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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 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Ayano T, Oki M. IMD2, which is located near the boundary of heterochromatin regions, is regulated by the use of multiple HAT-related factors. Genes Genet Syst 2024:23-00284. [PMID: 38382924 DOI: 10.1266/ggs.23-00284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024] Open
Abstract
In Saccharomyces cerevisiae, boundaries formed by DNA sequence-dependent or -independent histone modifications stop the spread of the heterochromatin region formed via the Sir complex. However, it is unclear whether the histone modifiers that control DNA sequence-independent boundaries function in a chromosome-specific or -nonspecific manner. In this study, we evaluated the effects of the SAGA complex, a histone acetyltransferase (HAT) complex, and its relationship with other histone-modifying enzymes to clarify the mechanism underlying boundary regulation of the IMD2 gene on the right subtelomere of chromosome VIII. We found that Spt8, a component of the SAGA complex, is important for boundary formation in this region and that the inclusion of Spt8 in the SAGA complex is more important than its interaction with TATA-binding protein and TFIIS. In addition to SAGA, various HAT-related factors, such as NuA4 and Rtt109, also functioned in this region. In particular, the SAGA complex induced weak IMD2 expression throughout the cell, whereas NuA4 induced strong expression. These results indicate that multiple HATs contribute to the regulation of boundary formation and IMD2 expression on the right subtelomeres of chromosome VIII and that IMD2 expression is determined by the balance between these factors.
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Affiliation(s)
- Takahito Ayano
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui
- Research Fellowships of Japan Society for the Promotion of Science for Young Scientists (JSPS)
| | - Masaya Oki
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui
- Life Science Innovation Center, University of Fukui
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Librais GMN, Jiang Y, Razzaq I, Brandl CJ, Shapiro RS, Lajoie P. Evolutionary diversity of the control of the azole response by Tra1 across yeast species. G3 (Bethesda) 2024; 14:jkad250. [PMID: 37889998 PMCID: PMC10849324 DOI: 10.1093/g3journal/jkad250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 02/16/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023]
Abstract
Tra1 is an essential coactivator protein of the yeast SAGA and NuA4 acetyltransferase complexes that regulate gene expression through multiple mechanisms including the acetylation of histone proteins. Tra1 is a pseudokinase of the PIKK family characterized by a C-terminal PI3K domain with no known kinase activity. However, mutations of specific arginine residues to glutamine in the PI3K domains (an allele termed tra1Q3) result in reduced growth and increased sensitivity to multiple stresses. In the opportunistic fungal pathogen Candida albicans, the tra1Q3 allele reduces pathogenicity and increases sensitivity to the echinocandin antifungal drug caspofungin, which disrupts the fungal cell wall. Here, we found that compromised Tra1 function, in contrast to what is seen with caspofungin, increases tolerance to the azole class of antifungal drugs, which inhibits ergosterol synthesis. In C. albicans, tra1Q3 increases the expression of genes linked to azole resistance, such as ERG11 and CDR1. CDR1 encodes a multidrug ABC transporter associated with efflux of multiple xenobiotics, including azoles. Consequently, cells carrying tra1Q3 show reduced intracellular accumulation of fluconazole. In contrast, a tra1Q3 Saccharomyces cerevisiae strain displayed opposite phenotypes: decreased tolerance to azole, decreased expression of the efflux pump PDR5, and increased intracellular accumulation of fluconazole. Therefore, our data provide evidence that Tra1 differentially regulates the antifungal response across yeast species.
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Affiliation(s)
| | - Yuwei Jiang
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Iqra Razzaq
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Christopher J Brandl
- Department of Biochemistry, The University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Rebecca S Shapiro
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Patrick Lajoie
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, Ontario, N6A 5C1, Canada
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4
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Yu CK, Stephenson CJ, Villamor TC, Dyba TG, Schulz BL, Fraser JA. SAGA Complex Subunit Hfi1 Is Important in the Stress Response and Pathogenesis of Cryptococcus neoformans. J Fungi (Basel) 2023; 9:1198. [PMID: 38132798 PMCID: PMC10744473 DOI: 10.3390/jof9121198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/23/2023] Open
Abstract
The Spt-Ada-Gcn Acetyltransferase (SAGA) complex is a highly conserved co-activator found across eukaryotes. It is composed of a number of modules which can vary between species, but all contain the core module. Hfi1 (known as TADA1 in Homo sapiens) is one of the proteins that forms the core module, and has been shown to play an important role in maintaining complex structural integrity in both brewer's yeast and humans. In this study we successfully identified the gene encoding this protein in the important fungal pathogen, Cryptococcus neoformans, and named it HFI1. The hfi1Δ mutant is highly pleiotropic in vitro, influencing phenotypes, ranging from temperature sensitivity and melanin production to caffeine resistance and titan cell morphogenesis. In the absence of Hfi1, the transcription of several other SAGA genes is impacted, as is the acetylation and deubiquination of several histone residues. Importantly, loss of the gene significantly impacts virulence in a murine inhalation model of cryptococcosis. In summary, we have established that Hfi1 modulates multiple pathways that directly affect virulence and survival in C. neoformans, and provided deeper insight into the importance of the non-enzymatic components of the SAGA complex.
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Affiliation(s)
| | | | | | | | | | - James A. Fraser
- School of Chemistry & Molecular Biosciences, Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia; (C.K.Y.); (C.J.S.); (T.C.V.); (T.G.D.); (B.L.S.)
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Lin CJ, Yang SY, Hsu LH, Yu SJ, Chen YL. The Gcn5-Ada2-Ada3 histone acetyltransferase module has divergent roles in pathogenesis of Candida glabrata. Med Mycol 2023; 61:myad004. [PMID: 36715154 DOI: 10.1093/mmy/myad004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/04/2023] [Accepted: 01/27/2023] [Indexed: 01/31/2023] Open
Abstract
Candida glabrata is an opportunistic fungal pathogen and the second most prevalent species isolated from candidiasis patients. C. glabrata has intrinsic tolerance to antifungal drugs and oxidative stresses and the ability to adhere to mucocutaneous surfaces. However, knowledge about the regulation of its virulence traits is limited. The Spt-Ada-Gcn5 acetyltransferase (SAGA) complex modulates gene transcription by histone acetylation through the histone acetyltransferase (HAT) module comprised of Gcn5-Ada2-Ada3. Previously, we showed that the ada2 mutant was hypervirulent but displayed decreased tolerance to antifungal drugs and cell wall perturbing agents. In this study, we further characterized the functions of Ada3 and Gcn5 in C. glabrata. We found that single, double, or triple deletions of the HAT module, as expected, resulted in a decreased level of acetylation on histone H3 lysine 9 (H3K9) and defective growth. These mutants were more susceptible to antifungal drugs, oxidative stresses, and cell wall perturbing agents compared with the wild-type. In addition, HAT module mutants exhibited enhanced agar invasion and upregulation of adhesin and proteases encoding genes, whereas the biofilm formation of those mutants was impaired. Interestingly, HAT module mutants exhibited enhanced induction of catalases (CTA1) expression upon treatment with H2O2 compared with the wild-type. Lastly, although ada3 and gcn5 exhibited marginal hypervirulence, the HAT double and triple mutants were hypervirulent in a murine model of candidiasis. In conclusion, the HAT module of the SAGA complex plays unique roles in H3K9 acetylation, drug tolerance, oxidative stress response, adherence, and virulence in C. glabrata.
