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Anglès F, Gupta V, Wang C, Balch WE. COPII cage assembly factor Sec13 integrates information flow regulating endomembrane function in response to human variation. Sci Rep 2024; 14:10160. [PMID: 38698045 PMCID: PMC11065896 DOI: 10.1038/s41598-024-60687-2] [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: 07/12/2023] [Accepted: 04/26/2024] [Indexed: 05/05/2024] Open
Abstract
How information flow is coordinated for managing transit of 1/3 of the genome through endomembrane pathways by the coat complex II (COPII) system in response to human variation remains an enigma. By examining the interactome of the COPII cage-assembly component Sec13, we show that it is simultaneously associated with multiple protein complexes that facilitate different features of a continuous program of chromatin organization, transcription, translation, trafficking, and degradation steps that are differentially sensitive to Sec13 levels. For the trafficking step, and unlike other COPII components, reduction of Sec13 expression decreased the ubiquitination and degradation of wild-type (WT) and F508del variant cargo protein cystic fibrosis transmembrane conductance regulator (CFTR) leading to a striking increase in fold stability suggesting that the events differentiating export from degradation are critically dependent on COPII cage assembly at the ER Golgi intermediate compartment (ERGIC) associated recycling and degradation step linked to COPI exchange. Given Sec13's multiple roles in protein complex assemblies that change in response to its expression, we suggest that Sec13 serves as an unanticipated master regulator coordinating information flow from the genome to the proteome to facilitate spatial covariant features initiating and maintaining design and function of membrane architecture in response to human variation.
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Affiliation(s)
- Frédéric Anglès
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Vijay Gupta
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Chao Wang
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - William E Balch
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA, 92037, USA.
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2
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Kopp J, Koch LA, Lyubenova H, Küchler O, Holtgrewe M, Ivanov A, Dubourg C, Launay E, Brachs S, Mundlos S, Ehmke N, Seelow D, Fradin M, Kornak U, Fischer-Zirnsak B. Loss-of-function variants affecting the STAGA complex component SUPT7L cause a developmental disorder with generalized lipodystrophy. Hum Genet 2024; 143:683-694. [PMID: 38592547 PMCID: PMC11098864 DOI: 10.1007/s00439-024-02669-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: 11/30/2023] [Accepted: 03/11/2024] [Indexed: 04/10/2024]
Abstract
Generalized lipodystrophy is a feature of various hereditary disorders, often leading to a progeroid appearance. In the present study we identified a missense and a frameshift variant in a compound heterozygous state in SUPT7L in a boy with intrauterine growth retardation, generalized lipodystrophy, and additional progeroid features. SUPT7L encodes a component of the transcriptional coactivator complex STAGA. By transcriptome sequencing, we showed the predicted missense variant to cause aberrant splicing, leading to exon truncation and thereby to a complete absence of SUPT7L in dermal fibroblasts. In addition, we found altered expression of genes encoding DNA repair pathway components. This pathway was further investigated and an increased rate of DNA damage was detected in proband-derived fibroblasts and genome-edited HeLa cells. Finally, we performed transient overexpression of wildtype SUPT7L in both cellular systems, which normalizes the number of DNA damage events. Our findings suggest SUPT7L as a novel disease gene and underline the link between genome instability and progeroid phenotypes.
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Affiliation(s)
- Johannes Kopp
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, 13353, Berlin, Germany
- Max Planck Institute for Molecular Genetics, FG Development and Disease, Berlin, Germany
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Leonard A Koch
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, 13353, Berlin, Germany
| | - Hristiana Lyubenova
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, 13353, Berlin, Germany
- Max Planck Institute for Molecular Genetics, FG Development and Disease, Berlin, Germany
| | - Oliver Küchler
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, 13353, Berlin, Germany
- Exploratory Diagnostic Sciences, Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Manuel Holtgrewe
- Core Unit Bioinformatics (CUBI), Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Andranik Ivanov
- Core Unit Bioinformatics (CUBI), Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Christele Dubourg
- Service de Génétique Moléculaire et Génomique, CHU, Rennes, F-35033, France
- Univercity Rennes, CNRS, INSERM, IGDR, UMR 6290, ERL U1305, Rennes, F-35000, France
| | - Erika Launay
- Service de Cytogénétique et Biologie cellulaire, Hôpital Pontchaillou - CHU Rennes, 2 rue Henri Le Guilloux - Rennes cedex 9, France, Rennes, F-35033, France
| | - Sebastian Brachs
- Department of Endocrinology and Metabolism, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117, Berlin, Germany
- German Centre for Cardiovascular Research, partner site Berlin, Berlin, Germany
| | - Stefan Mundlos
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, 13353, Berlin, Germany
- Max Planck Institute for Molecular Genetics, FG Development and Disease, Berlin, Germany
| | - Nadja Ehmke
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, 13353, Berlin, Germany
- Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Dominik Seelow
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, 13353, Berlin, Germany
- Exploratory Diagnostic Sciences, Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Mélanie Fradin
- Service de Génétique Clinique, Centre Référence Déficiences Intellectuelles CRDI, Hôpital Sud - CHU Rennes, 16 boulevard de Bulgarie - BP 90347, Rennes cedex 2, Rennes, F-35203, France
- Service de Génétique, CH Saint Brieuc, St Brieuc, 22000, France
| | - Uwe Kornak
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, 13353, Berlin, Germany
- Max Planck Institute for Molecular Genetics, FG Development and Disease, Berlin, Germany
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Björn Fischer-Zirnsak
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, 13353, Berlin, Germany.
- Max Planck Institute for Molecular Genetics, FG Development and Disease, Berlin, Germany.
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3
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Chen YJC, Bhaskara GB, Lu Y, Lin K, Dent SYR. The SAGA acetyltransferase module is required for the maintenance of MAF and MYC oncogenic gene expression programs in multiple myeloma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586811. [PMID: 38585845 PMCID: PMC10996596 DOI: 10.1101/2024.03.26.586811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Despite recent advances in therapeutic treatments, multiple myeloma (MM) remains an incurable malignancy. Epigenetic factors contribute to the initiation, progression, relapse, and clonal heterogeneity in MM, but our knowledge on epigenetic mechanisms underlying MM development is far from complete. The SAGA complex serves as a coactivator in transcription and catalyzes acetylation and deubiquitylation. Analyses of datasets in the Cancer Dependency Map Project revealed many SAGA components are selective dependencies in MM. To define SAGA-specific functions, we focused on ADA2B, the only subunit in the lysine acetyltransferase (KAT) module that specifically functions in SAGA. Integration of RNA-seq, ATAC-seq, and CUT&RUN results identified pathways directly regulated by ADA2B include MTORC1 signaling, MYC, E2F, and MM-specific MAF oncogenic programs. We discovered that ADA2B is recruited to MAF and MYC gene targets, and that MAF shares a majority of its targets with MYC in MM cells. Furthermore, we found the SANT domain of ADA2B is required for interaction with both GCN5 and PCAF acetyltransferases, incorporation into SAGA, and ADA2B protein stability. Our findings uncover previously unknown SAGA KAT module-dependent mechanisms controlling MM cell growth, revealing a vulnerability that might be exploited for future development of MM therapy.
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Affiliation(s)
- Ying-Jiun C. Chen
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- The Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Govinal Badiger Bhaskara
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- The Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yue Lu
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- The Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Kevin Lin
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- The Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Sharon Y. R. Dent
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- The Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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Romhányi D, Szabó K, Kemény L, Groma G. Histone and Histone Acetylation-Related Alterations of Gene Expression in Uninvolved Psoriatic Skin and Their Effects on Cell Proliferation, Differentiation, and Immune Responses. Int J Mol Sci 2023; 24:14551. [PMID: 37833997 PMCID: PMC10572426 DOI: 10.3390/ijms241914551] [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: 08/24/2023] [Revised: 09/11/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023] Open
Abstract
Psoriasis is a chronic immune-mediated skin disease in which the symptom-free, uninvolved skin carries alterations in gene expression, serving as a basis for lesion formation. Histones and histone acetylation-related processes are key regulators of gene expression, controlling cell proliferation and immune responses. Dysregulation of these processes is likely to play an important role in the pathogenesis of psoriasis. To gain a complete overview of these potential alterations, we performed a meta-analysis of a psoriatic uninvolved skin dataset containing differentially expressed transcripts from nearly 300 individuals and screened for histones and histone acetylation-related molecules. We identified altered expression of the replication-dependent histones HIST2H2AA3 and HIST2H4A and the replication-independent histones H2AFY, H2AFZ, and H3F3A/B. Eight histone chaperones were also identified. Among the histone acetyltransferases, ELP3 and KAT5 and members of the ATAC, NSL, and SAGA acetyltransferase complexes are affected in uninvolved skin. Histone deacetylation-related alterations were found to affect eight HDACs and members of the NCOR/SMRT, NURD, SIN3, and SHIP HDAC complexes. In this article, we discuss how histone and histone acetylation-related expression changes may affect proliferation and differentiation, as well as innate, macrophage-mediated, and T cell-mediated pro- and anti-inflammatory responses, which are known to play a central role in the development of psoriasis.
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Affiliation(s)
- Dóra Romhányi
- Department of Dermatology and Allergology, University of Szeged, H-6720 Szeged, Hungary; (D.R.); (K.S.); (L.K.)
| | - Kornélia Szabó
- Department of Dermatology and Allergology, University of Szeged, H-6720 Szeged, Hungary; (D.R.); (K.S.); (L.K.)
- Hungarian Centre of Excellence for Molecular Medicine-University of Szeged Skin Research Group (HCEMM-USZ Skin Research Group), H-6720 Szeged, Hungary
- HUN-REN-SZTE Dermatological Research Group, H-6720 Szeged, Hungary
| | - Lajos Kemény
- Department of Dermatology and Allergology, University of Szeged, H-6720 Szeged, Hungary; (D.R.); (K.S.); (L.K.)
- Hungarian Centre of Excellence for Molecular Medicine-University of Szeged Skin Research Group (HCEMM-USZ Skin Research Group), H-6720 Szeged, Hungary
- HUN-REN-SZTE Dermatological Research Group, H-6720 Szeged, Hungary
| | - Gergely Groma
- Department of Dermatology and Allergology, University of Szeged, H-6720 Szeged, Hungary; (D.R.); (K.S.); (L.K.)
