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Maji S, Waseem M, Sharma MK, Singh M, Singh A, Dwivedi N, Thakur P, Cooper DG, Bisht NC, Fassler JS, Subbarao N, Khurana JP, Bhavesh NS, Thakur JK. MediatorWeb: a protein-protein interaction network database for the RNA polymerase II Mediator complex. FEBS J 2024. [PMID: 38975839 DOI: 10.1111/febs.17225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 04/24/2024] [Accepted: 06/28/2024] [Indexed: 07/09/2024]
Abstract
The protein-protein interaction (PPI) network of the Mediator complex is very tightly regulated and depends on different developmental and environmental cues. Here, we present an interactive platform for comparative analysis of the Mediator subunits from humans, baker's yeast Saccharomyces cerevisiae, and model plant Arabidopsis thaliana in a user-friendly web-interface database called MediatorWeb. MediatorWeb provides an interface to visualize and analyze the PPI network of Mediator subunits. The database facilitates downloading the untargeted and unweighted network of Mediator complex, its submodules, and individual Mediator subunits to better visualize the importance of individual Mediator subunits or their submodules. Further, MediatorWeb offers network visualization of the Mediator complex and interacting proteins that are functionally annotated. This feature provides clues to understand functions of Mediator subunits in different processes. In an additional tab, MediatorWeb provides quick access to secondary and tertiary structures, as well as residue-level contact information for Mediator subunits in each of the three model organisms. Another useful feature of MediatorWeb is detection of interologs based on orthologous analyses, which can provide clues to understand the functions of Mediator complex in less explored kingdoms. Thus, MediatorWeb and its features can help the user to understand the role of Mediator complex and its subunits in the transcription regulation of gene expression.
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Grants
- BT/PR40146/BTIS/137/4/2020 Department of Biotechnology, Ministry of Science and Technology, India
- BT/PR40169/BTIS/137/71/2023 Department of Biotechnology, Ministry of Science and Technology, India
- BT/HRD/MK-YRFP/50/27/2021 Department of Biotechnology, Ministry of Science and Technology, India
- BT/HRD/MK-YRFP/50/26/2021 Department of Biotechnology, Ministry of Science and Technology, India
- SERB, Government of India
- ICMR
- Council of Scientific and Industrial Research, India
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Affiliation(s)
- Sourobh Maji
- Plant Transcription Regulation, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
- Transcription Regulation, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Mohd Waseem
- National Institute of Plant Genome Research, New Delhi, India
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, India
| | | | - Maninder Singh
- National Institute of Plant Genome Research, New Delhi, India
| | - Anamika Singh
- Plant Transcription Regulation, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Nidhi Dwivedi
- National Institute of Plant Genome Research, New Delhi, India
| | - Pallabi Thakur
- National Institute of Plant Genome Research, New Delhi, India
| | - David G Cooper
- Department of Pharmaceutical Sciences, Butler University, Indianapolis, IN, USA
| | - Naveen C Bisht
- National Institute of Plant Genome Research, New Delhi, India
| | | | - Naidu Subbarao
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Jitendra P Khurana
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Neel Sarovar Bhavesh
- Transcription Regulation, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Jitendra Kumar Thakur
- Plant Transcription Regulation, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
- National Institute of Plant Genome Research, New Delhi, India
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Chen SF, Chao TC, Kim HJ, Tang HC, Khadka S, Li T, Lee DF, Murakami K, Boyer TG, Tsai KL. Structural basis of the human transcriptional Mediator complex modulated by its dissociable Kinase module. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.01.601608. [PMID: 39005267 PMCID: PMC11244988 DOI: 10.1101/2024.07.01.601608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
The eukaryotic Mediator, comprising a large Core (cMED) and a dissociable CDK8 kinase module (CKM), regulates RNA Polymerase II (Pol II)-dependent transcription. cMED recruits Pol II and promotes pre-initiation complex (PIC) formation in a manner inhibited by the CKM, which is also implicated in post-initiation control of gene expression. Herein we report cryo-electron microscopy structures of the human complete Mediator and its CKM, which explains the basis for CKM inhibition of cMED-activated transcription. The CKM binds to cMED through an intrinsically disordered region (IDR) in MED13 and HEAT repeats in MED12. The CKM inhibits transcription by allocating its MED13 IDR to occlude binding of Pol II and MED26 to cMED and further obstructing cMED-PIC assembly through steric hindrance with TFIIH and the +1 nucleosome. Notably, MED12 binds to the cMED Hook, positioning CDK8 downstream of the transcription start site, which sheds new light on its stimulatory function in post-initiation events.
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Lambert GS, Rice BL, Maldonado RJK, Chang J, Parent LJ. Comparative analysis of retroviral Gag-host cell interactions: focus on the nuclear interactome. Retrovirology 2024; 21:13. [PMID: 38898526 PMCID: PMC11186191 DOI: 10.1186/s12977-024-00645-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 06/21/2024] Open
Abstract
Retroviruses exploit host proteins to assemble and release virions from infected cells. Previously, most studies focused on interacting partners of retroviral Gag proteins that localize to the cytoplasm or plasma membrane. Given that several full-length Gag proteins have been found in the nucleus, identifying the Gag-nuclear interactome has high potential for novel findings involving previously unknown host processes. Here we systematically compared nuclear factors identified in published HIV-1 proteomic studies and performed our own mass spectrometry analysis using affinity-tagged HIV-1 and RSV Gag proteins mixed with nuclear extracts. We identified 57 nuclear proteins in common between HIV-1 and RSV Gag, and a set of nuclear proteins present in our analysis and ≥ 1 of the published HIV-1 datasets. Many proteins were associated with nuclear processes which could have functional consequences for viral replication, including transcription initiation/elongation/termination, RNA processing, splicing, and chromatin remodeling. Examples include facilitating chromatin remodeling to expose the integrated provirus, promoting expression of viral genes, repressing the transcription of antagonistic cellular genes, preventing splicing of viral RNA, altering splicing of cellular RNAs, or influencing viral or host RNA folding or RNA nuclear export. Many proteins in our pulldowns common to RSV and HIV-1 Gag are critical for transcription, including PolR2B, the second largest subunit of RNA polymerase II (RNAPII), and LEO1, a PAF1C complex member that regulates transcriptional elongation, supporting the possibility that Gag influences the host transcription profile to aid the virus. Through the interaction of RSV and HIV-1 Gag with splicing-related proteins CBLL1, HNRNPH3, TRA2B, PTBP1 and U2AF1, we speculate that Gag could enhance unspliced viral RNA production for translation and packaging. To validate one putative hit, we demonstrated an interaction of RSV Gag with Mediator complex member Med26, required for RNA polymerase II-mediated transcription. Although 57 host proteins interacted with both Gag proteins, unique host proteins belonging to each interactome dataset were identified. These results provide a strong premise for future functional studies to investigate roles for these nuclear host factors that may have shared functions in the biology of both retroviruses, as well as functions specific to RSV and HIV-1, given their distinctive hosts and molecular pathology.
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Affiliation(s)
- Gregory S Lambert
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA, 17033, USA
| | - Breanna L Rice
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA, 17033, USA
| | - Rebecca J Kaddis Maldonado
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA, 17033, USA
- Department of Microbiology and Immunology, Penn State College of Medicine, 500 University Drive, Hershey, PA, 17033, USA
| | - Jordan Chang
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA, 17033, USA
| | - Leslie J Parent
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA, 17033, USA.
- Department of Microbiology and Immunology, Penn State College of Medicine, 500 University Drive, Hershey, PA, 17033, USA.
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Jin C, Zhao L, Zhao G, Liu Y, Ma W, Ma S, Yao L, Liu Y, Wu Q, Yuan H, Yang K, Ohgi K, Rich JN, Rosenfeld MG. Gene Amplification of Mediator Subunit 30 Redirects the MYC Transcriptional Program and Oncogenesis. RESEARCH SQUARE 2024:rs.3.rs-4326418. [PMID: 38766212 PMCID: PMC11100879 DOI: 10.21203/rs.3.rs-4326418/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Understanding the molecular mechanisms underlying tumorigenesis is crucial for developing effective cancer therapies. Here, we investigate the co-amplification of MED30 and MYC across diverse cancer types and its impact on oncogenic transcriptional programs. Transcriptional profiling of MYC and MED30 single or both overexpression/amplification revealed the over amount of MED30 lead MYC to a new transcriptional program that associate with poor prognosis. Mechanistically, MED30 overexpression/amplification recruits other Mediator components and binding of MYC to a small subset of novel genomic regulatory sites, changing the epigenetic marks and inducing the formation of new enhancers, which drive the expression of target genes crucial for cancer progression. In vivo studies in pancreatic ductal adenocarcinoma (PDAC) further validate the oncogenic potential of MED30, as its overexpression promotes tumor growth and can be attenuated by knockdown of MYC. Using another cancer type as an example, MED30 knockdown reduces tumor growth particularly in MYC high-expressed glioblastoma (GBM) cell lines. Overall, our study elucidates the critical role of MED30 overexpression in orchestrating oncogenic transcriptional programs and highlights its potential as a therapeutic target for MYC-amplified cancer.
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Affiliation(s)
| | | | | | | | - Wubin Ma
- University of California, San Diego
| | | | | | - Yuan Liu
- University of California, San Diego
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Voutsadakis IA. Targeting super-enhancer activity for colorectal cancer therapy. Am J Transl Res 2024; 16:700-719. [PMID: 38586095 PMCID: PMC10994804 DOI: 10.62347/qkhb5897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 02/28/2024] [Indexed: 04/09/2024]
Abstract
In addition to genetic variants and copy number alterations, epigenetic deregulation of oncogenes and tumor suppressors is a major contributor in cancer development and propagation. Regulatory elements for gene transcription regulation can be found in promoters which are located in the vicinity of transcription start sites but also at a distance, in enhancer sites, brought to interact with proximal sites when occupied by enhancer protein complexes. These sites provide most of the specific regulatory sequences recognized by transcription factors. A sub-set of enhancers characterized by a longer structure and stronger activity, called super-enhancers, are critical for the expression of specific genes, usually associated with individual cell type identity and function. Super-enhancers show deregulation in cancer, which may have profound repercussions for cancer cell survival and response to therapy. Dysfunction of super-enhancers may result from multiple mechanisms that include changes in their sequence, alterations in the topological neighborhoods where they belong, and alterations in the proteins that mediate their function, such as transcription factors and epigenetic modifiers. These can become potential targets for therapeutic interventions. Genes that are targets of super-enhancers are cell and cancer type specific and could also be of interest for therapeutic targeting. In colorectal cancer, a super-enhancer regulated and over-expressed oncogene is MYC, under the influence of the WNT/β-catenin pathway. Identification and targeting of additional oncogenes regulated by super-enhancers in colorectal cancer may pave the way for combination therapies targeting the super-enhancer machinery and signal transduction pathways that regulate the specific transcription factors operative on them.
