 DOI: 10.1038/s41580-022-00498-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/17/2022] [Indexed: 02/08/2023]
Abstract
The Mediator complex, which in humans is 1.4 MDa in size and includes 26 subunits, controls many aspects of RNA polymerase II (Pol II) function. Apart from its size, a defining feature of Mediator is its intrinsic disorder and conformational flexibility, which contributes to its ability to undergo phase separation and to interact with a myriad of regulatory factors. In this Review, we discuss Mediator structure and function, with emphasis on recent cryogenic electron microscopy data of the 4.0-MDa transcription preinitiation complex. We further discuss how Mediator and sequence-specific DNA-binding transcription factors enable enhancer-dependent regulation of Pol II function at distal gene promoters, through the formation of molecular condensates (or transcription hubs) and chromatin loops. Mediator regulation of Pol II reinitiation is also discussed, in the context of transcription bursting. We propose a working model for Mediator function that combines experimental results and theoretical considerations related to enhancer-promoter interactions, which reconciles contradictory data regarding whether enhancer-promoter communication is direct or indirect. We conclude with a discussion of Mediator's potential as a therapeutic target and of future research directions.
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Affiliation(s)
- William F Richter
- Department of Biochemistry, University of Colorado, Boulder, CO, USA
| | - Shraddha Nayak
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Janet Iwasa
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Dylan J Taatjes
- Department of Biochemistry, University of Colorado, Boulder, CO, USA.
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14
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Tanemoto F, Nangaku M, Mimura I. Epigenetic memory contributing to the pathogenesis of AKI-to-CKD transition. Front Mol Biosci 2022; 9:1003227. [PMID: 36213117 PMCID: PMC9532834 DOI: 10.3389/fmolb.2022.1003227] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/24/2022] [Indexed: 11/18/2022] Open
Abstract
Epigenetic memory, which refers to the ability of cells to retain and transmit epigenetic marks to their daughter cells, maintains unique gene expression patterns. Establishing programmed epigenetic memory at each stage of development is required for cell differentiation. Moreover, accumulating evidence shows that epigenetic memory acquired in response to environmental stimuli may be associated with diverse diseases. In the field of kidney diseases, the “memory” of acute kidney injury (AKI) leads to progression to chronic kidney disease (CKD); epidemiological studies show that patients who recover from AKI are at high risk of developing CKD. The underlying pathological processes include nephron loss, maladaptive epithelial repair, inflammation, and endothelial injury with vascular rarefaction. Further, epigenetic alterations may contribute as well to the pathophysiology of this AKI-to-CKD transition. Epigenetic changes induced by AKI, which can be recorded in cells, exert long-term effects as epigenetic memory. Considering the latest findings on the molecular basis of epigenetic memory and the pathophysiology of AKI-to-CKD transition, we propose here that epigenetic memory contributing to AKI-to-CKD transition can be classified according to the presence or absence of persistent changes in the associated regulation of gene expression, which we designate “driving” memory and “priming” memory, respectively. “Driving” memory, which persistently alters the regulation of gene expression, may contribute to disease progression by activating fibrogenic genes or inhibiting renoprotective genes. This process may be involved in generating the proinflammatory and profibrotic phenotypes of maladaptively repaired tubular cells after kidney injury. “Priming” memory is stored in seemingly successfully repaired tubular cells in the absence of detectable persistent phenotypic changes, which may enhance a subsequent transcriptional response to the second stimulus. This type of memory may contribute to AKI-to-CKD transition through the cumulative effects of enhanced expression of profibrotic genes required for wound repair after recurrent AKI. Further understanding of epigenetic memory will identify therapeutic targets of future epigenetic intervention to prevent AKI-to-CKD transition.
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15
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Sertori R, Lin JX, Martinez E, Rana S, Sharo A, Kazemian M, Sunderam U, Andrake M, Shinton S, Truong B, Dunbrack RM, Liu C, Srinivasan R, Brenner SE, Seroogy CM, Puck JM, Leonard WJ, Wiest DL. Investigation of the causal etiology in a patient with T-B+NK+ immunodeficiency. Front Immunol 2022; 13:928252. [PMID: 35967429 PMCID: PMC9372720 DOI: 10.3389/fimmu.2022.928252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/27/2022] [Indexed: 11/24/2022] Open
Abstract
Newborn screening for severe combined immunodeficiency (SCID) has not only accelerated diagnosis and improved treatment for affected infants, but also led to identification of novel genes required for human T cell development. A male proband had SCID newborn screening showing very low T cell receptor excision circles (TRECs), a biomarker for thymic output of nascent T cells. He had persistent profound T lymphopenia, but normal numbers of B and natural killer (NK) cells. Despite an allogeneic hematopoietic stem cell transplant from his brother, he failed to develop normal T cells. Targeted resequencing excluded known SCID genes; however, whole exome sequencing (WES) of the proband and parents revealed a maternally inherited X-linked missense mutation in MED14 (MED14V763A), a component of the mediator complex. Morpholino (MO)-mediated loss of MED14 function attenuated T cell development in zebrafish. Moreover, this arrest was rescued by ectopic expression of cDNA encoding the wild type human MED14 ortholog, but not by MED14V763A , suggesting that the variant impaired MED14 function. Modeling of the equivalent mutation in mouse (Med14V769A) did not disrupt T cell development at baseline. However, repopulation of peripheral T cells upon competitive bone marrow transplantation was compromised, consistent with the incomplete T cell reconstitution experienced by the proband upon transplantation with bone marrow from his healthy male sibling, who was found to have the same MED14V763A variant. Suspecting that the variable phenotypic expression between the siblings was influenced by further mutation(s), we sought to identify genetic variants present only in the affected proband. Indeed, WES revealed a mutation in the L1 cell adhesion molecule (L1CAMQ498H); however, introducing that mutation in vivo in mice did not disrupt T cell development. Consequently, immunodeficiency in the proband may depend upon additional, unidentified gene variants.
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Affiliation(s)
- Robert Sertori
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA, United States
| | - Jian-Xin Lin
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung, and Blood Institute, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Esteban Martinez
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA, United States
| | - Sadhna Rana
- Innovation Labs, Tata Consultancy Services, Hyderabad, India
| | - Andrew Sharo
- Center for Computational Biology, University of California, Berkeley, CA, United States
| | - Majid Kazemian
- Departments of Biochemistry and Computer Science, Purdue University, West Lafayette, IN, United States
| | - Uma Sunderam
- Innovation Labs, Tata Consultancy Services, Hyderabad, India
| | - Mark Andrake
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, PA, United States
| | - Susan Shinton
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA, United States
| | - Billy Truong
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA, United States
| | - Roland M. Dunbrack
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, PA, United States
| | - Chengyu Liu
- Transgenic Core, National Heart, Lung, and Blood Institute, National Institutes of Health (NIH), Bethesda, MD, United States
| | | | - Steven E. Brenner
- Center for Computational Biology, University of California, Berkeley, CA, United States
| | - Christine M. Seroogy
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| | - Jennifer M. Puck
- Department of Pediatrics, University of California San Francisco and UCSF Benioff Children’s Hospital, San Francisco, CA, United States
| | - Warren J. Leonard
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung, and Blood Institute, National Institutes of Health (NIH), Bethesda, MD, United States
| | - David L. Wiest
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA, United States
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16
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Fatima M, Gao J, Han T, Ding Y, Zhang Y, Wen E, Jia L, Wang R, Wang W, Zhao S, Bai L, Liu E. MED1 Deficiency in Macrophages Aggravates Isoproterenol-Induced Cardiac Fibrosis in Mice. THE AMERICAN JOURNAL OF PATHOLOGY 2022; 192:1016-1027. [PMID: 35461855 DOI: 10.1016/j.ajpath.2022.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 03/24/2022] [Accepted: 03/31/2022] [Indexed: 06/14/2023]
Abstract
Mediator 1 (MED1), a key subunit of the mediator complex, interacts with various nuclear receptors and functions in lipid metabolism and energy homeostasis. Dilated cardiomyopathy-related ventricular dilatation and heart failure have been reported in mice with cardiomyocyte-specific Med1 deficiency. However, the contribution of macrophage-specific MED1 in cardiac remodeling remains unclear. In this study, macrophage-specific Med1 knockout (Med1ΔMac) mice were generated and exposed to isoproterenol (ISO) to induce cardiac fibrosis; these mice showed aggravated cardiac fibrosis compared with Med1fl/fl mice. The levels of expression of marker genes for myofibroblast transdifferentiation [α-smooth muscle actin (SMA)] and of profibrotic genes, including Col1a1, Col3a1, Postn, Mmp2, Timp1, and Fn1, were significantly increased in the cardiac tissues of Med1ΔMac mice with ISO-induced myocardial fibrosis. In particular, the transforming growth factor (TGF)-β-Smad2/3 signaling pathway was activated. In bone marrow-derived and peritoneal macrophages, Med1 deficiency was also associated with elevated levels of expression of proinflammatory genes, including Il6, Tnfa, and Il1b. These findings indicate that macrophage-specific MED1 deficiency may aggravate ISO-induced cardiac fibrosis via the regulation of the TGF-β-SMAD2/3 pathway, and the underlying mechanism may involve MED1 deficiency triggering the activation of inflammatory cytokines in macrophages, which in turn may stimulate phenotypic switch of cardiac fibroblasts and accelerate cardiac fibrosis. Thus, MED1 is a potential therapeutic target for cardiac fibrosis.