- HUN-REN-SZTE Dermatological Research Group, H-6720 Szeged, Hungary
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5
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Lin CC, Lee WJ, Zeng CY, Chou MY, Lin TJ, Lin CS, Ho MC, Shih MC. SUB1A-1 anchors a regulatory cascade for epigenetic and transcriptional controls of submergence tolerance in rice. PNAS NEXUS 2023; 2:pgad229. [PMID: 37492276 PMCID: PMC10364326 DOI: 10.1093/pnasnexus/pgad229] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 06/28/2023] [Indexed: 07/27/2023]
Abstract
Most rice (Oryza sativa) cultivars cannot survive under prolonged submergence. However, some O. sativa ssp. indica cultivars, such as FR13A, are highly tolerant owing to the SUBMERGENCE 1A-1 (SUB1A-1) allele, which encodes a Group VII ethylene-responsive factor (ERFVII) protein; other submergence-intolerant cultivars contain a SUB1A-2 allele. The two alleles differ only by a single substitution at the 186th amino acid position from serine in SUB1A-1 to proline in SUB1A-2 resulting in only SUB1A-1 being able to be phosphorylated. Two other ERFVIIs, ERF66 and ERF67, function downstream of SUB1A-1 to form a regulatory cascade in response to submergence stress. Here, we show that SUB1A-1, but not SUB1A-2, interacts with ADA2b of the ADA2b-GCN5 acetyltransferase complex, in which GCN5 functions as a histone acetyltransferase. Phosphorylation of SUB1A-1 at serine 186 enhances the interaction of SUB1A-1 with ADA2b. ADA2b and GCN5 expression was induced under submergence, suggesting that these two genes might play roles in response to submergence stress. In transient assays, binding of SUB1A-1 to the ERF67 promoter and ERF67 transcription were highly induced when SUB1A-1 was expressed together with the ADA2b-GCN5 acetyltransferase complex. Taken together, these results suggest that phospho-SUB1A-1 recruits the ADA2-GCN5 acetyltransferase complex to modify the chromatin structure of the ERF66/ERF67 promoter regions and activate gene expression, which in turn enhances rice submergence tolerance.
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Affiliation(s)
| | | | - Cyong-Yu Zeng
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan
- Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan
| | - Mei-Yi Chou
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Ting-Jhen Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Choun-Sea Lin
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Meng-Chiao Ho
- To whom correspondence should be addressed: (M.C.S.); (M.C.H.)
| | - Ming-Che Shih
- To whom correspondence should be addressed: (M.C.S.); (M.C.H.)
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6
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Oliviero G, Kovalchuk S, Rogowska-Wrzesinska A, Schwämmle V, Jensen ON. Distinct and diverse chromatin-proteomes of ageing mouse organs reveal protein signatures that correlate with physiological functions. eLife 2022; 11:73524. [PMID: 35259090 PMCID: PMC8933006 DOI: 10.7554/elife.73524] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 03/07/2022] [Indexed: 11/13/2022] Open
Abstract
Temporal molecular changes in ageing mammalian organs are of relevance to disease aetiology because many age-related diseases are linked to changes in the transcriptional and epigenetic machinery that regulate gene expression. We performed quantitative proteome analysis of chromatin-enriched protein extracts to investigate the dynamics of the chromatin proteomes of the mouse brain, heart, lung, kidney, liver, and spleen at 3, 5, 10, and 15 months of age. Each organ exhibited a distinct chromatin proteome and sets of unique proteins. The brain and spleen chromatin proteomes were the most extensive, diverse, and heterogenous among the six organs. The spleen chromatin proteome appeared static during the lifespan, presenting a young phenotype that reflects the permanent alertness state and important role of this organ in physiological defence and immunity. We identified a total of 5928 proteins, including 2472 nuclear or chromatin-associated proteins across the six mouse organs. Up to 3125 proteins were quantified in each organ, demonstrating distinct and organ-specific temporal protein expression timelines and regulation at the post-translational level. Bioinformatics meta-analysis of these chromatin proteomes revealed distinct physiological and ageing-related features for each organ. Our results demonstrate the efficiency of organelle-specific proteomics for in vivo studies of a model organism and consolidate the hypothesis that chromatin-associated proteins are involved in distinct and specific physiological functions in ageing organs.
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Affiliation(s)
- Giorgio Oliviero
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Sergey Kovalchuk
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | | | - Veit Schwämmle
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Ole N Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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Huang J, Dai W, Xiao D, Xiong Q, Liu C, Hu J, Ge F, Yu X, Li S. Acetylation-dependent SAGA complex dimerization promotes nucleosome acetylation and gene transcription. Nat Struct Mol Biol 2022; 29:261-273. [PMID: 35301489 DOI: 10.1038/s41594-022-00736-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 11/30/2021] [Accepted: 02/02/2022] [Indexed: 11/09/2022]
Abstract
Cells reprogram their transcriptomes to adapt to external conditions. The SAGA (Spt-Ada-Gcn5 acetyltransferase) complex is a highly conserved transcriptional coactivator that plays essential roles in cell growth and development, in part by acetylating histones. Here, we uncover an autoregulatory mechanism of the Saccharomyces cerevisiae SAGA complex in response to environmental changes. Specifically, the SAGA complex acetylates its Ada3 subunit at three sites (lysines 8, 14 and 182) that are dynamically deacetylated by Rpd3. The acetylated Ada3 lysine residues are bound by bromodomains within SAGA subunits Gcn5 and Spt7 that synergistically facilitate formation of SAGA homo-dimers. Ada3-mediated dimerization is enhanced when cells are grown under sucrose or under phosphate-starvation conditions. Once dimerized, SAGA efficiently acetylates nucleosomes, promotes gene transcription and enhances cell resistance to stress. Collectively, our work reveals a mechanism for regulation of SAGA structure and activity and provides insights into how cells adapt to environmental conditions.
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Affiliation(s)
- Junhua Huang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China
| | - Wenjing Dai
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China
| | - Duncheng Xiao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China
| | - Qian Xiong
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Cuifang Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jie Hu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Feng Ge
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Xilan Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China.
| | - Shanshan Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China.
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Strachowska M, Gronkowska K, Michlewska S, Robaszkiewicz A. CBP/p300 Bromodomain Inhibitor-I-CBP112 Declines Transcription of the Key ABC Transporters and Sensitizes Cancer Cells to Chemotherapy Drugs. Cancers (Basel) 2021; 13:cancers13184614. [PMID: 34572840 PMCID: PMC8467251 DOI: 10.3390/cancers13184614] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 09/09/2021] [Accepted: 09/12/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Despite tremendous advances in cancer treatment, chemotherapy remains the first-line choice in many tumor types. The action of numerous chemotherapy drugs is limited by the occurrence of ABC proteins in cancer cell membranes, which remove medicines from cell compartments. In this paper, we show that one of bromodomain inhibitors, namely I-CBP112, was capable of repressing genes that are responsible for multidrug resistance in all three studied cancer cell lines. CBP/p300 bromodomain inhibitor allows for the higher drug accumulation inside cells and considerably potentiated drug effects. At the molecular level, I-CBP112 caused rearrangement of chromatin at the ABC gene promoters by inducing recruitment of LSD1, which removes transcription-promoting histone marks. I-CBP112 emerges as a promising compound to overcome ABC-dependent cancer drug resistance. Abstract The high expression of some ATP-binding cassette (ABC) transporters is linked to multidrug resistance in cancer cells. We aimed to determine if I-CBP112, which is a CBP/p300 bromodomain inhibitor, altered the vulnerability of the MDA-MB-231 cell line to chemotherapy drugs, which are used in neoadjuvant therapy in patients with triple negative breast cancer (TNBC). MDA-MB-231 cells represent TNBC, which is negative for the expression of estrogen and progesterone receptors and HER2 protein. An I-CBP112-induced decrease in the expression of all the studied ABCs in the breast, but also in the lung (A549), and hepatic (HepG2) cancer cell lines was associated with increased accumulation of doxorubicin, daunorubicin, and methotrexate inside the cells as well as with considerable cell sensitization to a wide range of chemotherapeutics. Gene promoters repressed by I-CBP112 in MDA-MB-231 cells, such as ABCC1 and ABCC10, were characterized by enhanced nucleosome acetylation and, simultaneously, by considerably lower trimethylation in the transcription-promoting form of H3K4me3. The CBP/p300 bromodomain inhibitor induced the recruitment of LSD1 to the gene promoters. The inhibition of this demethylase in the presence of I-CBP112 prevented the repression of ABCC1 and ABCC10 and, to a considerable extent, cancer cells’ sensitization to drugs. In conclusion, the CBP/p300 bromodomain inhibitor I-CBP112 can be considered as a potent anti-multidrug-resistance agent, capable of repressing key ABC transporters responsible for drug efflux in various cancer types.
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Affiliation(s)
- Magdalena Strachowska
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland; (M.S.); (K.G.)
| | - Karolina Gronkowska
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland; (M.S.); (K.G.)
| | - Sylwia Michlewska
- Laboratory of Microscopic Imaging and Specialized Biological Techniques, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland;
| | - Agnieszka Robaszkiewicz
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland; (M.S.); (K.G.)
- Correspondence: ; Tel.: +4-84-2635-4144
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9
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Fischer V, Plassard D, Ye T, Reina-San-Martin B, Stierle M, Tora L, Devys D. The related coactivator complexes SAGA and ATAC control embryonic stem cell self-renewal through acetyltransferase-independent mechanisms. Cell Rep 2021; 36:109598. [PMID: 34433046 PMCID: PMC8430043 DOI: 10.1016/j.celrep.2021.109598] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 06/17/2021] [Accepted: 08/03/2021] [Indexed: 01/10/2023] Open
Abstract
SAGA (Spt-Ada-Gcn5 acetyltransferase) and ATAC (Ada-two-A-containing) are two related coactivator complexes, sharing the same histone acetyltransferase (HAT) subunit. The HAT activities of SAGA and ATAC are required for metazoan development, but the role of these complexes in RNA polymerase II transcription is less understood. To determine whether SAGA and ATAC have redundant or specific functions, we compare the effects of HAT inactivation in each complex with that of inactivation of either SAGA or ATAC core subunits in mouse embryonic stem cells (ESCs). We show that core subunits of SAGA or ATAC are required for complex assembly and mouse ESC growth and self-renewal. Surprisingly, depletion of HAT module subunits causes a global decrease in histone H3K9 acetylation, but does not result in significant phenotypic or transcriptional defects. Thus, our results indicate that SAGA and ATAC are differentially required for self-renewal of mouse ESCs by regulating transcription through different pathways in a HAT-independent manner.
