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Zhang Z, Yu H, Yao W, Zhu N, Miao R, Liu Z, Song X, Xue C, Cai C, Cheng M, Lin K, Qi D. RRP9 promotes gemcitabine resistance in pancreatic cancer via activating AKT signaling pathway. Cell Commun Signal 2022; 20:188. [PMID: 36434608 PMCID: PMC9700947 DOI: 10.1186/s12964-022-00974-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 09/18/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Pancreatic cancer (PC) is a highly lethal malignancy regarding digestive system, which is the fourth leading factor of cancer-related mortalities in the globe. Prognosis is poor due to diagnosis at advanced disease stage, low rates of surgical resection, and resistance to traditional radiotherapy and chemotherapy. In order to develop novel therapeutic strategies, further elucidation of the molecular mechanisms underlying PC chemoresistance is required. Ribosomal RNA biogenesis has been implicated in tumorigenesis. Small nucleolar RNAs (snoRNAs) is responsible for post-transcriptional modifications of ribosomal RNAs during biogenesis, which have been identified as potential markers of various cancers. Here, we investigate the U3 snoRNA-associated protein RRP9/U3-55 K along with its role in the development of PC and gemcitabine resistance. METHODS qRT-PCR, western blot and immunohistochemical staining assays were employed to detect RRP9 expression in human PC tissue samples and cell lines. RRP9-overexpression and siRNA-RRP9 plasmids were constructed to test the effects of RRP9 overexpression and knockdown on cell viability investigated by MTT assay, colony formation, and apoptosis measured by FACS and western blot assays. Immunoprecipitation and immunofluorescence staining were utilized to demonstrate a relationship between RRP9 and IGF2BP1. A subcutaneous xenograft tumor model was elucidated in BALB/c nude mice to examine the RRP9 role in PC in vivo. RESULTS Significantly elevated RRP9 expression was observed in PC tissues than normal tissues, which was negatively correlated with patient prognosis. We found that RRP9 promoted gemcitabine resistance in PC in vivo and in vitro. Mechanistically, RRP9 activated AKT signaling pathway through interacting with DNA binding region of IGF2BP1 in PC cells, thereby promoting PC progression, and inducing gemcitabine resistance through a reduction in DNA damage and inhibition of apoptosis. Treatment with a combination of the AKT inhibitor MK-2206 and gemcitabine significantly inhibited tumor proliferation induced by overexpression of RRP9 in vitro and in vivo. CONCLUSIONS Our data reveal that RRP9 has a critical function to induce gemcitabine chemoresistance in PC through the IGF2BP1/AKT signaling pathway activation, which might be a candidate to sensitize PC cells to gemcitabine. Video abstract.
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Affiliation(s)
- Zhiqi Zhang
- grid.24516.340000000123704535Department of Hepatic-Biliary-Pancreatic Surgery, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, No.1279 Sanmen Road, Hongkou District, Shanghai, 200434 China
| | - Haitao Yu
- grid.415468.a0000 0004 1761 4893Intensive Care Unit, Qingdao Municipal Hospital, Qingdao, 266001 Shandong Province China
| | - Wenyan Yao
- grid.24516.340000000123704535Department of Hepatic-Biliary-Pancreatic Surgery, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, No.1279 Sanmen Road, Hongkou District, Shanghai, 200434 China
| | - Na Zhu
- grid.24516.340000000123704535Department of Hepatic-Biliary-Pancreatic Surgery, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, No.1279 Sanmen Road, Hongkou District, Shanghai, 200434 China
| | - Ran Miao
- grid.24516.340000000123704535Department of Hepatic-Biliary-Pancreatic Surgery, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, No.1279 Sanmen Road, Hongkou District, Shanghai, 200434 China
| | - Zhiquan Liu
- grid.24516.340000000123704535Department of Hepatic-Biliary-Pancreatic Surgery, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, No.1279 Sanmen Road, Hongkou District, Shanghai, 200434 China
| | - Xuwei Song
- grid.24516.340000000123704535Department of Hepatic-Biliary-Pancreatic Surgery, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, No.1279 Sanmen Road, Hongkou District, Shanghai, 200434 China
| | - Chunhua Xue
- grid.24516.340000000123704535Department of Hepatic-Biliary-Pancreatic Surgery, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, No.1279 Sanmen Road, Hongkou District, Shanghai, 200434 China
| | - Cheng Cai
- grid.24516.340000000123704535Department of Hepatic-Biliary-Pancreatic Surgery, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, No.1279 Sanmen Road, Hongkou District, Shanghai, 200434 China
| | - Ming Cheng
- grid.24516.340000000123704535Department of Hepatic-Biliary-Pancreatic Surgery, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, No.1279 Sanmen Road, Hongkou District, Shanghai, 200434 China
| | - Ke Lin
- grid.203458.80000 0000 8653 0555Intensive Care Unit, University-Town Hospital of Chongqing Medical University, Chongqing, 401331 China