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Affiliation(s)
- Chi-Jan Lin
- Institute of Molecular Biology, National Chung Hsing University, 40227 Taichung, Taiwan
- Department of Plant Pathology and Microbiology, National Taiwan University, 10617 Taipei, Taiwan
| | - Sheng-Yung Yang
- Department of Plant Pathology and Microbiology, National Taiwan University, 10617 Taipei, Taiwan
| | - Li-Hang Hsu
- Department of Plant Pathology and Microbiology, National Taiwan University, 10617 Taipei, Taiwan
| | - Shang-Jie Yu
- Department of Plant Pathology and Microbiology, National Taiwan University, 10617 Taipei, Taiwan
| | - Ying-Lien Chen
- Department of Plant Pathology and Microbiology, National Taiwan University, 10617 Taipei, Taiwan
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Bari KA, Berg MD, Genereaux J, Brandl CJ, Lajoie P. Tra1 controls the transcriptional landscape of the aging cell. G3 (Bethesda) 2022; 13:6782959. [PMID: 36315064 PMCID: PMC9836359 DOI: 10.1093/g3journal/jkac287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 10/25/2022] [Indexed: 11/07/2022]
Abstract
Gene expression undergoes considerable changes during the aging process. The mechanisms regulating the transcriptional response to cellular aging remain poorly understood. Here, we employ the budding yeast Saccharomyces cerevisiae to better understand how organisms adapt their transcriptome to promote longevity. Chronological lifespan assays in yeast measure the survival of nondividing cells at stationary phase over time, providing insights into the aging process of postmitotic cells. Tra1 is an essential component of both the yeast Spt-Ada-Gcn5 acetyltransferase/Spt-Ada-Gcn5 acetyltransferase-like and nucleosome acetyltransferase of H4 complexes, where it recruits these complexes to acetylate histones at targeted promoters. Importantly, Tra1 regulates the transcriptional response to multiple stresses. To evaluate the role of Tra1 in chronological aging, we took advantage of a previously characterized mutant allele that carries mutations in the TRA1 PI3K domain (tra1Q3). We found that loss of functions associated with tra1Q3 sensitizes cells to growth media acidification and shortens lifespan. Transcriptional profiling reveals that genes differentially regulated by Tra1 during the aging process are enriched for components of the response to stress. Notably, expression of catalases (CTA1, CTT1) involved in hydrogen peroxide detoxification decreases in chronologically aged tra1Q3 cells. Consequently, they display increased sensitivity to oxidative stress. tra1Q3 cells are unable to grow on glycerol indicating a defect in mitochondria function. Aged tra1Q3 cells also display reduced expression of peroxisomal genes, exhibit decreased numbers of peroxisomes, and cannot grow on media containing oleate. Thus, Tra1 emerges as an important regulator of longevity in yeast via multiple mechanisms.
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Affiliation(s)
- Khaleda Afrin Bari
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Matthew D Berg
- Present address for Matthew D Berg: Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Julie Genereaux
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, ON N6A 5C1, Canada,Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Christopher J Brandl
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Patrick Lajoie
- Corresponding author: Department of Anatomy and Cell Biology, The University of Western Ontario, London, ON N6A 5C1, Canada.
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7
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Geng Q, Li H, Wang D, Sheng RC, Zhu H, Klosterman SJ, Subbarao KV, Chen JY, Chen FM, Zhang DD. The Verticillium dahliae Spt-Ada-Gcn5 Acetyltransferase Complex Subunit Ada1 Is Essential for Conidia and Microsclerotia Production and Contributes to Virulence. Front Microbiol 2022; 13:852571. [PMID: 35283850 PMCID: PMC8905346 DOI: 10.3389/fmicb.2022.852571] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 01/31/2022] [Indexed: 12/16/2022] Open
Abstract
Verticillium dahliae is a destructive soil-borne pathogen of many economically important dicots. The genetics of pathogenesis in V. dahliae has been extensively studied. Spt-Ada-Gcn5 acetyltransferase complex (SAGA) is an ATP-independent multifunctional chromatin remodeling complex that contributes to diverse transcriptional regulatory functions. As members of the core module in the SAGA complex in Saccharomyces cerevisiae, Ada1, together with Spt7 and Spt20, play an important role in maintaining the integrity of the complex. In this study, we identified homologs of the SAGA complex in V. dahliae and found that deletion of the Ada1 subunit (VdAda1) causes severe defects in the formation of conidia and microsclerotia, and in melanin biosynthesis and virulence. The effect of VdAda1 on histone acetylation in V. dahliae was confirmed by western blot analysis. The deletion of VdAda1 resulted in genome-wide alteration of the V. dahliae transcriptome, including genes encoding transcription factors and secreted proteins, suggesting its prominent role in the regulation of transcription and virulence. Overall, we demonstrated that VdAda1, a member of the SAGA complex, modulates multiple physiological processes by regulating global gene expression that impinge on virulence and survival in V. dahliae.
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Affiliation(s)
- Qi Geng
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Huan Li
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Dan Wang
- Team of Crop Verticillium Wilt, State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ruo-Cheng Sheng
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - He Zhu
- National Cotton Industry Technology System Liaohe Comprehensive Experimental Station, The Cotton Research Center of Liaoning Academy of Agricultural Sciences, Liaoning Provincial Institute of Economic Crops, Liaoyang, China
| | - Steven J Klosterman
- United States Department of Agriculture, Agricultural Research Service, Crop Improvement and Protection Research Unit, Salinas, CA, United States
| | - Krishna V Subbarao
- Department of Plant Pathology, c/o U.S. Agricultural Research Station, University of California, Davis, Salinas, CA, United States
| | - Jie-Yin Chen
- Team of Crop Verticillium Wilt, State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Feng-Mao Chen
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Dan-Dan Zhang
- Team of Crop Verticillium Wilt, State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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Fernandes KE, Fraser JA, Carter DA. Lineages Derived from Cryptococcus neoformans Type Strain H99 Support a Link between the Capacity to Be Pleomorphic and Virulence. mBio 2022;:e0028322. [PMID: 35258331 DOI: 10.1128/mbio.00283-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The pathogenic yeast Cryptococcus neoformans causes nearly 200,000 deaths annually in immunocompromised individuals. Cryptococcus cells can undergo substantial morphological change during mammalian infection, including increased capsule and cell size, the release of shed capsule, and the production of titan (>10 μm), micro (<2 μm)-, and irregular cells. We examined phenotypic variation under conditions designed to simulate in vivo stress in a collection of nine lineages derived from the C. neoformans type strain H99. These lineages are highly genetically similar but have a range of virulence levels. Strains from hypervirulent lineages had a larger average capsule size, greater variation in cell size, and an increased production of microcells and shed capsule. We tested whether disruption of SGF29, which encodes a component of the SAGA histone acetylation complex that has previously been implicated in the hypervirulence of some lineages, also has a role in the production of morphological variants. Deletion of SGF29 in a lineage with intermediate virulence substantially increased its production of microcells and released capsule, consistent with a switch to hypervirulence. We further examined SGF29 in a set of 52 clinical isolates and found loss-of-function mutations were significantly correlated with patient death. Expansion of a TA repeat in the second intron of SGF29 was positively correlated with cell and capsule size, suggesting it also affects Sgf29 function. This study extends the evidence for a link between pleomorphism and virulence in Cryptococcus, with a likely role for epigenetic mechanisms mediated by SAGA-induced histone acetylation.