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Affiliation(s)
- Mehreen Fatima
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Jie Gao
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Tuo Han
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China
| | - Yiming Ding
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China
| | - Yali Zhang
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Ergang Wen
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Linying Jia
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Rong Wang
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Weirong Wang
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Sihai Zhao
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Liang Bai
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.
| | - Enqi Liu
- Institute of Cardiovascular Science, Translational Medicine Institute, Health Science Center, Xi'an Jiaotong University, Xi'an, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China.
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17
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XIST loss impairs mammary stem cell differentiation and increases tumorigenicity through Mediator hyperactivation. Cell 2022; 185:2164-2183.e25. [PMID: 35597241 DOI: 10.1016/j.cell.2022.04.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 01/10/2022] [Accepted: 04/27/2022] [Indexed: 12/27/2022]
Abstract
X inactivation (XCI) is triggered by upregulation of XIST, which coats the chromosome in cis, promoting formation of a heterochromatic domain (Xi). XIST role beyond initiation of XCI is only beginning to be elucidated. Here, we demonstrate that XIST loss impairs differentiation of human mammary stem cells (MaSCs) and promotes emergence of highly tumorigenic and metastatic carcinomas. On the Xi, XIST deficiency triggers epigenetic changes and reactivation of genes overlapping Polycomb domains, including Mediator subunit MED14. MED14 overdosage results in increased Mediator levels and hyperactivation of the MaSC enhancer landscape and transcriptional program, making differentiation less favorable. We further demonstrate that loss of XIST and Xi transcriptional instability is common among human breast tumors of poor prognosis. We conclude that XIST is a gatekeeper of human mammary epithelium homeostasis, thus unveiling a paradigm in the control of somatic cell identity with potential consequences for our understanding of gender-specific malignancies.
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18
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Bick G, Zhang J, Lower EE, Zhang X. Transcriptional coactivator MED1 in the interface of anti-estrogen and anti-HER2 therapeutic resistance. CANCER DRUG RESISTANCE (ALHAMBRA, CALIF.) 2022; 5:498-510. [PMID: 35800368 PMCID: PMC9255246 DOI: 10.20517/cdr.2022.33] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 03/30/2022] [Accepted: 04/02/2022] [Indexed: 11/18/2022]
Abstract
Breast cancer is one of the most common cancer and leading causes of death in women in the United States and Worldwide. About 90% of breast cancers belong to ER+ or HER2+ subtypes and are driven by key breast cancer genes Estrogen Receptor and HER2, respectively. Despite the advances in anti-estrogen (endocrine) and anti-HER2 therapies for the treatment of these breast cancer subtypes, unwanted side effects, frequent recurrence and resistance to these treatments remain major clinical challenges. Recent studies have identified ER coactivator MED1 as a key mediator of ER functions and anti-estrogen treatment resistance. Interestingly, MED1 is also coamplified with HER2 and activated by the HER2 signaling cascade, and plays critical roles in HER2-mediated tumorigenesis and response to anti-HER2 treatment as well. Thus, MED1 represents a novel crosstalk point of the HER2 and ER pathways and a highly promising new therapeutic target for ER+ and HER2+ breast cancer treatment. In this review, we will discuss the recent progress on the role of this key ER/HER2 downstream effector MED1 in breast cancer therapy resistance and our development of an innovative RNA nanotechnology-based approach to target MED1 for potential future breast cancer therapy to overcome treatment resistance.
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Affiliation(s)
- Gregory Bick
- Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Jasmine Zhang
- Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Elyse E. Lower
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA. ,University of Cincinnati Cancer Center, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Xiaoting Zhang
- Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.,Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA. ,University of Cincinnati Cancer Center, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.,Correspondence to: Prof. Xiaoting Zhang, Professor and Thomas Boat Endowed Chair, Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267, USA. E-mail:
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19
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Eigenhuis KN, Somsen HB, van den Berg DLC. Transcription Pause and Escape in Neurodevelopmental Disorders. Front Neurosci 2022; 16:846272. [PMID: 35615272 PMCID: PMC9125161 DOI: 10.3389/fnins.2022.846272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 04/11/2022] [Indexed: 11/17/2022] Open
Abstract
Transcription pause-release is an important, highly regulated step in the control of gene expression. Modulated by various factors, it enables signal integration and fine-tuning of transcriptional responses. Mutations in regulators of pause-release have been identified in a range of neurodevelopmental disorders that have several common features affecting multiple organ systems. This review summarizes current knowledge on this novel subclass of disorders, including an overview of clinical features, mechanistic details, and insight into the relevant neurodevelopmental processes.
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20
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Structural insights into nuclear transcription by eukaryotic DNA-dependent RNA polymerases. Nat Rev Mol Cell Biol 2022; 23:603-622. [PMID: 35505252 DOI: 10.1038/s41580-022-00476-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2022] [Indexed: 02/07/2023]
Abstract
The eukaryotic transcription apparatus synthesizes a staggering diversity of RNA molecules. The labour of nuclear gene transcription is, therefore, divided among multiple DNA-dependent RNA polymerases. RNA polymerase I (Pol I) transcribes ribosomal RNA, Pol II synthesizes messenger RNAs and various non-coding RNAs (including long non-coding RNAs, microRNAs and small nuclear RNAs) and Pol III produces transfer RNAs and other short RNA molecules. Pol I, Pol II and Pol III are large, multisubunit protein complexes that associate with a multitude of additional factors to synthesize transcripts that largely differ in size, structure and abundance. The three transcription machineries share common characteristics, but differ widely in various aspects, such as numbers of RNA polymerase subunits, regulatory elements and accessory factors, which allows them to specialize in transcribing their specific RNAs. Common to the three RNA polymerases is that the transcription process consists of three major steps: transcription initiation, transcript elongation and transcription termination. In this Review, we outline the common principles and differences between the Pol I, Pol II and Pol III transcription machineries and discuss key structural and functional insights obtained into the three stages of their transcription processes.
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21
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22
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Chen Z, Ye Z, Soccio RE, Nakadai T, Hankey W, Zhao Y, Huang F, Yuan F, Wang H, Cui Z, Sunkel B, Wu D, Dzeng RK, Thomas-Ahner JM, Huang THM, Clinton SK, Huang J, Lazar MA, Jin VX, Roeder RG, Wang Q. Phosphorylated MED1 links transcription recycling and cancer growth. Nucleic Acids Res 2022; 50:4450-4463. [PMID: 35394046 PMCID: PMC9071494 DOI: 10.1093/nar/gkac246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/10/2022] [Accepted: 03/29/2022] [Indexed: 11/29/2022] Open
Abstract
Mediator activates RNA polymerase II (Pol II) function during transcription, but it remains unclear whether Mediator is able to travel with Pol II and regulate Pol II transcription beyond the initiation and early elongation steps. By using in vitro and in vivo transcription recycling assays, we find that human Mediator 1 (MED1), when phosphorylated at the mammal-specific threonine 1032 by cyclin-dependent kinase 9 (CDK9), dynamically moves along with Pol II throughout the transcribed genes to drive Pol II recycling after the initial round of transcription. Mechanistically, MED31 mediates the recycling of phosphorylated MED1 and Pol II, enhancing mRNA output during the transcription recycling process. Importantly, MED1 phosphorylation increases during prostate cancer progression to the lethal phase, and pharmacological inhibition of CDK9 decreases prostate tumor growth by decreasing MED1 phosphorylation and Pol II recycling. Our results reveal a novel role of MED1 in Pol II transcription and identify phosphorylated MED1 as a targetable driver of dysregulated Pol II recycling in cancer.