| | - Dachuan Qi
- grid.24516.340000000123704535Department of Hepatic-Biliary-Pancreatic Surgery, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, No.1279 Sanmen Road, Hongkou District, Shanghai, 200434 China
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Telomere and Telomerase-Associated Proteins in Endometrial Carcinogenesis and Cancer-Associated Survival. Int J Mol Sci 2022; 23:ijms23020626. [PMID: 35054812 PMCID: PMC8775816 DOI: 10.3390/ijms23020626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 12/29/2021] [Accepted: 12/31/2021] [Indexed: 12/30/2022] Open
Abstract
Risk of relapse of endometrial cancer (EC) after surgical treatment is 13% and recurrent disease carries a poor prognosis. Research into prognostic indicators is essential to improve EC management and outcome. "Immortality" of most cancer cells is dependent on telomerase, but the role of associated proteins in the endometrium is poorly understood. The Cancer Genome Atlas data highlighted telomere/telomerase associated genes (TTAGs) with prognostic relevance in the endometrium, and a recent in silico study identified a group of TTAGs and proteins as key regulators within a network of dysregulated genes in EC. We characterise relevant telomere/telomerase associated proteins (TTAPs) NOP10, NHP2, NOP56, TERF1, TERF2 and TERF2IP in the endometrium using quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC). qPCR data demonstrated altered expression of multiple TTAPs; specifically, increased NOP10 (p = 0.03) and reduced NHP2 (p = 0.01), TERF2 (p = 0.01) and TERF2IP (p < 0.003) in EC relative to post-menopausal endometrium. Notably, we report reduced NHP2 in EC compared to post-menopausal endometrium in qPCR and IHC (p = 0.0001) data; with survival analysis indicating high immunoscore is favourable in EC (p = 0.0006). Our findings indicate a potential prognostic role for TTAPs in EC, particularly NHP2. Further evaluation of the prognostic and functional role of the examined TTAPs is warranted to develop novel treatment strategies.
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Baldini L, Charpentier B, Labialle S. Emerging Data on the Diversity of Molecular Mechanisms Involving C/D snoRNAs. Noncoding RNA 2021; 7:ncrna7020030. [PMID: 34066559 PMCID: PMC8162545 DOI: 10.3390/ncrna7020030] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 12/15/2022] Open
Abstract
Box C/D small nucleolar RNAs (C/D snoRNAs) represent an ancient family of small non-coding RNAs that are classically viewed as housekeeping guides for the 2′-O-methylation of ribosomal RNA in Archaea and Eukaryotes. However, an extensive set of studies now argues that they are involved in mechanisms that go well beyond this function. Here, we present these pieces of evidence in light of the current comprehension of the molecular mechanisms that control C/D snoRNA expression and function. From this inventory emerges that an accurate description of these activities at a molecular level is required to let the snoRNA field enter in a second age of maturity.
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Affiliation(s)
| | - Bruno Charpentier
- Correspondence: (B.C.); (S.L.); Tel.: +33-3-72-74-66-27 (B.C.); +33-3-72-74-66-51 (S.L.)
| | - Stéphane Labialle
- Correspondence: (B.C.); (S.L.); Tel.: +33-3-72-74-66-27 (B.C.); +33-3-72-74-66-51 (S.L.)
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4
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Lemus-Diaz N, Ferreira RR, Bohnsack KE, Gruber J, Bohnsack MT. The human box C/D snoRNA U3 is a miRNA source and miR-U3 regulates expression of sortin nexin 27. Nucleic Acids Res 2020; 48:8074-8089. [PMID: 32609813 PMCID: PMC7430653 DOI: 10.1093/nar/gkaa549] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 05/29/2020] [Accepted: 06/22/2020] [Indexed: 02/06/2023] Open
Abstract
MicroRNAs (miRNAs) are important regulators of eukaryotic gene expression and their dysfunction is often associated with cancer. Alongside the canonical miRNA biogenesis pathway involving stepwise processing and export of pri- and pre-miRNA transcripts by the microprocessor complex, Exportin 5 and Dicer, several alternative mechanisms of miRNA production have been described. Here, we reveal that the atypical box C/D snoRNA U3, which functions as a scaffold during early ribosome assembly, is a miRNA source. We show that a unique stem-loop structure in the 5' domain of U3 is processed to form short RNA fragments that associate with Argonaute. miR-U3 production is independent of Drosha, and an increased amount of U3 in the cytoplasm in the absence of Dicer suggests that a portion of the full length snoRNA is exported to the cytoplasm where it is efficiently processed into miRNAs. Using reporter assays, we demonstrate that miR-U3 can act as a low proficiency miRNA in vivo and our data support the 3' UTR of the sortin nexin SNX27 mRNA as an endogenous U3-derived miRNA target. We further reveal that perturbation of U3 snoRNP assembly induces miR-U3 production, highlighting potential cross-regulation of target mRNA expression and ribosome production.
