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Xu J, Zhang Z, Han K, Yang Z, Guo F. EXOSC5: a novel biomarker for poor prognosis in lung adenocarcinoma. BMC Cancer 2025; 25:681. [PMID: 40229765 PMCID: PMC11995474 DOI: 10.1186/s12885-025-14059-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2025] [Accepted: 04/01/2025] [Indexed: 04/16/2025] Open
Abstract
BACKGROUND Exosome complex gene 5 (EXOSC5), a member of the exosome complex family, is highly tumorigenic in various cancers. However, its prognostic value and underlying mechanisms in lung adenocarcinoma (LUAD) remain unclear. METHODS We analysed LUAD data from The Cancer Genome Atlas (TCGA) via bioinformatics tools. Logistic regression was used to assess the associations between clinical information and EXOSC5 expression in LUAD patients. EXOSC5 expression was validated by immunohistochemistry (IHC) and western blotting, and its functional role was investigated through gene set enrichment analysis (GSEA) and in vitro experiments. RESULTS EXOSC5 was significantly upregulated in LUAD and associated with poor prognosis. The risk model based on EXOSC5 expression outperformed the traditional staging system for prognosis prediction. EXOSC5 promoted tumor progression by regulating the cell cycle, proliferation, and immune cell infiltration. High EXOSC5 expression was correlated with resistance to anti-PD1 immunotherapy. CONCLUSION EXOSC5 is a novel oncogenic factor in LUAD that promotes tumor progression and immune evasion and may serve as a prognostic biomarker and therapeutic target.
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Affiliation(s)
- Jianxun Xu
- Affiliated Hospital of Nantong University, Nantong, China
| | - Zhengwei Zhang
- Affiliated Hospital of Nantong University, Nantong, China
| | - Keyao Han
- Affiliated Hospital of Nantong University, Nantong, China
| | - Zhen Yang
- Affiliated Hospital of Nantong University, Nantong, China.
| | - Fengmei Guo
- Affiliated Hospital of Nantong University, Nantong, China.
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Chaudhuri A, Paul S, Banerjea M, Das B. Polyadenylated versions of small non-coding RNAs in Saccharomyces cerevisiae are degraded by Rrp6p/Rrp47p independent of the core nuclear exosome. MICROBIAL CELL (GRAZ, AUSTRIA) 2024; 11:155-186. [PMID: 38783922 PMCID: PMC11115967 DOI: 10.15698/mic2024.05.823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/03/2024] [Accepted: 03/05/2024] [Indexed: 05/25/2024]
Abstract
In Saccharomyces cerevisiae, polyadenylated forms of mature (and not precursor) small non-coding RNAs (sncRNAs) those fail to undergo proper 3'-end maturation are subject to an active degradation by Rrp6p and Rrp47p, which does not require the involvement of core exosome and TRAMP components. In agreement with this finding, Rrp6p/Rrp47p is demonstrated to exist as an exosome-independent complex, which preferentially associates with mature polyadenylated forms of these sncRNAs. Consistent with this observation, a C-terminally truncated version of Rrp6p (Rrp6p-ΔC2) lacking physical association with the core nuclear exosome supports their decay just like its full-length version. Polyadenylation is catalyzed by both the canonical and non-canonical poly(A) polymerases, Pap1p and Trf4p. Analysis of the polyadenylation profiles in WT and rrp6-Δ strains revealed that the majority of the polyadenylation sites correspond to either one to three nucleotides upstream or downstream of their mature ends and their poly(A) tails ranges from 10-15 adenylate residues. Most interestingly, the accumulated polyadenylated snRNAs are functional in the rrp6-Δ strain and are assembled into spliceosomes. Thus, Rrp6p-Rrp47p defines a core nuclear exosome-independent novel RNA turnover system in baker's yeast targeting imperfectly processed polyadenylated sncRNAs that accumulate in the absence of Rrp6p.
