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Li Q, Liu X, Wen J, Chen X, Xie B, Zhao Y. Enhancer RNAs: mechanisms in transcriptional regulation and functions in diseases. Cell Commun Signal 2023; 21:191. [PMID: 37537618 PMCID: PMC10398997 DOI: 10.1186/s12964-023-01206-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 06/23/2023] [Indexed: 08/05/2023] Open
Abstract
In recent years, increasingly more non-coding RNAs have been detected with the development of high-throughput sequencing technology, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), small nucleolar RNAs (snoRNAs), and piwi-interacting RNA (piRNAs). The discovery of enhancer RNAs (eRNAs) in 2010 has further broadened the range of non-coding RNAs revealed. eRNAs are non-coding RNA molecules produced by the transcription of DNA cis-acting elements, enhancer fragments. Recent studies revealed that the transcription of eRNAs may be a biological marker responding to enhancer activity that can participate in the regulation of coding gene transcription. In this review, we discussed the biological characteristics of eRNAs, their functions in transcriptional regulation, the regulation factors of eRNAs production, and the research progress of eRNAs in different diseases. Video Abstract.
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Affiliation(s)
- Qianhui Li
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangdong Province, Guangzhou City, 510150, People's Republic of China
| | - Xin Liu
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangdong Province, Guangzhou City, 510150, People's Republic of China
| | - Jingtao Wen
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangdong Province, Guangzhou City, 510150, People's Republic of China
| | - Xi Chen
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangdong Province, Guangzhou City, 510150, People's Republic of China
| | - Bumin Xie
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangdong Province, Guangzhou City, 510150, People's Republic of China
| | - Yang Zhao
- Department of Obstetrics and Gynecology, Department of Gynecologic Oncology Research Office, Guangzhou Key Laboratory of Targeted Therapy for Gynecologic Oncology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, No.63 Duobao Road, Liwan District, Guangdong Province, Guangzhou City, 510150, People's Republic of China.
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Falchi FA, Pizzoccheri R, Briani F. Activity and Function in Human Cells of the Evolutionary Conserved Exonuclease Polynucleotide Phosphorylase. Int J Mol Sci 2022; 23:ijms23031652. [PMID: 35163574 PMCID: PMC8836086 DOI: 10.3390/ijms23031652] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 01/28/2022] [Accepted: 01/28/2022] [Indexed: 02/04/2023] Open
Abstract
Polynucleotide phosphorylase (PNPase) is a phosphorolytic RNA exonuclease highly conserved throughout evolution. Human PNPase (hPNPase) is located in mitochondria and is essential for mitochondrial function and homeostasis. Not surprisingly, mutations in the PNPT1 gene, encoding hPNPase, cause serious diseases. hPNPase has been implicated in a plethora of processes taking place in different cell compartments and involving other proteins, some of which physically interact with hPNPase. This paper reviews hPNPase RNA binding and catalytic activity in relation with the protein structure and in comparison, with the activity of bacterial PNPases. The functions ascribed to hPNPase in different cell compartments are discussed, highlighting the gaps that still need to be filled to understand the physiological role of this ancient protein in human cells.
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Li J, Liu X, Yin Z, Hu Z, Zhang KQ. An Overview on Identification and Regulatory Mechanisms of Long Non-coding RNAs in Fungi. Front Microbiol 2021; 12:638617. [PMID: 33995298 PMCID: PMC8113380 DOI: 10.3389/fmicb.2021.638617] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/06/2021] [Indexed: 01/04/2023] Open
Abstract
For decades, more and more long non-coding RNAs (lncRNAs) have been confirmed to play important functions in key biological processes of different organisms. At present, most identified lncRNAs and those with known functional roles are from mammalian systems. However, lncRNAs have also been found in primitive eukaryotic fungi, and they have different functions in fungal development, metabolism, and pathogenicity. In this review, we highlight some recent researches on lncRNAs in the primitive eukaryotic fungi, particularly focusing on the identification of lncRNAs and their regulatory roles in diverse biological processes.