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Affiliation(s)
- Nicolas Lemus-Diaz
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
- Junior Research Group Medical RNA Biology, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Rafael Rinaldi Ferreira
- Junior Research Group Medical RNA Biology, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Jens Gruber
- Junior Research Group Medical RNA Biology, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
- Göttingen Center for Molecular Biosciences, Georg-August University, Göttingen, Justus-von-Liebig-Weg 11, 37077 Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC)
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5
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Clerget G, Bourguignon-Igel V, Marmier-Gourrier N, Rolland N, Wacheul L, Manival X, Charron C, Kufel J, Méreau A, Senty-Ségault V, Tollervey D, Lafontaine DLJ, Branlant C, Rederstorff M. Synergistic defects in pre-rRNA processing from mutations in the U3-specific protein Rrp9 and U3 snoRNA. Nucleic Acids Res 2020; 48:3848-3868. [PMID: 31996908 PMCID: PMC7144924 DOI: 10.1093/nar/gkaa066] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 01/17/2020] [Accepted: 01/22/2020] [Indexed: 01/24/2023] Open
Abstract
U3 snoRNA and the associated Rrp9/U3-55K protein are essential for 18S rRNA production by the SSU-processome complex. U3 and Rrp9 are required for early pre-rRNA cleavages at sites A0, A1 and A2, but the mechanism remains unclear. Substitution of Arg 289 in Rrp9 to Ala (R289A) specifically reduced cleavage at sites A1 and A2. Surprisingly, R289 is located on the surface of the Rrp9 β-propeller structure opposite to U3 snoRNA. To understand this, we first characterized the protein-protein interaction network of Rrp9 within the SSU-processome. This identified a direct interaction between the Rrp9 β-propeller domain and Rrp36, the strength of which was reduced by the R289A substitution, implicating this interaction in the observed processing phenotype. The Rrp9 R289A mutation also showed strong synergistic negative interactions with mutations in U3 that destabilize the U3/pre-rRNA base-pair interactions or reduce the length of their linking segments. We propose that the Rrp9 β-propeller and U3/pre-rRNA binding cooperate in the structure or stability of the SSU-processome. Additionally, our analysis of U3 variants gave insights into the function of individual segments of the 5′-terminal 72-nt sequence of U3. We interpret these data in the light of recently reported SSU-processome structures.
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Affiliation(s)
| | | | | | | | - Ludivine Wacheul
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S/FNRS), Université Libre de Bruxelles (ULB), and Center for Microscopy and Molecular Imaging (CMMI), B-6041 Charleroi-Gosselies, Belgium
| | - Xavier Manival
- Université de Lorraine, CNRS, IMoPA, F-54000 Nancy, France
| | | | - Joanna Kufel
- Wellcome Center for Cell Biology, University of Edinburgh, Scotland, UK
| | - Agnès Méreau
- Université de Lorraine, CNRS, IMoPA, F-54000 Nancy, France
| | | | - David Tollervey
- Wellcome Center for Cell Biology, University of Edinburgh, Scotland, UK
| | - Denis L J Lafontaine
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S/FNRS), Université Libre de Bruxelles (ULB), and Center for Microscopy and Molecular Imaging (CMMI), B-6041 Charleroi-Gosselies, Belgium
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Gaviraghi M, Vivori C, Tonon G. How Cancer Exploits Ribosomal RNA Biogenesis: A Journey beyond the Boundaries of rRNA Transcription. Cells 2019; 8:cells8091098. [PMID: 31533350 PMCID: PMC6769540 DOI: 10.3390/cells8091098] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/13/2019] [Accepted: 09/15/2019] [Indexed: 02/06/2023] Open
Abstract
The generation of new ribosomes is a coordinated process essential to sustain cell growth. As such, it is tightly regulated according to cell needs. As cancer cells require intense protein translation to ensure their enhanced growth rate, they exploit various mechanisms to boost ribosome biogenesis. In this review, we will summarize how oncogenes and tumor suppressors modulate the biosynthesis of the RNA component of ribosomes, starting from the description of well-characterized pathways that converge on ribosomal RNA transcription while including novel insights that reveal unexpected regulatory networks hacked by cancer cells to unleash ribosome production.
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Affiliation(s)
- Marco Gaviraghi
- Experimental Imaging Center; Ospedale San Raffaele, 20132 Milan, Italy.
- Functional Genomics of Cancer Unit, Division of Experimental Oncology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, 20132 Milan, Italy.
| | - Claudia Vivori
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, 08003 Barcelona, Spain.
| | - Giovanni Tonon
- Functional Genomics of Cancer Unit, Division of Experimental Oncology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, 20132 Milan, Italy.
- Center for Translational Genomics and Bioinformatics, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, 20132 Milan, Italy.