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Abstract
The SAGA complex is an evolutionarily conserved transcriptional coactivator that regulates gene expression through its histone acetyltransferase and deubiquitylase activities, recognition of specific histone modifications, and interactions with transcription factors. Multiple lines of evidence indicate the existence of distinct variants of SAGA among organisms as well as within a species, permitting diverse functions to dynamically regulate cellular pathways. Our co-expression analysis of genes encoding human SAGA components showed enrichment in reproductive organs, brain tissues and the skeletal muscle, which corresponds to their established roles in developmental programs, emerging roles in neurodegenerative diseases, and understudied functions in specific cell types. SAGA subunits modulate growth, development and response to various stresses from yeast to plants and metazoans. In metazoans, SAGA further participates in the regulation of differentiation and maturation of both innate and adaptive immune cells, and is associated with initiation and progression of diseases including a broad range of cancers. The evolutionary conservation of SAGA highlights its indispensable role in eukaryotic life, thus deciphering the mechanisms of action of SAGA is key to understanding fundamental biological processes throughout evolution. To illuminate the diversity and conservation of this essential complex, here we discuss variations in composition, essentiality and co-expression of component genes, and its prominent functions across Fungi, Plantae and Animalia kingdoms.
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Affiliation(s)
- Ying-Jiun C Chen
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, 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, Smithville, TX, USA.
- The Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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Nikolenko JV, Vdovina YA, Fefelova EI, Glukhova AA, Nabirochkina EN, Kopytova DV. [The SAGA Deubiquitinilation (DUB) Module Participates in Pol III-Dependent Transcription]. Mol Biol (Mosk) 2021; 55:500-509. [PMID: 34097684 DOI: 10.31857/s0026898421030137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 10/21/2020] [Indexed: 11/24/2022]
Abstract
SAGA, the multicomponent complex responsible for acetylation of histone N-terminal lysine residues, is involved in the transcription activation of a wide range of eukaryote genes. SAGA contains a protein module, DUB, which is responsible for histone deubiquitination. In this paper we show that the DUB module may be found within cells independently of SAGA. In the absence of" SAGA, the DUB module may be recruited to the promoters of Pol III-transcribed genes, but not to the Pol II-dependent promoters. The DUB module is required to recruit transcription factor Brfl, a subunit of the Pol III-recruiting TFIIIB complex, to the promoters of Pol III-dependent genes. The DUB-module interacts with Pol III in vivo. The DUB-module is essential for recruiting both TFIIIB complexes and PBP complexes to the promoters of Pol III-dependent genes.
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Affiliation(s)
- J V Nikolenko
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
| | - Y A Vdovina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
| | - E I Fefelova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
| | - A A Glukhova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
| | - E N Nabirochkina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
| | - D V Kopytova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia.,
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Srivastav MK, Agarwal N, Poonia P, Natarajan K. Interplay between transcriptional regulators and the SAGA chromatin modifying complex fine-tune iron homeostasis. J Biol Chem 2021; 297:100727. [PMID: 33933457 DOI: 10.1016/j.jbc.2021.100727] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/26/2021] [Accepted: 04/28/2021] [Indexed: 11/20/2022] Open
Abstract
The human fungal pathogen Candida albicans responds to iron deprivation by a global transcriptome reconfiguration known to be controlled by the transcriptional regulators Hap43 (also known as Cap2), Sef1, and the trimeric Hap2-Hap3-Hap5 complex. However, the relative roles of these regulators are not known. To dissect this system, we focused on the FRP1 and ACO1 genes, which are induced and repressed, respectively, under iron deprivation conditions. Chromatin immunoprecipitation assays showed that the trimeric HAP complex and Sef1 are recruited to both FRP1 and ACO1 promoters. While the HAP complex occupancy at the FRP1 promoter was Sef1-dependent, occupancy of Sef1 was not dependent on the HAP complex. Furthermore, iron deprivation elicited histone H3-Lys9 hyperacetylation and Pol II recruitment mediated by the trimeric HAP complex and Sef1 at the FRP1 promoter. In contrast, at the ACO1 promoter, the HAP trimeric complex and Hap43 promoted histone deacetylation and also limited Pol II recruitment under iron deprivation conditions. Mutational analysis showed that the SAGA subunits Gcn5, Spt7, and Spt20 are required for C. albicans growth in iron-deficient medium and for H3-K9 acetylation and transcription from the FRP1 promoter. Thus, the trimeric HAP complex promotes FRP1 transcription by stimulating H3K9Ac and Pol II recruitment and, along with Hap43, functions as a repressor of ACO1 by maintaining a deacetylated promoter under iron-deficient conditions. Thus, a regulatory network involving iron-responsive transcriptional regulators and the SAGA histone modifying complex functions as a molecular switch to fine-tune tight control of iron homeostasis gene expression in C. albicans.
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Cornelio-Parra DV, Goswami R, Costanzo K, Morales-Sosa P, Mohan RD. Function and regulation of the Spt-Ada-Gcn5-Acetyltransferase (SAGA) deubiquitinase module. Biochim Biophys Acta Gene Regul Mech 2020; 1864:194630. [PMID: 32911111 DOI: 10.1016/j.bbagrm.2020.194630] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 12/27/2022]
Abstract
The Spt-Ada-Gcn5 Acetyltransferase (SAGA) chromatin modifying complex is a critical regulator of gene expression and is highly conserved across species. Subunits of SAGA arrange into discrete modules with lysine aceyltransferase and deubiquitinase activities housed separately. Mutation of the SAGA deubiquitinase module can lead to substantial biological misfunction and diseases such as cancer, neurodegeneration, and blindness. Here, we review the structure and functions of the SAGA deubiquitinase module and regulatory mechanisms acting to control these.
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Helmlinger D, Papai G, Devys D, Tora L. What do the structures of GCN5-containing complexes teach us about their function? Biochim Biophys Acta Gene Regul Mech 2021; 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] [What about the content of this article? (0)] [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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Grasser KD, Rubio V, Barneche F. Multifaceted activities of the plant SAGA complex. Biochim Biophys Acta Gene Regul Mech 2020; 1864:194613. [PMID: 32745625 DOI: 10.1016/j.bbagrm.2020.194613] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/27/2020] [Accepted: 07/27/2020] [Indexed: 12/22/2022]
Abstract
From yeast to human, the Spt-Ada-GCN5-acetyltransferase (SAGA) gigantic complex modifies chromatin during RNA polymerase II initiation and elongation steps to facilitate transcription. Its enzymatic activity involves a histone acetyltransferase module (HATm) that acetylates multiple lysine residues on the N-terminal tails of histones H2B and H3 and a deubiquitination module (DUBm) that triggers co-transcriptional deubiquitination of histone H2B. With a few notable exceptions described in this review, most SAGA subunits identified in yeast and metazoa are present in plants. Studies from the last 20 years have unveiled that different SAGA subunits are involved in gene expression regulation during the plant life cycle and in response to various types of stress or environmental cues. Their functional analysis in the Arabidopsis thaliana model species is increasingly shedding light on their intrinsic properties and how they can themselves be regulated during plant adaptive responses. Recent biochemical studies have also uncovered multiple associations between plant SAGA and chromatin machineries linked to RNA Pol II transcription. Still, considerably less is known about the molecular links between SAGA or SAGA-like complexes and chromatin dynamics during transcription in Arabidopsis and other plant species. We summarize the emerging knowledge on plant SAGA complex composition and activity, with a particular focus on the best-characterized subunits from its HAT (such as GCN5) and DUB (such as UBP22) modules, and implication of these ensembles in plant development and adaptive responses.
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Affiliation(s)
- Klaus D Grasser
- Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany.
| | - Vicente Rubio
- Plant Molecular Genetics Dept., Centro Nacional de Biotecnología (CNB-CSIC), Darwin, 3, 28049 Madrid, Spain.
| | - Fredy Barneche
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France.