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Affiliation(s)
- Ioannis A Voutsadakis
- Algoma District Cancer Program, Sault Area HospitalSault Ste. Marie, ON, Canada
- Division of Clinical Sciences, Section of Internal Medicine, Northern Ontario School of MedicineSudbury, ON, Canada
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Franzese M, Zanfardino M, Soricelli A, Coppola A, Maiello C, Salvatore M, Schiano C, Napoli C. Familial Dilated Cardiomyopathy: A Novel MED9 Short Isoform Identification. Int J Mol Sci 2024; 25:3057. [PMID: 38474301 DOI: 10.3390/ijms25053057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 02/21/2024] [Accepted: 02/26/2024] [Indexed: 03/14/2024] Open
Abstract
Familial dilated cardiomyopathy (DCM) is among the leading indications for heart transplantation. DCM alters the transcriptomic profile. The alteration or activation/silencing of physiologically operating transcripts may explain the onset and progression of this pathological state. The mediator complex (MED) plays a fundamental role in the transcription process. The aim of this study is to investigate the MED subunits, which are altered in DCM, to identify target crossroads genes. RNA sequencing allowed us to identify specific MED subunits that are altered during familial DCM, transforming into human myocardial samples. N = 13 MED subunits were upregulated and n = 7 downregulated. MED9 alone was significantly reduced in patients compared to healthy subjects (HS) (FC = -1.257; p < 0.05). Interestingly, we found a short MED9 isoform (MED9s) (ENSG00000141026.6), which was upregulated when compared to the full-transcript isoform (MED9f). Motif identification analysis yielded several significant matches (p < 0.05), such as GATA4, which is downregulated in CHD. Moreover, although the protein-protein interaction network showed FOG2/ZFPM2, FOS and ID2 proteins to be the key interacting partners of GATA4, only FOG2/ZFPM2 overexpression showed an interaction score of "high confidence" ≥ 0.84. A significant change in the MED was observed during HF. For the first time, the MED9 subunit was significantly reduced between familial DCM and HS (p < 0.05), showing an increased MED9s isoform in DCM patients with respect to its full-length transcript. MED9 and GATA4 shared the same sequence motif and were involved in a network with FOG2/ZFPM2, FOS, and ID2, proteins already implicated in cardiac development.
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Affiliation(s)
| | | | - Andrea Soricelli
- IRCCS SYNLAB SDN, 80143 Naples, Italy
- Department of Exercise and Wellness Sciences, University of Naples Parthenope, 80133 Naples, Italy
| | - Annapaola Coppola
- Department of Advanced Medical and Surgical Sciences (DAMSS), University of Campania Luigi Vanvitelli, 81100 Naples, Italy
| | - Ciro Maiello
- Department of Cardiothoracic Science, U.O.S.D. of Heart Transplantation, Monaldi Hospital, 80131 Naples, Italy
| | | | - Concetta Schiano
- Department of Advanced Medical and Surgical Sciences (DAMSS), University of Campania Luigi Vanvitelli, 81100 Naples, Italy
| | - Claudio Napoli
- IRCCS SYNLAB SDN, 80143 Naples, Italy
- Department of Advanced Medical and Surgical Sciences (DAMSS), University of Campania Luigi Vanvitelli, 81100 Naples, Italy
- Clinical Department of Internal Medicine and Specialistic Units, Division of Clinical Immunology, Immunohematology, Transfusion Medicine and Transplant Immunology (SIMT), Azienda Universitaria Policlinico (AOU), 80131 Naples, Italy
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Lambert GS, Rice BL, Kaddis Maldonado RJ, Chang J, Parent LJ. Comparative analysis of retroviral Gag-host cell interactions: focus on the nuclear interactome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.18.575255. [PMID: 38293010 PMCID: PMC10827203 DOI: 10.1101/2024.01.18.575255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Retroviruses exploit a variety of host proteins to assemble and release virions from infected cells. To date, most studies that examined possible interacting partners of retroviral Gag proteins focused on host proteins that localize primarily to the cytoplasm or plasma membrane. Given the recent findings that several full-length Gag proteins localize to the nucleus, identifying the Gag-nuclear interactome has high potential for novel findings that reveal previously unknown host processes. In this study, we systematically compared nuclear factors identified in published HIV-1 proteomic studies which had used a variety of experimental approaches. In addition, to contribute to this body of knowledge, we report results from a mass spectrometry approach using affinity-tagged (His6) HIV-1 and RSV Gag proteins mixed with nuclear extracts. Taken together, the previous studies-as well as our own-identified potential binding partners of HIV-1 and RSV Gag involved in several nuclear processes, including transcription, splicing, RNA modification, and chromatin remodeling. Although a subset of host proteins interacted with both Gag proteins, there were also unique host proteins belonging to each interactome dataset. To validate one of the novel findings, we demonstrated the interaction of RSV Gag with a member of the Mediator complex, Med26, which is required for RNA polymerase II-mediated transcription. These results provide a strong premise for future functional studies to investigate roles for these nuclear host factors that may have shared functions in the biology of both retroviruses, as well as functions specific to RSV and HIV-1, given their distinctive hosts and molecular pathology.
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Affiliation(s)
- Gregory S. Lambert
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Breanna L. Rice
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Rebecca J. Kaddis Maldonado
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
- Department of Microbiology and Immunology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Jordan Chang
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Leslie J. Parent
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
- Department of Microbiology and Immunology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
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Fletcher J, O’Connor-Moneley J, Frawley D, Flanagan PR, Alaalm L, Menendez-Manjon P, Estevez SV, Hendricks S, Woodruff AL, Buscaino A, Anderson MZ, Sullivan DJ, Moran GP. Deletion of the Candida albicans TLO gene family using CRISPR-Cas9 mutagenesis allows characterisation of functional differences in α-, β- and γ- TLO gene function. PLoS Genet 2023; 19:e1011082. [PMID: 38048294 PMCID: PMC10721199 DOI: 10.1371/journal.pgen.1011082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 12/14/2023] [Accepted: 11/22/2023] [Indexed: 12/06/2023] Open
Abstract
The Candida albicans genome contains between ten and fifteen distinct TLO genes that all encode a Med2 subunit of Mediator. In order to investigate the biological role of Med2/Tlo in C. albicans we deleted all fourteen TLO genes using CRISPR-Cas9 mutagenesis. ChIP-seq analysis showed that RNAP II localized to 55% fewer genes in the tloΔ mutant strain compared to the parent, while RNA-seq analysis showed that the tloΔ mutant exhibited differential expression of genes required for carbohydrate metabolism, stress responses, white-opaque switching and filamentous growth. Consequently, the tloΔ mutant grows poorly in glucose- and galactose-containing media, is unable to grow as true hyphae, is more sensitive to oxidative stress and is less virulent in the wax worm infection model. Reintegration of genes representative of the α-, β- and γ-TLO clades resulted in the complementation of the mutant phenotypes, but to different degrees. TLOα1 could restore phenotypes and gene expression patterns similar to wild-type and was the strongest activator of glycolytic and Tye7-regulated gene expression. In contrast, the two γ-TLO genes examined (i.e., TLOγ5 and TLOγ11) had a far lower impact on complementing phenotypic and transcriptomic changes. Uniquely, expression of TLOβ2 in the tloΔ mutant stimulated filamentous growth in YEPD medium and this phenotype was enhanced when Tloβ2 expression was increased to levels far in excess of Med3. In contrast, expression of reintegrated TLO genes in a tloΔ/med3Δ double mutant background failed to restore any of the phenotypes tested, suggesting that complementation of these Tlo-regulated processes requires a functional Mediator tail module. Together, these data confirm the importance of Med2/Tlo in a wide range of C. albicans cellular activities and demonstrate functional diversity within the gene family which may contribute to the success of this yeast as a coloniser and pathogen of humans.
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Affiliation(s)
- Jessica Fletcher
- Division of Oral Biosciences, Dublin Dental University Hospital, & University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - James O’Connor-Moneley
- Division of Oral Biosciences, Dublin Dental University Hospital, & University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - Dean Frawley
- Division of Oral Biosciences, Dublin Dental University Hospital, & University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - Peter R. Flanagan
- Division of Oral Biosciences, Dublin Dental University Hospital, & University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - Leenah Alaalm
- Division of Oral Biosciences, Dublin Dental University Hospital, & University of Dublin, Trinity College Dublin, Dublin, Ireland
| | | | | | - Shane Hendricks
- Department of Microbiology, The Ohio State University, Columbus, Ohio, United States of America
| | - Andrew L. Woodruff
- Department of Microbiology, The Ohio State University, Columbus, Ohio, United States of America
| | - Alessia Buscaino
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Matthew Z. Anderson
- Department of Microbiology, The Ohio State University, Columbus, Ohio, United States of America
| | - Derek J. Sullivan
- Division of Oral Biosciences, Dublin Dental University Hospital, & University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - Gary P. Moran
- Division of Oral Biosciences, Dublin Dental University Hospital, & University of Dublin, Trinity College Dublin, Dublin, Ireland
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Ruoff R, Weber H, Wang Y, Huang H, Shapiro E, Fenyö D, Garabedian MJ. MED19 encodes two unique protein isoforms that confer prostate cancer growth under low androgen through distinct gene expression programs. Sci Rep 2023; 13:18227. [PMID: 37880276 PMCID: PMC10600210 DOI: 10.1038/s41598-023-45199-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/17/2023] [Indexed: 10/27/2023] Open
Abstract
MED19, a component of the mediator complex and a co-regulator of the androgen receptor (AR), is pivotal in prostate cancer cell proliferation. MED19 has two isoforms: a full-length "canonical" and a shorter "alternative" variant. Specific antibodies were developed to investigate these isoforms. Both exhibit similar expression in normal prostate development and adult prostate tissue, but the canonical isoform is elevated in prostate adenocarcinomas. Overexpression of canonical MED19 in LNCaP cells promotes growth under conditions of androgen deprivation in vitro and in vivo, mirroring earlier findings with alternative MED19-overexpressing LNCaP cells. Interestingly, alternative MED19 cells displayed strong colony formation in clonogenic assays under conditions of androgen deprivation, while canonical MED19 cells did not, suggesting distinct functional roles. These isoforms also modulated gene expression differently. Canonical MED19 triggered genes related to extracellular matrix remodeling while suppressing those involved in androgen-inactivating glucuronidation. In contrast, alternative MED19 elevated genes tied to cell movement and reduced those associated with cell adhesion and differentiation. The ratio of MED19 isoform expression in prostate cancers shifts with the disease stage. Early-stage cancers exhibit higher canonical MED19 expression than alternative MED19, consistent with canonical MED19's ability to promote cell proliferation under androgen deprivation. Conversely, alternative MED19 levels were higher in later-stage metastatic prostate cancer than in canonical MED19, reflecting alternative MED19's capability to enhance cell migration and autonomous cell growth. Our findings suggest that MED19 isoforms play unique roles in prostate cancer progression and highlights MED19 as a potential therapeutic target for both early and late-stage prostate cancer.