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7
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Sloan KE, Knox AA, Wells GR, Schneider C, Watkins NJ. Interactions and activities of factors involved in the late stages of human 18S rRNA maturation. RNA Biol 2019; 16:196-210. [PMID: 30638116 PMCID: PMC6380343 DOI: 10.1080/15476286.2018.1564467] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Ribosome production is an essential cellular process involving a plethora of trans-acting factors, such as nucleases, methyltransferases, RNA helicases and kinases that catalyse key maturation steps. Precise temporal and spatial regulation of such enzymes is essential to ensure accurate and efficient subunit assembly. Here, we focus on the maturation of the 3ʹ end of the 18S rRNA in human cells. We reveal that human RIO2 is an active kinase that phosphorylates both itself and the rRNA methyltransferase DIM1 in vitro. In contrast to yeast, our data confirm that human DIM1 predominantly acts in the nucleus and we further demonstrate that the 21S pre-rRNA is the main target for DIM1-catalysed methylation. We show that the PIN domain of the endonuclease NOB1 is required for site 3 cleavage, while the zinc ribbon domain is essential for pre-40S recruitment. Furthermore, we also demonstrate that NOB1, PNO1 and DIM1 bind to a region of the pre-rRNA encompassing the 3ʹ end of 18S and the start of ITS1, in vitro. Interestingly, NOB1 is present in the cell at higher levels than other pre-40S factors. We provide evidence that NOB1 is multimeric within the cell and show that NOB1 multimerisation is lost when ribosome biogenesis is blocked. Taken together, our data indicate a dynamic interplay of key factors associated with the 3ʹ end of the 18S rRNA during human pre-40S biogenesis and highlight potential mechanisms by which this process can be regulated.
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Affiliation(s)
- Katherine Elizabeth Sloan
- a Institute for Cell and Molecular Biosciences, The Medical School , Newcastle University , Newcastle upon Tyne , UK.,b Department of Molecular Biology , University Medical Centre, Goettingen , Goettingen , Germany
| | - Andrew Alexander Knox
- a Institute for Cell and Molecular Biosciences, The Medical School , Newcastle University , Newcastle upon Tyne , UK
| | - Graeme Raymond Wells
- a Institute for Cell and Molecular Biosciences, The Medical School , Newcastle University , Newcastle upon Tyne , UK
| | - Claudia Schneider
- a Institute for Cell and Molecular Biosciences, The Medical School , Newcastle University , Newcastle upon Tyne , UK
| | - Nicholas James Watkins
- a Institute for Cell and Molecular Biosciences, The Medical School , Newcastle University , Newcastle upon Tyne , UK
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Rothé B, Manival X, Rolland N, Charron C, Senty-Ségault V, Branlant C, Charpentier B. Implication of the box C/D snoRNP assembly factor Rsa1p in U3 snoRNP assembly. Nucleic Acids Res 2017; 45:7455-7473. [PMID: 28505348 PMCID: PMC5499572 DOI: 10.1093/nar/gkx424] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 05/02/2017] [Indexed: 01/23/2023] Open
Abstract
The U3 box C/D snoRNA is one key element of 90S pre-ribosome. It contains a 5΄ domain pairing with pre-rRNA and the U3B/C and U3C΄/D motifs for U3 packaging into a unique small nucleolar ribonucleoprotein particle (snoRNP). The RNA-binding protein Snu13/SNU13 nucleates on U3B/C the assembly of box C/D proteins Nop1p/FBL and Nop56p/NOP56, and the U3-specific protein Rrp9p/U3-55K. Snu13p/SNU13 has a much lower affinity for U3C΄/D but nevertheless forms on this motif an RNP with box C/D proteins Nop1p/FBL and Nop58p/NOP58. In this study, we characterized the influence of the RNP assembly protein Rsa1 in the early steps of U3 snoRNP biogenesis in yeast and we propose a refined model of U3 snoRNP biogenesis. While recombinant Snu13p enhances the binding of Rrp9p to U3B/C, we observed that Rsa1p has no effect on this activity but forms with Snu13p and Rrp9p a U3B/C pre-RNP. In contrast, we found that Rsa1p enhances Snu13p binding on U3C΄/D. RNA footprinting experiments indicate that this positive effect most likely occurs by direct contacts of Rsa1p with the U3 snoRNA 5΄ domain. In light of the recent U3 snoRNP cryo-EM structures, our data suggest that Rsa1p has a dual role by also preventing formation of a pre-mature functional U3 RNP.