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15
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Makio T, Wozniak RW. Passive diffusion through nuclear pore complexes regulates levels of the yeast SAGA and SLIK coactivator complexes. J Cell Sci 2020; 133:jcs237156. [PMID: 32051285 DOI: 10.1242/jcs.237156] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 01/31/2020] [Indexed: 11/20/2022] Open
Abstract
Nuclear pore complexes (NPCs) control gene expression by regulating the bi-directional exchange of proteins and RNAs between nuclear and cytoplasmic compartments, including access of transcriptional regulators to the nucleoplasm. Here, we show that the yeast (Saccharomyces cerevisiae) nucleoporin Nup170, in addition to binding and silencing subtelomeric genes, supports transcription of genes regulated by the SAGA transcriptional activator complex. Specifically, we show that a lower amount of SAGA complex is bound to target genes in the absence of Nup170. Consistent with this observation, levels of the SAGA complex are decreased in cells lacking Nup170, while those of the SAGA-related SLIK complexes are increased. This change in the ratio of SAGA to SLIK complexes is due to increased nuclear activity of Pep4, a protease responsible for production of the SLIK complex. Further analyses of various nucleoporin mutants revealed that the increased nuclear entry of Pep4 observed in the nup170Δ mutant likely occurs as the consequence of an increase in the sieving limits of the NPC diffusion channel. On the basis of these results, we propose that changes in passive diffusion rates represent a mechanism for regulating SAGA- and SLIK complex-mediated transcriptional events.
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Affiliation(s)
- Tadashi Makio
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada, T6G 2H7
| | - Richard W Wozniak
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada, T6G 2H7
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Cloud V, Thapa A, Morales-Sosa P, Miller TM, Miller SA, Holsapple D, Gerhart PM, Momtahan E, Jack JL, Leiva E, Rapp SR, Shelton LG, Pierce RA, Martin-Brown S, Florens L, Washburn MP, Mohan RD. Ataxin-7 and Non-stop coordinate SCAR protein levels, subcellular localization, and actin cytoskeleton organization. eLife 2019; 8:e49677. [PMID: 31348003 PMCID: PMC6693919 DOI: 10.7554/elife.49677] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 07/22/2019] [Indexed: 12/18/2022] Open
Abstract
Atxn7, a subunit of SAGA chromatin remodeling complex, is subject to polyglutamine expansion at the amino terminus, causing spinocerebellar ataxia type 7 (SCA7), a progressive retinal and neurodegenerative disease. Within SAGA, the Atxn7 amino terminus anchors Non-stop, a deubiquitinase, to the complex. To understand the scope of Atxn7-dependent regulation of Non-stop, substrates of the deubiquitinase were sought. This revealed Non-stop, dissociated from Atxn7, interacts with Arp2/3 and WAVE regulatory complexes (WRC), which control actin cytoskeleton assembly. There, Non-stop countered polyubiquitination and proteasomal degradation of WRC subunit SCAR. Dependent on conserved WRC interacting receptor sequences (WIRS), Non-stop augmentation increased protein levels, and directed subcellular localization, of SCAR, decreasing cell area and number of protrusions. In vivo, heterozygous mutation of SCAR did not significantly rescue knockdown of Atxn7, but heterozygous mutation of Atxn7 rescued haploinsufficiency of SCAR.
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Affiliation(s)
- Veronica Cloud
- University of Missouri - Kansas CityKansas CityUnited States
| | - Ada Thapa
- University of Missouri - Kansas CityKansas CityUnited States
| | | | - Tayla M Miller
- University of Missouri - Kansas CityKansas CityUnited States
| | - Sara A Miller
- University of Missouri - Kansas CityKansas CityUnited States
| | | | - Paige M Gerhart
- University of Missouri - Kansas CityKansas CityUnited States
| | - Elaheh Momtahan
- University of Missouri - Kansas CityKansas CityUnited States
| | - Jarrid L Jack
- University of Missouri - Kansas CityKansas CityUnited States
| | - Edgardo Leiva
- University of Missouri - Kansas CityKansas CityUnited States
| | - Sarah R Rapp
- University of Missouri - Kansas CityKansas CityUnited States
| | | | | | | | | | - Michael P Washburn
- Stowers Institute for Medical ResearchKansas CityUnited States
- Department of Pathology and Laboratory MedicineUniversity of Kansas Medical CenterKansas CityUnited States
| | - Ryan D Mohan
- University of Missouri - Kansas CityKansas CityUnited States
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18
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Shih PY, Liao YT, Tseng YK, Deng FS, Lin CH. A Potential Antifungal Effect of Chitosan Against Candida albicans Is Mediated via the Inhibition of SAGA Complex Component Expression and the Subsequent Alteration of Cell Surface Integrity. Front Microbiol 2019; 10:602. [PMID: 30972050 PMCID: PMC6443709 DOI: 10.3389/fmicb.2019.00602] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/11/2019] [Indexed: 12/21/2022] Open
Abstract
Due to the high incidence of nosocomial Candida albicans infection, the first-line drugs for C. albicans infection have been heavily used, and the emergence of drug-resistant strains has gradually increased. Thus, a new antifungal drug or therapeutic method is needed. Chitosan, a product of chitin deacetylation, is considered to be potentially therapeutic for fungal infections because of its excellent biocompatibility, biodegradability and low toxicity. The biocidal action of chitosan against C. albicans shows great commercial potential, but the exact mechanisms underlying its antimicrobial activity are unclear. To reveal these mechanisms, mutant library screening was performed. ADA2 gene, which encodes a histone acetylation coactivator in the SAGA complex, was identified. Transmission electronic microscopy images showed that the surface of chitosan-treated ada2Δ cells was substantially disrupted and displayed an irregular morphology. Interestingly, the cell wall of ada2Δ cells was significantly thinner than that of wild-type cells, with a thickness similar to that seen in the chitosan-treated wild-type strain. Although ADA2 is required for chitosan tolerance, expression of ADA2 and several Ada2-mediated cell wall-related genes (ALS2, PGA45, and ACE2) and efflux transporter genes (MDR1 and CDR1) were significantly inhibited by chitosan. Furthermore, GCN5 encoding a SAGA complex catalytic subunit was inhibited by chitosan, and gcn5Δ cells exhibited phenotypes comparable to those of ada2Δ cells in response to chitosan and other cell surface-disrupting agents. This study demonstrated that a potential antifungal mechanism of chitosan against C. albicans operates by inhibiting SAGA complex gene expression, which decreases the protection of the cell surface against chitosan.
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Affiliation(s)
- Pei-Yu Shih
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yu-Ting Liao
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yi-Kai Tseng
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Fu-Sheng Deng
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ching-Hsuan Lin
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
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19
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Abstract
SAGA and TFIID are related transcription complexes, which were proposed to alternatively deliver TBP at different promoter classes. Recent genome-wide studies in yeast revealed that both complexes are required for the transcription of a vast majority of genes by RNA polymerase II raising new questions about the role of coactivators.