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Affiliation(s)
- Rachel Ruoff
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Hannah Weber
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Ying Wang
- Institute for Systems Genetics, New York University Grossman School of Medicine, New York, NY, 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Hongying Huang
- Department of Urology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Ellen Shapiro
- Department of Urology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - David Fenyö
- Institute for Systems Genetics, New York University Grossman School of Medicine, New York, NY, 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Michael J Garabedian
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, 10016, USA.
- Department of Urology, New York University Grossman School of Medicine, New York, NY, 10016, USA.
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10
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O'Connor-Moneley J, Alaalm L, Moran GP, Sullivan DJ. The role of the Mediator complex in fungal pathogenesis and response to antifungal agents. Essays Biochem 2023; 67:843-851. [PMID: 37013399 PMCID: PMC10500203 DOI: 10.1042/ebc20220238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 04/05/2023]
Abstract
Mediator is a complex of polypeptides that plays a central role in the recruitment of RNA polymerase II to promoters and subsequent transcriptional activation in eukaryotic organisms. Studies have now shown that Mediator has a role in regulating expression of genes implicated in virulence and antifungal drug resistance in pathogenic fungi. The roles of specific Mediator subunits have been investigated in several species of pathogenic fungi, particularly in the most pathogenic yeast Candida albicans. Uniquely, pathogenic yeast also present several interesting examples of divergence in Mediator structure and function, most notably in C. glabrata, which possesses two orthologues of Med15, and in C. albicans, which has a massively expanded family of Med2 orthologues known as the TLO gene family. This review highlights specific examples of recent progress in characterizing the role of Mediator in pathogenic fungi.
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Affiliation(s)
- James O'Connor-Moneley
- Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - Leenah Alaalm
- Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - Gary P Moran
- Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - Derek J Sullivan
- Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin, Ireland
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Xu W, Li X. Regulation of Pol II Pausing during Daily Gene Transcription in Mouse Liver. BIOLOGY 2023; 12:1107. [PMID: 37626993 PMCID: PMC10452108 DOI: 10.3390/biology12081107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/20/2023] [Accepted: 08/03/2023] [Indexed: 08/27/2023]
Abstract
Cell autonomous circadian oscillation is present in central and various peripheral tissues. The intrinsic tissue clock and various extrinsic cues drive gene expression rhythms. Transcription regulation is thought to be the main driving force for gene rhythms. However, how transcription rhythms arise remains to be fully characterized due to the fact that transcription is regulated at multiple steps. In particular, Pol II recruitment, pause release, and premature transcription termination are critical regulatory steps that determine the status of Pol II pausing and transcription output near the transcription start site (TSS) of the promoter. Recently, we showed that Pol II pausing exhibits genome-wide changes during daily transcription in mouse liver. In this article, we review historical as well as recent findings on the regulation of transcription rhythms by the circadian clock and other transcription factors, and the potential limitations of those results in explaining rhythmic transcription at the TSS. We then discuss our results on the genome-wide characteristics of daily changes in Pol II pausing, the possible regulatory mechanisms involved, and their relevance to future research on circadian transcription regulation.
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Affiliation(s)
| | - Xiaodong Li
- College of Life Sciences, Wuhan University, Wuhan 430072, China;
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12
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Pal S, Biswas D. Promoter-proximal regulation of gene transcription: Key factors involved and emerging role of general transcription factors in assisting productive elongation. Gene 2023:147571. [PMID: 37331491 DOI: 10.1016/j.gene.2023.147571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/02/2023] [Accepted: 06/13/2023] [Indexed: 06/20/2023]
Abstract
The pausing of RNA polymerase II (Pol II) at the promoter-proximal sites is a key rate-limiting step in gene expression. Cells have dedicated a specific set of proteins that sequentially establish pause and then release the Pol II from promoter-proximal sites. A well-controlled pausing and subsequent release of Pol II is crucial for thefine tuning of expression of genes including signal-responsive and developmentally-regulated ones. The release of paused Pol II broadly involves its transition from initiation to elongation. In this review article, we will discuss the phenomenon of Pol II pausing, the underlying mechanism, and also the role of different known factors, with an emphasis on general transcription factors, involved in this overall regulation. We will further discuss some recent findings suggesting a possible role (underexplored) of initiation factors in assisting the transition of transcriptionally-engaged paused Pol II into productive elongation.
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Affiliation(s)
- Sujay Pal
- Laboratory of Transcription Biology, Molecular Genetics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata - 32, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Debabrata Biswas
- Laboratory of Transcription Biology, Molecular Genetics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata - 32, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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13
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Suzuki H, Furugori K, Abe R, Ogawa S, Ito S, Akiyama T, Horiuchi K, Takahashi H. MED26-containing Mediator may orchestrate multiple transcription processes through organization of nuclear bodies. Bioessays 2023; 45:e2200178. [PMID: 36852638 DOI: 10.1002/bies.202200178] [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: 09/07/2022] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 03/01/2023]
Abstract
Mediator is a coregulatory complex that plays essential roles in multiple processes of transcription regulation. One of the human Mediator subunits, MED26, has a role in recruitment of the super elongation complex (SEC) to polyadenylated genes and little elongation complex (LEC) to non-polyadenylated genes, including small nuclear RNAs (snRNAs) and replication-dependent histone (RDH) genes. MED26-containing Mediator plays a role in 3' Pol II pausing at the proximal region of transcript end sites in RDH genes through recruitment of Cajal bodies (CBs) to histone locus bodies (HLBs). This finding suggests that Mediator is involved in the association of CBs with HLBs to facilitate 3' Pol II pausing and subsequent 3'-end processing by supplying 3'-end processing factors from CBs. Thus, we argue the possibility that Mediator is involved in the organization of nuclear bodies to orchestrate multiple processes of gene transcription.
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Affiliation(s)
- Hidefumi Suzuki
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Kazuki Furugori
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Ryota Abe
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Shintaro Ogawa
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Sayaka Ito
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Tomohiko Akiyama
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Keiko Horiuchi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Hidehisa Takahashi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
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14
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Molecular Mechanisms Contributing to the Etiology of Congenital Diaphragmatic Hernia: A Review and Novel Cases. J Pediatr 2022; 246:251-265.e2. [PMID: 35314152 DOI: 10.1016/j.jpeds.2022.03.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 03/01/2022] [Accepted: 03/15/2022] [Indexed: 12/25/2022]
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15
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Suzuki H, Abe R, Shimada M, Hirose T, Hirose H, Noguchi K, Ike Y, Yasui N, Furugori K, Yamaguchi Y, Toyoda A, Suzuki Y, Yamamoto T, Saitoh N, Sato S, Tomomori-Sato C, Conaway RC, Conaway JW, Takahashi H. The 3' Pol II pausing at replication-dependent histone genes is regulated by Mediator through Cajal bodies' association with histone locus bodies. Nat Commun 2022; 13:2905. [PMID: 35614107 PMCID: PMC9133132 DOI: 10.1038/s41467-022-30632-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 05/10/2022] [Indexed: 11/09/2022] Open
Abstract
Non-polyadenylated mRNAs of replication-dependent histones (RDHs) are synthesized by RNA polymerase II (Pol II) at histone locus bodies (HLBs). HLBs frequently associate with Cajal bodies (CBs), in which 3'-end processing factors for RDH genes are enriched; however, this association's role in transcription termination of RDH genes remains unclear. Here, we show that Pol II pauses immediately upstream of transcript end sites of RDH genes and Mediator plays a role in this Pol II pausing through CBs' association with HLBs. Disruption of the Mediator docking site for Little elongation complex (LEC)-Cap binding complex (CBC)-Negative elongation factor (NELF), components of CBs, interferes with CBs' association with HLBs and 3' Pol II pausing, resulting in increased aberrant unprocessed RDH gene transcripts. Our findings suggest Mediator's involvement in CBs' association with HLBs to facilitate 3' Pol II pausing and subsequent 3'-end processing of RDH genes by supplying 3'-end processing factors.
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Affiliation(s)
- Hidefumi Suzuki
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Ryota Abe
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Miho Shimada
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Tomonori Hirose
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Hiroko Hirose
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Keisuke Noguchi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Yoko Ike
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Nanami Yasui
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Kazuki Furugori
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Yuki Yamaguchi
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama, Kanagawa, 226-8501, Japan
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Yutaka Suzuki
- Laboratory of Systems Genomics, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan
| | - Tatsuro Yamamoto
- Division of Cancer Biology, The Cancer Institute of JFCR, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan
| | - Noriko Saitoh
- Division of Cancer Biology, The Cancer Institute of JFCR, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan
| | - Shigeo Sato
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Chieri Tomomori-Sato
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Ronald C Conaway
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA.,Department of Biochemistry & Molecular Biology, University of Kansas Medical Center, Kansas City, MO, 66160, USA
| | - Joan W Conaway
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA.,Department of Biochemistry & Molecular Biology, University of Kansas Medical Center, Kansas City, MO, 66160, USA
| | - Hidehisa Takahashi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan.
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16
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17
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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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18
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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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19
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Abuhashem A, Garg V, Hadjantonakis AK. RNA polymerase II pausing in development: orchestrating transcription. Open Biol 2022; 12:210220. [PMID: 34982944 PMCID: PMC8727152 DOI: 10.1098/rsob.210220] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The coordinated regulation of transcriptional networks underpins cellular identity and developmental progression. RNA polymerase II promoter-proximal pausing (Pol II pausing) is a prevalent mechanism by which cells can control and synchronize transcription. Pol II pausing regulates the productive elongation step of transcription at key genes downstream of a variety of signalling pathways, such as FGF and Nodal. Recent advances in our understanding of the Pol II pausing machinery and its role in transcription call for an assessment of these findings within the context of development. In this review, we discuss our current understanding of the molecular basis of Pol II pausing and its function during organismal development. By critically assessing the tools used to study this process we conclude that combining recently developed genomics approaches with refined perturbation systems has the potential to expand our understanding of Pol II pausing mechanistically and functionally in the context of development and beyond.