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Affiliation(s)
- Zhong Chen
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Zhenqing Ye
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, 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 at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tomoyoshi Nakadai
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, NY 10065, USA
| | - William Hankey
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Yue Zhao
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA.,Department of Pathology, College of Basic Medical Sciences and First Affiliated Hospital, China Medical University, Shenyang 110122, China
| | - Furong Huang
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Fuwen Yuan
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Hongyan Wang
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Zhifen Cui
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Benjamin Sunkel
- Department of Cancer Biology and Genetics, The Ohio State University College of Medicine, Columbus, OH 43210, USA
| | - Dayong Wu
- Department of Cancer Biology and Genetics, The Ohio State University College of Medicine, Columbus, OH 43210, USA
| | - Richard K Dzeng
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Department of Genetics, and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jennifer M Thomas-Ahner
- Division of Medical Oncology, The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Tim H M Huang
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Steven K Clinton
- Division of Medical Oncology, The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Jiaoti Huang
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, 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 at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Victor X Jin
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Robert G Roeder
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, NY 10065, USA
| | - Qianben Wang
- Department of Pathology and Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA
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Willis SD, Hanley SE, Doyle SJ, Beluch K, Strich R, Cooper KF. Cyclin C-Cdk8 Kinase Phosphorylation of Rim15 Prevents the Aberrant Activation of Stress Response Genes. Front Cell Dev Biol 2022; 10:867257. [PMID: 35433688 PMCID: PMC9008841 DOI: 10.3389/fcell.2022.867257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/22/2022] [Indexed: 11/13/2022] Open
Abstract
Cells facing adverse environmental cues respond by inducing signal transduction pathways resulting in transcriptional reprograming. In the budding yeast Saccharomyces cerevisiae, nutrient deprivation stimulates stress response gene (SRG) transcription critical for entry into either quiescence or gametogenesis depending on the cell type. The induction of a subset of SRGs require nuclear translocation of the conserved serine-threonine kinase Rim15. However, Rim15 is also present in unstressed nuclei suggesting that additional activities are required to constrain its activity in the absence of stress. Here we show that Rim15 is directly phosphorylated by cyclin C-Cdk8, the conserved kinase module of the Mediator complex. Several results indicate that Cdk8-dependent phosphorylation prevents Rim15 activation in unstressed cells. First, Cdk8 does not control Rim15 subcellular localization and rim15∆ is epistatic to cdk8∆ with respect to SRG transcription and the execution of starvation programs required for viability. Next, Cdk8 phosphorylates a residue in the conserved PAS domain in vitro. This modification appears important as introducing a phosphomimetic at Cdk8 target residues reduces Rim15 activity. Moreover, the Rim15 phosphomimetic only compromises cell viability in stresses that induce cyclin C destruction as well as entrance into meiosis. Taken together, these findings suggest a model in which Cdk8 phosphorylation contributes to Rim15 repression whilst it cycles through the nucleus. Cyclin C destruction in response to stress inactivates Cdk8 which in turn stimulates Rim15 to maximize SRG transcription and cell survival.
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24
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Yang C, Fujiwara R, Kim HJ, Basnet P, Zhu Y, Colón JJG, Steimle S, Garcia BA, Kaplan CD, Murakami K. Structural visualization of de novo transcription initiation by Saccharomyces cerevisiae RNA polymerase II. Mol Cell 2022; 82:660-676.e9. [PMID: 35051353 PMCID: PMC8818039 DOI: 10.1016/j.molcel.2021.12.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 11/04/2021] [Accepted: 12/15/2021] [Indexed: 02/05/2023]
Abstract
Previous structural studies of the initiation-elongation transition of RNA polymerase II (pol II) transcription have relied on the use of synthetic oligonucleotides, often artificially discontinuous to capture pol II in the initiating state. Here, we report multiple structures of initiation complexes converted de novo from a 33-subunit yeast pre-initiation complex (PIC) through catalytic activities and subsequently stalled at different template positions. We determine that PICs in the initially transcribing complex (ITC) can synthesize a transcript of ∼26 nucleotides before transitioning to an elongation complex (EC) as determined by the loss of general transcription factors (GTFs). Unexpectedly, transition to an EC was greatly accelerated when an ITC encountered a downstream EC stalled at promoter proximal regions and resulted in a collided head-to-end dimeric EC complex. Our structural analysis reveals a dynamic state of TFIIH, the largest of GTFs, in PIC/ITC with distinct functional consequences at multiple steps on the pathway to elongation.
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Affiliation(s)
- Chun Yang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A
| | - Rina Fujiwara
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A.,Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Hee Jong Kim
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A.,Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA,Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Pratik Basnet
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Yunye Zhu
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Jose J. Gorbea Colón
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A.,Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Stefan Steimle
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A
| | - Benjamin A. Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A.,Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Craig D. Kaplan
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Kenji Murakami
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A.,Lead contact,Correspondence to:
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25
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MED1 Deficiency in Macrophages Accelerates Intimal Hyperplasia via ROS Generation and Inflammation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:3010577. [PMID: 34853629 PMCID: PMC8629658 DOI: 10.1155/2021/3010577] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/17/2021] [Accepted: 11/07/2021] [Indexed: 11/17/2022]
Abstract
Mediator complex subunit 1 (MED1) is a component of the mediator complex and functions as a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Previously, we showed that MED1 in macrophages has a protective effect on atherosclerosis; however, the effect of MED1 on intimal hyperplasia and mechanisms regulating proinflammatory cytokine production after macrophage MED1 deletion are still unknown. In this study, we report that MED1 macrophage-specific knockout (MED1 ΔMac) mice showed aggravated neointimal hyperplasia, vascular smooth muscle cells (VSMCs), and macrophage accumulation in injured arteries. Moreover, MED1 ΔMac mice showed increased proinflammatory cytokine production after an injury to the artery. After lipopolysaccharide (LPS) treatment, MED1 ΔMac macrophages showed increased generation of reactive oxygen species (ROS) and reduced expression of peroxisome proliferative activated receptor gamma coactivator-1α (PGC1α) and antioxidant enzymes, including catalase and glutathione reductase. The overexpression of PGC1α attenuated the effects of MED1 deficiency in macrophages. In vitro, conditioned media from MED1 ΔMac macrophages induced more proliferation and migration of VSMCs. To explore the potential mechanisms by which MED1 affects inflammation, macrophages were treated with BAY11-7082 before LPS treatment, and the results showed that MED1 ΔMac macrophages exhibited increased expression of phosphorylated-p65 and phosphorylated signal transducer and activator of transcription 1 (p-STAT1) compared with the control macrophages, suggesting the enhanced activation of NF-κB and STAT1. In summary, these data showed that MED1 deficiency enhanced inflammation and the proliferation and migration of VSMCs in injured vascular tissue, which may result from the activation of NF-κB and STAT1 due to the accumulation of ROS.
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26
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Bhardwaj R, Thakur JK, Kumar S. MedProDB: A database of Mediator proteins. Comput Struct Biotechnol J 2021; 19:4165-4176. [PMID: 34527190 PMCID: PMC8342855 DOI: 10.1016/j.csbj.2021.07.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 07/08/2021] [Accepted: 07/24/2021] [Indexed: 12/03/2022] Open
Abstract
Mediator complex is a key component of transcriptional regulation in eukaryotes. Identification of Mediator subunits was done by using computational approaches. Different physicochemical properties, and functions of Mediators were discussed. We have developed first database of Mediator proteins e.g. MedProDB. MedProDB contains different types of search and browse options, and various tools.
In the last three decades, the multi-subunit Mediator complex has emerged as the key component of transcriptional regulation of eukaryotic gene expression. Although there were initial hiccups, recent advancements in bioinformatics tools contributed significantly to in-silico prediction and characterization of Mediator subunits from several organisms belonging to different eukaryotic kingdoms. In this study, we have developed the first database of Mediator proteins named MedProDB with 33,971 Mediator protein entries. Out of those, 12531, 11545, and 9895 sequences belong to metazoans, plants, and fungi, respectively. Apart from the core information consisting of sequence, length, position, organism, molecular weight, and taxonomic lineage, additional information of each Mediator sequence like aromaticity, hydropathy, instability index, isoelectric point, functions, interactions, repeat regions, diseases, sequence alignment to Mediator subunit family, Intrinsically Disordered Regions (IDRs), Post-translation modifications (PTMs), and Molecular Recognition Features (MoRFs) may be of high utility to the users. Furthermore, different types of search and browse options with four different tools namely BLAST, Smith-Waterman Align, IUPred, and MoRF-Chibi_Light are provided at MedProDB to perform different types of analysis. Being a critical component of the transcriptional machinery and regulating almost all the aspects of transcription, it generated lots of interest in structural and functional studies of Mediator functioning. So, we think that the MedProDB database will be very useful for researchers studying the process of transcription. This database is freely available at www.nipgr.ac.in/MedProDB.