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Affiliation(s)
- Veronique Fischer
- a Institut de Génétique et de Biologie Moléculaire et Cellulaire , Illkirch , France.,b Centre National de la Recherche Scientifique , UMR7104 , Illkirch , France.,c Institut National de la Santé et de la Recherche Médicale , Illkirch , France.,d Université de Strasbourg , Illkirch , France
| | - Kenny Schumacher
- a Institut de Génétique et de Biologie Moléculaire et Cellulaire , Illkirch , France.,b Centre National de la Recherche Scientifique , UMR7104 , Illkirch , France.,c Institut National de la Santé et de la Recherche Médicale , Illkirch , France.,d Université de Strasbourg , Illkirch , France
| | - Laszlo Tora
- a Institut de Génétique et de Biologie Moléculaire et Cellulaire , Illkirch , France.,b Centre National de la Recherche Scientifique , UMR7104 , Illkirch , France.,c Institut National de la Santé et de la Recherche Médicale , Illkirch , France.,d Université de Strasbourg , Illkirch , France
| | - Didier Devys
- a Institut de Génétique et de Biologie Moléculaire et Cellulaire , Illkirch , France.,b Centre National de la Recherche Scientifique , UMR7104 , Illkirch , France.,c Institut National de la Santé et de la Recherche Médicale , Illkirch , France.,d Université de Strasbourg , Illkirch , France
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20
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Nassrallah A, Rougée M, Bourbousse C, Drevensek S, Fonseca S, Iniesto E, Ait-Mohamed O, Deton-Cabanillas AF, Zabulon G, Ahmed I, Stroebel D, Masson V, Lombard B, Eeckhout D, Gevaert K, Loew D, Genovesio A, Breyton C, De Jaeger G, Bowler C, Rubio V, Barneche F. DET1-mediated degradation of a SAGA-like deubiquitination module controls H2Bub homeostasis. eLife 2018; 7:37892. [PMID: 30192741 PMCID: PMC6128693 DOI: 10.7554/elife.37892] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 08/22/2018] [Indexed: 12/11/2022] Open
Abstract
DE-ETIOLATED 1 (DET1) is an evolutionarily conserved component of the ubiquitination machinery that mediates the destabilization of key regulators of cell differentiation and proliferation in multicellular organisms. In this study, we provide evidence from Arabidopsis that DET1 is essential for the regulation of histone H2B monoubiquitination (H2Bub) over most genes by controlling the stability of a deubiquitination module (DUBm). In contrast with yeast and metazoan DUB modules that are associated with the large SAGA complex, the Arabidopsis DUBm only comprises three proteins (hereafter named SGF11, ENY2 and UBP22) and appears to act independently as a major H2Bub deubiquitinase activity. Our study further unveils that DET1-DDB1-Associated-1 (DDA1) protein interacts with SGF11 in vivo, linking the DET1 complex to light-dependent ubiquitin-mediated proteolytic degradation of the DUBm. Collectively, these findings uncover a signaling path controlling DUBm availability, potentially adjusting H2Bub turnover capacity to the cell transcriptional status.
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Affiliation(s)
- Amr Nassrallah
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid, Spain
| | - Martin Rougée
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France.,Université Paris-Sud, Orsay, France
| | - Clara Bourbousse
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France.,Université Paris-Sud, Orsay, France
| | - Stephanie Drevensek
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Sandra Fonseca
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid, Spain
| | - Elisa Iniesto
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid, Spain
| | - Ouardia Ait-Mohamed
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Anne-Flore Deton-Cabanillas
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Gerald Zabulon
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Ikhlak Ahmed
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - David Stroebel
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Vanessa Masson
- Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, Institut Curie PSL Research University, 75005 Paris, France
| | - Berangere Lombard
- Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, Institut Curie PSL Research University, 75005 Paris, France
| | - Dominique Eeckhout
- Department of Plant Systems Biology, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Kris Gevaert
- Department of Biochemistry, Ghent University, Ghent, Belgium.,VIB Center for Medical Biotechnology, Ghent, Belgium
| | - Damarys Loew
- Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, Institut Curie PSL Research University, 75005 Paris, France
| | - Auguste Genovesio
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Cecile Breyton
- Université Grenoble Alpes, Institut de Biologie Structurale, Grenoble, France
| | - Geert De Jaeger
- Department of Plant Systems Biology, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Chris Bowler
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Vicente Rubio
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid, Spain
| | - Fredy Barneche
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
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21
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Berg MD, Genereaux J, Karagiannis J, Brandl CJ. The Pseudokinase Domain of Saccharomyces cerevisiae Tra1 Is Required for Nuclear Localization and Incorporation into the SAGA and NuA4 Complexes. G3 (Bethesda) 2018; 8:1943-1957. [PMID: 29626083 PMCID: PMC5982823 DOI: 10.1534/g3.118.200288] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/04/2018] [Indexed: 12/29/2022]
Abstract
Tra1 is an essential component of the SAGA/SLIK and NuA4 complexes in S. cerevisiae, recruiting these co-activator complexes to specific promoters. As a PIKK family member, Tra1 is characterized by a C-terminal phosphoinositide 3-kinase (PI3K) domain. Unlike other PIKK family members (e.g., Tor1, Tor2, Mec1, Tel1), Tra1 has no demonstrable kinase activity. We identified three conserved arginine residues in Tra1 that reside proximal or within the cleft between the N- and C-terminal subdomains of the PI3K domain. To establish a function for Tra1's PI3K domain and specifically the cleft region, we characterized a tra1 allele where these three arginine residues are mutated to glutamine. The half-life of the Tra1[Formula: see text] protein is reduced but its steady state level is maintained at near wild-type levels by a transcriptional feedback mechanism. The tra1[Formula: see text] allele results in slow growth under stress and alters the expression of genes also regulated by other components of the SAGA complex. Tra1[Formula: see text] is less efficiently transported to the nucleus than the wild-type protein. Likely related to this, Tra1[Formula: see text] associates poorly with SAGA/SLIK and NuA4. The ratio of Spt7SLIK to Spt7SAGA increases in the tra1[Formula: see text] strain and truncated forms of Spt20 become apparent upon isolation of SAGA/SLIK. Intragenic suppressor mutations of tra1[Formula: see text] map to the cleft region further emphasizing its importance. We propose that the PI3K domain of Tra1 is directly or indirectly important for incorporating Tra1 into SAGA and NuA4 and thus the biosynthesis and/or stability of the intact complexes.
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Affiliation(s)
- Matthew D Berg
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada N6A5C1
| | - Julie Genereaux
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada N6A5C1
| | - Jim Karagiannis
- Department of Biology, Western University, London, Ontario, Canada N6A5B7
| | - Christopher J Brandl
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada N6A5C1
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22
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Lu Z, Lu Q, Chen Y, Wu R, Huang J, Chen X, Chen D, Huang R. [Advances in Spt proteins and stress resistance of Saccharomyces cerevisiae]. Sheng Wu Gong Cheng Xue Bao 2018; 34:653-663. [PMID: 29893073 DOI: 10.13345/j.cjb.170395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Spt proteins are defined as a large family of transcription regulators of the yeast Saccharomyces cerevisiae. They are crucial components of the SAGA complex that regulates transcription through interaction with the TATA box in the upstream region of the target genes. About 10% of total gene transcriptions are related to Spt proteins and these genes are highly related to environmental stress response. Such vast regulation network and complex mechanisms have become a hotspot. Spt proteins are also important to suppress transposon-induced mutations, being a switch on regulation of transposon behaviors and adaptive evolution of Saccharomyces cerevisiae. Besides that, some Spt proteins are directly involved in regulating unsaturated lipid acids synthesis, which could remold the cell membrane to resist environmental stresses. Here, we review Spt proteins, the advances in Spt proteins study, and their potential applications in improving yeast's stress resistance through transcription regulation, transposon activity regulation and cell membrane alternation.