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Affiliation(s)
- Benjamin Rothé
- Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, BP 20199, 54505 Vandœuvre-lès-Nancy, France
| | - Xavier Manival
- Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, BP 20199, 54505 Vandœuvre-lès-Nancy, France
| | - Nicolas Rolland
- Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, BP 20199, 54505 Vandœuvre-lès-Nancy, France
| | - Christophe Charron
- Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, BP 20199, 54505 Vandœuvre-lès-Nancy, France
| | - Véronique Senty-Ségault
- Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, BP 20199, 54505 Vandœuvre-lès-Nancy, France
| | - Christiane Branlant
- Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, BP 20199, 54505 Vandœuvre-lès-Nancy, France
| | - Bruno Charpentier
- Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, BP 20199, 54505 Vandœuvre-lès-Nancy, France
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9
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Chen S, Blank MF, Iyer A, Huang B, Wang L, Grummt I, Voit R. SIRT7-dependent deacetylation of the U3-55k protein controls pre-rRNA processing. Nat Commun 2016; 7:10734. [PMID: 26867678 PMCID: PMC4754350 DOI: 10.1038/ncomms10734] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 01/15/2016] [Indexed: 01/20/2023] Open
Abstract
SIRT7 is an NAD+-dependent protein deacetylase with important roles in ribosome biogenesis and cell proliferation. Previous studies have established that SIRT7 is associated with RNA polymerase I, interacts with pre-ribosomal RNA (rRNA) and promotes rRNA synthesis. Here we show that SIRT7 is also associated with small nucleolar RNP (snoRNPs) that are involved in pre-rRNA processing and rRNA maturation. Knockdown of SIRT7 impairs U3 snoRNA dependent early cleavage steps that are necessary for generation of 18S rRNA. Mechanistically, SIRT7 deacetylates U3-55k, a core component of the U3 snoRNP complex, and reversible acetylation of U3-55k modulates the association of U3-55k with U3 snoRNA. Deacetylation by SIRT7 enhances U3-55k binding to U3 snoRNA, which is a prerequisite for pre-rRNA processing. Under stress conditions, SIRT7 is released from nucleoli, leading to hyperacetylation of U3-55k and attenuation of pre-rRNA processing. The results reveal a multifaceted role of SIRT7 in ribosome biogenesis, regulating both transcription and processing of rRNA. SIRT7 is a protein deacetylase with important roles in rRNA synthesis, ribosome biogenesis and cell proliferation. Here the authors show a role of SIRT7 in rRNA maturation via deacetylation of U3-55k, a core component of the U3 snoRNP complex.
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Affiliation(s)
- Sifan Chen
- Division of Molecular Biology of the Cell II, German Cancer Research Center, DKFZ-ZMBH Alliance, Im Neuenheimer Fed 581, 69120 Heidelberg, Germany
| | - Maximilian Felix Blank
- Division of Molecular Biology of the Cell II, German Cancer Research Center, DKFZ-ZMBH Alliance, Im Neuenheimer Fed 581, 69120 Heidelberg, Germany
| | - Aishwarya Iyer
- Division of Molecular Biology of the Cell II, German Cancer Research Center, DKFZ-ZMBH Alliance, Im Neuenheimer Fed 581, 69120 Heidelberg, Germany
| | - Bingding Huang
- Division of Theoretical Bioinformatics, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Lin Wang
- Genomics and Proteomics Core Facility, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Ingrid Grummt
- Division of Molecular Biology of the Cell II, German Cancer Research Center, DKFZ-ZMBH Alliance, Im Neuenheimer Fed 581, 69120 Heidelberg, Germany
| | - Renate Voit
- Division of Molecular Biology of the Cell II, German Cancer Research Center, DKFZ-ZMBH Alliance, Im Neuenheimer Fed 581, 69120 Heidelberg, Germany
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10
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Schröder A, Rohrbeck A, Just I, Pich A. Proteome Alterations of Hippocampal Cells Caused by Clostridium botulinum C3 Exoenzyme. J Proteome Res 2015; 14:4721-33. [PMID: 26393427 DOI: 10.1021/acs.jproteome.5b00591] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
C3bot from Clostridium botulinum is a bacterial mono-ADP-ribosylating enzyme, which transfers an ADP-ribose moiety onto the small GTPases Rho A/B/C. C3bot and the catalytic inactive mutant (C3E174Q) cause axonal and dendritic growth as well as branching in primary hippocampal neurons. In cultured murine hippocampal HT22 cells, protein abundances were analyzed in response to C3bot or C3E174Q treatment using a shotgun proteomics approach. Proteome analyses were performed at four time points over 6 days. More than 4000 protein groups were identified at each time point and quantified in triplicate analyses. On day one, 46 proteins showed an altered abundance, and after 6 days, more than 700 proteins responded to C3bot with an up- or down-regulation. In contrast, C3E174Q had no provable impact on protein abundance. Protein quantification was verified for several proteins by multiple reaction monitoring. Data analysis of altered proteins revealed different cellular processes that were affected by C3bot. They are particularly involved in mitochondrial and lysosomal processes, adhesion, carbohydrate and glucose metabolism, signal transduction, and nuclear proteins of translation and ribosome biogenesis. The results of this study gain novel insights into the function of C3bot in hippocampal cells.