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Affiliation(s)
- Abderhman Abuhashem
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA,Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10021, USA,Biochemistry, Cell and Molecular Biology Graduate Program, Weill Cornell Medical College, New York, NY 10021, USA
| | - Vidur Garg
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Anna-Katerina Hadjantonakis
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA,Biochemistry, Cell and Molecular Biology Graduate Program, Weill Cornell Medical College, New York, NY 10021, USA
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20
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Elongin functions as a loading factor for Mediator at ATF6α-regulated ER stress response genes. Proc Natl Acad Sci U S A 2021; 118:2108751118. [PMID: 34544872 DOI: 10.1073/pnas.2108751118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2021] [Indexed: 12/11/2022] Open
Abstract
The bZIP transcription factor ATF6α is a master regulator of endoplasmic reticulum (ER) stress response genes. In this report, we identify the multifunctional RNA polymerase II transcription factor Elongin as a cofactor for ATF6α-dependent transcription activation. Biochemical studies reveal that Elongin functions at least in part by facilitating ATF6α-dependent loading of Mediator at the promoters and enhancers of ER stress response genes. Depletion of Elongin from cells leads to impaired transcription of ER stress response genes and to defects in the recruitment of Mediator and its CDK8 kinase subunit. Taken together, these findings bring to light a role for Elongin as a loading factor for Mediator during the ER stress response.
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21
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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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22
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Zhang J, Yue W, Zhou Y, Liao M, Chen X, Hua J. Super enhancers-Functional cores under the 3D genome. Cell Prolif 2021; 54:e12970. [PMID: 33336467 PMCID: PMC7848964 DOI: 10.1111/cpr.12970] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/28/2020] [Accepted: 12/07/2020] [Indexed: 12/13/2022] Open
Abstract
Complex biochemical reactions take place in the nucleus all the time. Transcription machines must follow the rules. The chromatin state, especially the three-dimensional structure of the genome, plays an important role in gene regulation and expression. The super enhancers are important for defining cell identity in mammalian developmental processes and human diseases. It has been shown that the major components of transcriptional activation complexes are recruited by super enhancer to form phase-separated condensates. We summarize the current knowledge about super enhancer in the 3D genome. Furthermore, a new related transcriptional regulation model from super enhancer is outlined to explain its role in the mammalian cell progress.
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Affiliation(s)
- Juqing Zhang
- College of Veterinary MedicineShaanxi Centre of Stem Cells Engineering & TechnologyNorthwest A&F UniversityYanglingChina
| | - Wei Yue
- College of Veterinary MedicineShaanxi Centre of Stem Cells Engineering & TechnologyNorthwest A&F UniversityYanglingChina
| | - Yaqi Zhou
- College of Life ScienceNorthwest A&F UniversityYanglingChina
| | - Mingzhi Liao
- College of Life ScienceNorthwest A&F UniversityYanglingChina
| | - Xingqi Chen
- Department of Immunology, Genetics and PathologyUppsala UniversityUppsalaSweden
| | - Jinlian Hua
- College of Veterinary MedicineShaanxi Centre of Stem Cells Engineering & TechnologyNorthwest A&F UniversityYanglingChina
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23
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Maß L, Holtmannspötter M, Zachgo S. Dual-color 3D-dSTORM colocalization and quantification of ROXY1 and RNAPII variants throughout the transcription cycle in root meristem nuclei. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:1423-1436. [PMID: 32896918 DOI: 10.1111/tpj.14986] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/04/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
To unravel the function of a protein of interest, it is crucial to asses to what extent it associates via direct interactions or by overlapping expression with other proteins. ROXY1, a land plant-specific glutaredoxin, exerts a function in Arabidopsis flower development and interacts with TGA transcription factors in the nucleus. We detected a novel ROXY1 function in the root meristem. Root cells that lack chlorophyll reducing plant-specific background problems that can hamper colocalization 3D microscopy. Thus far, a super-resolution three-dimensional stochastic optical reconstruction microscopy (3D-dSTORM) approach has mainly been applied in animal studies. We established 3D-dSTORM using the roxy1 mutant complemented with green fluorescence protein-ROXY1 and investigated its colocalization with three distinct RNAPII isoforms. To quantify the colocalization results, 3D-dSTORM was coupled with the coordinate-based colocalization method. Interestingly, ROXY1 proteins colocalize with different RNA polymerase II (RNAPII) isoforms that are active at distinct transcription cycle steps. Our colocalization data provide new insights on nuclear glutaredoxin activities suggesting that ROXY1 is not only required in early transcription initiation events via interaction with transcription factors but likely also participates throughout further transcription processes until late termination steps. Furthermore, we showed the applicability of the combined approaches to detect and quantify responses to altered growth conditions, exemplified by analysis of H2 O2 treatment, causing a dissociation of ROXY1 and RNAPII isoforms. We envisage that the powerful dual-color 3D-dSTORM/coordinate-based colocalization combination offers plant cell biologists the opportunity to colocalize and quantify root meristem proteins at an increased, unprecedented resolution level <50 nm, which will enable the detection of novel subcellular protein associations and functions.
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Affiliation(s)
- Lucia Maß
- Botany Department, School of Biology and Chemistry, Osnabrück University, Osnabrück, 49076, Germany
| | - Michael Holtmannspötter
- Integrated Bioimaging Facility iBiOs, School of Biology and Chemistry, Osnabrück University, Osnabrück, 49076, Germany
- Center of Cellular Nanoanalytics Osnabrück, School of Biology and Chemistry, Osnabrück University, Osnabrück, 49076, Germany
| | - Sabine Zachgo
- Botany Department, School of Biology and Chemistry, Osnabrück University, Osnabrück, 49076, Germany
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24
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Dash S, Bhatt S, Falcon KT, Sandell LL, Trainor PA. Med23 Regulates Sox9 Expression during Craniofacial Development. J Dent Res 2020; 100:406-414. [PMID: 33155500 DOI: 10.1177/0022034520969109] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The etiology and pathogenesis of craniofacial birth defects are multifactorial and include both genetic and environmental factors. Despite the identification of numerous genes associated with congenital craniofacial anomalies, our understanding of their etiology remains incomplete, and many affected individuals have an unknown genetic diagnosis. Here, we show that conditional loss of a Mediator complex subunit protein, Med23 in mouse neural crest cells (Med23fx/fx;Wnt1-Cre), results in micrognathia, glossoptosis, and cleft palate, mimicking the phenotype of Pierre Robin sequence. Sox9 messenger RNA and protein levels are both upregulated in neural crest cell-derived mesenchyme surrounding Meckel's cartilage and in the palatal shelves in Med23fx/fx;Wnt1-Cre mutant embryos compared to controls. Consistent with these observations, we demonstrate that Med23 binds to the promoter region of Sox9 and represses Sox9 expression in vitro. Interestingly, Sox9 binding to β-catenin is enhanced in Med23fx/fx;Wnt1-Cre mutant embryos, which, together with downregulation of Col2a1 and Wnt signaling target genes, results in decreased proliferation and altered jaw skeletal differentiation and cleft palate. Altogether, our data support a cell-autonomous requirement for Med23 in neural crest cells, potentially linking the global transcription machinery through Med23 to the etiology and pathogenesis of craniofacial anomalies such as micrognathia and cleft palate.
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Affiliation(s)
- S Dash
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - S Bhatt
- Stowers Institute for Medical Research, Kansas City, MO, USA.,Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - K T Falcon
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - L L Sandell
- Department of Oral Immunology and Infectious Diseases, University of Louisville, School of Dentistry, Louisville, KY, USA
| | - P A Trainor
- Stowers Institute for Medical Research, Kansas City, MO, USA.,Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
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25
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Shukla A, Srivastava S, Darokar J, Kulshreshtha R. HIF1α and p53 Regulated MED30, a Mediator Complex Subunit, is Involved in Regulation of Glioblastoma Pathogenesis and Temozolomide Resistance. Cell Mol Neurobiol 2020; 41:1521-1535. [PMID: 32705436 DOI: 10.1007/s10571-020-00920-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 07/10/2020] [Indexed: 10/23/2022]
Abstract
Glioblastoma (GBM) is the most common, malignant, and aggressive form of glial cell cancer with unfavorable clinical outcomes. It is believed that a better understanding of the mechanisms of gene deregulation may lead to novel therapeutic approaches for this yet incurable cancer. Mediator complex is a crucial component of enhancer-based gene expression and works as a transcriptional co-activator. Many of the mediator complex subunits are found to be deregulated/mutated in various malignancies; however, their status and role in GBM remains little studied. We report that MED30, a core subunit of the head module, is overexpressed in GBM tissues and cell lines. MED30 was found to be induced by conditions present in the tumor microenvironment such as hypoxia, serum, and glucose deprivation. MED30 harbors hypoxia response elements (HREs) and p53 binding site in its promoter and is induced in a HIF1α and p53 dependent manner. Further, MED30 levels also significantly positively correlated with p53 and HIF1α levels in GBM tissues. Using both MED30 overexpression and knockdown approach, we show that MED30 promotes cell proliferation while reduces the migration capabilities in GBM cell lines. Notably, MED30 was also found to confer sensitivity to chemodrug, temozolomide, in GBM cells and modulate the level of p53 in vitro. Overall, this is the first report showing MED30 overexpression in GBM and its involvement in GBM pathogenesis suggesting its diagnostic and therapeutic potential urging the need for further systematic exploration of MED30 interactome and target networks.
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Affiliation(s)
- Anubha Shukla
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Srishti Srivastava
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Jayant Darokar
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Ritu Kulshreshtha
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110016, India.
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26
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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: 81] [Impact Index Per Article: 20.3] [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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27
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Takahashi H, Ranjan A, Chen S, Suzuki H, Shibata M, Hirose T, Hirose H, Sasaki K, Abe R, Chen K, He Y, Zhang Y, Takigawa I, Tsukiyama T, Watanabe M, Fujii S, Iida M, Yamamoto J, Yamaguchi Y, Suzuki Y, Matsumoto M, Nakayama KI, Washburn MP, Saraf A, Florens L, Sato S, Tomomori-Sato C, Conaway RC, Conaway JW, Hatakeyama S. The role of Mediator and Little Elongation Complex in transcription termination. Nat Commun 2020; 11:1063. [PMID: 32102997 PMCID: PMC7044329 DOI: 10.1038/s41467-020-14849-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 02/08/2020] [Indexed: 12/22/2022] Open
Abstract
Mediator is a coregulatory complex that regulates transcription of Pol II-dependent genes. Previously, we showed that human Mediator subunit MED26 plays a role in the recruitment of Super Elongation Complex (SEC) or Little Elongation Complex (LEC) to regulate the expression of certain genes. MED26 plays a role in recruiting SEC to protein-coding genes including c-myc and LEC to small nuclear RNA (snRNA) genes. However, how MED26 engages SEC or LEC to regulate distinct genes is unclear. Here, we provide evidence that MED26 recruits LEC to modulate transcription termination of non-polyadenylated transcripts including snRNAs and mRNAs encoding replication-dependent histone (RDH) at Cajal bodies. Our findings indicate that LEC recruited by MED26 promotes efficient transcription termination by Pol II through interaction with CBC-ARS2 and NELF/DSIF, and promotes 3′ end processing by enhancing recruitment of Integrator or Heat Labile Factor to snRNA or RDH genes, respectively. Mediator subunit MED26 was shown to help recruit Super Elongation Complex (SEC) or Little Elongation Complex (LEC) to control the expression of certain genes. Here, the authors provide evidence that MED26 recruits LEC to regulate transcription termination of non-polyadenylated genes, including snRNA and replication-dependent histone (RDH) genes at Cajal bodies.