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Affiliation(s)
- Zhilong Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530005, Guangxi, China.,College of Life Science and Technology, Guangxi University, Nanning 530005, Guangxi, China.,National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning 530007, Guangxi, China
| | - Qi Lu
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning 530007, Guangxi, China
| | - Ying Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530005, Guangxi, China.,College of Life Science and Technology, Guangxi University, Nanning 530005, Guangxi, China.,National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning 530007, Guangxi, China
| | - Renzhi Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530005, Guangxi, China.,College of Life Science and Technology, Guangxi University, Nanning 530005, Guangxi, China.,National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning 530007, Guangxi, China
| | - Jun Huang
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning 530007, Guangxi, China
| | - Xiaoling Chen
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning 530007, Guangxi, China
| | - Dong Chen
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning 530007, Guangxi, China
| | - Ribo Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530005, Guangxi, China.,College of Life Science and Technology, Guangxi University, Nanning 530005, Guangxi, China.,National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning 530007, Guangxi, China
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23
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Jeusset LM, McManus KJ. Ubiquitin Specific Peptidase 22 Regulates Histone H2B Mono-Ubiquitination and Exhibits Both Oncogenic and Tumor Suppressor Roles in Cancer. Cancers (Basel) 2017; 9:E167. [PMID: 29210986 DOI: 10.3390/cancers9120167] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 12/03/2017] [Accepted: 12/04/2017] [Indexed: 12/19/2022] Open
Abstract
Ubiquitin-Specific Peptidase 22 (USP22) is a ubiquitin hydrolase, notably catalyzing the removal of the mono-ubiquitin moiety from histone H2B (H2Bub1). Frequent overexpression of USP22 has been observed in various cancer types and is associated with poor patient prognosis. Multiple mechanisms have been identified to explain how USP22 overexpression contributes to cancer progression, and thus, USP22 has been proposed as a novel drug target in cancer. However, gene re-sequencing data from numerous cancer types show that USP22 expression is frequently diminished, suggesting it may also harbor tumor suppressor-like properties. This review will examine the current state of knowledge on USP22 expression in cancers, describe its impact on H2Bub1 abundance and present the mechanisms through which altered USP22 expression may contribute to oncogenesis, including an emerging role for USP22 in the maintenance of genome stability in cancer. Clarifying the impact aberrant USP22 expression and abnormal H2Bub1 levels have in oncogenesis is critical before precision medicine therapies can be developed that either directly target USP22 overexpression or exploit the loss of USP22 expression in cancer cells.
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24
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Baptista T, Grünberg S, Minoungou N, Koster MJE, Timmers HTM, Hahn S, Devys D, Tora L. SAGA Is a General Cofactor for RNA Polymerase II Transcription. Mol Cell 2017; 68:130-143.e5. [PMID: 28918903 PMCID: PMC5632562 DOI: 10.1016/j.molcel.2017.08.016] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/28/2017] [Accepted: 08/18/2017] [Indexed: 12/13/2022]
Abstract
Prior studies suggested that SAGA and TFIID are alternative factors that promote RNA polymerase II transcription with about 10% of genes in S. cerevisiae dependent on SAGA. We reassessed the role of SAGA by mapping its genome-wide location and role in global transcription in budding yeast. We find that SAGA maps to the UAS elements of most genes, overlapping with Mediator binding and irrespective of previous designations of SAGA or TFIID-dominated genes. Disruption of SAGA through mutation or rapid subunit depletion reduces transcription from nearly all genes, measured by newly-synthesized RNA. We also find that the acetyltransferase Gcn5 synergizes with Spt3 to promote global transcription and that Spt3 functions to stimulate TBP recruitment at all tested genes. Our data demonstrate that SAGA acts as a general cofactor required for essentially all RNA polymerase II transcription and is not consistent with the previous classification of SAGA and TFIID-dominated genes.
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Affiliation(s)
- Tiago Baptista
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, France
| | - Sebastian Grünberg
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Nadège Minoungou
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Maria J E Koster
- Molecular Cancer Research and Stem Cell Section, Regenerative Medicine Center and Center for Molecular Medicine, University Medical Center Utrecht c/o Hubrecht Institute, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - H T Marc Timmers
- Molecular Cancer Research and Stem Cell Section, Regenerative Medicine Center and Center for Molecular Medicine, University Medical Center Utrecht c/o Hubrecht Institute, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands; German Cancer Consortium (DKTK) partner site Freiburg, German Cancer Research Center (DKFZ) and Department of Urology, Medical Center-University of Freiburg, 79106 Freiburg, Germany
| | - Steve Hahn
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Didier Devys
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, France.
| | - László Tora
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Université de Strasbourg, 67404 Illkirch, France.
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25
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Li X, Seidel CW, Szerszen LT, Lange JJ, Workman JL, Abmayr SM. Enzymatic modules of the SAGA chromatin-modifying complex play distinct roles in Drosophila gene expression and development. Genes Dev 2017; 31:1588-1600. [PMID: 28887412 PMCID: PMC5630023 DOI: 10.1101/gad.300988.117] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 08/11/2017] [Indexed: 01/03/2023]
Abstract
In this study, Li et al. demonstrate that the two enzymatic modules of the Drosophila Spt–Ada–Gcn5–acetyltransferase (SAGA) chromatin-modifying complex are differently required in oogenesis. Their findings demonstrate that loss of the histone acetyltransferase (HAT) activity blocks oogenesis, while loss of H2B deubiquitinase (DUB) activity does not, suggesting that the DUB module has functions within SAGA as well as independent functions. The Spt–Ada–Gcn5–acetyltransferase (SAGA) chromatin-modifying complex is a transcriptional coactivator that contains four different modules of subunits. The intact SAGA complex has been well characterized for its function in transcription regulation and development. However, little is known about the roles of individual modules within SAGA and whether they have any SAGA-independent functions. Here we demonstrate that the two enzymatic modules of Drosophila SAGA are differently required in oogenesis. Loss of the histone acetyltransferase (HAT) activity blocks oogenesis, while loss of the H2B deubiquitinase (DUB) activity does not. However, the DUB module regulates a subset of genes in early embryogenesis, and loss of the DUB subunits causes defects in embryogenesis. ChIP-seq (chromatin immunoprecipitation [ChIP] combined with high-throughput sequencing) analysis revealed that both the DUB and HAT modules bind most SAGA target genes even though many of these targets do not require the DUB module for expression. Furthermore, we found that the DUB module can bind to chromatin and regulate transcription independently of the HAT module. Our results suggest that the DUB module has functions within SAGA and independent functions.
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Affiliation(s)
- Xuanying Li
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.,Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | | | - Leanne T Szerszen
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Jeffrey J Lange
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Jerry L Workman
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Susan M Abmayr
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.,Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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26
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Srivastava S, Mohibi S, Mirza S, Band H, Band V. Epidermal Growth Factor Receptor activation promotes ADA3 acetylation through the AKT-p300 pathway. Cell Cycle 2017; 16:1515-1525. [PMID: 28759294 PMCID: PMC5584872 DOI: 10.1080/15384101.2017.1339846] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The ADA3 (Alteration/Deficiency in Activation 3) protein is an essential adaptor component of several Lysine Acetyltransferase (KAT) complexes involved in chromatin modifications. Previously, we and others have demonstrated a crucial role of ADA3 in cell cycle progression and in maintenance of genomic stability. Recently, we have shown that acetylation of ADA3 is key to its role in cell cycle progression. Here, we demonstrate that AKT activation downstream of Epidermal Growth Factor Receptor (EGFR) family proteins stimulation leads to phosphorylation of p300, which in turn promotes the acetylation of ADA3. Inhibition of upstream receptor tyrosine kinases (RTKs), HER1 (EGFR)/HER2 by lapatinib and the accompanying reduction of phospho-AKT levels led to a decrease in p300 phosphorylation and ADA3 protein levels. The p300/PCAF inhibitor garcinol also destabilized the ADA3 protein in a proteasome-dependent manner and an ADA3 mutant with K→R mutations exhibited a marked increase in half-life, consistent with opposite role of acetylation and ubiquitination of ADA3 on shared lysine residues. ADA3 knockdown led to cell cycle inhibitory effects, as well as apoptosis similar to those induced by lapatinib treatment of HER2+ breast cancer cells, as seen by accumulation of CDK inhibitor p27, reduction in mitotic marker pH3(S10), and a decrease in the S-phase marker PCNA, as well as the appearance of cleaved PARP. Taken together our results reveal a novel RTK-AKT-p300-ADA3 signaling pathway involved in growth factor-induced cell cycle progression.