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Affiliation(s)
- Anke Schröder
- Institute of Toxicology, Hannover Medical School , Carl-Neuberg-Str.1, 30625 Hannover, Germany
| | - Astrid Rohrbeck
- Institute of Toxicology, Hannover Medical School , Carl-Neuberg-Str.1, 30625 Hannover, Germany
| | - Ingo Just
- Institute of Toxicology, Hannover Medical School , Carl-Neuberg-Str.1, 30625 Hannover, Germany
| | - Andreas Pich
- Institute of Toxicology, Hannover Medical School , Carl-Neuberg-Str.1, 30625 Hannover, Germany
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11
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Sloan KE, Bohnsack MT, Schneider C, Watkins NJ. The roles of SSU processome components and surveillance factors in the initial processing of human ribosomal RNA. RNA (NEW YORK, N.Y.) 2014; 20:540-50. [PMID: 24550520 PMCID: PMC3964915 DOI: 10.1261/rna.043471.113] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 12/19/2013] [Indexed: 05/19/2023]
Abstract
During eukaryotic ribosome biogenesis, three of the mature ribosomal (r)RNAs are released from a single precursor transcript (pre-rRNA) by an ordered series of endonucleolytic cleavages and exonucleolytic processing steps. Production of the 18S rRNA requires the removal of the 5' external transcribed spacer (5'ETS) by endonucleolytic cleavages at sites A0 and A1/site 1. In metazoans, an additional cleavage in the 5'ETS, at site A', upstream of A0, has also been reported. Here, we have investigated how A' processing is coordinated with assembly of the early preribosomal complex. We find that only the tUTP (UTP-A) complex is critical for A' cleavage, while components of the bUTP (UTP-B) and U3 snoRNP are important, but not essential, for efficient processing at this site. All other factors involved in the early stages of 18S rRNA processing that were tested here function downstream from this processing step. Interestingly, we show that the RNA surveillance factors XRN2 and MTR4 are also involved in A' cleavage in humans. A' cleavage is largely bypassed when XRN2 is depleted, and we also discover that A' cleavage is not always the initial processing event in all cell types. Together, our data suggest that A' cleavage is not a prerequisite for downstream pre-rRNA processing steps and may, in fact, represent a quality control step for initial pre-rRNA transcripts. Furthermore, we show that components of the RNA surveillance machinery, including the exosome and TRAMP complexes, also play key roles in the recycling of excised spacer fragments and degradation of aberrant pre-rRNAs in human cells.
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Affiliation(s)
- Katherine E. Sloan
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
- Centre for Biochemistry and Molecular Cell Biology, Georg-August University, 37073 Göttingen, Germany
| | - Markus T. Bohnsack
- Centre for Biochemistry and Molecular Cell Biology, Georg-August University, 37073 Göttingen, Germany
| | - Claudia Schneider
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Nicholas J. Watkins
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
- Corresponding authorE-mail
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12
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Srivastava A, Ahamad J, Ray AK, Kaur D, Bhattacharya A, Bhattacharya S. Analysis of U3 snoRNA and small subunit processome components in the parasitic protist Entamoeba histolytica. Mol Biochem Parasitol 2014; 193:82-92. [PMID: 24631428 DOI: 10.1016/j.molbiopara.2014.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 02/27/2014] [Accepted: 03/01/2014] [Indexed: 10/25/2022]
Abstract
In the early branching parasitic protist Entamoeba histolytica, pre-rRNA synthesis continues when cells are subjected to growth stress, but processing slows down and unprocessed pre-rRNA accumulates. To gain insight into the regulatory mechanisms leading to accumulation, it is necessary to define the pre-rRNA processing machinery in E. histolytica. We searched the E. histolytica genome sequence for homologs of the SSU processome, which contains the U3snoRNA, and 72 proteins in yeast. We could identify 57 of the proteins with high confidence. Of the rest, 6 were absent in human, and 4 were non-essential in yeast. The remaining 5 were absent in other parasite genomes as well. Analysis of U3snoRNA showed that the E. histolytica U3snoRNA adopted the same conserved secondary structure as seen in yeast and human. The predicted structure was verified by chemical modification followed by primer extension (SHAPE). Further we showed that the predicted interactions of Eh_U3snoRNA boxes A and A' with pre-18S rRNA were highly conserved both in position and sequence. The predicted interactions of 5'-hinge and 3'-hinge sequences of Eh_U3 snoRNA with the 5'-ETS sequences were conserved in position but not in sequence. Transcription of selected genes of SSU processome was tested by northern analysis, and transcripts of predicted sizes were obtained. During serum starvation, when unprocessed pre-RNA accumulated, the transcript levels of some of these genes declined. This is the first report on pre-rRNA processing machinery in E. histolytica, and shows that the components are well conserved with respect to yeast and human.