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Affiliation(s)
- Veronique Fischer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch Cedex, France; Université de Strasbourg, 67000 Strasbourg, France
| | - Damien Plassard
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch Cedex, France; Université de Strasbourg, 67000 Strasbourg, France; Plateforme GenomEast, infrastructure France Génomique, Illkirch, France
| | - Tao Ye
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch Cedex, France; Université de Strasbourg, 67000 Strasbourg, France; Plateforme GenomEast, infrastructure France Génomique, Illkirch, France
| | - Bernardo Reina-San-Martin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch Cedex, France; Université de Strasbourg, 67000 Strasbourg, France
| | - Matthieu Stierle
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch Cedex, France; Université de Strasbourg, 67000 Strasbourg, France
| | - Laszlo Tora
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch Cedex, France; Université de Strasbourg, 67000 Strasbourg, France
| | - Didier Devys
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch Cedex, France; Université de Strasbourg, 67000 Strasbourg, France.
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10
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Soffers JHM, Workman JL. The SAGA chromatin-modifying complex: the sum of its parts is greater than the whole. Genes Dev 2021; 34:1287-1303. [PMID: 33004486 PMCID: PMC7528701 DOI: 10.1101/gad.341156.120] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this review, Soffers and Workman discuss the initial discovery of the canonical SAGA complex, the subsequent studies that have shaped our view on the internal organization of its subunits into modules, and the latest structural work that visualizes the modules and provides insights into their function. There are many large protein complexes involved in transcription in a chromatin context. However, recent studies on the SAGA coactivator complex are generating new paradigms for how the components of these complexes function, both independently and in concert. This review highlights the initial discovery of the canonical SAGA complex 23 years ago, our evolving understanding of its modular structure and the relevance of its modular nature for its coactivator function in gene regulation.
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Affiliation(s)
- Jelly H M Soffers
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Jerry L Workman
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
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11
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Grant PA, Winston F, Berger SL. The biochemical and genetic discovery of the SAGA complex. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1864:194669. [PMID: 33338653 DOI: 10.1016/j.bbagrm.2020.194669] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/12/2022]
Abstract
One of the major advances in our understanding of gene regulation in eukaryotes was the discovery of factors that regulate transcription by controlling chromatin structure. Prominent among these discoveries was the demonstration that Gcn5 is a histone acetyltransferase, establishing a direct connection between transcriptional activation and histone acetylation. This breakthrough was soon followed by the purification of a protein complex that contains Gcn5, the SAGA complex. In this article, we review the early genetic and biochemical experiments that led to the discovery of SAGA and the elucidation of its multiple activities.
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Affiliation(s)
- Patrick A Grant
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, United States of America
| | - Fred Winston
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, United States of America.
| | - Shelley L Berger
- Department of Cell and Developmental Biology, Penn Epigenetics Institute, Department of Biology, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
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12
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Espinola-Lopez JM, Tan S. The Ada2/Ada3/Gcn5/Sgf29 histone acetyltransferase module. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1864:194629. [PMID: 32890768 DOI: 10.1016/j.bbagrm.2020.194629] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 01/14/2023]
Abstract
Histone post-translational modifications are essential for the regulation of gene expression in eukaryotes. Gcn5 (KAT2A) is a histone acetyltransferase that catalyzes the post-translational modification at multiple positions of histone H3 through the transfer of acetyl groups to the free amino group of lysine residues. Gcn5 catalyzes histone acetylation in the context of a HAT module containing the Ada2, Ada3 and Sgf29 subunits of the parent megadalton SAGA transcriptional coactivator complex. Biochemical and structural studies have elucidated mechanisms for Gcn5's acetyl- and other acyltransferase activities on histone substrates, for histone H3 phosphorylation and histone H3 methylation crosstalks with histone H3 acetylation, and for how Ada2 increases Gcn5's histone acetyltransferase activity. Other studies have identified Ada2 isoforms in SAGA-related complexes and characterized variant Gcn5 HAT modules containing these Ada2 isoforms. In this review, we highlight biochemical and structural studies of Gcn5 and its functional interactions with Ada2, Ada3 and Sgf29.
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Affiliation(s)
- Jose M Espinola-Lopez
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Song Tan
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.
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13
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What do the structures of GCN5-containing complexes teach us about their function? BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1864:194614. [PMID: 32739556 DOI: 10.1016/j.bbagrm.2020.194614] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022]
Abstract
Transcription initiation is a major regulatory step in eukaryotic gene expression. It involves the assembly of general transcription factors and RNA polymerase II into a functional pre-initiation complex at core promoters. The degree of chromatin compaction controls the accessibility of the transcription machinery to template DNA. Co-activators have critical roles in this process by actively regulating chromatin accessibility. Many transcriptional coactivators are multisubunit complexes, organized into distinct structural and functional modules and carrying multiple regulatory activities. The first nuclear histone acetyltransferase (HAT) characterized was General Control Non-derepressible 5 (Gcn5). Gcn5 was subsequently identified as a subunit of the HAT module of the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex, which is an experimental paradigm for multifunctional co-activators. We know today that Gcn5 is the catalytic subunit of multiple distinct co-activator complexes with specific functions. In this review, we summarize recent advances in the structure of Gcn5-containing co-activator complexes, most notably SAGA, and discuss how these new structural insights contribute to better understand their functions.
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14
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Torres-Zelada EF, Weake VM. The Gcn5 complexes in Drosophila as a model for metazoa. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1864:194610. [PMID: 32735945 DOI: 10.1016/j.bbagrm.2020.194610] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/21/2020] [Accepted: 07/22/2020] [Indexed: 01/14/2023]
Abstract
The histone acetyltransferase Gcn5 is conserved throughout eukaryotes where it functions as part of large multi-subunit transcriptional coactivator complexes that stimulate gene expression. Here, we describe how studies in the model insect Drosophila melanogaster have provided insight into the essential roles played by Gcn5 in the development of multicellular organisms. We outline the composition and activity of the four different Gcn5 complexes in Drosophila: the Spt-Ada-Gcn5 Acetyltransferase (SAGA), Ada2a-containing (ATAC), Ada2/Gcn5/Ada3 transcription activator (ADA), and Chiffon Histone Acetyltransferase (CHAT) complexes. Whereas the SAGA and ADA complexes are also present in the yeast Saccharomyces cerevisiae, ATAC has only been identified in other metazoa such as humans, and the CHAT complex appears to be unique to insects. Each of these Gcn5 complexes is nucleated by unique Ada2 homologs or splice isoforms that share conserved N-terminal domains, and differ only in their C-terminal domains. We describe the common and specialized developmental functions of each Gcn5 complex based on phenotypic analysis of mutant flies. In addition, we outline how gene expression studies in mutant flies have shed light on the different biological roles of each complex. Together, these studies highlight the key role that Drosophila has played in understanding the expanded biological function of Gcn5 in multicellular eukaryotes.
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Affiliation(s)
| | - Vikki M Weake
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA; Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
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15
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Soffers JHM, Li X, Saraf A, Seidel CW, Florens L, Washburn MP, Abmayr SM, Workman JL. Characterization of a metazoan ADA acetyltransferase complex. Nucleic Acids Res 2019; 47:3383-3394. [PMID: 30715476 PMCID: PMC6468242 DOI: 10.1093/nar/gkz042] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/24/2018] [Accepted: 01/29/2019] [Indexed: 12/14/2022] Open
Abstract
The Gcn5 acetyltransferase functions in multiple acetyltransferase complexes in yeast and metazoans. Yeast Gcn5 is part of the large SAGA (Spt-Ada-Gcn5 acetyltransferase) complex and a smaller ADA acetyltransferase complex. In flies and mammals, Gcn5 (and its homolog pCAF) is part of various versions of the SAGA complex and another large acetyltransferase complex, ATAC (Ada2A containing acetyltransferase complex). However, a complex analogous to the small ADA complex in yeast has never been described in metazoans. Previous studies in Drosophila hinted at the existence of a small complex which contains Ada2b, a partner of Gcn5 in the SAGA complex. Here we have purified and characterized the composition of this complex and show that it is composed of Gcn5, Ada2b, Ada3 and Sgf29. Hence, we have named it the metazoan 'ADA complex'. We demonstrate that the fly ADA complex has histone acetylation activity on histones and nucleosome substrates. Moreover, ChIP-Sequencing experiments identified Ada2b peaks that overlap with another SAGA subunit, Spt3, as well as Ada2b peaks that do not overlap with Spt3 suggesting that the ADA complex binds chromosomal sites independent of the larger SAGA complex.
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Affiliation(s)
| | - Xuanying Li
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Anita Saraf
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | | | - Laurence Florens
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Michael P Washburn
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA.,Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Susan M Abmayr
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA.,Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS 66160, USA
| | - Jerry L Workman
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
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16
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Mustachio LM, Roszik J, Farria AT, Guerra K, Dent SYR. Repression of GCN5 expression or activity attenuates c-MYC expression in non-small cell lung cancer. Am J Cancer Res 2019; 9:1830-1845. [PMID: 31497362 PMCID: PMC6726999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/03/2019] [Indexed: 06/10/2023] Open
Abstract
Lung cancer causes the highest mortality in cancer-related deaths. As these cancers often become resistant to existing therapies, definition of novel molecular targets is needed. Epigenetic modifiers may provide such targets. Recent reports suggest that the histone acetyltransferase (HAT) module within the transcriptional coactivator SAGA complex plays a role in cancer, creating a new link between epigenetic regulators and this disease. GCN5 serves as a coactivator for MYC target genes, and here we investigate links between GCN5 and c-MYC in non-small cell lung cancer (NSCLC). Our data indicate that both GCN5 and c-MYC proteins are upregulated in mouse and human NSCLC cells compared to normal lung epithelial cells. This trend is observable only at the protein level, indicating that this upregulation occurs post-transcriptionally. Human NSCLC tissue data provided by The Cancer Genome Atlas (TCGA) indicates that GCN5 and c-MYC expression are positively associated with one another and with the expression of c-MYC target genes. Depletion of GCN5 in NSCLC cells reduces c-MYC expression, cell proliferation, and increases the population of necrotic cells. Similarly, inhibition of the GCN5 catalytic site using a commercially available probe reduces c-MYC expression, cell proliferation, and increases the percentage of cells undergoing apoptosis. Our findings suggest that GCN5 might provide a novel target for inhibition of NSCLC growth and progression.