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Affiliation(s)
- Rohan Bhardwaj
- Bioinformatics Lab, National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India.,Plant Mediator Lab, National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Jitendra Kumar Thakur
- Plant Mediator Lab, National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India.,Plant Transcription Regulation, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Shailesh Kumar
- Bioinformatics Lab, National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi 110067, India
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27
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Sun F, Sun T, Kronenberg M, Tan X, Huang C, Carey MF. The Pol II preinitiation complex (PIC) influences Mediator binding but not promoter-enhancer looping. Genes Dev 2021; 35:1175-1189. [PMID: 34301767 PMCID: PMC8336890 DOI: 10.1101/gad.348471.121] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 06/24/2021] [Indexed: 02/05/2023]
Abstract
Knowledge of how Mediator and TFIID cross-talk contributes to promoter-enhancer (P-E) communication is important for elucidating the mechanism of enhancer function. We conducted an shRNA knockdown screen in murine embryonic stem cells to identify the functional overlap between Mediator and TFIID subunits on gene expression. Auxin-inducible degrons were constructed for TAF12 and MED4, the subunits eliciting the greatest overlap. Degradation of TAF12 led to a dramatic genome-wide decrease in gene expression accompanied by destruction of TFIID, loss of Pol II preinitiation complex (PIC) at promoters, and significantly decreased Mediator binding to promoters and enhancers. Interestingly, loss of the PIC elicited only a mild effect on P-E looping by promoter capture Hi-C (PCHi-C). Degradation of MED4 had a minor effect on Mediator integrity but led to a consistent twofold loss in gene expression, decreased binding of Pol II to Mediator, and decreased recruitment of Pol II to the promoters, but had no effect on the other PIC components. PCHi-C revealed no consistent effect of MED4 degradation on P-E looping. Collectively, our data show that TAF12 and MED4 contribute mechanistically in different ways to P-E communication but neither factor appears to directly control P-E looping, thereby dissociating P-E communication from physical looping.
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Affiliation(s)
- Fei Sun
- Department of Biological Chemistry, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Terrence Sun
- Department of Biological Chemistry, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Michael Kronenberg
- Department of Biological Chemistry, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Xianglong Tan
- Department of Biological Chemistry, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Chengyang Huang
- Center for Neurobiology, Shantou University Medical College, Shantou 515041, China
| | - Michael F Carey
- Department of Biological Chemistry, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, California 90095, USA
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28
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Schier AC, Taatjes DJ. Everything at once: cryo-EM yields remarkable insights into human RNA polymerase II transcription. Nat Struct Mol Biol 2021; 28:540-543. [PMID: 34131334 PMCID: PMC10676001 DOI: 10.1038/s41594-021-00613-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
After years of only low-resolution and partial assemblies, the entire human pre-initiation complex (PIC), including the large and flexible Mediator and TFIID complexes, has come into focus. Five recent papers from three different research groups have transformed our understanding of transcription initiation by RNA polymerase II.
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Affiliation(s)
| | - Dylan J Taatjes
- Dept. of Biochemistry, University of Colorado, Boulder, CO, USA.
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29
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Stanek TJ, Gennaro VJ, Tracewell MA, Di Marcantonio D, Pauley KL, Butt S, McNair C, Wang F, Kossenkov AV, Knudsen KE, Butt T, Sykes SM, McMahon SB. The SAGA complex regulates early steps in transcription via its deubiquitylase module subunit USP22. EMBO J 2021; 40:e102509. [PMID: 34155658 PMCID: PMC8365265 DOI: 10.15252/embj.2019102509] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 04/10/2021] [Accepted: 04/26/2021] [Indexed: 12/12/2022] Open
Abstract
The SAGA coactivator complex is essential for eukaryotic transcription and comprises four distinct modules, one of which contains the ubiquitin hydrolase USP22. In yeast, the USP22 ortholog deubiquitylates H2B, resulting in Pol II Ser2 phosphorylation and subsequent transcriptional elongation. In contrast to this H2B-associated role in transcription, we report here that human USP22 contributes to the early stages of stimulus-responsive transcription, where USP22 is required for pre-initiation complex (PIC) stability. Specifically, USP22 maintains long-range enhancer-promoter contacts and controls loading of Mediator tail and general transcription factors (GTFs) onto promoters, with Mediator core recruitment being USP22-independent. In addition, we identify Mediator tail subunits MED16 and MED24 and the Pol II subunit RBP1 as potential non-histone substrates of USP22. Overall, these findings define a role for human SAGA within the earliest steps of transcription.
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Affiliation(s)
- Timothy J Stanek
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Victoria J Gennaro
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Mason A Tracewell
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Daniela Di Marcantonio
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Kristen L Pauley
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Sabrina Butt
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Christopher McNair
- Department of Cancer Biology, Sidney Kimmel Medical College and Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | | | | | - Karen E Knudsen
- Department of Cancer Biology, Sidney Kimmel Medical College and Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Stephen M Sykes
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Steven B McMahon
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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30
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Compe E, Egly JM. The Long Road to Understanding RNAPII Transcription Initiation and Related Syndromes. Annu Rev Biochem 2021; 90:193-219. [PMID: 34153211 DOI: 10.1146/annurev-biochem-090220-112253] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In eukaryotes, transcription of protein-coding genes requires the assembly at core promoters of a large preinitiation machinery containing RNA polymerase II (RNAPII) and general transcription factors (GTFs). Transcription is potentiated by regulatory elements called enhancers, which are recognized by specific DNA-binding transcription factors that recruit cofactors and convey, following chromatin remodeling, the activating cues to the preinitiation complex. This review summarizes nearly five decades of work on transcription initiation by describing the sequential recruitment of diverse molecular players including the GTFs, the Mediator complex, and DNA repair factors that support RNAPII to enable RNA synthesis. The elucidation of the transcription initiation mechanism has greatly benefited from the study of altered transcription components associated with human diseases that could be considered transcription syndromes.
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Affiliation(s)
- Emmanuel Compe
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS, INSERM, Université de Strasbourg, 67404 Illkirch CEDEX, Commune Urbaine de Strasbourg, France; ,
| | - Jean-Marc Egly
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS, INSERM, Université de Strasbourg, 67404 Illkirch CEDEX, Commune Urbaine de Strasbourg, France; , .,College of Medicine, National Taiwan University, Taipei 10051, Taiwan
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31
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Chen X, Yin X, Li J, Wu Z, Qi Y, Wang X, Liu W, Xu Y. Structures of the human Mediator and Mediator-bound preinitiation complex. Science 2021; 372:science.abg0635. [DOI: 10.1126/science.abg0635] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/15/2021] [Accepted: 04/27/2021] [Indexed: 12/18/2022]
Abstract
The 1.3-megadalton transcription factor IID (TFIID) is required for preinitiation complex (PIC) assembly and RNA polymerase II (Pol II)–mediated transcription initiation on almost all genes. The 26-subunit Mediator stimulates transcription and cyclin-dependent kinase 7 (CDK7)–mediated phosphorylation of the Pol II C-terminal domain (CTD). We determined the structures of human Mediator in the Tail module–extended (at near-atomic resolution) and Tail-bent conformations and structures of TFIID-based PIC-Mediator (76 polypeptides, ~4.1 megadaltons) in four distinct conformations. PIC-Mediator assembly induces concerted reorganization (Head-tilting and Middle-down) of Mediator and creates a Head-Middle sandwich, which stabilizes two CTD segments and brings CTD to CDK7 for phosphorylation; this suggests a CTD-gating mechanism favorable for phosphorylation. The TFIID-based PIC architecture modulates Mediator organization and TFIIH stabilization, underscoring the importance of TFIID in orchestrating PIC-Mediator assembly.
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Affiliation(s)
- Xizi Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xiaotong Yin
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Jiabei Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zihan Wu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yilun Qi
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xinxin Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Weida Liu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
- International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
- Human Phenome Institute, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200433, China
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32
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Structure of the human Mediator–RNA polymerase II pre-initiation complex. Nature 2021; 594:129-133. [DOI: 10.1038/s41586-021-03555-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/14/2021] [Indexed: 12/25/2022]
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33
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Abdella R, Talyzina A, Chen S, Inouye CJ, Tjian R, He Y. Structure of the human Mediator-bound transcription preinitiation complex. Science 2021; 372:52-56. [PMID: 33707221 PMCID: PMC8117670 DOI: 10.1126/science.abg3074] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/03/2021] [Indexed: 12/24/2022]
Abstract
Eukaryotic transcription requires the assembly of a multisubunit preinitiation complex (PIC) composed of RNA polymerase II (Pol II) and the general transcription factors. The coactivator Mediator is recruited by transcription factors, facilitates the assembly of the PIC, and stimulates phosphorylation of the Pol II C-terminal domain (CTD) by the TFIIH subunit CDK7. Here, we present the cryo-electron microscopy structure of the human Mediator-bound PIC at a resolution below 4 angstroms. Transcription factor binding sites within Mediator are primarily flexibly tethered to the tail module. CDK7 is stabilized by multiple contacts with Mediator. Two binding sites exist for the Pol II CTD, one between the head and middle modules of Mediator and the other in the active site of CDK7, providing structural evidence for Pol II CTD phosphorylation within the Mediator-bound PIC.