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Affiliation(s)
- Juan Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
| | - Xiaoying Liu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
| | - Ziyu Yin
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
| | - Zhihong Hu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
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Zhou C, Zhang J, Hu X, Li C, Wang L, Huang Q, Chen W. RNase II binds to RNase E and modulates its endoribonucleolytic activity in the cyanobacterium Anabaena PCC 7120. Nucleic Acids Res 2020; 48:3922-3934. [PMID: 32055835 PMCID: PMC7144899 DOI: 10.1093/nar/gkaa092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 02/03/2020] [Accepted: 02/10/2020] [Indexed: 11/16/2022] Open
Abstract
In Escherichia coli, the endoribonuclease E (RNase E) can recruit several other ribonucleases and regulatory proteins via its noncatalytic domain to form an RNA degradosome that controls cellular RNA turnover. Similar RNA degradation complexes have been found in other bacteria; however, their compositions are varied among different bacterial species. In cyanobacteria, only the exoribonuclease PNPase was shown to bind to the noncatalytic domain of RNase E. Here, we showed that Alr1240, a member of the RNB family of exoribonucleases, could be co-isolated with RNase E from the lysate of the cyanobacterium Anabaena PCC 7120. Enzymatic analysis revealed that Alr1240 is an exoribonuclease II (RNase II), as it only degrades non-structured single-stranded RNA substrates. In contrast to known RNase E-interacting ribonucleases, which bind to the noncatalytic domain of RNase E, the Anabaena RNase II was shown to associate with the catalytic domain of RNase E. Using a strain in which RNase E and RNase II were tagged in situ with GFP and BFP, respectively, we showed that RNase E and RNase II form a compact complex in vivo by a fluorescence resonance energy transfer (FRET) assay. RNase E activity on several synthetic substrates was boosted in the presence of RNase II, suggesting that the activity of RNase E could be regulated by RNase II-RNase E interaction. To our knowledge, Anabaena RNase II is an unusual ribonuclease that interacts with the catalytic domain of RNase E, and it may represent a new type of RNA degradosome and a novel mechanism for regulating the activity of the RNA degradosome. As Anabaena RNase E interacts with RNase II and PNPase via different regions, it is very likely that the three ribonucleases form a large complex and cooperatively regulate RNA metabolism in the cell.
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Affiliation(s)
- Cong Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Juyuan Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430070, China
| | - Xinyu Hu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Changchang Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Li Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenli Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
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5
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Zhang B, Zhao N, Jia L, Che J, He X, Liu K, Bao B. Identification and application of piwi-interacting RNAs from seminal plasma exosomes in Cynoglossus semilaevis. BMC Genomics 2020; 21:302. [PMID: 32293248 PMCID: PMC7158113 DOI: 10.1186/s12864-020-6660-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 03/09/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Piwi-interacting RNAs (piRNAs) have been linked to epigenetic and post-transcriptional gene silencing of retrotransposons in germ line cells, particularly in spermatogenesis. Exosomes are important mediators of vesicle transport, and the piRNAs in exosomes might play an important role in cell communication and signal pathway regulation. Moreover, exosomic piRNAs are promising biomarkers for disease diagnosis and physiological status indication. We used Cynoglossus semilaevis because of its commercial value and its sexual dimorphism, particularly the sex reversed "pseudomales" who have a female karyotype, produce sperm, and copulate with normal females to produce viable offspring. RESULTS To determine whether piRNAs from fish germ line cells have similar features, seminal plasma exosomes from half-smooth tongue sole, C. semilaevis, were identified, and their small RNAs were sequenced and analysed. We identified six signature piRNAs as biomarkers in exosomes of seminal plasma from males and pseudomale C. semilaevis. Bioinformatic analysis showed that all six signatures were sex-related, and four were DNA methylation-related and transposition-related piRNAs. Their expression profiles were verified using real-time quantitative PCR. The expression of the signature piRNAs was markedly higher in males than in pseudomales. The signature piRNAs could be exploited as male-specific biomarkers in this fish. CONCLUSIONS These signatures provide an effective tool to explore the regulatory mechanism of sex development in C. semilaevis and may provide guidance for future research on the function of piRNAs in the generative mechanism of sex reversed "pseudomales" in C. semilaevis.
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Affiliation(s)
- Bo Zhang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China.,Tianjin Sea Fisheries Research Institute, Tianjin, China
| | - Na Zhao
- Tianjin Medicine Biotechnology Co, Ltd, Tianjin, China
| | - Lei Jia
- Tianjin Sea Fisheries Research Institute, Tianjin, China
| | - Jinyuan Che
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Xiaoxu He
- Tianjin Sea Fisheries Research Institute, Tianjin, China
| | - Kefeng Liu
- Tianjin Sea Fisheries Research Institute, Tianjin, China
| | - Baolong Bao
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China.
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6
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Januszyk K, Lima CD. Reconstitution of the Schizosaccharomyces pombe RNA Exosome. Methods Mol Biol 2020; 2062:449-465. [PMID: 31768990 PMCID: PMC8596990 DOI: 10.1007/978-1-4939-9822-7_22] [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] [Indexed: 10/18/2023]
Abstract
In this chapter, we describe methods to clone, express, purify, and reconstitute active S. pombe RNA exosomes. Reconstitution procedures are similar to methods that have been successful for the human and budding yeast exosome systems using protein subunits purified from the recombinant host E. coli. By applying these strategies, we can successfully reconstitute the S. pombe noncatalytic exosome core as well as complexes that contain the exoribonucleases Dis3 and Rrp6, cofactors Cti1 (equivalent to budding yeast Rrp47) and Mpp6 as well as the RNA helicase Mtr4.
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Affiliation(s)
- Kurt Januszyk
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Christopher D Lima
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Howard Hughes Medical Institute, New York, NY, USA.