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Affiliation(s)
- Lisa Maria Mustachio
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
- Department of Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
| | - Jason Roszik
- Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
| | - Aimee T Farria
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
- Department of Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
- Department of Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
| | - Karla Guerra
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
| | - Sharon YR Dent
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
- Department of Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
- Department of Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer CenterHouston, Texas 77030, USA
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17
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Lai J, Jiang J, Wu Q, Mao N, Han D, Hu H, Yang C. The Transcriptional Coactivator ADA2b Recruits a Structural Maintenance Protein to Double-Strand Breaks during DNA Repair in Plants. PLANT PHYSIOLOGY 2018; 176:2613-2622. [PMID: 29463775 PMCID: PMC5884601 DOI: 10.1104/pp.18.00123] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 02/12/2018] [Indexed: 06/01/2023]
Abstract
DNA damage occurs in all cells and can hinder chromosome stability and cell viability. Structural Maintenance of Chromosomes5/6 (SMC5/6) is a protein complex that functions as an evolutionarily conserved chromosomal ATPase critical for repairing DNA double-strand breaks (DSBs). However, the mechanisms regulating this complex in plants are poorly understood. Here, we identified the transcriptional coactivator ALTERATION/DEFICIENCY IN ACTIVATION2B (ADA2b) as an interactor of SMC5 in Arabidopsis (Arabidopsis thaliana). ADA2b is a conserved component of the Spt-Ada-Gcn5 acetyltransferase complex, which functions in transcriptional regulation. Characterization of mutant and knockdown Arabidopsis lines showed that disruption of either SMC5 or ADA2b resulted in enhanced DNA damage. Both SMC5 and ADA2b were associated with γ-H2AX, a marker of DSBs, and the recruitment of SMC5 onto DSBs was dependent on ADA2b. In addition, overexpression of SMC5 in the ada2b mutant background stimulated cell death. Collectively, our results show that the interaction between ADA2b and SMC5 mediates DNA repair in plant cells, suggesting a functional association between these conserved proteins and further elucidating mechanisms of DNA damage repair in plants.
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Affiliation(s)
- Jianbin Lai
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Jieming Jiang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Qian Wu
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Ning Mao
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Danlu Han
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Huan Hu
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Chengwei Yang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China
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18
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Martel A, Brar H, Mayer BF, Charron JB. Diversification of the Histone Acetyltransferase GCN5 through Alternative Splicing in Brachypodium distachyon. FRONTIERS IN PLANT SCIENCE 2017; 8:2176. [PMID: 29312415 PMCID: PMC5743026 DOI: 10.3389/fpls.2017.02176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 12/12/2017] [Indexed: 06/07/2023]
Abstract
The epigenetic modulatory SAGA complex is involved in various developmental and stress responsive pathways in plants. Alternative transcripts of the SAGA complex's enzymatic subunit GCN5 have been identified in Brachypodium distachyon. These splice variants differ based on the presence and integrity of their conserved domain sequences: the histone acetyltransferase domain, responsible for catalytic activity, and the bromodomain, involved in acetyl-lysine binding and genomic loci targeting. GCN5 is the wild-type transcript, while alternative splice sites result in the following transcriptional variants: L-GCN5, which is missing the bromodomain and S-GCN5, which lacks the bromodomain as well as certain motifs of the histone acetyltransferase domain. Absolute mRNA quantification revealed that, across eight B. distachyon accessions, GCN5 was the dominant transcript isoform, accounting for up to 90% of the entire transcript pool, followed by L-GCN5 and S-GCN5. A cycloheximide treatment further revealed that the S-GCN5 splice variant was degraded through the nonsense-mediated decay pathway. All alternative BdGCN5 transcripts displayed similar transcript profiles, being induced during early exposure to heat and displaying higher levels of accumulation in the crown, compared to aerial tissues. All predicted protein isoforms localize to the nucleus, which lends weight to their purported epigenetic functions. S-GCN5 was incapable of forming an in vivo protein interaction with ADA2, the transcriptional adaptor that links the histone acetyltransferase subunit to the SAGA complex, while both GCN5 and L-GCN5 interacted with ADA2, which suggests that a complete histone acetyltransferase domain is required for BdGCN5-BdADA2 interaction in vivo. Thus, there has been a diversification in BdGCN5 through alternative splicing that has resulted in differences in conserved domain composition, transcript fate and in vivo protein interaction partners. Furthermore, our results suggest that B. distachyon may harbor compositionally distinct SAGA-like complexes that differ based on their histone acetyltransferase subunit.
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Che1/AATF interacts with subunits of the histone acetyltransferase core module of SAGA complexes. PLoS One 2017; 12:e0189193. [PMID: 29232376 PMCID: PMC5726650 DOI: 10.1371/journal.pone.0189193] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 11/21/2017] [Indexed: 12/12/2022] Open
Abstract
General Control Non-derepressible 5 (GCN5) and Alteration/Deficiency in Activation 2 and 3 proteins (ADA2 and ADA3, respectively) are subunits of the Histone AcetylTransferase (HAT) module of SAGA- and ATAC-type co-activators. We previously reported four new interacting partners of human ADA3 identified by screening a human fetal brain cDNA library using yeast two hybrid technology. One of these partners was Apoptosis-Antagonizing Transcription Factor (AATF), also known as Che-1, an RNA polymerase II-binding protein with a number of roles in different cellular processes including regulation of transcription, cell proliferation, cell cycle control, DNA damage responses and apoptosis. Che-1/AATF is a potential therapeutic target for cancer treatments. In this study, we aimed to identify whether besides ADA3, other components of the HAT modules of SAGA and ATAC complexes, human ADA2 and GCN5 also interact with Che-1/AATF. Co-immunoprecipitation and co-localization experiments were used to demonstrate association of AATF both with two ADA2 isoforms, ADA2A and ADA2B and with GCN5 proteins in human cells and yeast two-hybrid assays to delineate domains in the ADA2 and GCN5 proteins required for these interactions. These findings provide new insights into the pathways regulated by ADA-containing protein complexes.
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20
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Acetylation of Mammalian ADA3 Is Required for Its Functional Roles in Histone Acetylation and Cell Proliferation. Mol Cell Biol 2016; 36:2487-502. [PMID: 27402865 PMCID: PMC5021379 DOI: 10.1128/mcb.00342-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 06/30/2016] [Indexed: 12/16/2022] Open
Abstract
Alteration/deficiency in activation 3 (ADA3) is an essential component of specific histone acetyltransferase (HAT) complexes. We have previously shown that ADA3 is required for establishing global histone acetylation patterns and for normal cell cycle progression (S. Mohibi et al., J Biol Chem 287:29442-29456, 2012, http://dx.doi.org/10.1074/jbc.M112.378901). Here, we report that these functional roles of ADA3 require its acetylation. We show that ADA3 acetylation, which is dynamically regulated in a cell cycle-dependent manner, reflects a balance of coordinated actions of its associated HATs, GCN5, PCAF, and p300, and a new partner that we define, the deacetylase SIRT1. We use mass spectrometry and site-directed mutagenesis to identify major sites of ADA3 acetylated by GCN5 and p300. Acetylation-defective mutants are capable of interacting with HATs and other components of HAT complexes but are deficient in their ability to restore ADA3-dependent global or locus-specific histone acetylation marks and cell proliferation in Ada3-deleted murine embryonic fibroblasts (MEFs). Given the key importance of ADA3-containing HAT complexes in the regulation of various biological processes, including the cell cycle, our study presents a novel mechanism to regulate the function of these complexes through dynamic ADA3 acetylation.
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21
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Riss A, Scheer E, Joint M, Trowitzsch S, Berger I, Tora L. Subunits of ADA-two-A-containing (ATAC) or Spt-Ada-Gcn5-acetyltrasferase (SAGA) Coactivator Complexes Enhance the Acetyltransferase Activity of GCN5. J Biol Chem 2015; 290:28997-9009. [PMID: 26468280 DOI: 10.1074/jbc.m115.668533] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Indexed: 11/06/2022] Open
Abstract
Histone acetyl transferases (HATs) play a crucial role in eukaryotes by regulating chromatin architecture and locus specific transcription. GCN5 (KAT2A) is a member of the GNAT (Gcn5-related N-acetyltransferase) family of HATs. In metazoans this enzyme is found in two functionally distinct coactivator complexes, SAGA (Spt Ada Gcn5 acetyltransferase) and ATAC (Ada Two A-containing). These two multiprotein complexes comprise complex-specific and shared subunits, which are organized in functional modules. The HAT module of ATAC is composed of GCN5, ADA2a, ADA3, and SGF29, whereas in the SAGA HAT module ADA2b is present instead of ADA2a. To better understand how the activity of human (h) hGCN5 is regulated in the two related, but different, HAT complexes we carried out in vitro HAT assays. We compared the activity of hGCN5 alone with its activity when it was part of purified recombinant hATAC or hSAGA HAT modules or endogenous hATAC or hSAGA complexes using histone tail peptides and full-length histones as substrates. We demonstrated that the subunit environment of the HAT complexes into which GCN5 incorporates determines the enhancement of GCN5 activity. On histone peptides we show that all the tested GCN5-containing complexes acetylate mainly histone H3K14. Our results suggest a stronger influence of ADA2b as compared with ADA2a on the activity of GCN5. However, the lysine acetylation specificity of GCN5 on histone tails or full-length histones was not changed when incorporated in the HAT modules of ATAC or SAGA complexes. Our results thus demonstrate that the catalytic activity of GCN5 is stimulated by subunits of the ADA2a- or ADA2b-containing HAT modules and is further increased by incorporation of the distinct HAT modules in the ATAC or SAGA holo-complexes.