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Affiliation(s)
- Anusha Chaudhuri
- Present Position: Zentrum fǜr Molekulare, Medizin, Institut fǜr Kardiovaskuläre Regeneration, Haus 25B, Goethe-Universität, Theodor-Stern-Kai 7, Universitätsklinikum, 60590 Frankfurt am Main, Germany
| | - Soumita Paul
- Department of Life Science and Biotechnology, Jadavpur University, 188 Raja S.C. Mullick Road, Kolkata – 700 032, West Bengal, India
| | - Mayukh Banerjea
- Department of Life Science and Biotechnology, Jadavpur University, 188 Raja S.C. Mullick Road, Kolkata – 700 032, West Bengal, India
| | - Biswadip Das
- Department of Life Science and Biotechnology, Jadavpur University, 188 Raja S.C. Mullick Road, Kolkata – 700 032, West Bengal, India
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Huang YH, Wang WL, Wang PH, Lee HT, Chang WW. EXOSC5 maintains cancer stem cell activity in endometrial cancer by regulating the NTN4/integrin β1 signalling axis. Int J Biol Sci 2024; 20:265-279. [PMID: 38164180 PMCID: PMC10750274 DOI: 10.7150/ijbs.86275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 10/31/2023] [Indexed: 01/03/2024] Open
Abstract
Endometrial carcinoma (EC) is a common type of uterine cancer in developed countries, originating from the uterine epithelium. The incidence rate of EC in Taiwan has doubled from 2005. Cancer stem cells (CSCs) are a subpopulation of cancer cells that have high tumorigenicity and play a crucial role in the malignant processes of cancer. Targeting molecules associated with CSCs is essential for effective cancer treatments. This study delves into the role of Exosome component 5 (EXOSC5) in EC. Data from The Cancer Genome Atlas suggests a correlation between high EXOSC5 mRNA expression and unfavorable EC prognosis. EXOSC5 knockdown diminished EC-CSC self-renewal and reduced expression of key cancer stemness proteins, including c-MYC and SOX2. Intriguingly, this knockdown significantly curtailed tumorigenicity and CSC frequency in EC tumor spheres. A mechanistic examination revealed a reduction in netrin4 (NTN4) levels in EXOSC5-depleted EC cells. Moreover, NTN4 treatment amplified EC cell CSC activity and, when secreted, NTN4 partnered with integrin β1, subsequently triggering the FAK/SRC axis to elevate c-MYC activity. A clear positive relation between EXOSC5 and NTN4 was evident in 93 EC tissues. In conclusion, EXOSC5 augments NTN4 expression, activating c-MYC via the integrin β1/FAK/SRC pathway, offering potential avenues for EC diagnosis and treatment.
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Affiliation(s)
- Yu-Hao Huang
- Program in Molecular Medicine, National Yang Ming Chiao Tung University and Academia Sinica, Taipei 112304, Taiwan
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung 402306, Taiwan
| | - Wen-Ling Wang
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung 402306, Taiwan
| | - Po-Hui Wang
- Institute of Medicine, Chung Shan Medical University, Taichung 402306, Taiwan
- Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital, Taichung 402306, Taiwan
- School of Medicine, Chung Shan Medical University, Taichung 402306, Taiwan
| | - Hsueh-Te Lee
- Program in Molecular Medicine, National Yang Ming Chiao Tung University and Academia Sinica, Taipei 112304, Taiwan
- Institute of Anatomy & Cell Biology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Taiwan International Graduate Program in Molecular Medicine, National Yang Ming Chiao Tung University and Academia Sinica, Taipei 115024, Taiwan
- Brain Research Center, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Wen-Wei Chang
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung 402306, Taiwan
- Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402306, Taiwan
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Genome-Wide Analysis of the RNase T2 Family and Identification of Interacting Proteins of Four ClS-RNase Genes in ‘XiangShui’ Lemon. Int J Mol Sci 2022; 23:ijms231810431. [PMID: 36142343 PMCID: PMC9499183 DOI: 10.3390/ijms231810431] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 11/29/2022] Open
Abstract
S-RNase plays vital roles in the process of self-incompatibility (SI) in Rutaceae plants. Data have shown that the rejection phenomenon during self-pollination is due to the degradation of pollen tube RNA by S-RNase. The cytoskeleton microfilaments of pollen tubes are destroyed, and other components cannot extend downwards from the stigma and, ultimately, cannot reach the ovary to complete fertilisation. In this study, four S-RNase gene sequences were identified from the ‘XiangShui’ lemon genome and ubiquitome. Sequence analysis revealed that the conserved RNase T2 domains within S-RNases in ‘XiangShui’ lemon are the same as those within other species. Expression pattern analysis revealed that S3-RNase and S4-RNase are specifically expressed in the pistils, and spatiotemporal expression analysis showed that the S3-RNase expression levels in the stigmas, styles and ovaries were significantly higher after self-pollination than after cross-pollination. Subcellular localisation analysis showed that the S1-RNase, S2-RNase, S3-RNase and S4-RNase were found to be expressed in the nucleus according to laser confocal microscopy. In addition, yeast two-hybrid (Y2H) assays showed that S3-RNase interacted with F-box, Bifunctional fucokinase/fucose pyrophosphorylase (FKGP), aspartic proteinase A1, RRP46, pectinesterase/pectinesterase inhibitor 51 (PME51), phospholipid:diacylglycerol acyltransferase 1 (PDAT1), gibberellin receptor GID1B, GDT1-like protein 4, putative invertase inhibitor, tRNA ligase, PAP15, PAE8, TIM14-2, PGIP1 and p24beta2. Moreover, S3-RNase interacted with TOPP4. Therefore, S3-RNase may play an important role in the SI of ‘XiangShui’ lemon.