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7
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Abstract
The exoribonuclease Rrp6p is critical for RNA decay in the nucleus. While Rrp6p acts on a large range of diverse substrates, it does not indiscriminately degrade all RNAs. How Rrp6p accomplishes this task is not understood. Here, we measure Rrp6p-RNA binding and degradation kinetics in vitro at single-nucleotide resolution and find an intrinsic substrate selectivity that enables Rrp6p to discriminate against specific RNAs. RNA length and the four 3'-terminal nucleotides contribute most to substrate selectivity and collectively enable Rrp6p to discriminate between different RNAs by several orders of magnitude. The most pronounced discrimination is seen against RNAs ending with CCA-3'. These RNAs correspond to 3' termini of uncharged tRNAs, which are not targeted by Rrp6p in cells. The data show that in contrast to many other proteins that use substrate selectivity to preferentially interact with specific RNAs, Rrp6p utilizes its selectivity to discriminate against specific RNAs. This ability allows Rrp6p to target diverse substrates while avoiding a subset of RNAs.
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8
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François-Moutal L, Jahanbakhsh S, Nelson ADL, Ray D, Scott DD, Hennefarth MR, Moutal A, Perez-Miller S, Ambrose AJ, Al-Shamari A, Coursodon P, Meechoovet B, Reiman R, Lyons E, Beilstein M, Chapman E, Morris QD, Van Keuren-Jensen K, Hughes TR, Khanna R, Koehler C, Jen J, Gokhale V, Khanna M. A Chemical Biology Approach to Model Pontocerebellar Hypoplasia Type 1B (PCH1B). ACS Chem Biol 2018; 13:3000-3010. [PMID: 30141626 DOI: 10.1021/acschembio.8b00745] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Mutations of EXOSC3 have been linked to the rare neurological disorder known as Pontocerebellar Hypoplasia type 1B (PCH1B). EXOSC3 is one of three putative RNA-binding structural cap proteins that guide RNA into the RNA exosome, the cellular machinery that degrades RNA. Using RNAcompete, we identified a G-rich RNA motif binding to EXOSC3. Surface plasmon resonance (SPR) and microscale thermophoresis (MST) indicated an affinity in the low micromolar range of EXOSC3 for long and short G-rich RNA sequences. Although several PCH1B-causing mutations in EXOSC3 did not engage a specific RNA motif as shown by RNAcompete, they exhibited lower binding affinity to G-rich RNA as demonstrated by MST. To test the hypothesis that modification of the RNA-protein interface in EXOSC3 mutants may be phenocopied by small molecules, we performed an in-silico screen of 50 000 small molecules and used enzyme-linked immunosorbant assays (ELISAs) and MST to assess the ability of the molecules to inhibit RNA-binding by EXOSC3. We identified a small molecule, EXOSC3-RNA disrupting (ERD) compound 3 (ERD03), which ( i) bound specifically to EXOSC3 in saturation transfer difference nuclear magnetic resonance (STD-NMR), ( ii) disrupted the EXOSC3-RNA interaction in a concentration-dependent manner, and ( iii) produced a PCH1B-like phenotype with a 50% reduction in the cerebellum and an abnormally curved spine in zebrafish embryos. This compound also induced modification of zebrafish RNA expression levels similar to that observed with a morpholino against EXOSC3. To our knowledge, this is the first example of a small molecule obtained by rational design that models the abnormal developmental effects of a neurodegenerative disease in a whole organism.
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Affiliation(s)
- Liberty François-Moutal
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona 85724, United States
- Center for Innovation in Brain Science, Tucson, Arizona 85721, United States
| | - Shahriyar Jahanbakhsh
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Andrew D. L. Nelson
- School of Plant Sciences, University of Arizona, Tucson, Arizona 85721, United States
| | - Debashish Ray
- Donnelly Centre, University of Toronto, Toronto, Canada M5S 3E1
| | - David D. Scott
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona 85724, United States
- Center for Innovation in Brain Science, Tucson, Arizona 85721, United States
| | - Matthew R. Hennefarth
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Aubin Moutal
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona 85724, United States
| | - Samantha Perez-Miller
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona 85724, United States
- Center for Innovation in Brain Science, Tucson, Arizona 85721, United States
| | - Andrew J. Ambrose
- Pharmacology and Toxicology, School of Pharmacy, University of Arizona, Tucson, Arizona 85724, United States
| | - Ahmed Al-Shamari
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona 85724, United States
| | - Philippe Coursodon
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona 85724, United States
| | | | - Rebecca Reiman
- Neurogenomics Division, TGen, Phoenix, Arizona 85004, United States
| | - Eric Lyons
- School of Plant Sciences, University of Arizona, Tucson, Arizona 85721, United States
| | - Mark Beilstein
- School of Plant Sciences, University of Arizona, Tucson, Arizona 85721, United States
| | - Eli Chapman
- Pharmacology and Toxicology, School of Pharmacy, University of Arizona, Tucson, Arizona 85724, United States
| | - Quaid D. Morris
- Donnelly Centre, University of Toronto, Toronto, Canada M5S 3E1
- Department of Molecular Genetics, University of Toronto, Toronto, Canada M5S 1A8