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Affiliation(s)
- Anne Riss
- From the Cellular Signaling and Nuclear Dynamics Program and
| | | | - Mathilde Joint
- Proteomics platform, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR 7104, INSERM U964, Université de Strasbourg, BP 10142, 67404 Illkirch Cedex, CU de Strasbourg, France and
| | - Simon Trowitzsch
- EMBL Grenoble Outstation, 6 rue Jules Horowitz BP 181, F-38042 Grenoble Cedex, France and The School of Biochemistry, University of Bristol, University Walk, Clifton BS8 1TD, United Kingdom
| | - Imre Berger
- EMBL Grenoble Outstation, 6 rue Jules Horowitz BP 181, F-38042 Grenoble Cedex, France and The School of Biochemistry, University of Bristol, University Walk, Clifton BS8 1TD, United Kingdom
| | - László Tora
- From the Cellular Signaling and Nuclear Dynamics Program and
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22
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Mohibi S, Srivastava S, Wang-France J, Mirza S, Zhao X, Band H, Band V. Alteration/Deficiency in Activation 3 (ADA3) Protein, a Cell Cycle Regulator, Associates with the Centromere through CENP-B and Regulates Chromosome Segregation. J Biol Chem 2015; 290:28299-28310. [PMID: 26429915 DOI: 10.1074/jbc.m115.685511] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Indexed: 02/01/2023] Open
Abstract
ADA3 (alteration/deficiency in activation 3) is a conserved component of several transcriptional co-activator and histone acetyltransferase (HAT) complexes. Recently, we generated Ada3 knock-out mice and demonstrated that deletion of Ada3 leads to early embryonic lethality. The use of Ada3(FL/FL) mouse embryonic fibroblasts with deletion of Ada3 using adenovirus Cre showed a critical role of ADA3 in cell cycle progression through mitosis. Here, we demonstrate an association of ADA3 with the higher order repeat region of the α-satellite region on human X chromosome centromeres that is consistent with its role in mitosis. Given the role of centromere proteins (CENPs) in mitosis, we next analyzed whether ADA3 associates with the centromere through CENPs. Both an in vivo proximity ligation assay and immunofluorescence studies confirmed the association of ADA3 with CENP-B protein, a highly conserved centromeric protein that binds to the 17-bp DNA sequences on α-satellite DNA. Deletional analysis showed that ADA3 directly associates with CENP-B through its N terminus, and a CENP-B binding-deficient mutant of ADA3 was incompetent in cell proliferation rescue. Notably, knockdown of ADA3 decreased binding of CENP-B onto the centromeres, suggesting that ADA3 is required for the loading of CENP-B onto the centromeres. Finally, we show that deletion of Ada3 from Ada3(FL/FL) mouse embryonic fibroblasts exhibited various chromosome segregation defects. Taken together, we demonstrate a novel ADA3 interaction with CENP-B-centromere that may account for its previously known function in mitosis. This study, together with its known function in maintaining genomic stability and its mislocalization in cancers, suggests an important role of ADA3 in mitosis.
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Affiliation(s)
| | | | | | - Sameer Mirza
- Department of Genetics, Cell Biology, and Anatomy
| | | | - Hamid Band
- Department of Genetics, Cell Biology, and Anatomy; Departments of Biochemistry and Molecular Biology, Pathology and Microbiology, and Pharmacology and Experimental Neuroscience, College of Medicine; Eppley Institute for Cancer and Allied Diseases; Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, Nebraska 68198.
| | - Vimla Band
- Department of Genetics, Cell Biology, and Anatomy; Eppley Institute for Cancer and Allied Diseases; Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, Nebraska 68198
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23
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Nguyen-Huynh NT, Sharov G, Potel C, Fichter P, Trowitzsch S, Berger I, Lamour V, Schultz P, Potier N, Leize-Wagner E. Chemical cross-linking and mass spectrometry to determine the subunit interaction network in a recombinant human SAGA HAT subcomplex. Protein Sci 2015; 24:1232-46. [PMID: 25753033 DOI: 10.1002/pro.2676] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/03/2015] [Accepted: 03/03/2015] [Indexed: 01/04/2023]
Abstract
Understanding the way how proteins interact with each other to form transient or stable protein complexes is a key aspect in structural biology. In this study, we combined chemical cross-linking with mass spectrometry to determine the binding stoichiometry and map the protein-protein interaction network of a human SAGA HAT subcomplex. MALDI-MS equipped with high mass detection was used to follow the cross-linking reaction using bis[sulfosuccinimidyl] suberate (BS3) and confirm the heterotetrameric stoichiometry of the specific stabilized subcomplex. Cross-linking with isotopically labeled BS3 d0-d4 followed by trypsin digestion allowed the identification of intra- and intercross-linked peptides using two dedicated search engines: pLink and xQuest. The identified interlinked peptides suggest a strong network of interaction between GCN5, ADA2B and ADA3 subunits; SGF29 is interacting with GCN5 and ADA3 but not with ADA2B. These restraint data were combined to molecular modeling and a low-resolution interacting model for the human SAGA HAT subcomplex could be proposed, illustrating the potential of an integrative strategy using cross-linking and mass spectrometry for addressing the structural architecture of multiprotein complexes.
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Affiliation(s)
- Nha-Thi Nguyen-Huynh
- Laboratoire de Spectrométrie de Masse des Interactions et des Systèmes (LSMIS) UMR 7140 CNRS/Université de Strasbourg - "Chimie de la Matière Complexe", 1 Rue Blaise Pascal, 67008, Strasbourg, France
| | - Grigory Sharov
- Integrated Structural Biology Department, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, INSERM U964, 1 rue Laurent Fries, 67404, Illkirch, France
| | - Clément Potel
- Laboratoire de Spectrométrie de Masse des Interactions et des Systèmes (LSMIS) UMR 7140 CNRS/Université de Strasbourg - "Chimie de la Matière Complexe", 1 Rue Blaise Pascal, 67008, Strasbourg, France
| | - Pélagie Fichter
- Integrated Structural Biology Department, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, INSERM U964, 1 rue Laurent Fries, 67404, Illkirch, France
| | - Simon Trowitzsch
- European Molecular Biology Laboratory (EMBL), Grenoble Outstation, 6 rue Jules Horowitz, 38042 Grenoble, France
| | - Imre Berger
- European Molecular Biology Laboratory (EMBL), Grenoble Outstation, 6 rue Jules Horowitz, 38042 Grenoble, France
| | - Valérie Lamour
- Integrated Structural Biology Department, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, INSERM U964, 1 rue Laurent Fries, 67404, Illkirch, France
| | - Patrick Schultz
- Integrated Structural Biology Department, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, INSERM U964, 1 rue Laurent Fries, 67404, Illkirch, France
| | - Noëlle Potier
- Laboratoire de Spectrométrie de Masse des Interactions et des Systèmes (LSMIS) UMR 7140 CNRS/Université de Strasbourg - "Chimie de la Matière Complexe", 1 Rue Blaise Pascal, 67008, Strasbourg, France
| | - Emmanuelle Leize-Wagner
- Laboratoire de Spectrométrie de Masse des Interactions et des Systèmes (LSMIS) UMR 7140 CNRS/Université de Strasbourg - "Chimie de la Matière Complexe", 1 Rue Blaise Pascal, 67008, Strasbourg, France
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Moraga F, Aquea F. Composition of the SAGA complex in plants and its role in controlling gene expression in response to abiotic stresses. FRONTIERS IN PLANT SCIENCE 2015; 6:865. [PMID: 26528322 PMCID: PMC4604261 DOI: 10.3389/fpls.2015.00865] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/30/2015] [Indexed: 05/07/2023]
Abstract
Protein complexes involved in epigenetic regulation of transcription have evolved as molecular strategies to face environmental stress in plants. SAGA (Spt-Ada-Gcn5 Acetyltransferase) is a transcriptional co-activator complex that regulates numerous cellular processes through the coordination of multiple post-translational histone modifications, including acetylation, deubiquitination, and chromatin recognition. The diverse functions of the SAGA complex involve distinct modules that are highly conserved between yeast, flies, and mammals. In this review, the composition of the SAGA complex in plants is described and its role in gene expression regulation under stress conditions summarized. Some of these proteins are likely involved in the regulation of the inducible expression of genes under light, cold, drought, salt, and iron stress, although the functions of several of its components remain unknown.
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Affiliation(s)
- Felipe Moraga
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
| | - Felipe Aquea
- Laboratorio de Bioingeniería, Facultad de Ingeniería y Ciencias, Universidad Adolfo IbáñezSantiago, Chile
- Center for Applied Ecology and SustainabilitySantiago, Chile
- *Correspondence: Felipe Aquea
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Bonnet J, Wang CY, Baptista T, Vincent SD, Hsiao WC, Stierle M, Kao CF, Tora L, Devys D. The SAGA coactivator complex acts on the whole transcribed genome and is required for RNA polymerase II transcription. Genes Dev 2014; 28:1999-2012. [PMID: 25228644 PMCID: PMC4173158 DOI: 10.1101/gad.250225.114] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The SAGA coactivator complex contains distinct chromatin-modifying activities and is recruited by DNA-bound activators to regulate the expression of a subset of genes. Bonnet et al. discovered that SAGA acetylates the promoters and deubiquitinates the transcribed region of all expressed genes. SAGA also plays a critical role for RNA polymerase II recruitment at all expressed genes. This study uncovers a new function for SAGA as a bona fide cofactor for all RNA polymerase II transcription. The SAGA (Spt–Ada–Gcn5 acetyltransferase) coactivator complex contains distinct chromatin-modifying activities and is recruited by DNA-bound activators to regulate the expression of a subset of genes. Surprisingly, recent studies revealed little overlap between genome-wide SAGA-binding profiles and changes in gene expression upon depletion of subunits of the complex. As indicators of SAGA recruitment on chromatin, we monitored in yeast and human cells the genome-wide distribution of histone H3K9 acetylation and H2B ubiquitination, which are respectively deposited or removed by SAGA. Changes in these modifications after inactivation of the corresponding enzyme revealed that SAGA acetylates the promoters and deubiquitinates the transcribed region of all expressed genes. In agreement with this broad distribution, we show that SAGA plays a critical role for RNA polymerase II recruitment at all expressed genes. In addition, through quantification of newly synthesized RNA, we demonstrated that SAGA inactivation induced a strong decrease of mRNA synthesis at all tested genes. Analysis of the SAGA deubiquitination activity further revealed that SAGA acts on the whole transcribed genome in a very fast manner, indicating a highly dynamic association of the complex with chromatin. Thus, our study uncovers a new function for SAGA as a bone fide cofactor for all RNA polymerase II transcription.