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Lange H, Gagliardi D. Catalytic activities, molecular connections, and biological functions of plant RNA exosome complexes. THE PLANT CELL 2022; 34:967-988. [PMID: 34954803 PMCID: PMC8894942 DOI: 10.1093/plcell/koab310] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/16/2021] [Indexed: 05/08/2023]
Abstract
RNA exosome complexes provide the main 3'-5'-exoribonuclease activities in eukaryotic cells and contribute to the maturation and degradation of virtually all types of RNA. RNA exosomes consist of a conserved core complex that associates with exoribonucleases and with multimeric cofactors that recruit the enzyme to its RNA targets. Despite an overall high level of structural and functional conservation, the enzymatic activities and compositions of exosome complexes and their cofactor modules differ among eukaryotes. This review highlights unique features of plant exosome complexes, such as the phosphorolytic activity of the core complex, and discusses the exosome cofactors that operate in plants and are dedicated to the maturation of ribosomal RNA, the elimination of spurious, misprocessed, and superfluous transcripts, or the removal of mRNAs cleaved by the RNA-induced silencing complex and other mRNAs prone to undergo silencing.
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Affiliation(s)
- Heike Lange
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
- Author for correspondence:
| | - Dominique Gagliardi
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
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Abstract
The RNA exosome is a ribonucleolytic multiprotein complex that is conserved and essential in all eukaryotes. Although we tend to speak of "the" exosome complex, it should be more correctly viewed as several different subtypes that share a common core. Subtypes of the exosome complex are present in the cytoplasm, the nucleus and the nucleolus of all eukaryotic cells, and carry out the 3'-5' processing and/or degradation of a wide range of RNA substrates.Because the substrate specificity of the exosome complex is determined by cofactors, the system is highly adaptable, and different organisms have adjusted the machinery to their specific needs. Here, we present an overview of exosome complexes and their cofactors that have been described in different eukaryotes.
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Affiliation(s)
- Cornelia Kilchert
- Institut für Biochemie, Justus-Liebig-Universität Gießen, Gießen, Germany.