- Department of Computer Science, University of Toronto, Toronto, Canada M5S 2E4
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Canada M5S3G4
| | | | - Timothy R. Hughes
- Donnelly Centre, University of Toronto, Toronto, Canada M5S 3E1
- Department of Molecular Genetics, University of Toronto, Toronto, Canada M5S 1A8
| | - Rajesh Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona 85724, United States
- Center for Innovation in Brain Science, Tucson, Arizona 85721, United States
| | - Carla Koehler
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Joanna Jen
- Mount Sinai, New York, New York 10029, United States
| | - Vijay Gokhale
- Bio5 Institute, University of Arizona, Tucson, Arizona, United States
| | - May Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, Arizona 85724, United States
- Center for Innovation in Brain Science, Tucson, Arizona 85721, United States
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Jiang N, Yu S, Yang N, Feng Y, Sang X, Wang Y, Wahlgren M, Chen Q. Characterization of the Catalytic Subunits of the RNA Exosome-like Complex in Plasmodium falciparum. J Eukaryot Microbiol 2018; 65:843-853. [PMID: 29664138 PMCID: PMC6282785 DOI: 10.1111/jeu.12625] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 04/02/2018] [Accepted: 04/03/2018] [Indexed: 12/21/2022]
Abstract
The eukaryotic ribonucleic acid (RNA) exosome is a versatile multiribonuclease complex that mediates the processing, surveillance, and degradation of virtually all classes of RNA in both the nucleus and cytoplasm. The complex, composed of 10 to 11 subunits, has been widely described in many organisms. Bioinformatic analyses revealed that there may be also an exosome‐like complex in Plasmodium falciparum, a parasite of great importance in public health, with eight predicted subunits having high sequence similarity to their counterparts in yeast and human. In this work, the putative RNA catalytic components, designated as PfRrp4, PfRrp41, PfDis3, and PfRrp6, were identified and systematically analyzed. Quantitative polymerase chain reaction (QPCR) analyses suggested that all of them were transcribed steadily throughout the asexual stage. The expression of these proteins was determined by Western blot, and their localization narrowed to the cytoplasm of the parasite by indirect immunofluorescence. The recombinant proteins of PfRrp41, PfDis3, and PfRrp6 exhibited catalytic activity for single‐stranded RNA (ssRNA), whereas PfRrp4 showed no processing activity of both ssRNA and dsRNA. The identification of these putative components of the RNA exosome complex opens up new perspectives for a deep understanding of RNA metabolism in the malarial parasite P. falciparum.
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Affiliation(s)
- Ning Jiang
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China
| | - Shengchao Yu
- Key Laboratory of Zoonosis, Jilin University, 53333 Xi An Da Lu, Changchun, 130062, China
| | - Na Yang
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China
| | - Ying Feng
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China
| | - Xiaoyu Sang
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China
| | - Yao Wang
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China
| | - Mats Wahlgren
- Department of Microbiology, Tumour and Cellular Biology, Karolinska Institutet, Nobels väg 16, Stockholm, Sweden
| | - Qijun Chen
- Key Laboratory of Zoonosis, Shenyang Agricultural University, 120 Dongling Road, Shenyang, China.,Department of Microbiology, Tumour and Cellular Biology, Karolinska Institutet, Nobels väg 16, Stockholm, Sweden
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10
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Han J, van Hoof A. The RNA Exosome Channeling and Direct Access Conformations Have Distinct In Vivo Functions. Cell Rep 2018; 16:3348-3358. [PMID: 27653695 DOI: 10.1016/j.celrep.2016.08.059] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 06/06/2016] [Accepted: 08/18/2016] [Indexed: 10/21/2022] Open
Abstract
The RNA exosome is a 3'-5' ribonuclease complex that is composed of nine core subunits and an essential catalytic subunit, Rrp44. Two distinct conformations of Rrp44 were revealed in previous structural studies, suggesting that Rrp44 may change its conformation to exert its function. In the channeling conformation, (Rrp44(ch)), RNA accesses the active site after traversing the central channel of the RNA exosome, whereas in the other conformation, (Rrp44(da)), RNA gains direct access to the active site. Here, we show that the Rrp44(da) exosome is important for nuclear function of the RNA exosome. Defects caused by disrupting the direct access conformation are distinct from those caused by channel-occluding mutations, indicating specific functions for each conformation. Our genetic analyses provide in vivo evidence that the RNA exosome employs a direct-access route to recruit specific substrates, indicating that the RNA exosome uses alternative conformations to act on different RNA substrates.
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Affiliation(s)
- Jaeil Han
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 1.212, Houston, TX 77030, USA; The University of Texas Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 1.212, Houston, TX 77030, USA
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 1.212, Houston, TX 77030, USA; The University of Texas Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 1.212, Houston, TX 77030, USA.