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Affiliation(s)
- Jacques Bonnet
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France
| | - Chen-Yi Wang
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Tiago Baptista
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France
| | - Stéphane D Vincent
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France
| | - Wei-Chun Hsiao
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Matthieu Stierle
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France
| | - Cheng-Fu Kao
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - László Tora
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France
| | - Didier Devys
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; UMR7104, Centre National de la Recherche Scientifique, 67404 Illkirch, France; U964, Institut National de la Santé et de la Recherche Médicale, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, Cedex, France;
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26
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Dimeric structure of p300/CBP associated factor. BMC STRUCTURAL BIOLOGY 2014; 14:2. [PMID: 24423233 PMCID: PMC3897949 DOI: 10.1186/1472-6807-14-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 01/10/2014] [Indexed: 12/30/2022]
Abstract
Background p300/CBP associating factor (PCAF, also known as KAT2B for lysine acetyltransferase 2B) is a catalytic subunit of megadalton metazoan complex ATAC (Ada-Two-A containing complex) for acetylation of histones. However, relatively little is known about the regulation of the enzymatic activity of PCAF. Results Here we present two dimeric structures of the PCAF acetyltransferase (HAT) domain. These dimerizations are mediated by either four-helical hydrophobic interactions or a ß-sheet extension. Our chemical cross-linking experiments in combined with site-directed mutagenesis demonstrated that the PCAF HAT domain mainly forms a dimer in solution through one of the observed interfaces. The results of maltose binding protein (MBP)-pulldown, co-immunoprecipitation and multiangle static light scattering experiments further indicated that PCAF dimeric state is detectable and may possibly exist in vivo. Conclusions Taken together, our structural and biochemical studies indicate that PCAF appears to be a dimer in its functional ATAC complex.
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27
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Kamata K, Goswami G, Kashio S, Urano T, Nakagawa R, Uchida H, Oki M. The N-terminus and Tudor domains of Sgf29 are important for its heterochromatin boundary formation function. ACTA ACUST UNITED AC 2013; 155:159-71. [DOI: 10.1093/jb/mvt108] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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28
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Identification of transcriptional and phosphatase regulators as interaction partners of human ADA3, a component of histone acetyltransferase complexes. Biochem J 2013; 450:311-20. [PMID: 23167988 DOI: 10.1042/bj20120452] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
ADA (alteration/deficiency in activation) 3 is a conserved component of several transcriptional adaptor and HAT (histone acetyltransferase) complexes that regulate RNA polymerase II-mediated gene expression. Within the HAT complexes ADA3 is associated with ADA2 and the HAT GCN5 (general control non-repressed 5). ADA3 plays roles in diverse cellular processes and also in malignancies by modulating GCN5 catalytic activity and/or by interactions with other regulators. To gain a better understanding of ADA3 function, we used a yeast two-hybrid approach to screen a human fetal cDNA library for proteins that interacted with hADA3 (human ADA3). We identified three novel hADA3-interacting partners, a transcriptional regulator, AATF (apoptosis-antagonizing transcription factor), and regulatory subunits of the PP1 (protein phosphatase 1) and PP2A (protein phosphatase 2A) [PPP1R7 (PP1 regulatory subunit 7) and PPP2R5D (PP2A 56 kDa regulatory subunit δ isoform) respectively]. Analysis of truncated versions of hADA3 indicated that the C-terminal ADA2-interacting domain was not required for these interactions. Fluorescent microscopy analysis and co-immunoprecipitation provided support for the co-localization and interaction of hADA3 with these proteins in human cells. Expression of the interacting proteins altered expression of an hADA3-regulated reporter gene, suggesting functional consequences for the interactions. The detected interactions of hADA3 might extend the spectrum of mechanisms by which ADA3 can contribute to the regulation of gene expression and shed light on processes mediated by these newly identified ADA3 partners.
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29
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Pankotai T, Zsindely N, Vamos EE, Komonyi O, Bodai L, Boros IM. Functional characterization and gene expression profiling of Drosophila melanogaster short dADA2b isoform-containing dSAGA complexes. BMC Genomics 2013; 14:44. [PMID: 23336284 PMCID: PMC3598691 DOI: 10.1186/1471-2164-14-44] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 01/16/2013] [Indexed: 12/27/2022] Open
Abstract
Background ADA2 proteins, together with ADA3, SGF29 and GCN5 form the acetyltransferase module of GNAT-type histone acetyltransferase complexes. ADA2b is present in the SAGA complex, which plays roles in various chromatin-related processes via histone H3 modifications and by other mechanisms. Results In this report we present findings showing that during Drosophila melanogaster development two dADA2b isoforms (dADA2bS and dADA2bL) - which differ in their C-terminal domains - are expressed at various levels. Genetic complementation experiments indicate that dADA2bS alone can support development but cannot fully complement dAda2b mutations. In the presence of dADA2bS, the SAGA-specific histone H3 acetylation level is partially restored in dAda2b mutants. Comparison of whole transcriptome profiles of dAda2b null and dAda2bS transgene-carrier dAda2b null larvae indicates partial overlap between affected genes. mRNA levels corresponding to selected genes which are either up- or down-regulated in dAda2b mutants are altered by dADA2bS expression to different extents, ranging from complete restoration to wild type levels to no restoration at all. The short (dADA2bS) isoform of dADA2b seems to be more capable of restoring lost dSAGA functions that cause mRNA level up-regulation than those that lead to decreased mRNA levels. Conclusions The data presented here are in accord with results of genetic complementation experiments, and support the hypothesis that different isoforms of dADA2b contribute to the functional variations of dSAGA multiprotein HAT complexes.
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Affiliation(s)
- Tibor Pankotai
- Department of Biochemistry and Molecular Biology, University of Szeged, Középfasor 52, H-6726, Szeged, Hungary
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30
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Comparative Analysis of SWIRM Domain-Containing Proteins in Plants. Comp Funct Genomics 2012; 2012:310402. [PMID: 22924025 PMCID: PMC3424641 DOI: 10.1155/2012/310402] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 06/16/2012] [Accepted: 06/24/2012] [Indexed: 12/16/2022] Open
Abstract
Chromatin-remodeling complexes affect gene expression by using the energy of ATP hydrolysis to locally disrupt or alter the association of histones with DNA. SWIRM (Swi3p, Rsc8p, and Moira) domain is an alpha-helical domain of about 85 residues in chromosomal proteins. SWIRM domain-containing proteins make up large multisubunit complexes by interacting with other chromatin modification factors and may have an important function in plants. However, little is known about SWIRM domain-containing proteins in plants. In this study, 67 SWIRM domain-containing proteins from 6 plant species were identified and analyzed. Plant SWIRM domain proteins can be divided into three distinct types: Swi-type, LSD1-type, and Ada2-type. Generally, the SWIRM domain forms a helix-turn-helix motif commonly found in DNA-binding proteins. The genes encoding SWIRM domain proteins in Oryza sativa are widely expressed, especially in pistils. In addition, OsCHB701 and OsHDMA701 were downregulated by cold stress, whereas OsHDMA701 and OsHDMA702 were significantly induced by heat stress. These observations indicate that SWIRM domain proteins may play an essential role in plant development and plant responses to environmental stress.
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31
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Vamos EE, Boros IM. The C-terminal domains of ADA2 proteins determine selective incorporation into GCN5-containing complexes that target histone H3 or H4 for acetylation. FEBS Lett 2012; 586:3279-86. [PMID: 22796493 DOI: 10.1016/j.febslet.2012.06.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 06/28/2012] [Accepted: 06/29/2012] [Indexed: 10/28/2022]
Abstract
ADA2 adaptor proteins are essential subunits of GCN5-containing histone acetyltransferase (HAT) complexes. In metazoa ADA2a is present in the histone H4-specific ATAC, and ADA2b in the histone H3-specific SAGA complex. Using domain-swapped ADA2 chimeras, we determined that the in vivo function of Drosophila melanogaster SAGA and ATAC HAT complexes depend on the C-terminal region of the ADA2 subunit they contain. Our findings demonstrate that the ADA2 C-terminal regions play an important role in the specific incorporation of ADA2 into SAGA- or ATAC-type complexes, which in turn determines H3- or H4-specific histone targeting.
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Affiliation(s)
- Edith E Vamos
- Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary
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32
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Choi NM, Boss JM. Multiple histone methyl and acetyltransferase complex components bind the HLA-DRA gene. PLoS One 2012; 7:e37554. [PMID: 22701520 PMCID: PMC3365104 DOI: 10.1371/journal.pone.0037554] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 04/25/2012] [Indexed: 01/17/2023] Open
Abstract
Major histocompatibility complex class II (MHC-II) genes are fundamental components that contribute to adaptive immune responses. While characterization of the chromatin features at the core promoter region of these genes has been studied, the scope of histone modifications and the modifying factors responsible for activation of these genes are less well defined. Using the MHC-II gene HLA-DRA as a model, the extent and distribution of major histone modifications associated with active expression were defined in interferon-γ induced epithelial cells, B cells, and B-cell mutants for MHC-II expression. With active transcription, nucleosome density around the proximal regulatory region was diminished and histone acetylation and methylation modifications were distributed throughout the gene in distinct patterns that were dependent on the modification examined. Irrespective of the location, the majority of these modifications were dependent on the binding of either the X-box binding factor RFX or the class II transactivator (CIITA) to the proximal regulatory region. Importantly, once established, the modifications were stable through multiple cell divisions after the activating stimulus was removed, suggesting that activation of this system resulted in an epigenetic state. A dual crosslinking chromatin immunoprecipitation method was used to detect histone modifying protein components that interacted across the gene. Components of the MLL methyltransferase and GCN5 acetyltransferase complexes were identified. Some MLL complex components were found to be CIITA independent, including MLL1, ASH2L and RbBP5. Likewise, GCN5 containing acetyltransferase complex components belonging to the ATAC and STAGA complexes were also identified. These results suggest that multiple complexes are either used or are assembled as the gene is activated for expression. Together the results define and illustrate a complex network of histone modifying proteins and multisubunit complexes participating in MHC-II transcription.