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Affiliation(s)
- Ankita Srivastava
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
| | - Jamaluddin Ahamad
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
| | - Ashwini Kumar Ray
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
| | - Devinder Kaur
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
| | - Alok Bhattacharya
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
| | - Sudha Bhattacharya
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
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13
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Burger K, Mühl B, Rohrmoser M, Coordes B, Heidemann M, Kellner M, Gruber-Eber A, Heissmeyer V, Strässer K, Eick D. Cyclin-dependent kinase 9 links RNA polymerase II transcription to processing of ribosomal RNA. J Biol Chem 2013; 288:21173-21183. [PMID: 23744076 DOI: 10.1074/jbc.m113.483719] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ribosome biogenesis is a process required for cellular growth and proliferation. Processing of ribosomal RNA (rRNA) is highly sensitive to flavopiridol, a specific inhibitor of cyclin-dependent kinase 9 (Cdk9). Cdk9 has been characterized as the catalytic subunit of the positive transcription elongation factor b (P-TEFb) of RNA polymerase II (RNAPII). Here we studied the connection between RNAPII transcription and rRNA processing. We show that inhibition of RNAPII activity by α-amanitin specifically blocks processing of rRNA. The block is characterized by accumulation of 3' extended unprocessed 47 S rRNAs and the entire inhibition of other 47 S rRNA-specific processing steps. The transcription rate of rRNA is moderately reduced after inhibition of Cdk9, suggesting that defective 3' processing of rRNA negatively feeds back on RNAPI transcription. Knockdown of Cdk9 caused a strong reduction of the levels of RNAPII-transcribed U8 small nucleolar RNA, which is essential for 3' rRNA processing in mammalian cells. Our data demonstrate a pivotal role of Cdk9 activity for coupling of RNAPII transcription with small nucleolar RNA production and rRNA processing.
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Affiliation(s)
- Kaspar Burger
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Bastian Mühl
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Michaela Rohrmoser
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Britta Coordes
- Gene Center and Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig Maximilians University of Munich, Feodor-Lynen-Strasse 25, 81377 Munich, Germany, and
| | - Martin Heidemann
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Markus Kellner
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Anita Gruber-Eber
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Vigo Heissmeyer
- Institute of Molecular Immunology, Helmholtz Center Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Katja Strässer
- Gene Center and Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig Maximilians University of Munich, Feodor-Lynen-Strasse 25, 81377 Munich, Germany, and
| | - Dirk Eick
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany,.
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14
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Zhang L, Lin J, Ye K. Structural and functional analysis of the U3 snoRNA binding protein Rrp9. RNA (NEW YORK, N.Y.) 2013; 19:701-711. [PMID: 23509373 PMCID: PMC3677284 DOI: 10.1261/rna.037580.112] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 02/06/2013] [Indexed: 06/01/2023]
Abstract
The U3 snoRNA is required for 18S rRNA processing and small subunit ribosome formation in eukaryotes. Different from other box C/D snoRNAs, U3 contains an extra 5' domain that pairs with pre-rRNA and a unique B/C motif essential for recruitment of the U3-specific Rrp9 protein. Here, we analyze the structure and function of Rrp9 with crystallographic, biochemical, and cellular approaches. Rrp9 is composed of a WD repeat domain and an N-terminal region. The crystal structures of the WD domain of yeast Rrp9 and its human ortholog U3-55K were determined, revealing a typical seven-bladed propeller fold. Several conserved surface patches on the WD domain were identified, and their function in RNP assembly and yeast growth were analyzed by mutagenesis. Prior association of Snu13 with the B/C motif was found to enhance the specific binding of the WD domain. We show that a conserved 7bc loop is crucial for specific recognition of U3, nucleolar localization of Rrp9, and yeast growth. In addition, we show that the N-terminal region of Rrp9 contains a bipartite nuclear localization signal that is dispensable for nucleolar localization. Our results provide insight into the functional sites of Rrp9.
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MESH Headings
- Amino Acid Sequence/genetics
- Binding Sites
- Crystallography, X-Ray
- Humans
- Nucleic Acid Conformation
- Protein Folding
- Protein Structure, Tertiary
- RNA Processing, Post-Transcriptional
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 18S/metabolism
- RNA, Small Nucleolar/chemistry
- RNA, Small Nucleolar/genetics
- RNA-Binding Proteins/chemistry
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Ribonucleoproteins, Small Nucleolar/chemistry
- Ribonucleoproteins, Small Nucleolar/genetics
- Ribonucleoproteins, Small Nucleolar/metabolism
- Ribosome Subunits, Small, Eukaryotic/genetics
- Saccharomyces cerevisiae/chemistry
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
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Affiliation(s)
- Liman Zhang
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
- National Institute of Biological Sciences, Beijing, Beijing 102206, China
| | - Jinzhong Lin
- National Institute of Biological Sciences, Beijing, Beijing 102206, China
| | - Keqiong Ye
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
- National Institute of Biological Sciences, Beijing, Beijing 102206, China
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15
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Sloan KE, Mattijssen S, Lebaron S, Tollervey D, Pruijn GJM, Watkins NJ. Both endonucleolytic and exonucleolytic cleavage mediate ITS1 removal during human ribosomal RNA processing. ACTA ACUST UNITED AC 2013; 200:577-88. [PMID: 23439679 PMCID: PMC3587827 DOI: 10.1083/jcb.201207131] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human ribosome production is up-regulated during tumorogenesis and is defective in many genetic diseases (ribosomopathies). We have undertaken a detailed analysis of human precursor ribosomal RNA (pre-rRNA) processing because surprisingly little is known about this important pathway. Processing in internal transcribed spacer 1 (ITS1) is a key step that separates the rRNA components of the large and small ribosomal subunits. We report that this was initiated by endonuclease cleavage, which required large subunit biogenesis factors. This was followed by 3' to 5' exonucleolytic processing by RRP6 and the exosome, an enzyme complex not previously linked to ITS1 removal. In contrast, RNA interference-mediated knockdown of the endoribonuclease MRP did not result in a clear defect in ITS1 processing. Despite the apparently high evolutionary conservation of the pre-rRNA processing pathway and ribosome synthesis factors, each of these features of human ITS1 processing is distinct from those in budding yeast. These results also provide significant insight into the links between ribosomopathies and ribosome production in human cells.