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Affiliation(s)
- R Abdella
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - A Talyzina
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - S Chen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - C J Inouye
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, Berkeley, CA, USA
- CIRM Center of Excellence, University of California, Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA
| | - R Tjian
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
- Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, Berkeley, CA, USA
- CIRM Center of Excellence, University of California, Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Y He
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, Chicago, IL, USA
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34
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van Eeuwen T, Li T, Kim HJ, Gorbea Colón JJ, Parker MI, Dunbrack RL, Garcia BA, Tsai KL, Murakami K. Structure of TFIIK for phosphorylation of CTD of RNA polymerase II. SCIENCE ADVANCES 2021; 7:eabd4420. [PMID: 33827808 PMCID: PMC8026125 DOI: 10.1126/sciadv.abd4420] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
During transcription initiation, the general transcription factor TFIIH marks RNA polymerase II by phosphorylating Ser5 of the carboxyl-terminal domain (CTD) of Rpb1, which is followed by extensive modifications coupled to transcription elongation, mRNA processing, and histone dynamics. We have determined a 3.5-Å resolution cryo-electron microscopy (cryo-EM) structure of the TFIIH kinase module (TFIIK in yeast), which is composed of Kin28, Ccl1, and Tfb3, yeast homologs of CDK7, cyclin H, and MAT1, respectively. The carboxyl-terminal region of Tfb3 was lying at the edge of catalytic cleft of Kin28, where a conserved Tfb3 helix served to stabilize the activation loop in its active conformation. By combining the structure of TFIIK with the previous cryo-EM structure of the preinitiation complex, we extend the previously proposed model of the CTD path to the active site of TFIIK.
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Affiliation(s)
- Trevor van Eeuwen
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tao Li
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Hee Jong Kim
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jose J Gorbea Colón
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitchell I Parker
- Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
- Molecular and Cell Biology and Genetics Program, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | - Roland L Dunbrack
- Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Benjamin A Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kuang-Lei Tsai
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| | - Kenji Murakami
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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35
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Chen X, Qi Y, Wu Z, Wang X, Li J, Zhao D, Hou H, Li Y, Yu Z, Liu W, Wang M, Ren Y, Li Z, Yang H, Xu Y. Structural insights into preinitiation complex assembly on core promoters. Science 2021; 372:science.aba8490. [PMID: 33795473 DOI: 10.1126/science.aba8490] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 02/01/2021] [Accepted: 03/25/2021] [Indexed: 12/24/2022]
Abstract
Transcription factor IID (TFIID) recognizes core promoters and supports preinitiation complex (PIC) assembly for RNA polymerase II (Pol II)-mediated eukaryotic transcription. We determined the structures of human TFIID-based PIC in three stepwise assembly states and revealed two-track PIC assembly: stepwise promoter deposition to Pol II and extensive modular reorganization on track I (on TATA-TFIID-binding element promoters) versus direct promoter deposition on track II (on TATA-only and TATA-less promoters). The two tracks converge at an ~50-subunit holo PIC in identical conformation, whereby TFIID stabilizes PIC organization and supports loading of cyclin-dependent kinase (CDK)-activating kinase (CAK) onto Pol II and CAK-mediated phosphorylation of the Pol II carboxyl-terminal domain. Unexpectedly, TBP of TFIID similarly bends TATA box and TATA-less promoters in PIC. Our study provides structural visualization of stepwise PIC assembly on highly diversified promoters.
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Affiliation(s)
- Xizi Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yilun Qi
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zihan Wu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xinxin Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Jiabei Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Dan Zhao
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Haifeng Hou
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yan Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zishuo Yu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Weida Liu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Mo Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yulei Ren
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Ze Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Huirong Yang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China. .,The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China.,Human Phenome Institute, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200433, China
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Meng L, Isohanni P, Shao Y, Graham BH, Hickey SE, Brooks S, Suomalainen A, Joset P, Steindl K, Rauch A, Hackenberg A, High FA, Armstrong-Javors A, Mencacci NE, Gonzàlez-Latapi P, Kamel WA, Al-Hashel JY, Bustos BI, Hernandez AV, Krainc D, Lubbe SJ, Van Esch H, De Luca C, Ballon K, Ravelli C, Burglen L, Qebibo L, Calame DG, Mitani T, Marafi D, Pehlivan D, Saadi NW, Sahin Y, Maroofian R, Efthymiou S, Houlden H, Maqbool S, Rahman F, Gu S, Posey JE, Lupski JR, Hunter JV, Wangler MF, Carroll CJ, Yang Y. MED27 Variants Cause Developmental Delay, Dystonia, and Cerebellar Hypoplasia. Ann Neurol 2021; 89:828-833. [PMID: 33443317 DOI: 10.1002/ana.26019] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 01/10/2021] [Accepted: 01/11/2021] [Indexed: 12/30/2022]
Abstract
The Mediator multiprotein complex functions as a regulator of RNA polymerase II-catalyzed gene transcription. In this study, exome sequencing detected biallelic putative disease-causing variants in MED27, encoding Mediator complex subunit 27, in 16 patients from 11 families with a novel neurodevelopmental syndrome. Patient phenotypes are highly homogeneous, including global developmental delay, intellectual disability, axial hypotonia with distal spasticity, dystonic movements, and cerebellar hypoplasia. Seizures and cataracts were noted in severely affected individuals. Identification of multiple patients with biallelic MED27 variants supports the critical role of MED27 in normal human neural development, particularly for the cerebellum. ANN NEUROL 2021;89:828-833.
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Affiliation(s)
- Linyan Meng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Baylor Genetics, Houston, TX
| | - Pirjo Isohanni
- Research Programs Unit, Stem Cells and Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Child Neurology, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Yunru Shao
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Department of Pediatrics, Baylor College of Medicine, Houston, TX
- Texas Children's Hospital, Houston, TX
| | - Brett H Graham
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
| | - Scott E Hickey
- Department of Pediatrics, Ohio State University College of Medicine, Division of Genetic and Genomic Medicine, Nationwide Children's Hospital, Columbus, OH
| | - Stephanie Brooks
- Department of Pediatrics, Ohio State University College of Medicine, Division of Genetic and Genomic Medicine, Nationwide Children's Hospital, Columbus, OH
| | - Anu Suomalainen
- Research Programs Unit, Stem Cells and Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Pascal Joset
- Institute of Medical Genetics, University of Zürich, Schlieren-Zürich, Switzerland
| | - Katharina Steindl
- Institute of Medical Genetics, University of Zürich, Schlieren-Zürich, Switzerland
| | - Anita Rauch
- Institute of Medical Genetics, University of Zürich, Schlieren-Zürich, Switzerland
| | - Annette Hackenberg
- Department of Pediatric Neurology, University Children's Hospital Zürich, University of Zürich, Zürich, Switzerland
| | - Frances A High
- Division of Medical Genetics, Massachusetts General Hospital, Boston, MA
- Harvard Medical School, Boston, MA
| | - Amy Armstrong-Javors
- Harvard Medical School, Boston, MA
- Department of Pediatric Neurology, Massachusetts General Hospital, Boston, MA
| | - Niccolò E Mencacci
- Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL
- Simpson Querrey Center for Neurogenetics, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Paulina Gonzàlez-Latapi
- Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Walaa A Kamel
- Department of Neurology, Ibn Sina Hospital, Kuwait City, Kuwait
- Department of Neurology, Faculty of Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Jasem Y Al-Hashel
- Department of Neurology, Ibn Sina Hospital, Kuwait City, Kuwait
- Department of Medicine, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Bernabé I Bustos
- Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL
- Simpson Querrey Center for Neurogenetics, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Alejandro V Hernandez
- Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Dimitri Krainc
- Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL
- Simpson Querrey Center for Neurogenetics, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Steven J Lubbe
- Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL
- Simpson Querrey Center for Neurogenetics, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Hilde Van Esch
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Chiara De Luca
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Katleen Ballon
- Centre for Developmental Disabilities, University Hospitals Leuven, Leuven, Belgium
| | - Claudia Ravelli
- Pediatric Neurology Department, Neurogenetics Reference Center, I-motion Institute, Public Hospital Network of Paris, Sorbonne University, Armand Trousseau Hospital, Paris, France