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Affiliation(s)
- Hidehisa Takahashi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa, 216-0004, Japan.
| | - Amol Ranjan
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Shiyuan Chen
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Hidefumi Suzuki
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa, 216-0004, Japan
| | - Mio Shibata
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo, Hokkaido, 060-8638, Japan
| | - Tomonori Hirose
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa, 216-0004, Japan
| | - Hiroko Hirose
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa, 216-0004, Japan
| | - Kazunori Sasaki
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa, 216-0004, Japan
| | - Ryota Abe
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa, 216-0004, Japan
| | - Kai Chen
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Yanfeng He
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Ying Zhang
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Ichigaku Takigawa
- Graduate School of Information Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo, Hokkaido, 060-0814, Japan
| | - Tadasuke Tsukiyama
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo, Hokkaido, 060-8638, Japan
| | - Masashi Watanabe
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo, Hokkaido, 060-8638, Japan
| | - Satoshi Fujii
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka, 820-8502, Japan
| | - Midori Iida
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka, 820-8502, Japan
| | - Junichi Yamamoto
- Department of Nanoparticle Translational Research Tokyo Medical University, 6-7-1, Nishi-Shinjuku, Tokyo, Shinjuku-ku, 160-0023, Japan
| | - Yuki Yamaguchi
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Kanagawa, 226-8501, Japan
| | - Yutaka Suzuki
- Laboratory of Systems Genomics, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan
| | - Masaki Matsumoto
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka, 812-8582, Japan.,Division of Proteomics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka, 812-8582, Japan
| | - Keiichi I Nakayama
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka, 812-8582, Japan.,Division of Proteomics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka, 812-8582, Japan
| | - Michael P Washburn
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA.,Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Anita Saraf
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Shigeo Sato
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Chieri Tomomori-Sato
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA
| | - Ronald C Conaway
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA.,Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Joan W Conaway
- Stowers Institute for Medical Research, 1000E 50th Street, Kansas City, MO, 64110, USA. .,Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
| | - Shigetsugu Hatakeyama
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo, Hokkaido, 060-8638, Japan.
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28
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Wu F, Deng L, Zhai Q, Zhao J, Chen Q, Li C. Mediator Subunit MED25 Couples Alternative Splicing of JAZ Genes with Fine-Tuning of Jasmonate Signaling. THE PLANT CELL 2020; 32:429-448. [PMID: 31852773 PMCID: PMC7008490 DOI: 10.1105/tpc.19.00583] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/24/2019] [Accepted: 12/16/2019] [Indexed: 05/19/2023]
Abstract
JASMONATE ZIM-DOMAIN (JAZ) transcriptional repressors are key regulators of jasmonate (JA) signaling in plants. At the resting stage, the C-terminal Jas motifs of JAZ proteins bind the transcription factor MYC2 to repress JA signaling. Upon hormone elicitation, the Jas motif binds the hormone receptor CORONATINE INSENSITIVE1, which mediates proteasomal degradation of JAZs and thereby allowing the Mediator subunit MED25 to activate MYC2. Subsequently, plants desensitize JA signaling by feedback generation of dominant JAZ splice variants that repress MYC2. Here we report the mechanistic function of Arabidopsis (Arabidopsis thaliana) MED25 in regulating the alternative splicing of JAZ genes through recruiting the splicing factors PRE-mRNA-PROCESSING PROTEIN 39a (PRP39a) and PRP40a. We demonstrate that JA-induced generation of JAZ splice variants depends on MED25 and that MED25 recruits PRP39a and PRP40a to promote the full splicing of JAZ genes. Therefore, MED25 forms a module with PRP39a and PRP40a to prevent excessive desensitization of JA signaling mediated by JAZ splice variants.
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Affiliation(s)
- Fangming Wu
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Lei Deng
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Qingzhe Zhai
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- Chinese Academy of Sciences Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiuhai Zhao
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Shandong Province, Tai'an 271018, China
| | - Qian Chen
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Shandong Province, Tai'an 271018, China
| | - Chuanyou Li
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- Chinese Academy of Sciences Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
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29
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Mao X, Weake VM, Chapple C. Mediator function in plant metabolism revealed by large-scale biology. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5995-6003. [PMID: 31504746 DOI: 10.1093/jxb/erz372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/07/2019] [Indexed: 05/16/2023]
Abstract
Mediator is a multisubunit transcriptional co-regulator that is involved in the regulation of an array of processes including plant metabolism. The pathways regulated by Mediator-dependent processes include those for the synthesis of phenylpropanoids (MED5), cellulose (MED16), lipids (MED15 and CDK8), and the regulation of iron homeostasis (MED16 and MED25). Traditional genetic and biochemical approaches laid the foundation for our understanding of Mediator function, but recent transcriptomic and metabolomic studies have provided deeper insights into how specific subunits cooperate in the regulation of plant metabolism. In this review, we highlight recent developments in the investigation of Mediator and plant metabolism, with particular emphasis on the large-scale biology studies of med mutants.
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Affiliation(s)
- Xiangying Mao
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, USA
| | - Vikki M Weake
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, USA
| | - Clint Chapple
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, USA
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30
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El Khattabi L, Zhao H, Kalchschmidt J, Young N, Jung S, Van Blerkom P, Kieffer-Kwon P, Kieffer-Kwon KR, Park S, Wang X, Krebs J, Tripathi S, Sakabe N, Sobreira DR, Huang SC, Rao SSP, Pruett N, Chauss D, Sadler E, Lopez A, Nóbrega MA, Aiden EL, Asturias FJ, Casellas R. A Pliable Mediator Acts as a Functional Rather Than an Architectural Bridge between Promoters and Enhancers. Cell 2019; 178:1145-1158.e20. [PMID: 31402173 PMCID: PMC7533040 DOI: 10.1016/j.cell.2019.07.011] [Citation(s) in RCA: 148] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 05/24/2019] [Accepted: 07/09/2019] [Indexed: 12/11/2022]
Abstract
While Mediator plays a key role in eukaryotic transcription, little is known about its mechanism of action. This study combines CRISPR-Cas9 genetic screens, degron assays, Hi-C, and cryoelectron microscopy (cryo-EM) to dissect the function and structure of mammalian Mediator (mMED). Deletion analyses in B, T, and embryonic stem cells (ESC) identified a core of essential subunits required for Pol II recruitment genome-wide. Conversely, loss of non-essential subunits mostly affects promoters linked to multiple enhancers. Contrary to current models, however, mMED and Pol II are dispensable to physically tether regulatory DNA, a topological activity requiring architectural proteins. Cryo-EM analysis revealed a conserved core, with non-essential subunits increasing structural complexity of the tail module, a primary transcription factor target. Changes in tail structure markedly increase Pol II and kinase module interactions. We propose that Mediator's structural pliability enables it to integrate and transmit regulatory signals and act as a functional, rather than an architectural bridge, between promoters and enhancers.
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Affiliation(s)
| | - Haiyan Zhao
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical School, Aurora CO 80045, USA
| | | | - Natalie Young
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical School, Aurora CO 80045, USA
| | - Seolkyoung Jung
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Peter Van Blerkom
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical School, Aurora CO 80045, USA
| | | | | | - Solji Park
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Xiang Wang
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Jordan Krebs
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD 20892, USA
| | | | - Noboru Sakabe
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Débora R Sobreira
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Su-Chen Huang
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Suhas S P Rao
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | - Daniel Chauss
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Erica Sadler
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Andrea Lopez
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD 20892, USA
| | - Marcelo A Nóbrega
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Erez Lieberman Aiden
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA; Center for Theoretical Biological Physics, Rice University, Houston, TX 77030, USA; Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Francisco J Asturias
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical School, Aurora CO 80045, USA.
| | - Rafael Casellas
- Lymphocyte Nuclear Biology, NIAMS, NIH, Bethesda, MD 20892, USA; Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, USA.
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31
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Miao YL, Gambini A, Zhang Y, Padilla-Banks E, Jefferson WN, Bernhardt ML, Huang W, Li L, Williams CJ. Mediator complex component MED13 regulates zygotic genome activation and is required for postimplantation development in the mouse. Biol Reprod 2019; 98:449-464. [PMID: 29325037 DOI: 10.1093/biolre/ioy004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 01/08/2018] [Indexed: 12/21/2022] Open
Abstract
Understanding factors that regulate zygotic genome activation (ZGA) is critical for determining how cells are reprogrammed to become totipotent or pluripotent. There is limited information regarding how this process occurs physiologically in early mammalian embryos. Here, we identify a mediator complex subunit, MED13, as translated during mouse oocyte maturation and transcribed early from the zygotic genome. Knockdown and conditional knockout approaches demonstrate that MED13 is essential for ZGA in the mouse, in part by regulating expression of the embryo-specific chromatin remodeling complex, esBAF. The role of MED13 in ZGA is mediated in part by interactions with E2F transcription factors. In addition to MED13, its paralog, MED13L, is required for successful preimplantation embryo development. MED13L partially compensates for loss of MED13 function in preimplantation knockout embryos, but postimplantation development is not rescued by MED13L. Our data demonstrate an essential role for MED13 in supporting chromatin reprogramming and directed transcription of essential genes during ZGA.