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Affiliation(s)
- Shashank Srivastava
- a Genetics, Cell Biology and Anatomy , University of Nebraska Medical Center , Omaha , NE , USA
| | - Shakur Mohibi
- a Genetics, Cell Biology and Anatomy , University of Nebraska Medical Center , Omaha , NE , USA
| | - Sameer Mirza
- a Genetics, Cell Biology and Anatomy , University of Nebraska Medical Center , Omaha , NE , USA
| | - Hamid Band
- a Genetics, Cell Biology and Anatomy , University of Nebraska Medical Center , Omaha , NE , USA.,b Pathology & Microbiology , University of Nebraska Medical Center , Omaha , NE , USA.,c Biochemistry & Molecular Biology , College of Medicine, University of Nebraska Medical Center , Omaha , NE , USA.,d Eppley Institute for Cancer and Allied Diseases, University of Nebraska Medical Center , Omaha , NE , USA.,e Fred & Pamela Buffett Cancer Center; University of Nebraska Medical Center , Omaha , NE , USA
| | - Vimla Band
- a Genetics, Cell Biology and Anatomy , University of Nebraska Medical Center , Omaha , NE , USA.,d Eppley Institute for Cancer and Allied Diseases, University of Nebraska Medical Center , Omaha , NE , USA.,e Fred & Pamela Buffett Cancer Center; University of Nebraska Medical Center , Omaha , NE , USA
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27
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Canzonetta C, Vernarecci S, Iuliani M, Marracino C, Belloni C, Ballario P, Filetici P. SAGA DUB-Ubp8 Deubiquitylates Centromeric Histone Variant Cse4. G3 (Bethesda) 2015; 6:287-98. [PMID: 26613948 DOI: 10.1534/g3.115.024877] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Aneuploidy, the unbalanced segregation of chromosomes during cell division, is recurrent in many tumors and the cause of birth defects and genetic diseases. Centromeric chromatin represents the chromosome attachment site to the mitotic spindle, marked by specialized nucleosomes containing a specific histone variant, CEN-H3/Cse4, in yeast. Mislocalization of Cse4 outside the centromere is deleterious and may cause aberrant chromosome behavior and mitotic loss. For this reason, ubiquitylation by the E3-ubiquitin ligase Psh1 and subsequent proteolysis tightly regulates its restricted localization. Among multiproteic machineries, the SAGA complex is not merely engaged in acetylation but also directly involved in deubiquitylation. In this study, we investigated the role of SAGA-DUB’s Ubp8-driven deubiquitylation of the centromeric histone variant Cse4 in budding yeast. We found that Ubp8 works in concert with the E3-ubiquitin ligase Psh1, and that its loss causes defective deubiquitylation and the accumulation of a short ubiquitin oligomer on Cse4. We also show that lack of Ubp8 and defective deubiquitylation increase mitotic instability, cause faster Cse4 proteolysis and induce mislocalization of the centromeric histone outside the centromere. Our data provide evidence for a fundamental role of DUB-Ubp8 in deubiquitylation and the stability of the centromeric histone in budding yeast.
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28
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Abstract
The SAGA chromatin modifying complex functions as a transcriptional coactivator for a large number of genes, and SAGA dysfunction has been linked to carcinogenesis and neurodegenerative disease. The protein complex is comprised of approximately 20 subunits, arranged in a modular fashion, and includes 2 enzymatic subunits: the Gcn5 acetyltransferase and the Non-stop deubiquitinase. As we learn more about SAGA, it becomes evident that this complex functions through sophisticated mechanisms that support very precise regulation of gene expression. Here we describe recent findings in which a Drosophila loss-of-function model revealed novel mechanisms for regulation of SAGA-mediated histone H2B deubiquitination. This model also yielded novel and surprising insights into mechanisms that underlie progressive neurodegenerative disease. Lastly, we comment on the utility of Drosophila as a model for neurodegenerative disease through which crucial and conserved mechanisms may be revealed.
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Affiliation(s)
- Ryan D Mohan
- a Stowers Institute for Medical Research ; Kansas City , MO USA
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29
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Yang H, Liu S, He WT, Zhao J, Jiang LL, Hu HY. Aggregation of Polyglutamine-expanded Ataxin 7 Protein Specifically Sequesters Ubiquitin-specific Protease 22 and Deteriorates Its Deubiquitinating Function in the Spt-Ada-Gcn5-Acetyltransferase (SAGA) Complex. J Biol Chem 2015. [PMID: 26195632 DOI: 10.1074/jbc.m114.631663] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human ataxin 7 (Atx7) is a component of the deubiquitination module (DUBm) in the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex for transcriptional regulation, and expansion of its polyglutamine (polyQ) tract leads to spinocerebellar ataxia type 7. However, how polyQ expansion of Atx7 affects DUBm function remains elusive. We investigated the effects of polyQ-expanded Atx7 on ubiquitin-specific protease (USP22), an interacting partner of Atx7 functioning in deubiquitination of histone H2B. The results showed that the inclusions or aggregates formed by polyQ-expanded Atx7 specifically sequester USP22 through their interactions mediated by the N-terminal zinc finger domain of Atx7. The mutation of the zinc finger domain in Atx7 that disrupts its interaction with USP22 dramatically abolishes sequestration of USP22. Moreover, polyQ expansion of Atx7 decreases the deubiquitinating activity of USP22 and, consequently, increases the level of monoubiquitinated H2B. Therefore, we propose that polyQ-expanded Atx7 forms insoluble aggregates that sequester USP22 into a catalytically inactive state, and then the impaired DUBm loses the function to deubiquitinate monoubiquitinated histone H2B or H2A. This may result in dysfunction of the SAGA complex and transcriptional dysregulation in spinocerebellar ataxia type 7 disease.
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Affiliation(s)
- Hui Yang
- From the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. 320 Yue-Yang Road, Shanghai 200031, China
| | - Shuai Liu
- From the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. 320 Yue-Yang Road, Shanghai 200031, China
| | - Wen-Tian He
- From the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. 320 Yue-Yang Road, Shanghai 200031, China
| | - Jian Zhao
- From the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. 320 Yue-Yang Road, Shanghai 200031, China
| | - Lei-Lei Jiang
- From the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. 320 Yue-Yang Road, Shanghai 200031, China
| | - Hong-Yu Hu
- From the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. 320 Yue-Yang Road, Shanghai 200031, China
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30
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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. Front Plant Sci 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] [What about the content of this article? (0)] [Affiliation(s)] [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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31
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Elmore ZC, Beckley JR, Chen JS, Gould KL. Histone H2B ubiquitination promotes the function of the anaphase-promoting complex/cyclosome in Schizosaccharomyces pombe. G3 (Bethesda) 2014; 4:1529-38. [PMID: 24948786 DOI: 10.1534/g3.114.012625] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ubiquitination and deubiquitination of proteins are reciprocal events involved in many cellular processes, including the cell cycle. During mitosis, the metaphase to anaphase transition is regulated by the ubiquitin ligase activity of the anaphase-promoting complex/cyclosome (APC/C). Although the E3 ubiquitin ligase function of the APC/C has been well characterized, it is not clear whether deubiquitinating enzymes (DUBs) play a role in reversing APC/C substrate ubiquitination. Here we performed a genetic screen to determine what DUB, if any, antagonizes the function of the APC/C in the fission yeast Schizosaccharomyces pombe. We found that deletion of ubp8, encoding the Spt-Ada-Gcn5-Acetyl transferase (SAGA) complex associated DUB, suppressed temperature-sensitive phenotypes of APC/C mutants cut9-665, lid1-6, cut4-533, and slp1-362. Our analysis revealed that Ubp8 antagonizes APC/C function in a mechanism independent of the spindle assembly checkpoint and proteasome activity. Notably, suppression of APC/C mutants was linked to loss of Ubp8 catalytic activity and required histone H2B ubiquitination. On the basis of these data, we conclude that Ubp8 antagonizes APC/C function indirectly by modulating H2B ubiquitination status.