| | - Lydie Burglen
- Cerebellar Malformations and Congenital Diseases Reference Center and Neurogenetics Lab, Department of Genetics, Public Hospital Network of Paris, Sorbonne University, Armand Trousseau Hospital, Paris, France
- Developmental Brain Disorders Laboratory, Imagine Institute, Paris, France
| | - Leila Qebibo
- Cerebellar Malformations and Congenital Diseases Reference Center and Neurogenetics Lab, Department of Genetics, Public Hospital Network of Paris, Sorbonne University, Armand Trousseau Hospital, Paris, France
| | - Daniel G Calame
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Texas Children's Hospital, Houston, TX
- Division of Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Tadahiro Mitani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Dana Marafi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Department of Pediatrics, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Texas Children's Hospital, Houston, TX
- Division of Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Nebal W Saadi
- College of Medicine, Baghdad University, Baghdad, Iraq
- Children Welfare Teaching Hospital, Baghdad, Iraq
| | - Yavuz Sahin
- Department of Medical Genetics, Genoks Genetic Center, Ankara, Turkey
| | - Reza Maroofian
- Department of Neuromuscular Disorders, University College London Institute of Neurology, London, UK
| | - Stephanie Efthymiou
- Department of Neuromuscular Disorders, University College London Institute of Neurology, London, UK
| | - Henry Houlden
- Department of Neuromuscular Disorders, University College London Institute of Neurology, London, UK
| | - Shazia Maqbool
- Development and Behavioral Pediatrics Department, Institute of Child Health and Children Hospital, Lahore, Pakistan
| | - Fatima Rahman
- Development and Behavioral Pediatrics Department, Institute of Child Health and Children Hospital, Lahore, Pakistan
| | - Shen Gu
- School of Biomedical Sciences, Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Department of Pediatrics, Baylor College of Medicine, Houston, TX
- Texas Children's Hospital, Houston, TX
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
| | - Jill V Hunter
- Edward B. Singleton Department of Pediatric Radiology, Texas Children's Hospital, Houston, TX
- Department of Radiology, Baylor College of Medicine, Houston, TX
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Department of Child Neurology, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Jan and Dan Neurological Research Institute, Texas Children's Hospital, Houston, TX
| | - Christopher J Carroll
- Research Programs Unit, Stem Cells and Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London, United Kingdom
| | - Yaping Yang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Baylor Genetics, Houston, TX
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37
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Ohama N, Moo TL, Chua NH. Differential requirement of MED14/17 recruitment for activation of heat inducible genes. THE NEW PHYTOLOGIST 2021; 229:3360-3376. [PMID: 33251584 DOI: 10.1111/nph.17119] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 11/09/2020] [Indexed: 05/06/2023]
Abstract
The mechanism of heat stress response in plants has been studied, focusing on the function of transcription factors (TFs). Generally, TFs recruit coactivators, such as Mediator, are needed to assemble the transcriptional machinery. However, despite the close relationship with TFs, how coactivators are involved in transcriptional regulation under heat stress conditions is largely unclear. We found a severe thermosensitive phenotype of Arabidopsis mutants of MED14 and MED17. Transcriptomic analysis revealed that a quarter of the heat stress (HS)-inducible genes were commonly downregulated in these mutants. Furthermore, chromatin immunoprecipitation assay showed that the recruitment of Mediator by HsfA1s, the master regulators of heat stress response, is an important step for the expression of HS-inducible genes. There was a differential requirement of Mediator among genes; TF genes have a high requirement whereas heat shock proteins (HSPs) have a low requirement. Furthermore, artificial activation of HsfA1d mimicking perturbation of protein homeostasis induced HSP gene expression without MED14 recruitment but not TF gene expression. Considering the essential role of MED14 in Mediator function, other coactivators may play major roles in HSP activation depending on the cellular conditions. Our findings highlight the importance of differential recruitment of Mediator for the precise control of HS responses in plants.
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Affiliation(s)
- Naohiko Ohama
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604, Singapore
| | - Teck Lim Moo
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604, Singapore
| | - Nam-Hai Chua
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604, Singapore
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38
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Zhao H, Young N, Kalchschmidt J, Lieberman J, El Khattabi L, Casellas R, Asturias FJ. Structure of mammalian Mediator complex reveals Tail module architecture and interaction with a conserved core. Nat Commun 2021; 12:1355. [PMID: 33649303 PMCID: PMC7921410 DOI: 10.1038/s41467-021-21601-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 02/01/2021] [Indexed: 01/04/2023] Open
Abstract
The Mediator complex plays an essential and multi-faceted role in regulation of RNA polymerase II transcription in all eukaryotes. Structural analysis of yeast Mediator has provided an understanding of the conserved core of the complex and its interaction with RNA polymerase II but failed to reveal the structure of the Tail module that contains most subunits targeted by activators and repressors. Here we present a molecular model of mammalian (Mus musculus) Mediator, derived from a 4.0 Å resolution cryo-EM map of the complex. The mammalian Mediator structure reveals that the previously unresolved Tail module, which includes a number of metazoan specific subunits, interacts extensively with core Mediator and has the potential to influence its conformation and interactions.
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Affiliation(s)
- Haiyan Zhao
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical School, Aurora, CO, USA
| | - Natalie Young
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical School, Aurora, CO, USA
| | | | | | - Laila El Khattabi
- Institut Cochin Laboratoire de Cytogénétique Constitutionnelle Pré et Post Natale, Paris, France
| | - Rafael Casellas
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD, USA.,Center for Cancer Research, NCI, NIH, Bethesda, MD, USA
| | - Francisco J Asturias
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical School, Aurora, CO, USA.
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39
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Sweta K, Sharma N. Functional interaction between ELL transcription elongation factor and Epe1 reveals the role of Epe1 in the regulation of transcription outside heterochromatin. Mol Microbiol 2021; 116:80-96. [PMID: 33533152 DOI: 10.1111/mmi.14691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 11/30/2022]
Abstract
Eleven-nineteen lysine-rich leukemia (ELL) is a eukaryotic RNA polymerase II transcription elongation factor. In Schizosaccharomyces pombe, it is important for survival under genotoxic stress conditions. However, the molecular basis underlying this function of ELL in S. pombe is yet to be deciphered. Here, we carried out a genetic screen to identify multicopy suppressor(s) that could restore normal growth of ell1 deletion mutant in the presence of DNA damaging agent. Sequence analysis of the identified suppressors revealed the anti-silencing protein, Epe1, as one of the suppressors of ell1 deletion associated genotoxic stress sensitivity. Our results further demonstrate that the overexpression of Epe1 could suppress all other phenotypes associated with the absence of Ell1. Moreover, transcriptional defect of ell1Δ strain could also be alleviated by the overexpression of Epe1. Epe1 also showed a physical interaction with Ell1. Interestingly, we also observed that the region of Epe1 encompassing 403-948 amino acids was indispensable for all the above functions. Furthermore, our results show that the overexpression of Epe1 causes increased H3K9 acetylation and RNA polymerase II recruitment. Taken together, our results show a functional interaction between Epe1 and Ell1, and this function is independent of the well-known JmjC and N-terminal transcriptional activation domains of Epe1 in S. pombe.
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Affiliation(s)
- Kumari Sweta
- University School of Biotechnology, G.G.S. Indraprastha University, New Delhi, India
| | - Nimisha Sharma
- University School of Biotechnology, G.G.S. Indraprastha University, New Delhi, India
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40
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Zhang H, Chen DH, Mattoo RUH, Bushnell DA, Wang Y, Yuan C, Wang L, Wang C, Davis RE, Nie Y, Kornberg RD. Mediator structure and conformation change. Mol Cell 2021; 81:1781-1788.e4. [PMID: 33571424 DOI: 10.1016/j.molcel.2021.01.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/29/2020] [Accepted: 01/19/2021] [Indexed: 01/22/2023]
Abstract
Mediator is a universal adaptor for transcription control. It serves as an interface between gene-specific activator or repressor proteins and the general RNA polymerase II (pol II) transcription machinery. Previous structural studies revealed a relatively small part of Mediator and none of the gene activator-binding regions. We have determined the cryo-EM structure of the Mediator at near-atomic resolution. The structure reveals almost all amino acid residues in ordered regions, including the major targets of activator proteins, the Tail module, and the Med1 subunit of the Middle module. Comparison of Mediator structures with and without pol II reveals conformational changes that propagate across the entire Mediator, from Head to Tail, coupling activator- and pol II-interacting regions.