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Affiliation(s)
- Yi-Liang Miao
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA.,Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction, Ministry of Education College of Animal Science and Technology, Huazhong Agricultural University, China
| | - Andrés Gambini
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Yingpei Zhang
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Elizabeth Padilla-Banks
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Wendy N Jefferson
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Miranda L Bernhardt
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Weichun Huang
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Leping Li
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Carmen J Williams
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
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32
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Napoli C, Schiano C, Soricelli A. Increasing evidence of pathogenic role of the Mediator (MED) complex in the development of cardiovascular diseases. Biochimie 2019; 165:1-8. [PMID: 31255603 DOI: 10.1016/j.biochi.2019.06.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/24/2019] [Indexed: 12/20/2022]
Abstract
Cardiovascular diseases (CVDs) are the first cause of death in the World. Mediator (MED) is an evolutionarily conserved protein complex, which mediates distinct protein-protein interactions. Pathogenic events in MED subunit have been associated with human diseases. Novel increasing evidence showed that missense mutations in MED13L gene are associated with transposition of great arteries while MED12, MED13, MED15, and MED30, have been correlated with heart development. Moreover, MED23 and MED25 have been associated with heart malformations in humans. Relevantly, MED1, MED13, MED14, MED15, MED23, MED25, and CDK8, were found modify glucose and/or lipid metabolism. Indeed, MED1, MED15, MED25, and CDK8 interact in the PPAR- and SREBP-mediated signaling pathways. MED1, MED14 and MED23 are involved in adipocyte differentiation, whereas MED23 mediates smooth muscle cell differentiation. MED12, MED19, MED23, and MED30 regulate endothelial differentiation by alternative splicing mechanism. Thus, MEDs have a central role in early pathogenic events involved in CVDs representing novel targets for clinical prevention and therapeutic approaches.
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Affiliation(s)
- C Napoli
- University Department of Advanced Medical and Surgical Sciences, Clinical Department of Internal Medicine and Specialistic Units, University of Campania "L. Vanvitelli", 80138, Naples, Italy
| | | | - A Soricelli
- IRCCS SDN, 80143, Naples, Italy; Department of Motor Sciences and Healthiness, University of Naples Parthenope, 80134, Naples, Italy
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33
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Dittmar G, Hernandez DP, Kowenz-Leutz E, Kirchner M, Kahlert G, Wesolowski R, Baum K, Knoblich M, Hofstätter M, Muller A, Wolf J, Reimer U, Leutz A. PRISMA: Protein Interaction Screen on Peptide Matrix Reveals Interaction Footprints and Modifications- Dependent Interactome of Intrinsically Disordered C/EBPβ. iScience 2019; 13:351-370. [PMID: 30884312 PMCID: PMC6424098 DOI: 10.1016/j.isci.2019.02.026] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 01/20/2019] [Accepted: 02/23/2019] [Indexed: 12/13/2022] Open
Abstract
CCAAT enhancer-binding protein beta (C/EBPβ) is a pioneer transcription factor that specifies cell differentiation. C/EBPβ is intrinsically unstructured, a molecular feature common to many proteins involved in signal processing and epigenetics. The structure of C/EBPβ differs depending on alternative translation initiation and multiple post-translational modifications (PTM). Mutation of distinct PTM sites in C/EBPβ alters protein interactions and cell differentiation, suggesting that a C/EBPβ PTM indexing code determines epigenetic outcomes. Herein, we systematically explored the interactome of C/EBPβ using an array technique based on spot-synthesized C/EBPβ-derived linear tiling peptides with and without PTM, combined with mass spectrometric proteomic analysis of protein interactions. We identified interaction footprints of ∼1,300 proteins in nuclear extracts, many with chromatin modifying, chromatin remodeling, and RNA processing functions. The results suggest that C/EBPβ acts as a multi-tasking molecular switchboard, integrating signal-dependent modifications and structural plasticity to orchestrate interactions with numerous protein complexes directing cell fate and function.
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Affiliation(s)
- Gunnar Dittmar
- Proteome and Genome Research Laboratory, Luxembourg Institute of Health, 1a Rue Thomas Edison, 1445 Strassen, Luxembourg; Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany; BIH Core Facility Proteomics, Robert-Roessle Strasse 10, 10125 Berlin, Germany.
| | - Daniel Perez Hernandez
- Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany; BIH Core Facility Proteomics, Robert-Roessle Strasse 10, 10125 Berlin, Germany
| | - Elisabeth Kowenz-Leutz
- Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Marieluise Kirchner
- Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany; BIH Core Facility Proteomics, Robert-Roessle Strasse 10, 10125 Berlin, Germany
| | - Günther Kahlert
- Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Radoslaw Wesolowski
- Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Katharina Baum
- Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Maria Knoblich
- Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Maria Hofstätter
- Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Arnaud Muller
- Proteome and Genome Research Laboratory, Luxembourg Institute of Health, 1a Rue Thomas Edison, 1445 Strassen, Luxembourg
| | - Jana Wolf
- Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Ulf Reimer
- JPT Peptide Technologies GmbH, Volmerstrasse 5, 12489 Berlin, Germany
| | - Achim Leutz
- Max Delbrück Center for Molecular Medicine, Robert-Roessle Strasse 10, 13125 Berlin, Germany; Humboldt-University of Berlin, Institute of Biology, 10115 Berlin, Germany.
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Twenty years of Mediator complex structural studies. Biochem Soc Trans 2019; 47:399-410. [PMID: 30733343 PMCID: PMC6393861 DOI: 10.1042/bst20180608] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/14/2019] [Accepted: 01/16/2019] [Indexed: 11/18/2022]
Abstract
Mediator is a large multiprotein complex conserved in all eukaryotes that plays an essential role in transcriptional regulation. Mediator comprises 25 subunits in yeast and 30 subunits in humans that form three main modules and a separable four-subunit kinase module. For nearly 20 years, because of its size and complexity, Mediator has posed a formidable challenge to structural biologists. The first two-dimensional electron microscopy (EM) projection map of Mediator leading to the canonical view of its division in three topological modules named Head, Middle and Tail, was published in 1999. Within the last few years, optimization of Mediator purification combined with technical and methodological advances in cryo-electron microscopy (cryo-EM) have revealed unprecedented details of Mediator subunit organization, interactions with RNA polymerase II and parts of its core structure at high resolution. To celebrate the twentieth anniversary of the first Mediator EM reconstruction, we look back on the structural studies of Mediator complex from a historical perspective and discuss them in the light of our current understanding of its role in transcriptional regulation.
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Sierecki E. The Mediator complex and the role of protein-protein interactions in the gene regulation machinery. Semin Cell Dev Biol 2018; 99:20-30. [PMID: 30278226 DOI: 10.1016/j.semcdb.2018.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 08/13/2018] [Accepted: 08/13/2018] [Indexed: 12/11/2022]
Abstract
At the core of gene regulation, a complex network of dynamic interactions between proteins, DNA and RNA has to be integrated in order to generate a binary biological output. Large protein complexes, called adaptors, transfer information from the transcription factors to the transcription machinery [1,2]. Here we focus on Mediator, one of the largest adaptor proteins in humans [3]. Assembled from 30 different subunits, this system provides extraordinary illustrations for the various roles played by protein-protein interactions. Recruitment of new subunits during evolution is an adaptive mechanism to the growing complexity of the organism. Integration of information happens at multiple scales, with allosteric effects at the level of individual subunits resulting in large conformational changes. Mediator is also rich in disordered regions that increase the potential for interactions by presenting a malleable surface to its environment. Potentially, 3000 transcription factors can interact with Mediator and so understanding the molecular mechanisms that support the processing of this overload of information is one of the great challenges in molecular biology.
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Affiliation(s)
- Emma Sierecki
- EMBL Australia Node in Single Molecule Science, and School of Medical Sciences, Faculty of Medecine, The University of New South Wales, Sydney, Australia.
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Balas MM, Porman AM, Hansen KC, Johnson AM. SILAC-MS Profiling of Reconstituted Human Chromatin Platforms for the Study of Transcription and RNA Regulation. J Proteome Res 2018; 17:3475-3484. [PMID: 30192551 DOI: 10.1021/acs.jproteome.8b00395] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
DNA packaged into chromatin is the core structure of the human genome. Nearly all eukaryotic genome regulation must interface with this genomic structure, and modification of the chromatin can influence molecular mechanisms that regulate the underlying DNA. Many processes are governed by regulated stepwise assembly mechanisms that build complex machinery on chromatin to license a specific activity such as transcription. Transcriptional activators drive the initial steps of gene expression, regulated in part by chromatin. Here we describe tools to study the stepwise assembly of protein complexes on chromatin in a highly controlled manner using reconstituted human chromatin platforms and quantitative proteomic profiling. We profile the early steps in transcriptional activation and highlight the potential for understanding the multiple ways chromatin can influence transcriptional regulation. We also describe modifications of this approach to study the activity of a long noncoding RNA to act as a dynamic scaffold for proteins to be recruited to chromatin. This approach has the potential to provide a more comprehensive understanding of important macromolecular complex assembly that occurs on the human genome. The reconstituted nature of the chromatin substrate offers a tunable system that can be trapped at specific substeps to understand how chromatin interfaces with genome regulation machinery.
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Functional diversification of the NleG effector family in enterohemorrhagic Escherichia coli. Proc Natl Acad Sci U S A 2018; 115:10004-10009. [PMID: 30217892 DOI: 10.1073/pnas.1718350115] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The pathogenic strategy of Escherichia coli and many other gram-negative pathogens relies on the translocation of a specific set of proteins, called effectors, into the eukaryotic host cell during infection. These effectors act in concert to modulate host cell processes in favor of the invading pathogen. Injected by the type III secretion system (T3SS), the effector arsenal of enterohemorrhagic E. coli (EHEC) O157:H7 features at least eight individual NleG effectors, which are also found across diverse attaching and effacing pathogens. NleG effectors share a conserved C-terminal U-box E3 ubiquitin ligase domain that engages with host ubiquitination machinery. However, their specific functions and ubiquitination targets have remained uncharacterized. Here, we identify host proteins targeted for ubiquitination-mediated degradation by two EHEC NleG family members, NleG5-1 and NleG2-3. NleG5-1 localizes to the host cell nucleus and targets the MED15 subunit of the Mediator complex, while NleG2-3 resides in the host cytosol and triggers degradation of Hexokinase-2 and SNAP29. Our structural studies of NleG5-1 reveal a distinct N-terminal α/β domain that is responsible for interacting with host protein targets. The core of this domain is conserved across the NleG family, suggesting this domain is present in functionally distinct NleG effectors, which evolved diversified surface residues to interact with specific host proteins. This is a demonstration of the functional diversification and the range of host proteins targeted by the most expanded effector family in the pathogenic arsenal of E. coli.