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11
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Bern MM. Extracellular vesicles: how they interact with endothelium, potentially contributing to metastatic cancer cell implants. Clin Transl Med 2017; 6:33. [PMID: 28933058 PMCID: PMC5607152 DOI: 10.1186/s40169-017-0165-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 08/13/2017] [Indexed: 02/07/2023] Open
Abstract
Extracellular vesicles (EV) are blebs of cellular membranes, which entrap small portions of subjacent cytosol. They are released from a variety of cells, circulate in the blood for an unknown length of time and come to rest on endothelial surfaces. They contribute to an array of physiologic pathways, the complexity of which is still being investigated. They contribute to metastatic malignant cell implants and tumor-related angiogenesis, possibly abetted by the tissue factor that they carry. It is thought that the adherence of the EV to endothelium is dependent upon a combination of their P-selectin glycoprotein ligand-1 and exposed phosphatidylserine, the latter of which is normally hidden on the inner bilayer of the intact cellular membrane. This manuscript reviews what is known about EV origins, their clearance from the circulation and how they contribute to malignant cell implants upon endothelium surfaces and subsequent tumor growth.
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Affiliation(s)
- Murray M Bern
- University of New Mexico Comprehensive Cancer Center, 1201 Camino de Salud, Albuquerque, NM, 87131, USA.
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12
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Hoskins JW, Ibrahim A, Emmanuel MA, Manmiller SM, Wu Y, O’Neill M, Jia J, Collins I, Zhang M, Thomas JV, Rost LM, Das S, Parikh H, Haake JM, Matters GL, Kurtz RC, Bamlet WR, Klein A, Stolzenberg-Solomon R, Wolpin BM, Yarden R, Wang Z, Smith J, Olson SH, Andresson T, Petersen GM, Amundadottir LT. Functional characterization of a chr13q22.1 pancreatic cancer risk locus reveals long-range interaction and allele-specific effects on DIS3 expression. Hum Mol Genet 2016; 25:4726-4738. [PMID: 28172817 PMCID: PMC5815622 DOI: 10.1093/hmg/ddw300] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 07/08/2016] [Accepted: 08/26/2016] [Indexed: 12/20/2022] Open
Abstract
Genome-wide association studies (GWAS) have identified multiple common susceptibility loci for pancreatic cancer. Here we report fine-mapping and functional analysis of one such locus residing in a 610 kb gene desert on chr13q22.1 (marked by rs9543325). The closest candidate genes, KLF5, KLF12, PIBF1, DIS3 and BORA, range in distance from 265-586 kb. Sequencing three sub-regions containing the top ranked SNPs by imputation P-value revealed a 30 bp insertion/deletion (indel) variant that was significantly associated with pancreatic cancer risk (rs386772267, P = 2.30 × 10-11, OR = 1.22, 95% CI 1.15-1.28) and highly correlated to rs9543325 (r2 = 0.97 in the 1000 Genomes EUR population). This indel was the most significant cis-eQTL variant in a set of 222 histologically normal pancreatic tissue samples (β = 0.26, P = 0.004), with the insertion (risk-increasing) allele associated with reduced DIS3 expression. DIS3 encodes a catalytic subunit of the nuclear RNA exosome complex that mediates RNA processing and decay, and is mutated in several cancers. Chromosome conformation capture revealed a long range (570 kb) physical interaction between a sub-region of the risk locus, containing rs386772267, and a region ∼6 kb upstream of DIS3 Finally, repressor regulatory activity and allele-specific protein binding by transcription factors of the TCF/LEF family were observed for the risk-increasing allele of rs386772267, indicating that expression regulation at this risk locus may be influenced by the Wnt signaling pathway. In conclusion, we have identified a putative functional indel variant at chr13q22.1 that associates with decreased DIS3 expression in carriers of pancreatic cancer risk-increasing alleles, and could therefore affect nuclear RNA processing and/or decay.