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Affiliation(s)
- Nancy M. Choi
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Jeremy M. Boss
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- * E-mail:
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33
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Svensson JP, Fry RC, Wang E, Somoza LA, Samson LD. Identification of novel human damage response proteins targeted through yeast orthology. PLoS One 2012; 7:e37368. [PMID: 22615993 PMCID: PMC3353887 DOI: 10.1371/journal.pone.0037368] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Accepted: 04/21/2012] [Indexed: 01/09/2023] Open
Abstract
Studies in Saccharomyces cerevisiae show that many proteins influence cellular survival upon exposure to DNA damaging agents. We hypothesized that human orthologs of these S. cerevisiae proteins would also be required for cellular survival after treatment with DNA damaging agents. For this purpose, human homologs of S. cerevisiae proteins were identified and mapped onto the human protein-protein interaction network. The resulting human network was highly modular and a series of selection rules were implemented to identify 45 candidates for human toxicity-modulating proteins. The corresponding transcripts were targeted by RNA interference in human cells. The cell lines with depleted target expression were challenged with three DNA damaging agents: the alkylating agents MMS and 4-NQO, and the oxidizing agent t-BuOOH. A comparison of the survival revealed that the majority (74%) of proteins conferred either sensitivity or resistance. The identified human toxicity-modulating proteins represent a variety of biological functions: autophagy, chromatin modifications, RNA and protein metabolism, and telomere maintenance. Further studies revealed that MMS-induced autophagy increase the survival of cells treated with DNA damaging agents. In summary, we show that damage recovery proteins in humans can be identified through homology to S. cerevisiae and that many of the same pathways are represented among the toxicity modulators.
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Affiliation(s)
- J. Peter Svensson
- Biological Engineering Department, Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Rebecca C. Fry
- Biological Engineering Department, Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Computation and Systems Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Emma Wang
- Biological Engineering Department, Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Luis A. Somoza
- Biological Engineering Department, Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Leona D. Samson
- Biological Engineering Department, Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Computation and Systems Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
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34
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Spedale G, Timmers HTM, Pijnappel WWMP. ATAC-king the complexity of SAGA during evolution. Genes Dev 2012; 26:527-41. [PMID: 22426530 DOI: 10.1101/gad.184705.111] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The yeast SAGA (Spt-Ada-Gcn5-acetyltransferase) coactivator complex exerts functions in gene expression, including activator interaction, histone acetylation, histone deubiquitination, mRNA export, chromatin recognition, and regulation of the basal transcription machinery. These diverse functions involve distinct modules within this multiprotein complex. It has now become clear that yeast SAGA has diverged during metazoan evolution into two related complexes, SAGA and ATAC, which exist in two flavors in vertebrates. The compositions of metazoan ATAC and SAGA complexes have been characterized, and functional analyses indicate that these complexes have important but distinct roles in transcription, histone modification, signaling pathways, and cell cycle regulation.
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Affiliation(s)
- Gianpiero Spedale
- Molecular Cancer Research, Netherlands Proteomics Center, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
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35
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Shukla A, Lahudkar S, Durairaj G, Bhaumik SR. Sgf29p facilitates the recruitment of TATA box binding protein but does not alter SAGA's global structural integrity in vivo. Biochemistry 2012; 51:706-14. [PMID: 22224423 DOI: 10.1021/bi201708z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Although Sgf29p has been biochemically implicated as a component of SAGA (Spt-Ada-Gcn5 acetyltransferase), its precise mechanism of action in transcription is not clearly understood in vivo. Here, using a formaldehyde-based in vivo cross-linking and chromatin immunoprecipitation (ChIP) assay in conjunction with transcriptional and mutational analyses, we show that Sgf29p along with other SAGA components is recruited to the upstream activating sequence (UAS) of a SAGA-regulated gene, GAL1, in an activation domain-dependent manner. However, Sgf29p does not alter the recruitment of Spt20p that maintains the overall structural and functional integrity of SAGA. The recruitment of other SAGA components such as TAF10p, TAF12p, and Ubp8p to the GAL1 UAS is also not altered in the absence of Sgf29p. Interestingly, we find that the recruitment of TBP (TATA box binding protein that nucleates the assembly of general transcription factors to form the preinitiation complex for transcriptional initiation) to the core promoter of GAL1 is weakened in Δsgf29. Likewise, Sgf29p also enhances the recruitment of TBP to other SAGA-regulated promoters. Such weakening of recruitment of TBP to these promoters subsequently decreases the level of transcription. Taken together, these results support the idea that SAGA-associated Sgf29p facilitates the recruitment of TBP (and hence transcription) without altering the global structural integrity of SAGA in vivo.
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Affiliation(s)
- Abhijit Shukla
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901, United States
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Krebs AR, Karmodiya K, Lindahl-Allen M, Struhl K, Tora L. SAGA and ATAC histone acetyl transferase complexes regulate distinct sets of genes and ATAC defines a class of p300-independent enhancers. Mol Cell 2011; 44:410-423. [PMID: 22055187 DOI: 10.1016/j.molcel.2011.08.037] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 05/30/2011] [Accepted: 08/15/2011] [Indexed: 11/17/2022]
Abstract
Histone acetyltransferase (HAT) complexes are coactivators that are important for transcriptional activation by modifying chromatin. Metazoan SAGA and ATAC are distinct multisubunits complexes that share the same catalytic HAT subunit (GCN5 or PCAF). Here, we show that these human HAT complexes are targeted to different genomic loci representing functionally distinct regulatory elements both at broadly expressed and tissue-specific genes. While SAGA can principally be found at promoters, ATAC is recruited to promoters and enhancers, yet only its enhancer binding is cell-type specific. Furthermore, we show that ATAC functions at a set of enhancers that are not bound by p300, revealing a class of enhancers not yet identified. These findings demonstrate important functional differences between SAGA and ATAC coactivator complexes at the level of the genome and define a role for the ATAC complex in the regulation of a set of enhancers.
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Affiliation(s)
- Arnaud R Krebs
- Program of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique UMR 7104, Institut National de la Santé et de la Recherche Médicale U964, Université de Strasbourg, BP 10142, 67404 Illkirch Cedex, CU de Strasbourg, France
| | - Krishanpal Karmodiya
- Program of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique UMR 7104, Institut National de la Santé et de la Recherche Médicale U964, Université de Strasbourg, BP 10142, 67404 Illkirch Cedex, CU de Strasbourg, France
| | - Marianne Lindahl-Allen
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, C-315240 Longwood Avenue, Boston, MA 02115, USA
| | - Kevin Struhl
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, C-315240 Longwood Avenue, Boston, MA 02115, USA
| | - Làszlò Tora
- Program of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique UMR 7104, Institut National de la Santé et de la Recherche Médicale U964, Université de Strasbourg, BP 10142, 67404 Illkirch Cedex, CU de Strasbourg, France
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García-Oliver E, García-Molinero V, Rodríguez-Navarro S. mRNA export and gene expression: the SAGA-TREX-2 connection. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1819:555-65. [PMID: 22178374 DOI: 10.1016/j.bbagrm.2011.11.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 11/29/2011] [Accepted: 11/30/2011] [Indexed: 01/07/2023]
Abstract
In the gene expression field, different steps have been traditionally viewed as discrete and unconnected events. Nowadays, genetic and functional studies support the model of a coupled network of physical and functional connections to carry out mRNA biogenesis. Gene expression is a coordinated process that comprises different linked steps like transcription, RNA processing, export to the cytoplasm, translation and degradation of mRNAs. Its regulation is essential for cellular survival and can occur at many different levels. Transcription is the central function that occurs in the nucleus, and RNAPII plays an essential role in mRNA biogenesis. During transcription, nascent mRNA is associated with the mRNA-binding proteins involved in processing and export of the mRNA particle. Cells have developed a network of multi-protein complexes whose functions regulate the different factors involved both temporally and spatially. This coupling mechanism acts as a quality control to solve some of the organization problems of gene expression in vivo, where all the factors implicated ensure that mRNAs are ready to be exported and translated. In this review, we focus on the functional coupling of gene transcription and mRNA export, and place particular emphasis on the relationship between the NPC-associated complex, TREX2, and the transcription co-activator, SAGA. We have pinpointed the experimental evidence for Sus1's roles in transcription initiation, transcription elongation and mRNA export. In addition, we have reviewed other NPC-related processes such as gene gating to the nuclear envelope, the chromatin structure and the cellular context in which these processes take place. This article is part of a Special Issue entitled: Nuclear Transport and RNA Processing.
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Affiliation(s)
- Encar García-Oliver
- Centro de Investigación Príncipe Felipe (CIPF), Gene Expression coupled with RNA Transport Laboratory, Valencia, Spain
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Cai L, Sutter BM, Li B, Tu BP. Acetyl-CoA induces cell growth and proliferation by promoting the acetylation of histones at growth genes. Mol Cell 2011; 42:426-37. [PMID: 21596309 DOI: 10.1016/j.molcel.2011.05.004] [Citation(s) in RCA: 505] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 04/06/2011] [Accepted: 05/05/2011] [Indexed: 12/16/2022]
Abstract
The decision by a cell to enter a round of growth and division must be intimately coordinated with nutrient availability and its metabolic state. These metabolic and nutritional requirements, and the mechanisms by which they induce cell growth and proliferation, remain poorly understood. Herein, we report that acetyl-CoA is the downstream metabolite of carbon sources that represents a critical metabolic signal for growth and proliferation. Upon entry into growth, intracellular acetyl-CoA levels increase substantially and consequently induce the Gcn5p/SAGA-catalyzed acetylation of histones at genes important for growth, thereby enabling their rapid transcription and commitment to growth. Thus, acetyl-CoA functions as a carbon-source rheostat that signals the initiation of the cellular growth program by promoting the acetylation of histones specifically at growth genes.