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Pan H, Pan J, Song S, Ji L, Lv H, Yang Z. EXOSC5 as a Novel Prognostic Marker Promotes Proliferation of Colorectal Cancer via Activating the ERK and AKT Pathways. Front Oncol 2019; 9:643. [PMID: 31380280 PMCID: PMC6659499 DOI: 10.3389/fonc.2019.00643] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/01/2019] [Indexed: 12/24/2022] Open
Abstract
Background and Objective: Exosome component 5 (EXOSC5) is a novel cancer-related gene that is aberrantly expressed in various malignances. However, the molecular mechanism and biological role of EXOSC5 have not been explored in colorectal cancer (CRC). In this study, we investigated the functions and mechanisms by which EXOSC5 promotes the progression of CRC. Methods: EXOSC5 expressions in CRC cell lines and paired CRC and adjacent normal tissues were measured via quantitative real-time PCR (qRT-PCR), Western blot and immunohistochemistry (IHC). In vitro experiments including colony formation, Cell Counting Kit-8 (CCK-8), and flow cytometry and in vivo tumorigenesis assay were performed to explore the effects of EXOSC5 on growth of CRC. The impacts of EXOSC5 on ERK and Akt signaling pathways were measured by Western blot. Results: The mRNA and protein expression levels of EXOSC5 were up-regulated in CRC as compared to adjacent normal tissues. IHC analysis indicated that high EXOSC5 level was positively associated with poor prognosis. EXOSC5 overexpression facilitated the growth of CRC cells, while EXOSC5 knockdown led to decreased proliferation, G1/S phase transition arrest. The oncogenic functions of EXOSC5 were associated with activation of the ERK and Akt pathways in CRC. Conclusion: EXOSC5 is overexpressed in CRC and promotes CRC growth partly through activation of ERK and Akt signaling pathways. Accordingly, EXOSC5 may be a novel oncogene, and acts as a therapeutic target, or prognostic factor for CRC.
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Affiliation(s)
- Hongda Pan
- Department of Gastric Surgery, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China.,Department of Hematology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.,Department of Gastrointestinal Surgery, Beijing Hospital, Beijing, China
| | - Jingxin Pan
- Department of Hematology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - Shibo Song
- Department of Gastrointestinal Surgery, Beijing Hospital, Beijing, China
| | - Lei Ji
- Department of Gastric Surgery, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Hong Lv
- Department of Gastric Surgery, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhangru Yang
- Department of Gastric Surgery, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
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8
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The Leishmania donovani IMPACT-like protein possesses non-specific nuclease activity. Int J Biol Macromol 2018; 119:962-973. [DOI: 10.1016/j.ijbiomac.2018.07.175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 07/22/2018] [Accepted: 07/27/2018] [Indexed: 12/22/2022]
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9
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Sikorska N, Zuber H, Gobert A, Lange H, Gagliardi D. RNA degradation by the plant RNA exosome involves both phosphorolytic and hydrolytic activities. Nat Commun 2017; 8:2162. [PMID: 29255150 PMCID: PMC5735172 DOI: 10.1038/s41467-017-02066-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 11/03/2017] [Indexed: 12/21/2022] Open
Abstract
The RNA exosome provides eukaryotic cells with an essential 3'-5' exoribonucleolytic activity, which processes or eliminates many classes of RNAs. Its nine-subunit core (Exo9) is structurally related to prokaryotic phosphorolytic exoribonucleases. Yet, yeast and animal Exo9s have lost the primordial phosphorolytic capacity and rely instead on associated hydrolytic ribonucleases for catalytic activity. Here, we demonstrate that Arabidopsis Exo9 has retained a distributive phosphorolytic activity, which contributes to rRNA maturation processes, the hallmark of exosome function. High-density mapping of 3' extremities of rRNA maturation intermediates reveals the intricate interplay between three exoribonucleolytic activities coordinated by the plant exosome. Interestingly, the analysis of RRP41 protein diversity across eukaryotes suggests that Exo9's intrinsic activity operates throughout the green lineage, and possibly in some earlier-branching non-plant eukaryotes. Our results reveal a remarkable evolutionary variation of this essential RNA degradation machine in eukaryotes.
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Affiliation(s)
- Natalia Sikorska
- IBMP, CNRS, University of Strasbourg, 12 rue du général Zimmer, 67000, Strasbourg, France
| | - Hélène Zuber
- IBMP, CNRS, University of Strasbourg, 12 rue du général Zimmer, 67000, Strasbourg, France
| | - Anthony Gobert
- IBMP, CNRS, University of Strasbourg, 12 rue du général Zimmer, 67000, Strasbourg, France
| | - Heike Lange
- IBMP, CNRS, University of Strasbourg, 12 rue du général Zimmer, 67000, Strasbourg, France
| | - Dominique Gagliardi
- IBMP, CNRS, University of Strasbourg, 12 rue du général Zimmer, 67000, Strasbourg, France.