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Affiliation(s)
- Heqiao Zhang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210 Shanghai, China; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Dong-Hua Chen
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Rayees U H Mattoo
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - David A Bushnell
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yannan Wang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210 Shanghai, China
| | - Chao Yuan
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210 Shanghai, China
| | - Lin Wang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210 Shanghai, China
| | - Chunnian Wang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210 Shanghai, China
| | - Ralph E Davis
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yan Nie
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210 Shanghai, China.
| | - Roger D Kornberg
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210 Shanghai, China; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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41
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Kyrchanova O, Georgiev P. Mechanisms of Enhancer-Promoter Interactions in Higher Eukaryotes. Int J Mol Sci 2021; 22:ijms22020671. [PMID: 33445415 PMCID: PMC7828040 DOI: 10.3390/ijms22020671] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/28/2020] [Accepted: 01/09/2021] [Indexed: 12/13/2022] Open
Abstract
In higher eukaryotes, enhancers determine the activation of developmental gene transcription in specific cell types and stages of embryogenesis. Enhancers transform the signals produced by various transcription factors within a given cell, activating the transcription of the targeted genes. Often, developmental genes can be associated with dozens of enhancers, some of which are located at large distances from the promoters that they regulate. Currently, the mechanisms underlying specific distance interactions between enhancers and promoters remain poorly understood. This review briefly describes the properties of enhancers and discusses the mechanisms of distance interactions and potential proteins involved in this process.
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42
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Osman S, Mohammad E, Lidschreiber M, Stuetzer A, Bazsó FL, Maier KC, Urlaub H, Cramer P. The Cdk8 kinase module regulates interaction of the mediator complex with RNA polymerase II. J Biol Chem 2021; 296:100734. [PMID: 33933450 PMCID: PMC8191332 DOI: 10.1016/j.jbc.2021.100734] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 04/20/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022] Open
Abstract
The Cdk8 kinase module (CKM) is a dissociable part of the coactivator complex mediator, which regulates gene transcription by RNA polymerase II. The CKM has both negative and positive functions in gene transcription that remain poorly understood at the mechanistic level. In order to reconstitute the role of the CKM in transcription initiation, we prepared recombinant CKM from the yeast Saccharomyces cerevisiae. We showed that CKM bound to the core mediator (cMed) complex, sterically inhibiting cMed from binding to the polymerase II preinitiation complex (PIC) in vitro. We further showed that the Cdk8 kinase activity of the CKM weakened CKM-cMed interaction, thereby facilitating dissociation of the CKM and enabling mediator to bind the PIC in order to stimulate transcription initiation. Finally, we report that the kinase activity of Cdk8 is required for gene activation during the stressful condition of heat shock in vivo but not under steady-state growth conditions. Based on these results, we propose a model in which the CKM negatively regulates mediator function at upstream-activating sequences by preventing mediator binding to the PIC at the gene promoter. However, during gene activation in response to stress, the Cdk8 kinase activity of the CKM may release mediator and allow its binding to the PIC, thereby accounting for the positive function of CKM. This may impart improved adaptability to stress by allowing a rapid transcriptional response to environmental changes, and we speculate that a similar mechanism in metazoans may allow the precise timing of developmental transcription programs.
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Affiliation(s)
- Sara Osman
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Eusra Mohammad
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Michael Lidschreiber
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Alexandra Stuetzer
- Bioanalytical Mass Spectrometry Group, Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany; Bioanalytics Research Group, Institute for Clinical Chemistry, University Medical Center, Göttingen, Germany
| | - Fanni Laura Bazsó
- Bioanalytical Mass Spectrometry Group, Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany; Bioanalytics Research Group, Institute for Clinical Chemistry, University Medical Center, Göttingen, Germany
| | - Kerstin C Maier
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany; Bioanalytics Research Group, Institute for Clinical Chemistry, University Medical Center, Göttingen, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
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43
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Li YC, Chao TC, Kim HJ, Cholko T, Chen SF, Li G, Snyder L, Nakanishi K, Chang CE, Murakami K, Garcia BA, Boyer TG, Tsai KL. Structure and noncanonical Cdk8 activation mechanism within an Argonaute-containing Mediator kinase module. SCIENCE ADVANCES 2021; 7:7/3/eabd4484. [PMID: 33523904 PMCID: PMC7810384 DOI: 10.1126/sciadv.abd4484] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/25/2020] [Indexed: 05/02/2023]
Abstract
The Cdk8 kinase module (CKM) in Mediator, comprising Med13, Med12, CycC, and Cdk8, regulates RNA polymerase II transcription through kinase-dependent and -independent functions. Numerous pathogenic mutations causative for neurodevelopmental disorders and cancer congregate in CKM subunits. However, the structure of the intact CKM and the mechanism by which Cdk8 is non-canonically activated and functionally affected by oncogenic CKM alterations are poorly understood. Here, we report a cryo-electron microscopy structure of Saccharomyces cerevisiae CKM that redefines prior CKM structural models and explains the mechanism of Med12-dependent Cdk8 activation. Med12 interacts extensively with CycC and activates Cdk8 by stabilizing its activation (T-)loop through conserved Med12 residues recurrently mutated in human tumors. Unexpectedly, Med13 has a characteristic Argonaute-like bi-lobal architecture. These findings not only provide a structural basis for understanding CKM function and pathological dysfunction, but also further impute a previously unknown regulatory mechanism of Mediator in transcriptional modulation through its Med13 Argonaute-like features.
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Affiliation(s)
- Yi-Chuan Li
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Ti-Chun Chao
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Hee Jong Kim
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Timothy Cholko
- Department of Chemistry, University of California, Riverside, CA, USA
| | - Shin-Fu Chen
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Guojie Li
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Laura Snyder
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kotaro Nakanishi
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Chia-En Chang
- Department of Chemistry, University of California, Riverside, CA, USA
| | - Kenji Murakami
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Benjamin A Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas G Boyer
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
| | - Kuang-Lei Tsai
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA.
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
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44
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Wu D, Zhang Z, Chen X, Yan Y, Liu X. Angel or Devil ? - CDK8 as the new drug target. Eur J Med Chem 2020; 213:113043. [PMID: 33257171 DOI: 10.1016/j.ejmech.2020.113043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 12/19/2022]
Abstract
Cyclin-dependent kinase 8 (CDK8) plays an momentous role in transcription regulation by forming kinase module or transcription factor phosphorylation. A large number of evidences have identified CDK8 as an important factor in cancer occurrence and development. In addition, CDK8 also participates in the regulation of cancer cell stress response to radiotherapy and chemotherapy, assists tumor cell invasion, metastasis, and drug resistance. Therefore, CDK8 is regarded as a promising target for cancer therapy. Most studies in recent years supported the role of CDK8 as a carcinogen, however, under certain conditions, CDK8 exists as a tumor suppressor. The functional diversity of CDK8 and its exceptional role in different types of cancer have aroused great interest from scientists but even more controversy during the discovery of CDK8 inhibitors. In addition, CDK8 appears to be an effective target for inflammation diseases and immune system disorders. Therefore, we summarized the research results of CDK8, involving physiological/pathogenic mechanisms and the development status of compounds targeting CDK8, provide a reference for the feasibility evaluation of CDK8 as a therapeutic target, and guidance for researchers who are involved in this field for the first time.
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Affiliation(s)
- Dan Wu
- School of Biological Engineering, Hefei Technology College, Hefei, 238000, PR China
| | - Zhaoyan Zhang
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, Anhui Medical University, Hefei, 230032, PR China
| | - Xing Chen
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, Anhui Medical University, Hefei, 230032, PR China
| | - Yaoyao Yan
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, Anhui Medical University, Hefei, 230032, PR China
| | - Xinhua Liu
- School of Pharmacy, Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, Anhui Medical University, Hefei, 230032, PR China.
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Abstract
Gene transcription by RNA polymerase II (Pol II) is the first step in the expression of the eukaryotic genome and a focal point for cellular regulation during development, differentiation, and responses to the environment. Two decades after the determination of the structure of Pol II, the mechanisms of transcription have been elucidated with studies of Pol II complexes with nucleic acids and associated proteins. Here we provide an overview of the nearly 200 available Pol II complex structures and summarize how these structures have elucidated promoter-dependent transcription initiation, promoter-proximal pausing and release of Pol II into active elongation, and the mechanisms that Pol II uses to navigate obstacles such as nucleosomes and DNA lesions. We predict that future studies will focus on how Pol II transcription is interconnected with chromatin transitions, RNA processing, and DNA repair.