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Affiliation(s)
- Katherine E Sloan
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, England, UK
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16
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Bower-Phipps KR, Taylor DW, Wang HW, Baserga SJ. The box C/D sRNP dimeric architecture is conserved across domain Archaea. RNA (NEW YORK, N.Y.) 2012; 18:1527-1540. [PMID: 22753779 PMCID: PMC3404373 DOI: 10.1261/rna.033134.112] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 05/26/2012] [Indexed: 06/01/2023]
Abstract
Box C/D small (nucleolar) ribonucleoproteins [s(no)RNPs] catalyze RNA-guided 2'-O-ribose methylation in two of the three domains of life. Recent structural studies have led to a controversy over whether box C/D sRNPs functionally assemble as monomeric or dimeric macromolecules. The archaeal box C/D sRNP from Methanococcus jannaschii (Mj) has been shown by glycerol gradient sedimentation, gel filtration chromatography, native gel analysis, and single-particle electron microscopy (EM) to adopt a di-sRNP architecture, containing four copies of each box C/D core protein and two copies of the Mj sR8 sRNA. Subsequently, investigators used a two-stranded artificial guide sRNA, CD45, to assemble a box C/D sRNP from Sulfolobus solfataricus with a short RNA methylation substrate, yielding a crystal structure of a mono-sRNP. To more closely examine box C/D sRNP architecture, we investigate the role of the omnipresent sRNA loop as a structural determinant of sRNP assembly. We show through sRNA mutagenesis, native gel electrophoresis, and single-particle EM that a di-sRNP is the near exclusive architecture obtained when reconstituting box C/D sRNPs with natural or artificial sRNAs containing an internal loop. Our results span three distantly related archaeal species--Sulfolobus solfataricus, Pyrococcus abyssi, and Archaeoglobus fulgidus--indicating that the di-sRNP architecture is broadly conserved across the entire archaeal domain.
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Affiliation(s)
| | | | | | - Susan J. Baserga
- Department of Molecular Biophysics and Biochemistry
- Department of Genetics
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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17
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Turner AJ, Knox AA, Watkins NJ. Nucleolar disruption leads to the spatial separation of key 18S rRNA processing factors. RNA Biol 2012; 9:175-86. [PMID: 22418842 DOI: 10.4161/rna.18811] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Many chemotherapeutic drugs cause the downregulation of ribosome production and the disruption of nucleolar function. This stabilizes p53 and leads to either cell cycle arrest or apoptosis. It is not clear, however, how these agents cause nucleolar disruption and block ribosome production. The small subunit (SSU) processome, which has been primarily studied in yeast, is responsible for the processing of the 18S rRNA and assembly of the small ribosomal subunit. Here we have characterized the human homologs of seven SSU processome components. Furthermore, we have investigated the effects of three chemotherapeutic drugs, Actinomycin D (ActD), camptothecin (CPT) and 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB) on the subcellular distribution of key SSU processome components and the formation of this processing complex. Interestingly, ActD- and DRB-treatment resulted in the majority of U3 small nucleolar RNP (snoRNP) localizing separately to other key components of the SSU processome. All three agents affected RNA polymerase I transcription, primarily at the level of elongation but only ActD resulted in a clear reduction in SSU processome levels. Taken together, our data indicate that different chemotherapeutic agents, each of which initiates a stress response and cause nucleolar disruption, have different effects on the formation and localization of the SSU processome.
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Affiliation(s)
- Amy Jane Turner
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
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18
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Watkins NJ, Bohnsack MT. The box C/D and H/ACA snoRNPs: key players in the modification, processing and the dynamic folding of ribosomal RNA. WILEY INTERDISCIPLINARY REVIEWS-RNA 2011; 3:397-414. [DOI: 10.1002/wrna.117] [Citation(s) in RCA: 347] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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