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Affiliation(s)
- Ling Cai
- Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9038, USA
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Bhaumik SR. Distinct regulatory mechanisms of eukaryotic transcriptional activation by SAGA and TFIID. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1809:97-108. [PMID: 20800707 DOI: 10.1016/j.bbagrm.2010.08.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Revised: 08/18/2010] [Accepted: 08/19/2010] [Indexed: 01/08/2023]
Abstract
A growing number of human diseases are linked to abnormal gene expression which is largely controlled at the level of transcriptional initiation. The gene-specific activator promotes the initiation of transcription through its interaction with one or more components of the transcriptional initiation machinery, hence leading to stimulated transcriptional initiation or activation. However, all activator proteins do not target the same component(s) of the transcriptional initiation machinery. Rather, they can have different target specificities, and thus, can lead to distinct mechanisms of transcriptional activation. Two such distinct mechanisms of transcriptional activation in yeast are mediated by the SAGA (Spt-Ada-Gcn5-Acetyltransferase) and TFIID (Transcription factor IID) complexes, and are termed as "SAGA-dependent" and "TFIID-dependent" transcriptional activation, respectively. SAGA is the target of the activator in case of SAGA-dependent transcriptional activation, while the targeting of TFIID by the activator leads to TFIID-dependent transcriptional activation. Both the SAGA and TFIID complexes are highly conserved from yeast to human, and play crucial roles in gene activation among eukaryotes. The regulatory mechanisms of eukaryotic transcriptional activation by SAGA and TFIID are discussed here. This article is part of a Special Issue entitled The 26S Proteasome: When degradation is just not enough!
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Affiliation(s)
- Sukesh R Bhaumik
- Department of Biochemistry and Molecular Biology, Southern Illnois University School of Medicine, Carbondale, IL 62901, USA.
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Pan Y, Nussinov R. Lysine120 interactions with p53 response elements can allosterically direct p53 organization. PLoS Comput Biol 2010; 6:e1000878. [PMID: 20700496 PMCID: PMC2916859 DOI: 10.1371/journal.pcbi.1000878] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2010] [Accepted: 07/08/2010] [Indexed: 01/02/2023] Open
Abstract
p53 can serve as a paradigm in studies aiming to figure out how allosteric perturbations in transcription factors (TFs) triggered by small changes in DNA response element (RE) sequences, can spell selectivity in co-factor recruitment. p53-REs are 20-base pair (bp) DNA segments specifying diverse functions. They may be located near the transcription start sites or thousands of bps away in the genome. Their number has been estimated to be in the thousands, and they all share a common motif. A key question is then how does the p53 protein recognize a particular p53-RE sequence among all the similar ones? Here, representative p53-REs regulating diverse functions including cell cycle arrest, DNA repair, and apoptosis were simulated in explicit solvent. Among the major interactions between p53 and its REs involving Lys120, Arg280 and Arg248, the bps interacting with Lys120 vary while the interacting partners of other residues are less so. We observe that each p53-RE quarter site sequence has a unique pattern of interactions with p53 Lys120. The allosteric, DNA sequence-induced conformational and dynamic changes of the altered Lys120 interactions are amplified by the perturbation of other p53-DNA interactions. The combined subtle RE sequence-specific allosteric effects propagate in the p53 and in the DNA. The resulting amplified allosteric effects far away are reflected in changes in the overall p53 organization and in the p53 surface topology and residue fluctuations which play key roles in selective co-factor recruitment. As such, these observations suggest how similar p53-RE sequences can spell the preferred co-factor binding, which is the key to the selective gene transactivation and consequently different functional effects.
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Affiliation(s)
- Yongping Pan
- Basic Science Program, Science Applications International Corporation-Frederick, Inc., Center for Cancer Research Nanobiology Program, National Cancer Institute-Frederick, Frederick, Maryland, United States of America
| | - Ruth Nussinov
- Basic Science Program, Science Applications International Corporation-Frederick, Inc., Center for Cancer Research Nanobiology Program, National Cancer Institute-Frederick, Frederick, Maryland, United States of America
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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The ATAC acetyl transferase complex controls mitotic progression by targeting non-histone substrates. EMBO J 2010; 29:2381-94. [PMID: 20562830 DOI: 10.1038/emboj.2010.125] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Accepted: 05/14/2010] [Indexed: 11/08/2022] Open
Abstract
All DNA-related processes rely on the degree of chromatin compaction. The highest level of chromatin condensation accompanies transition to mitosis, central for cell cycle progression. Covalent modifications of histones, mainly deacetylation, have been implicated in this transition, which also involves transcriptional repression. Here, we show that the Gcn5-containing histone acetyl transferase complex, Ada Two A containing (ATAC), controls mitotic progression through the regulation of the activity of non-histone targets. RNAi for the ATAC subunits Ada2a/Ada3 results in delayed M/G1 transition and pronounced cell division defects such as centrosome multiplication, defective spindle and midbody formation, generation of binucleated cells and hyperacetylation of histone H4K16 and alpha-tubulin. We show that ATAC localizes to the mitotic spindle and controls cell cycle progression through direct acetylation of Cyclin A/Cdk2. Our data describes a new pathway in which the ATAC complex controls Cyclin A/Cdk2 mitotic function: ATAC/Gcn5-mediated acetylation targets Cyclin A for degradation, which in turn regulates the SIRT2 deacetylase activity. Thus, we have uncovered an essential function for ATAC in regulating Cyclin A activity and consequent mitotic progression.
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Koutelou E, Hirsch CL, Dent SYR. Multiple faces of the SAGA complex. Curr Opin Cell Biol 2010; 22:374-82. [PMID: 20363118 DOI: 10.1016/j.ceb.2010.03.005] [Citation(s) in RCA: 190] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 01/26/2010] [Accepted: 03/03/2010] [Indexed: 02/07/2023]
Abstract
The SAGA complex provides a paradigm for multisubunit histone modifying complexes. Although first characterized as a histone acetyltransferase, because of the Gcn5 subunit, SAGA is now known to contain a second activity, a histone deubiquitinase, as well as subunits important for interactions with transcriptional activators and the general transcription machinery. The functions of SAGA in transcriptional activation are well-established in Saccharomyces cerevisiae. Recent studies in S. pombe, Drosophila, and mammalian systems reveal that SAGA also has important roles in transcript elongation, the regulation of protein stability, and telomere maintenance. These functions are essential for normal embryo development in flies and mice, and mutations or altered expression of SAGA subunits correlate with neurological disease and aggressive cancers in humans.
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Affiliation(s)
- Evangelia Koutelou
- Department of Biochemistry and Molecular Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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McCullough SD, Grant PA. Histone acetylation, acetyltransferases, and ataxia--alteration of histone acetylation and chromatin dynamics is implicated in the pathogenesis of polyglutamine-expansion disorders. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2010; 79:165-203. [PMID: 20621284 DOI: 10.1016/s1876-1623(10)79005-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Eukaryotic chromosomal DNA is packaged into nucleosomes to form a dynamic structure known as chromatin. The compaction of DNA within chromatin poses a unique hindrance with regards to the accessibility of the DNA to enzymes involved in replication, transcriptional regulation, and repair. The physical structure and physiological activity of chromatin are regulated through a diverse set of posttranslational modifications, histone exchange, and structural remodeling. Of the covalent chromatin modifications, the acetylation of lysine residues within histone proteins by acetyltransferase enzymes, such as GCN5, is one of the most prevalent and important steps in the regulation of chromatin function. Alteration of histone acetyltransferase activity can easily result in the dysregulation of gene transcription and ultimately the onset of a disease state. Many transcription factors contain polyglutamine regions within their primary sequence. Mutations resulting in the elongation of these polyglutamine tracts are associated with a disease family known as the polyglutamine expansion disorders. Spinocerebellar ataxia type 7 (SCA7) is one of the nine diseases that are grouped in this family and is caused by polyglutamine expansion of the ataxin-7 protein, which is a component of the GCN5-containing human SAGA histone acetyltransferase complex. Mutation of ataxin-7 in this manner has been shown to disrupt the structural integrity of the SAGA complex and result in aberrant chromatin acetylation patterns at the promoters of genes involved in the normal function of tissues that are affected by the disease. The specific aspects of molecular pathology are not currently understood; however, studies carried out in laboratory systems ranging from the budding yeast Saccharomyces cerevisiae to transgenic mouse models and cultured human cells are poised to allow for the elucidation of disease mechanisms and subsequent therapeutic approaches.
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Affiliation(s)
- Shaun D McCullough
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA
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Abstract
The cellular role of the Ada2 coactivator is currently understood in the context of the SAGA histone acetyltransferase (HAT) complex, where Ada2 increases the HAT activity of Gcn5 and interacts with transcriptional activators. Here we report a new function for Ada2 in promoting transcriptional silencing at telomeres and ribosomal DNA. This silencing function is the first characterized role for Ada2 distinct from its involvement with Gcn5. Ada2 binds telomeric chromatin and the silencing protein Sir2 in vivo. Loss of ADA2 causes the spreading of Sir2 and Sir3 into subtelomeric regions and decreased histone H4 K16 acetylation. This previously uncharacterized boundary activity of Ada2 is functionally similar to, but mechanistically distinct from, that of the MYST family HAT Sas2. Mounting evidence in the literature indicates that boundary activities create chromosomal domains important for regulating gene expression in response to environmental changes. Consistent with this, we show that upon nutritional changes, Ada2 occupancy increases at a subtelomeric region proximal to a SAGA-inducible gene and causes derepression of a silenced telomeric reporter gene. Thus, Ada2, likely in the context of SAGA, is positioned at chromosomal termini to participate in both transcriptional repression and activation in response to nutrient signaling.
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