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Affiliation(s)
- Jason W. Hoskins
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Abdisamad Ibrahim
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Mickey A. Emmanuel
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sarah M. Manmiller
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yinglun Wu
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Maura O’Neill
- Protein Characterization Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Jinping Jia
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Irene Collins
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Mingfeng Zhang
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Janelle V. Thomas
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lauren M. Rost
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sudipto Das
- Protein Characterization Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Hemang Parikh
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Health Informatics Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Jefferson M. Haake
- Department of Human Science, NHS, Georgetown University Medical Center, NW, Washington DC, USA
| | - Gail L. Matters
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Robert C. Kurtz
- Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
| | - William R. Bamlet
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota, USA
| | - Alison Klein
- Department of Oncology, the Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Epidemiology, the Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Rachael Stolzenberg-Solomon
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Brian M. Wolpin
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Ronit Yarden
- Department of Human Science, NHS, Georgetown University Medical Center, NW, Washington DC, USA
| | - Zhaoming Wang
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Department of Computational Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Jill Smith
- Department of Medicine, Georgetown University Hospital, Washington, DC, and Department of Medicine, Penn State University College of Medicine, Hershey PA, USA
| | - Sara H. Olson
- Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Thorkell Andresson
- Protein Characterization Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Gloria M. Petersen
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota, USA
| | - Laufey T. Amundadottir
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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13
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CryoEM structure of yeast cytoplasmic exosome complex. Cell Res 2016; 26:822-37. [PMID: 27174052 DOI: 10.1038/cr.2016.56] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 01/26/2016] [Accepted: 03/07/2016] [Indexed: 01/25/2023] Open
Abstract
The eukaryotic multi-subunit RNA exosome complex plays crucial roles in 3'-to-5' RNA processing and decay. Rrp6 and Ski7 are the major cofactors for the nuclear and cytoplasmic exosomes, respectively. In the cytoplasm, Ski7 helps the exosome to target mRNAs for degradation and turnover via a through-core pathway. However, the interaction between Ski7 and the exosome complex has remained unclear. The transaction of RNA substrates within the exosome is also elusive. In this work, we used single-particle cryo-electron microscopy to solve the structures of the Ski7-exosome complex in RNA-free and RNA-bound forms at resolutions of 4.2 Å and 5.8 Å, respectively. These structures reveal that the N-terminal domain of Ski7 adopts a structural arrangement and interacts with the exosome in a similar fashion to the C-terminal domain of nuclear Rrp6. Further structural analysis of exosomes with RNA substrates harboring 3' overhangs of different length suggests a switch mechanism of RNA-induced exosome activation in the through-core pathway of RNA processing.
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14
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Pefanis E, Wang J, Rothschild G, Lim J, Kazadi D, Sun J, Federation A, Chao J, Elliott O, Liu ZP, Economides AN, Bradner JE, Rabadan R, Basu U. RNA exosome-regulated long non-coding RNA transcription controls super-enhancer activity. Cell 2016; 161:774-89. [PMID: 25957685 DOI: 10.1016/j.cell.2015.04.034] [Citation(s) in RCA: 325] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 03/11/2015] [Accepted: 04/20/2015] [Indexed: 01/19/2023]
Abstract
We have ablated the cellular RNA degradation machinery in differentiated B cells and pluripotent embryonic stem cells (ESCs) by conditional mutagenesis of core (Exosc3) and nuclear RNase (Exosc10) components of RNA exosome and identified a vast number of long non-coding RNAs (lncRNAs) and enhancer RNAs (eRNAs) with emergent functionality. Unexpectedly, eRNA-expressing regions accumulate R-loop structures upon RNA exosome ablation, thus demonstrating the role of RNA exosome in resolving deleterious DNA/RNA hybrids arising from active enhancers. We have uncovered a distal divergent eRNA-expressing element (lncRNA-CSR) engaged in long-range DNA interactions and regulating IgH 3' regulatory region super-enhancer function. CRISPR-Cas9-mediated ablation of lncRNA-CSR transcription decreases its chromosomal looping-mediated association with the IgH 3' regulatory region super-enhancer and leads to decreased class switch recombination efficiency. We propose that the RNA exosome protects divergently transcribed lncRNA expressing enhancers by resolving deleterious transcription-coupled secondary DNA structures, while also regulating long-range super-enhancer chromosomal interactions important for cellular function.
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Affiliation(s)
- Evangelos Pefanis
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA; Regeneron Pharmaceuticals and Regeneron Genetics Center, Tarrytown, NY 10591, USA
| | - Jiguang Wang
- Department of Biomedical Informatics and Department of Systems Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Gerson Rothschild
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Junghyun Lim
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - David Kazadi
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Jianbo Sun
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | | | - Jaime Chao
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Oliver Elliott
- Department of Biomedical Informatics and Department of Systems Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Zhi-Ping Liu
- Department of Biomedical Engineering, School of Control Science and Engineering, Shandong University, Jinan, Shandong 250061, China
| | - Aris N Economides
- Regeneron Pharmaceuticals and Regeneron Genetics Center, Tarrytown, NY 10591, USA
| | - James E Bradner
- Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02115, USA
| | - Raul Rabadan
- Department of Biomedical Informatics and Department of Systems Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
| | - Uttiya Basu
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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15
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Tseng YT, Chiou NT, Gogiraju R, Lin-Chao S. The Protein Interaction of RNA Helicase B (RhlB) and Polynucleotide Phosphorylase (PNPase) Contributes to the Homeostatic Control of Cysteine in Escherichia coli. J Biol Chem 2015; 290:29953-63. [PMID: 26494621 PMCID: PMC4705995 DOI: 10.1074/jbc.m115.691881] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Indexed: 11/12/2022] Open
Abstract
PNPase, one of the major enzymes with 3′ to 5′ single-stranded RNA degradation and processing activities, can interact with the RNA helicase RhlB independently of RNA degradosome formation in Escherichia coli. Here, we report that loss of interaction between RhlB and PNPase impacts cysteine homeostasis in E. coli. By random mutagenesis, we identified a mutant RhlBP238L that loses 75% of its ability to interact with PNPase but retains normal interaction with RNase E and RNA, in addition to exhibiting normal helicase activity. Applying microarray analyses to an E. coli strain with impaired RNA degradosome formation, we investigated the biological consequences of a weakened interaction between RhlB and PNPase. We found significant increases in 11 of 14 genes involved in cysteine biosynthesis. Subsequent Northern blot analyses showed that the up-regulated transcripts were the result of stabilization of the cysB transcript encoding a transcriptional activator for the cys operons. Furthermore, Northern blots of PNPase or RhlB mutants showed that RhlB-PNPase plays both a catalytic and structural role in regulating cysB degradation. Cells expressing the RhlBP238L mutant exhibited an increase in intracellular cysteine and an enhanced anti-oxidative response. Collectively, this study suggests a mechanism by which bacteria use the PNPase-RhlB exosome-like complex to combat oxidative stress by modulating cysB mRNA degradation.