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Chen YC, Li CL, Hsiao YY, Duh Y, Yuan HS. Structure and function of TatD exonuclease in DNA repair. Nucleic Acids Res 2014; 42:10776-85. [PMID: 25114049 PMCID: PMC4176340 DOI: 10.1093/nar/gku732] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
TatD is an evolutionarily conserved protein with thousands of homologues in all kingdoms of life. It has been suggested that TatD participates in DNA fragmentation during apoptosis in eukaryotic cells. However, the cellular functions and biochemical properties of TatD in bacterial and non-apoptotic eukaryotic cells remain elusive. Here we show that Escherichia coli TatD is a Mg(2+)-dependent 3'-5' exonuclease that prefers to digest single-stranded DNA and RNA. TatD-knockout cells are less resistant to the DNA damaging agent hydrogen peroxide, and TatD can remove damaged deaminated nucleotides from a DNA chain, suggesting that it may play a role in the H2O2-induced DNA repair. The crystal structure of the apo-form TatD and TatD bound to a single-stranded three-nucleotide DNA was determined by X-ray diffraction methods at a resolution of 2.0 and 2.9 Å, respectively. TatD has a TIM-barrel fold and the single-stranded DNA is bound at the loop region on the top of the barrel. Mutational studies further identify important conserved metal ion-binding and catalytic residues in the TatD active site for DNA hydrolysis. We thus conclude that TatD is a new class of TIM-barrel 3'-5' exonuclease that not only degrades chromosomal DNA during apoptosis but also processes single-stranded DNA during DNA repair.
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Affiliation(s)
- Yi-Chen Chen
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan, ROC
| | - Chia-Lung Li
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan, ROC
| | - Yu-Yuan Hsiao
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan, ROC
| | - Yulander Duh
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan, ROC
| | - Hanna S Yuan
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan, ROC Graduate Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei 10048, Taiwan, ROC
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Aleksandrushkina NI, Vanyushin BF. Endonucleases and apoptosis in animals. BIOCHEMISTRY (MOSCOW) 2013; 77:1436-51. [PMID: 23379520 DOI: 10.1134/s0006297912130032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Endonucleases are the main instruments of obligatory DNA degradation in apoptosis. Many endonucleases have marked processive action; initially they split DNA in chromatin into very large domains, and then they perform in it internucleosomal fragmentation of DNA followed by its hydrolysis to small fragments (oligonucleotides). During apoptosis, DNA of chromatin is attacked by many nucleases that are different in activity, specificity, and order of action. The activity of every endonuclease is regulated in the cell through its own regulatory mechanism (metal ions and other effectors, possibly also S-adenosylmethionine). Apoptosis is impossible without endonucleases as far as it leads to accumulation of unnecessary (defective) DNA, disorders in cell differentiation, embryogenesis, the organism's development, and is accompanied by various severe diseases. The interpretation of the structure and functions of endonucleases and of the nature and action of their modulating effectors is important not only for elucidation of mechanisms of apoptosis, but also for regulation and control of programmed cell death, cell differentiation, and development of organisms.
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Affiliation(s)
- N I Aleksandrushkina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
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Kiss DL, Andrulis ED. The exozyme model: a continuum of functionally distinct complexes. RNA (NEW YORK, N.Y.) 2011; 17:1-13. [PMID: 21068185 PMCID: PMC3004051 DOI: 10.1261/rna.2364811] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Exosome complexes are composed of 10 to 11 subunits and are involved in multiple facets of 3' → 5' RNA processing and turnover. The current paradigm stipulates that a uniform, stoichiometric core exosome, composed of single copies of each subunit, carries out all RNA metabolic functions in vivo. While core composition is well established in vitro, available genetic, cell biological, proteomic, and transcriptomic data raise questions about whether individual subunits contribute to RNA metabolic functions exclusively within the complex. Here, we recount the current understanding of the core exosome model and show predictions of the core model that are not satisfied by the available evidence. To resolve this discrepancy, we propose the exozyme hypothesis, a novel model stipulating that while exosome subunits can and do carry out certain functions within the core, subsets of exosome subunits and cofactors also assemble into a continuum of compositionally distinct complexes--exozymes--with different RNA specificities. The exozyme model is consistent with all published data and provides a new framework for understanding the general mechanisms and regulation of RNA processing and turnover.
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Affiliation(s)
- Daniel L Kiss
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4960, USA
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