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Mediator, known as a coactivator, can act in transcription initiation in an activator-independent manner in vivo. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:687-696. [DOI: 10.1016/j.bbagrm.2018.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 06/28/2018] [Accepted: 07/04/2018] [Indexed: 01/20/2023]
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Candida glabrata Med3 Plays a Role in Altering Cell Size and Budding Index To Coordinate Cell Growth. Appl Environ Microbiol 2018; 84:AEM.00781-18. [PMID: 29776932 DOI: 10.1128/aem.00781-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 05/14/2018] [Indexed: 12/11/2022] Open
Abstract
Candida glabrata is a promising microorganism for the production of organic acids. Here, we report deletion and quantitative-expression approaches to elucidate the role of C. glabrata Med3AB (CgMed3AB), a subunit of the mediator transcriptional coactivator, in regulating cell growth. Deletion of CgMed3AB caused an 8.6% decrease in final biomass based on growth curve plots and 10.5% lower cell viability. Based on transcriptomics data, the reason for this growth defect was attributable to changes in expression of genes involved in pyruvate and acetyl-coenzyme A (CoA)-related metabolism in a Cgmed3abΔ strain. Furthermore, the mRNA level of acetyl-CoA synthetase was downregulated after deleting Cgmed3ab, resulting in 22.8% and 21% lower activity of acetyl-CoA synthetase and cellular acetyl-CoA, respectively. Additionally, the mRNA level of CgCln3, whose expression depends on acetyl-CoA, was 34% lower in this strain. As a consequence, the cell size and budding index in the Cgmed3abΔ strain were both reduced. Conversely, overexpression of Cgmed3ab led to 16.8% more acetyl-CoA and 120% higher CgCln3 mRNA levels, as well as 19.1% larger cell size and a 13.3% higher budding index than in wild-type cells. Taken together, these results suggest that CgMed3AB regulates cell growth in C. glabrata by coordinating homeostasis between cellular acetyl-CoA and CgCln3.IMPORTANCE This study demonstrates that CgMed3AB can regulate cell growth in C. glabrata by coordinating the homeostasis of cellular acetyl-CoA metabolism and the cell cycle cyclin CgCln3. Specifically, we report that CgMed3AB regulates the cellular acetyl-CoA level, which induces the transcription of Cgcln3, finally resulting in alterations to the cell size and budding index. In conclusion, we report that CgMed3AB functions as a wheel responsible for driving cellular acetyl-CoA metabolism, indirectly inducing the transcription of Cgcln3 and coordinating cell growth. We propose that Mediator subunits may represent a vital regulatory target modulating cell growth in C. glabrata.
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Arnold CD, Nemčko F, Woodfin AR, Wienerroither S, Vlasova A, Schleiffer A, Pagani M, Rath M, Stark A. A high-throughput method to identify trans-activation domains within transcription factor sequences. EMBO J 2018; 37:embj.201798896. [PMID: 30006452 PMCID: PMC6092621 DOI: 10.15252/embj.201798896] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 06/15/2018] [Accepted: 06/15/2018] [Indexed: 11/09/2022] Open
Abstract
Even though transcription factors (TFs) are central players of gene regulation and have been extensively studied, their regulatory trans-activation domains (tADs) often remain unknown and a systematic functional characterization of tADs is lacking. Here, we present a novel high-throughput approach tAD-seq to functionally test thousands of candidate tADs from different TFs in parallel. The tADs we identify by pooled screening validate in individual luciferase assays, whereas neutral regions do not. Interestingly, the tADs are found at arbitrary positions within the TF sequences and can contain amino acid (e.g., glutamine) repeat regions or overlap structured domains, including helix-loop-helix domains that are typically annotated as DNA-binding. We also identified tADs in the non-native reading frames, confirming that random sequences can function as tADs, albeit weakly. The identification of tADs as short protein sequences sufficient for transcription activation will enable the systematic study of TF function, which-particularly for TFs of different transcription activating functionalities-is still poorly understood.
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Affiliation(s)
- Cosmas D Arnold
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Filip Nemčko
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Ashley R Woodfin
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | | | - Anna Vlasova
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Alexander Schleiffer
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria.,Institute of Molecular Biotechnology (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Michaela Pagani
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Martina Rath
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Alexander Stark
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria .,Medical University of Vienna, Vienna BioCenter (VBC), Vienna, Austria
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Putlyaev EV, Ibragimov AN, Lebedeva LA, Georgiev PG, Shidlovskii YV. Structure and Functions of the Mediator Complex. BIOCHEMISTRY (MOSCOW) 2018; 83:423-436. [PMID: 29626929 DOI: 10.1134/s0006297918040132] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Mediator is a key factor in the regulation of expression of RNA polymerase II-transcribed genes. Recent studies have shown that Mediator acts as a coordinator of transcription activation and participates in maintaining chromatin architecture in the cell nucleus. In this review, we present current concepts on the structure and functions of Mediator.
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Affiliation(s)
- E V Putlyaev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
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Abstract
Stem cell specification in multicellular organisms relies on the precise spatiotemporal control of RNA polymerase II (Pol II)-dependent gene transcription, in which the evolutionarily conserved Mediator coactivator complex plays an essential role. In Arabidopsis thaliana, SHORTROOT (SHR) and SCARECROW (SCR) orchestrate a transcriptional program that determines the fate and asymmetrical divisions of stem cells generating the root ground tissue. The mechanism by which SHR/SCR relays context-specific regulatory signals to the Pol II general transcription machinery is unknown. Here, we report the role of Mediator in controlling the spatiotemporal transcriptional output of SHR/SCR during asymmetrical division of stem cells and ground tissue patterning. The Mediator subunit MED31 interacted with SCR but not SHR. Reduction of MED31 disrupted the spatiotemporal activation of CYCLIND6;1 (CYCD6;1), leading to defective asymmetrical division of stem cells generating ground tissue. MED31 was recruited to the promoter of CYCD6;1 in an SCR-dependent manner. MED31 was involved in the formation of a dynamic MED31/SCR/SHR ternary complex through the interface protein SCR. We demonstrate that the relative protein abundance of MED31 and SHR in different cell types regulates the dynamic formation of the ternary complex, which provides a tunable switch to strictly control the spatiotemporal transcriptional output. This study provides valuable clues to understand the mechanism by which master transcriptional regulators control organ patterning.
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Pfab A, Bruckmann A, Nazet J, Merkl R, Grasser KD. The Adaptor Protein ENY2 Is a Component of the Deubiquitination Module of the Arabidopsis SAGA Transcriptional Co-activator Complex but not of the TREX-2 Complex. J Mol Biol 2018; 430:1479-1494. [PMID: 29588169 DOI: 10.1016/j.jmb.2018.03.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 03/20/2018] [Accepted: 03/20/2018] [Indexed: 12/26/2022]
Abstract
The conserved nuclear protein ENY2 (Sus1 in yeast) is involved in coupling transcription and mRNA export in yeast and metazoa, as it is a component both of the transcriptional co-activator complex SAGA and of the mRNA export complex TREX-2. Arabidopsis thaliana ENY2 is widely expressed in the plant and it localizes to the nucleoplasm, but unlike its yeast/metazoan orthologs, it is not enriched in the nuclear envelope. Affinity purification of ENY2 in combination with mass spectrometry revealed that it co-purified with SAGA components, but not with the nuclear pore-associated TREX-2. In addition, further targeted proteomics analyses by reciprocal tagging established the composition of the Arabidopsis SAGA complex consisting of the four modules HATm, SPTm, TAFm and DUBm, and that several SAGA subunits occur in alternative variants. While the HATm, SPTm and TAFm robustly co-purified with each other, the deubiquitination module (DUBm) appears to associate with the other SAGA modules more weakly/dynamically. Consistent with a homology model of the Arabidopsis DUBm, the SGF11 protein interacts directly with ENY2 and UBP22. Plants depleted in the DUBm components, SGF11 or ENY2, are phenotypically only mildly affected, but they contain increased levels of ubiquitinated histone H2B, indicating that the SAGA-DUBm has histone deubiquitination activity in plants. In addition to transcription-related proteins (i.e., transcript elongation factors, Mediator), many splicing factors were found to associate with SAGA, linking the SAGA complex and ongoing transcription with mRNA processing.
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Affiliation(s)
- Alexander Pfab
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Astrid Bruckmann
- Department for Biochemistry I, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Julian Nazet
- Department for Biochemistry II, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Rainer Merkl
- Department for Biochemistry II, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Klaus D Grasser
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany.
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Jeronimo C, Robert F. The Mediator Complex: At the Nexus of RNA Polymerase II Transcription. Trends Cell Biol 2017; 27:765-783. [DOI: 10.1016/j.tcb.2017.07.001] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 07/03/2017] [Accepted: 07/06/2017] [Indexed: 12/15/2022]
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Lens Z, Cantrelle FX, Peruzzini R, Hanoulle X, Dewitte F, Ferreira E, Baert JL, Monté D, Aumercier M, Villeret V, Verger A, Landrieu I. Solution Structure of the N-Terminal Domain of Mediator Subunit MED26 and Molecular Characterization of Its Interaction with EAF1 and TAF7. J Mol Biol 2017; 429:3043-3055. [PMID: 28893534 DOI: 10.1016/j.jmb.2017.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/04/2017] [Accepted: 09/04/2017] [Indexed: 12/21/2022]
Abstract
MED26 is a subunit of Mediator, a large complex central to the regulation of gene transcription by RNA Polymerase II. MED26 plays a role in the switch between the initiation and elongation phases of RNA Polymerase II-mediated transcription process. Regulation of these steps requires successive binding of MED26 N-terminal domain (NTD) to TATA-binding protein-associated factor 7 (TAF7) and Eleven-nineteen lysine-rich in leukemia-Associated Factor 1 (EAF1). In order to investigate the mechanism of regulation by MED26, MED26-NTD structure was solved by NMR, revealing a 4-helix bundle. EAF1 (239-268) and TAF7 (205-235) peptide interactions were both mapped to the same groove formed by H3 and H4 helices of MED26-NTD. Both interactions are characterized by dissociation constants in the 10-μM range. Further experiments revealed a folding-upon-binding mechanism that leads to the formation of EAF1 (N247-S260) and TAF7 (L214-S227) helices. Chemical shift perturbations and nuclear Overhauser enhancement contacts support the involvement of residues I222/F223 in anchoring TAF7 helix to a hydrophobic pocket of MED26-NTD, including residues L48, W80 and I84. In addition, Ala mutations of charged residues located in the C-terminal disordered part of TAF7 and EAF1 peptides affected the binding, with a loss of affinity characterized by a 10-time increase of dissociation constants. A structural model of MED26-NTD/TAF7 complex shows bi-partite components, combining ordered and disordered segments, as well as hydrophobic and electrostatic contributions to the binding. This study provides molecular detail that will help to decipher the mechanistic basis for the initiation to elongation switch-function mediated by MED26-NTD.