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Affiliation(s)
- Yi-Ting Tseng
- From the Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan, the Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10617, Taiwan
| | - Ni-Ting Chiou
- From the Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan, the Institute of Biochemistry & Molecular Biology, National Yang-Ming University, Taipei 11221, Taiwan
| | | | - Sue Lin-Chao
- From the Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan,
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16
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Kreimer S, Belov AM, Ghiran I, Murthy SK, Frank DA, Ivanov AR. Mass-spectrometry-based molecular characterization of extracellular vesicles: lipidomics and proteomics. J Proteome Res 2015; 14:2367-84. [PMID: 25927954 DOI: 10.1021/pr501279t] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review discusses extracellular vesicles (EVs), which are submicron-scale, anuclear, phospholipid bilayer membrane enclosed vesicles that contain lipids, metabolites, proteins, and RNA (micro and messenger). They are shed from many, if not all, cell types and are present in biological fluids and conditioned cell culture media. The term EV, as coined by the International Society of Extracellular Vesicles (ISEV), encompasses exosomes (30-100 nm in diameter), microparticles (100-1000 nm), apoptotic blebs, and other EV subsets. EVs have been implicated in cell-cell communication, coagulation, inflammation, immune response modulation, and disease progression. Multiple studies report that EV secretion from disease-affected cells contributes to disease progression, e.g., tumor niche formation and cancer metastasis. EVs are attractive sources of biomarkers due to their biological relevance and relatively noninvasive accessibility from a range of physiological fluids. This review is focused on the molecular profiling of the protein and lipid constituents of EVs, with emphasis on mass-spectrometry-based "omic" analytical techniques. The challenges in the purification and molecular characterization of EVs, including contamination of isolates and limitations in sample quantities, are discussed along with possible solutions. Finally, the review discusses the limited but growing investigation of post-translational modifications of EV proteins and potential strategies for future in-depth molecular characterization of EVs.
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Affiliation(s)
| | | | - Ionita Ghiran
- ∥Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, United States
| | | | - David A Frank
- ⊥Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, United States.,#Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, United States
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17
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Shin JH, Chekanova JA. Arabidopsis RRP6L1 and RRP6L2 function in FLOWERING LOCUS C silencing via regulation of antisense RNA synthesis. PLoS Genet 2014; 10:e1004612. [PMID: 25211139 PMCID: PMC4161302 DOI: 10.1371/journal.pgen.1004612] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 07/18/2014] [Indexed: 01/24/2023] Open
Abstract
The exosome complex functions in RNA metabolism and transcriptional gene silencing. Here, we report that mutations of two Arabidopsis genes encoding nuclear exosome components AtRRP6L1 and AtRRP6L2, cause de-repression of the main flowering repressor FLOWERING LOCUS C (FLC) and thus delay flowering in early-flowering Arabidopsis ecotypes. AtRRP6L mutations affect the expression of known FLC regulatory antisense (AS) RNAs AS I and II, and cause an increase in Histone3 K4 trimethylation (H3K4me3) at FLC. AtRRP6L1 and AtRRP6L2 function redundantly in regulation of FLC and also act independently of the exosome core complex. Moreover, we discovered a novel, long non-coding, non-polyadenylated antisense transcript (ASL, for Antisense Long) originating from the FLC locus in wild type plants. The AtRRP6L proteins function as the main regulators of ASL synthesis, as these mutants show little or no ASL transcript. Unlike ASI/II, ASL associates with H3K27me3 regions of FLC, suggesting that it could function in the maintenance of H3K27 trimethylation during vegetative growth. AtRRP6L mutations also affect H3K27me3 levels and nucleosome density at the FLC locus. Furthermore, AtRRP6L1 physically associates with the ASL transcript and directly interacts with the FLC locus. We propose that AtRRP6L proteins participate in the maintenance of H3K27me3 at FLC via regulating ASL. Furthermore, AtRRP6Ls might participate in multiple FLC silencing pathways by regulating diverse antisense RNAs derived from the FLC locus.