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Affiliation(s)
- Sara Osman
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany;,
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany;,
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46
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Trichoderma reesei XYR1 activates cellulase gene expression via interaction with the Mediator subunit TrGAL11 to recruit RNA polymerase II. PLoS Genet 2020; 16:e1008979. [PMID: 32877410 PMCID: PMC7467262 DOI: 10.1371/journal.pgen.1008979] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 07/06/2020] [Indexed: 12/22/2022] Open
Abstract
The ascomycete Trichoderma reesei is a highly prolific cellulase producer. While XYR1 (Xylanase regulator 1) has been firmly established to be the master activator of cellulase gene expression in T. reesei, its precise transcriptional activation mechanism remains poorly understood. In the present study, TrGAL11, a component of the Mediator tail module, was identified as a putative interacting partner of XYR1. Deletion of Trgal11 markedly impaired the induced expression of most (hemi)cellulase genes, but not that of the major β-glucosidase encoding genes. This differential involvement of TrGAL11 in the full induction of cellulase genes was reflected by the RNA polymerase II (Pol II) recruitment on their core promoters, indicating that TrGAL11 was required for the efficient transcriptional initiation of the majority of cellulase genes. In addition, we found that TrGAL11 recruitment to cellulase gene promoters largely occurred in an XYR1-dependent manner. Although xyr1 expression was significantly tuned down without TrGAL11, the binding of XYR1 to cellulase gene promoters did not entail TrGAL11. These results indicate that TrGAL11 represents a direct in vivo target of XYR1 and may play a critical role in contributing to Mediator and the following RNA Pol II recruitment to ensure the induced cellulase gene expression. As a model cellulolytic fungus, T. reesei is capable of rapidly producing a large quantity of (hemi)cellulases when appropriate substrates are present. This outstanding characteristic has made T. reesei a prominent producer of cellulase in industry and also a model organism for studying eukaryotic gene expression. The expression of these hydrolytic enzymes encoding genes in T. reesei is precisely regulated at a transcriptional level and controlled by a suite of transcription factors. Among others, the transcription activator XYR1 has been firmly established to be absolutely necessary for activating the expression of almost all cellulase genes. However, the precise mechanism it acts remains largely unknown. In eukaryotes, the multisubunit Mediator complex has been shown to be critical for expression of most, if not all, protein-coding genes by conveying regulatory information to the basal transcription machinery. Here, we find that XYR1 interacts with the Mediator tail module subunit, TrGAL11, which contributes to cellobiohydrolase (cbh) and endoglucanase (eg) genes but not β-glucosidase (bgl) genes expression. Thus, the induced XYR1 binding to cellulase gene promoters led to TrGAL11 and RNA Pol II recruitment to these promoters. These results show that TrGAL11 represents a direct in vivo target of XYR1 and provide evidence for not only the evolutionarily conserved function of Mediator, but also for the existence of some subtle difference in its action to mediate gene expression in different eukaryotes.
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47
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Lynch CJ, Bernad R, Calvo I, Serrano M. Manipulating the Mediator complex to induce naïve pluripotency. Exp Cell Res 2020; 395:112215. [PMID: 32771524 PMCID: PMC7584500 DOI: 10.1016/j.yexcr.2020.112215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/08/2020] [Accepted: 08/01/2020] [Indexed: 12/26/2022]
Abstract
Human naïve pluripotent stem cells (PSCs) represent an optimal homogenous starting point for molecular interventions and differentiation strategies. This is in contrast to the standard primed PSCs which fluctuate in identity and are transcriptionally heterogeneous. However, despite many efforts, the maintenance and expansion of human naïve PSCs remains a challenge. Here, we discuss our recent strategy for the stabilization of human PSC in the naïve state based on the use of a single chemical inhibitor of the related kinases CDK8 and CDK19. These kinases phosphorylate and negatively regulate the multiprotein Mediator complex, which is critical for enhancer-driven recruitment of RNA Pol II. The net effect of CDK8/19 inhibition is a global stimulation of enhancers, which in turn reinforces transcriptional programs including those related to cellular identity. In the case of pluripotent cells, the presence of CDK8/19i efficiently stabilizes the naïve state. Importantly, in contrast to previous chemical methods to induced the naïve state based on the inhibition of the FGF-MEK-ERK pathway, CDK8/19i-naïve human PSCs are chromosomally stable and retain developmental potential after long-term expansion. We suggest this could be related to the fact that CDK8/19 inhibition does not induce DNA demethylation. These principles may apply to other fate decisions.
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Affiliation(s)
- Cian J Lynch
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
| | - Raquel Bernad
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Isabel Calvo
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Manuel Serrano
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, 08010, Spain.
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48
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Liquid-liquid phase separation in biology: mechanisms, physiological functions and human diseases. SCIENCE CHINA. LIFE SCIENCES 2020; 63:953-985. [PMID: 32548680 DOI: 10.1007/s11427-020-1702-x] [Citation(s) in RCA: 147] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/20/2020] [Indexed: 02/06/2023]
Abstract
Cells are compartmentalized by numerous membrane-enclosed organelles and membraneless compartments to ensure that a wide variety of cellular activities occur in a spatially and temporally controlled manner. The molecular mechanisms underlying the dynamics of membrane-bound organelles, such as their fusion and fission, vesicle-mediated trafficking and membrane contactmediated inter-organelle interactions, have been extensively characterized. However, the molecular details of the assembly and functions of membraneless compartments remain elusive. Mounting evidence has emerged recently that a large number of membraneless compartments, collectively called biomacromolecular condensates, are assembled via liquid-liquid phase separation (LLPS). Phase-separated condensates participate in various biological activities, including higher-order chromatin organization, gene expression, triage of misfolded or unwanted proteins for autophagic degradation, assembly of signaling clusters and actin- and microtubule-based cytoskeletal networks, asymmetric segregations of cell fate determinants and formation of pre- and post-synaptic density signaling assemblies. Biomacromolecular condensates can transition into different material states such as gel-like structures and solid aggregates. The material properties of condensates are crucial for fulfilment of their distinct functions, such as biochemical reaction centers, signaling hubs and supporting architectures. Cells have evolved multiple mechanisms to ensure that biomacromolecular condensates are assembled and disassembled in a tightly controlled manner. Aberrant phase separation and transition are causatively associated with a variety of human diseases such as neurodegenerative diseases and cancers. This review summarizes recent major progress in elucidating the roles of LLPS in various biological pathways and diseases.
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49
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Selective Mediator dependence of cell-type-specifying transcription. Nat Genet 2020; 52:719-727. [PMID: 32483291 PMCID: PMC7610447 DOI: 10.1038/s41588-020-0635-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 04/24/2020] [Indexed: 12/15/2022]
Abstract
The Mediator complex directs signals from DNA-binding transcription factors to RNA polymerase (Pol) II. Despite this pivotal position, mechanistic understanding of Mediator in human cells remains incomplete. Here, we quantified Mediator-controlled Pol II kinetics by coupling rapid subunit degradation with orthogonal experimental readouts. Consistent with a model of condensate-driven transcription initiation, large clusters of hypo-phosphorylated Pol II rapidly disassembled upon Mediator degradation. This was accompanied by a selective and pronounced disruption of cell type-specifying transcriptional circuits, whose constituent genes featured exceptionally high rates of Pol II turnover. Notably, transcriptional output of most other genes was largely unaffected by acute Mediator ablation. Maintenance of transcriptional activity at these genes was linked to an unexpected, CDK9-dependent compensatory feedback loop that elevated Pol II pause release rates genome-wide. Collectively, our work positions human Mediator as a globally acting coactivator that selectively safeguards the functionality of cell type-specifying transcriptional networks.
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50
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Lyons DE, McMahon S, Ott M. A combinatorial view of old and new RNA polymerase II modifications. Transcription 2020; 11:66-82. [PMID: 32401151 DOI: 10.1080/21541264.2020.1762468] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The production of mRNA is a dynamic process that is highly regulated by reversible post-translational modifications of the C-terminal domain (CTD) of RNA polymerase II. The CTD is a highly repetitive domain consisting mostly of the consensus heptad sequence Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7. Phosphorylation of serine residues within this repeat sequence is well studied, but modifications of all residues have been described. Here, we focus on integrating newly identified and lesser-studied CTD post-translational modifications into the existing framework. We also review the growing body of work demonstrating crosstalk between different CTD modifications and the functional consequences of such crosstalk on the dynamics of transcriptional regulation.
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Affiliation(s)
- Danielle E Lyons
- Gladstone Institute of Virology and Immunology, San Francisco, CA, USA
| | - Sarah McMahon
- Gladstone Institute of Virology and Immunology, San Francisco, CA, USA.,Department of Medicine, University of California, San Francisco , San Francisco, CA, USA
| | - Melanie Ott
- Gladstone Institute of Virology and Immunology, San Francisco, CA, USA.,Department of Medicine, University of California, San Francisco , San Francisco, CA, USA
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