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Affiliation(s)
- Zoé Lens
- UMR8576 Lille University, CNRS, F-59000 Lille, France
| | | | | | | | | | | | | | - Didier Monté
- UMR8576 Lille University, CNRS, F-59000 Lille, France
| | | | | | - Alexis Verger
- UMR8576 Lille University, CNRS, F-59000 Lille, France
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Med15B Regulates Acid Stress Response and Tolerance in Candida glabrata by Altering Membrane Lipid Composition. Appl Environ Microbiol 2017; 83:AEM.01128-17. [PMID: 28710262 DOI: 10.1128/aem.01128-17] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 07/04/2017] [Indexed: 12/16/2022] Open
Abstract
Candida glabrata is a promising producer of organic acids. To elucidate the physiological function of the Mediator tail subunit Med15B in the response to low-pH stress, we constructed a deletion strain, C. glabratamed15BΔ, and an overexpression strain, C. glabrata HTUΔ/CgMED15B Deletion of MED15B caused biomass production, glucose consumption rate, and cell viability to decrease by 28.3%, 31.7%, and 26.5%, respectively, compared with those of the parent (HTUΔ) strain at pH 2.0. Expression of lipid metabolism-related genes was significantly downregulated in the med15BΔ strain, whereas key genes of ergosterol biosynthesis showed abnormal upregulation. This caused the proportion of C18:1 fatty acids, the ratio of unsaturated to saturated fatty acids (UFA/SFA), and the total phospholipid content to decrease by 11.6%, 27.4%, and 37.6%, respectively. Cells failed to synthesize fecosterol and ergosterol, leading to the accumulation and a 60.3-fold increase in the concentration of zymosterol. Additionally, cells showed reductions of 69.2%, 11.6%, and 21.8% in membrane integrity, fluidity, and H+-ATPase activity, respectively. In contrast, overexpression of Med15B increased the C18:1 levels, total phospholipids, ergosterol content, and UFA/SFA by 18.6%, 143.5%, 94.5%, and 18.7%, respectively. Membrane integrity, fluidity, and H+-ATPase activity also increased by 30.2%, 6.9%, and 51.8%, respectively. Furthermore, in the absence of pH buffering, dry weight of cells and pyruvate concentrations were 29.3% and 61.2% higher, respectively, than those of the parent strain. These results indicated that in C. glabrata, Med15B regulates tolerance toward low pH via transcriptional regulation of acid stress response genes and alteration in lipid composition.IMPORTANCE This study explored the role of the Mediator tail subunit Med15B in the metabolism of Candida glabrata under acidic conditions. Overexpression of MED15B enhanced yeast tolerance to low pH and improved biomass production, cell viability, and pyruvate yield. Membrane lipid composition data indicated that Med15B might play a critical role in membrane integrity, fluidity, and H+-ATPase activity homeostasis at low pH. Thus, controlling membrane composition may serve to increase C. glabrata productivity at low pH.
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CgMED3 Changes Membrane Sterol Composition To Help Candida glabrata Tolerate Low-pH Stress. Appl Environ Microbiol 2017; 83:AEM.00972-17. [PMID: 28667115 DOI: 10.1128/aem.00972-17] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 06/23/2017] [Indexed: 12/11/2022] Open
Abstract
Candida glabrata is a promising microorganism for organic acid production. The present study aimed to investigate the role of C. glabrata Mediator complex subunit 3 (CgMed3p) in protecting C. glabrata under low-pH conditions. To this end, genes CgMED3A and CgMED3B were deleted, resulting in the double-deletion Cgmed3ABΔ strain. The final biomass and cell viability levels of Cgmed3ABΔ decreased by 64.5% and 35.8%, respectively, compared to the wild-type strain results at pH 2.0. In addition, lack of CgMed3ABp resulted in selective repression of a subset of genes in the lipid biosynthesis and metabolism pathways. Furthermore, C18:1, lanosterol, zymosterol, fecosterol, and ergosterol were 13.2%, 80.4%, 40.4%, 78.1%, and 70.4% less abundant, respectively, in the Cgmed3ABΔ strain. In contrast, the concentration of squalene increased by about 44.6-fold. As a result, membrane integrity, rigidity, and H+-ATPase activity in the Cgmed3ABΔ strain were reduced by 62.7%, 13.0%, and 50.3%, respectively. In contrast, overexpression of CgMED3AB increased the levels of C18:0, C18:1, and ergosterol by 113.2%, 5.9%, and 26.4%, respectively. Moreover, compared to the wild-type results, dry cell weight and pyruvate production increased, irrespective of pH buffering. These results suggest that CgMED3AB regulates membrane composition, which in turn enables cells to tolerate low-pH stress. We propose that regulation of CgMed3ABp may provide a novel strategy for enhancing low-pH tolerance and increasing organic acid production by C. glabrataIMPORTANCE The objective of this study was to investigate the role of Candida glabrata Mediator complex subunit 3 (CgMed3ABp) and its regulation of gene expression at low pH in C. glabrata We found that CgMed3ABp was critical for cellular survival and pyruvate production during low-pH stress. Measures of the levels of plasma membrane fatty acids and sterol composition indicated that CgMed3ABp could play an important role in regulating homeostasis in C. glabrata We propose that controlling membrane lipid composition may enhance the robustness of C. glabrata for the production of organic acids.
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Petrenko N, Jin Y, Wong KH, Struhl K. Evidence that Mediator is essential for Pol II transcription, but is not a required component of the preinitiation complex in vivo. eLife 2017; 6. [PMID: 28699889 PMCID: PMC5529107 DOI: 10.7554/elife.28447] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 07/09/2017] [Indexed: 12/27/2022] Open
Abstract
The Mediator complex has been described as a general transcription factor, but it is unclear if it is essential for Pol II transcription and/or is a required component of the preinitiation complex (PIC) in vivo. Here, we show that depletion of individual subunits, even those essential for cell growth, causes a general but only modest decrease in transcription. In contrast, simultaneous depletion of all Mediator modules causes a drastic decrease in transcription. Depletion of head or middle subunits, but not tail subunits, causes a downstream shift in the Pol II occupancy profile, suggesting that Mediator at the core promoter inhibits promoter escape. Interestingly, a functional PIC and Pol II transcription can occur when Mediator is not detected at core promoters. These results provide strong evidence that Mediator is essential for Pol II transcription and stimulates PIC formation, but it is not a required component of the PIC in vivo. DOI:http://dx.doi.org/10.7554/eLife.28447.001
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Affiliation(s)
- Natalia Petrenko
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School Boston, Boston, United States
| | - Yi Jin
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School Boston, Boston, United States
| | - Koon Ho Wong
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Kevin Struhl
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School Boston, Boston, United States
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Asadollahi R, Zweier M, Gogoll L, Schiffmann R, Sticht H, Steindl K, Rauch A. Genotype-phenotype evaluation of MED13L defects in the light of a novel truncating and a recurrent missense mutation. Eur J Med Genet 2017. [PMID: 28645799 DOI: 10.1016/j.ejmg.2017.06.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A decade after the designation of MED13L as a gene and its link to intellectual disability (ID) and dextro-looped transposition of great arteries in 2003, we previously described a recognizable syndrome due to MED13L haploinsufficiency. Subsequent reports of 22 further patients diagnosed by genome-wide testing further delineated the syndrome with expansion of the phenotypic spectrum and showed reduced penetrance for congenital heart defects. We now report two novel patients identified by whole exome sequencing, one with a de novo MED13L truncating mutation and the other with a de novo missense mutation. The first patient indicates some facial resemblance to Kleefstra syndrome as a novel differential diagnosis, and the second patient shows, for the first time, recurrence of a MED13L missense mutation (p.(Asp860Gly)). Notably, our in silico modelling predicted this missense mutation to decrease the stability of an alpha-helix and thereby affecting the MED13L secondary structure, while the majority of published missense mutations remain variants of uncertain significance. Review of the reported patients with MED13L haploinsufficiency indicates moderate to severe ID and facial anomalies in all patients, as well as severe speech delay and muscular hypotonia in the majority. Further common signs include abnormal MRI findings of myelination defects and abnormal corpus callosum, ataxia and coordination problems, autistic features, seizures/abnormal EEG, or congenital heart defects, present in about 20-50% of the patients. With reference to facial anomalies, the majority of patients were reported to show broad/prominent forehead, low set ears, bitemporal narrowing, upslanting palpebral fissures, depressed/flat nasal bridge, bulbous nose, and abnormal chin, but macroglossia and horizontal eyebrows were also observed in ∼30%. The latter are especially important in the differential diagnosis of 1p36 deletion and Kleefstra syndromes, while the more common facial gestalt shows some resemblance to 22q11.2 deletion syndrome. Despite the fact that MED13L was found to be one of the most common ID genes in the Deciphering Developmental Disorders Study, further detailed patient descriptions are needed to explore the full clinical spectrum, potential genotype-phenotype correlations, as well as the role of missense mutations and potential mutational hotspots along the gene.
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Affiliation(s)
- Reza Asadollahi
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich, Switzerland
| | - Markus Zweier
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich, Switzerland
| | - Laura Gogoll
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich, Switzerland
| | - Raphael Schiffmann
- Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX, USA
| | - Heinrich Sticht
- Institute of Biochemistry, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Katharina Steindl
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich, Switzerland
| | - Anita Rauch
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland; Zurich Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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Uthe H, Vanselow JT, Schlosser A. Proteomic Analysis of the Mediator Complex Interactome in Saccharomyces cerevisiae. Sci Rep 2017; 7:43584. [PMID: 28240253 PMCID: PMC5327418 DOI: 10.1038/srep43584] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/25/2017] [Indexed: 12/02/2022] Open
Abstract
Here we present the most comprehensive analysis of the yeast Mediator complex interactome to date. Particularly gentle cell lysis and co-immunopurification conditions allowed us to preserve even transient protein-protein interactions and to comprehensively probe the molecular environment of the Mediator complex in the cell. Metabolic 15N-labeling thereby enabled stringent discrimination between bona fide interaction partners and nonspecifically captured proteins. Our data indicates a functional role for Mediator beyond transcription initiation. We identified a large number of Mediator-interacting proteins and protein complexes, such as RNA polymerase II, general transcription factors, a large number of transcriptional activators, the SAGA complex, chromatin remodeling complexes, histone chaperones, highly acetylated histones, as well as proteins playing a role in co-transcriptional processes, such as splicing, mRNA decapping and mRNA decay. Moreover, our data provides clear evidence, that the Mediator complex interacts not only with RNA polymerase II, but also with RNA polymerases I and III, and indicates a functional role of the Mediator complex in rRNA processing and ribosome biogenesis.
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Affiliation(s)
- Henriette Uthe
- Rudolf Virchow Center for Experimental Biomedicine, University of Wuerzburg, Josef-Schneider-Str. 2, 97080, Wuerzburg, Germany
| | - Jens T Vanselow
- Rudolf Virchow Center for Experimental Biomedicine, University of Wuerzburg, Josef-Schneider-Str. 2, 97080, Wuerzburg, Germany
| | - Andreas Schlosser
- Rudolf Virchow Center for Experimental Biomedicine, University of Wuerzburg, Josef-Schneider-Str. 2, 97080, Wuerzburg, Germany
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