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32
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Mohan RD, Abmayr SM, Workman JL. Pulling complexes out of complex diseases: Spinocerebellar Ataxia 7. Rare Dis 2014; 2:e28859. [PMID: 25054097 PMCID: PMC4091419 DOI: 10.4161/rdis.28859] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/06/2014] [Accepted: 04/11/2014] [Indexed: 11/19/2022] Open
Abstract
Spinocerebellar ataxia 7 (SCA7) is an incurable disease caused by expansion of CAG trinucleotide sequences within the Ataxin-7 gene. This elongated CAG tract results in an Ataxin-7 protein bearing an expanded polyglutamine (PolyQ) repeat. SCA7 disease is characterized by progressive neural and retinal degeneration leading to ataxia and blindness. Evidence gathered from investigating SCA7 and other PolyQ diseases strongly suggest that misregulation of gene expression contributes to neurodegeneration. In fact, Ataxin-7 is a subunit of the essential Spt-Ada-Gcn5-Acetltransferase (SAGA) chromatin modifying complex that regulates expression of a large number of genes. Here we discuss recent insights into Ataxin-7 function and, considering these findings, propose a model for how polyglutamine expansion of Ataxin-7 may affect Ataxin-7 function to alter chromatin modifications and gene expression.
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Affiliation(s)
- Ryan D Mohan
- Stowers Institute for Medical Research; Kansas City, MO USA
| | - Susan M Abmayr
- Stowers Institute for Medical Research; Kansas City, MO USA
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33
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Mohan RD, Dialynas G, Weake VM, Liu J, Martin-Brown S, Florens L, Washburn MP, Workman JL, Abmayr SM. Loss of Drosophila Ataxin-7, a SAGA subunit, reduces H2B ubiquitination and leads to neural and retinal degeneration. Genes Dev 2014; 28:259-72. [PMID: 24493646 PMCID: PMC3923968 DOI: 10.1101/gad.225151.113] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The SAGA chromatin-modifying complex plays a critical role in gene regulation and has been implicated in processes such as carcinogenesis and neurodegeneration. SAGA bears both acetyltransferase and deubiquitinase activities, and Ataxin-7 anchors the deubiquitinase activity to the larger complex. Workman and colleagues now show that in contrast to yeast, loss of Drosophila Ataxin-7 results in a global reduction in H2B ubiquitination, an effect conserved in human cells. Furthermore, reduced Ataxin-7 results in neural and retinal degeneration, impaired movement, and decreased life span. The Spt–Ada–Gcn5–acetyltransferase (SAGA) chromatin-modifying complex possesses acetyltransferase and deubiquitinase activities. Within this modular complex, Ataxin-7 anchors the deubiquitinase activity to the larger complex. Here we identified and characterized Drosophila Ataxin-7 and found that reduction of Ataxin-7 protein results in loss of components from the SAGA complex. In contrast to yeast, where loss of Ataxin-7 inactivates the deubiquitinase and results in increased H2B ubiquitination, loss of Ataxin-7 results in decreased H2B ubiquitination and H3K9 acetylation without affecting other histone marks. Interestingly, the effect on ubiquitination was conserved in human cells, suggesting a novel mechanism regulating histone deubiquitination in higher organisms. Consistent with this mechanism in vivo, we found that a recombinant deubiquitinase module is active in the absence of Ataxin-7 in vitro. When we examined the consequences of reduced Ataxin-7 in vivo, we found that flies exhibited pronounced neural and retinal degeneration, impaired movement, and early lethality.
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Affiliation(s)
- Ryan D Mohan
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
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34
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Gao T, Zheng Z, Hou Y, Zhou M. Transcription factors spt3 and spt8 are associated with conidiation, mycelium growth, and pathogenicity in Fusarium graminearum. FEMS Microbiol Lett 2013; 351:42-50. [PMID: 24289742 DOI: 10.1111/1574-6968.12350] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 11/11/2013] [Accepted: 11/27/2013] [Indexed: 12/01/2022] Open
Abstract
Fusarium graminearum (teleomorph: Gibberella zeae), the dominant pathogen of Fusarium head blight (FHB) on wheat, can cause substantial economic losses. The Spt-Ada-Gcn5-acetyltransferase (SAGA) transcription coactivator plays multiple roles in regulating transcription because of the presence of functionally independent modules of subunits within the complex. The transcription factors spt3 and spt8 are components of the SAGA complex and they are important in yeasts and filamentous fungi including F. graminearum. In this study, we identified Fgspt3 and Fgspt8, homologs of Saccharomyces cerevisiae spt3 and spt8 from F. graminearum using the blastp program. The aim of the present study was to investigate the functions of Fgspt3 and Fgspt8 in F. graminearum. The deletion mutants grew significantly more slowly than the wild-type parent and did not produce conidia. Expression of the sporulation-related genes FgFlbC and FgRen1 were significantly down-regulated in the mutants. The mutants exhibited no sexual reproduction on infected wheat kernels and a 90% decrease in virulence on wheat. Pigment formation was also greatly altered in the mutants. All of the defects were restored by genetic complementation of the mutant with wild-type Fgspt3 and Fgspt8 genes. Overall, Fgspt3 and Fgspt8 are essential genes in F. graminearum.
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Affiliation(s)
- Tao Gao
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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35
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Georgakopoulos P, Lockington RA, Kelly JM. SAGA complex components and acetate repression in Aspergillus nidulans. G3 (Bethesda) 2012; 2:1357-67. [PMID: 23173087 DOI: 10.1534/g3.112.003913] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 09/05/2012] [Indexed: 11/30/2022]
Abstract
Alongside the well-established carbon catabolite repression by glucose and other sugars, acetate causes repression in Aspergillus nidulans. Mutations in creA, encoding the transcriptional repressor involved in glucose repression, also affect acetate repression, but mutations in creB or creC, encoding components of a deubiquitination system, do not. To understand the effects of acetate, we used a mutational screen that was similar to screens that uncovered mutations in creA, creB, and creC, except that glucose was replaced by acetate to identify mutations that were affected for repression by acetate but not by glucose. We uncovered mutations in acdX, homologous to the yeast SAGA component gene SPT8, which in growth tests showed derepression for acetate repression but not for glucose repression. We also made mutations in sptC, homologous to the yeast SAGA component gene SPT3, which showed a similar phenotype. We found that acetate repression is complex, and analysis of facA mutations (lacking acetyl CoA synthetase) indicates that acetate metabolism is required for repression of some systems (proline metabolism) but not for others (acetamide metabolism). Although plate tests indicated that acdX- and sptC-null mutations led to derepressed alcohol dehydrogenase activity, reverse-transcription quantitative real-time polymerase chain reaction showed no derepression of alcA or aldA but rather elevated induced levels. Our results indicate that acetate repression is due to repression via CreA together with metabolic changes rather than due to an independent regulatory control mechanism.
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