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Affiliation(s)
- Jun-Hye Shin
- School of Biological Sciences, University of Missouri - Kansas City, Kansas City, Missouri, United States of America
| | - Julia A. Chekanova
- School of Biological Sciences, University of Missouri - Kansas City, Kansas City, Missouri, United States of America
- * E-mail:
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18
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Evguenieva-Hackenberg E, Hou L, Glaeser S, Klug G. Structure and function of the archaeal exosome. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:623-35. [DOI: 10.1002/wrna.1234] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/28/2014] [Accepted: 03/06/2014] [Indexed: 11/10/2022]
Affiliation(s)
| | - Linlin Hou
- Institute of Microbiology and Molecular Biology; University of Giessen; Giessen Germany
| | - Stefanie Glaeser
- Institute of Applied Microbiology; University of Giessen; Giessen Germany
| | - Gabriele Klug
- Institute of Microbiology and Molecular Biology; University of Giessen; Giessen Germany
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19
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Poly(A) tail-mediated gene regulation by opposing roles of Nab2 and Pab2 nuclear poly(A)-binding proteins in pre-mRNA decay. Mol Cell Biol 2013; 33:4718-31. [PMID: 24081329 DOI: 10.1128/mcb.00887-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The 3' end of most eukaryotic transcripts is decorated by poly(A)-binding proteins (PABPs), which influence the fate of mRNAs throughout gene expression. However, despite the fact that multiple PABPs coexist in the nuclei of most eukaryotes, how functional interplay between these nuclear PABPs controls gene expression remains unclear. By characterizing the ortholog of the Nab2/ZC3H14 zinc finger PABP in Schizosaccharomyces pombe, we show here that the two major fission yeast nuclear PABPs, Pab2 and Nab2, have opposing roles in posttranscriptional gene regulation. Notably, we find that Nab2 functions in gene-specific regulation in a manner opposite to that of Pab2. By studying the ribosomal-protein-coding gene rpl30-2, which is negatively regulated by Pab2 via a nuclear pre-mRNA decay pathway that depends on the nuclear exosome subunit Rrp6, we show that Nab2 promotes rpl30-2 expression by acting at the level of the unspliced pre-mRNA. Our data support a model in which Nab2 impedes Pab2/Rrp6-mediated decay by competing with Pab2 for polyadenylated transcripts in the nucleus. The opposing roles of Pab2 and Nab2 reveal that interplay between nuclear PABPs can influence gene regulation.
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20
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Vilfan ID, Tsai YC, Clark TA, Wegener J, Dai Q, Yi C, Pan T, Turner SW, Korlach J. Analysis of RNA base modification and structural rearrangement by single-molecule real-time detection of reverse transcription. J Nanobiotechnology 2013; 11:8. [PMID: 23552456 PMCID: PMC3623877 DOI: 10.1186/1477-3155-11-8] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 01/25/2013] [Indexed: 01/05/2023] Open
Abstract
Background Zero-mode waveguides (ZMWs) are photonic nanostructures that create highly confined optical observation volumes, thereby allowing single-molecule-resolved biophysical studies at relatively high concentrations of fluorescent molecules. This principle has been successfully applied in single-molecule, real-time (SMRT®) DNA sequencing for the detection of DNA sequences and DNA base modifications. In contrast, RNA sequencing methods cannot provide sequence and RNA base modifications concurrently as they rely on complementary DNA (cDNA) synthesis by reverse transcription followed by sequencing of cDNA. Thus, information on RNA modifications is lost during the process of cDNA synthesis. Results Here we describe an application of SMRT technology to follow the activity of reverse transcriptase enzymes synthesizing cDNA on thousands of single RNA templates simultaneously in real time with single nucleotide turnover resolution using arrays of ZMWs. This method thereby obtains information from the RNA template directly. The analysis of the kinetics of the reverse transcriptase can be used to identify RNA base modifications, shown by example for N6-methyladenine (m6A) in oligonucleotides and in a specific mRNA extracted from total cellular mRNA. Furthermore, the real-time reverse transcriptase dynamics informs about RNA secondary structure and its rearrangements, as demonstrated on a ribosomal RNA and an mRNA template. Conclusions Our results highlight the feasibility of studying RNA modifications and RNA structural rearrangements in ZMWs in real time. In addition, they suggest that technology can be developed for direct RNA sequencing provided that the reverse transcriptase is optimized to resolve homonucleotide stretches in RNA.
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21
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Abstract
The bacterial Hfq protein is a versatile modulator of RNA function and is particularly important for regulation mediated by small non-coding RNAs. Hfq is a bacterial Sm protein but bears more similarity to the eukaryotic Sm-like (Lsm) family of proteins than the prototypical Sm proteins. Hfq and Lsm proteins share the ability to chaperone RNA-RNA and RNA/protein interactions and an interesting penchant for protecting the 3′ end of a transcript from exonucleolytic decay while encouraging degradation through other pathways. Our view of Lsm function in eukaryotes has historically been informed by studies of Hfq structure and function but mutational analyses and structural studies of Lsm sub-complexes have given important insights as well. Here, we aim to compare and contrast the roles of these evolutionarily related complexes and to highlight areas for future investigation.
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Affiliation(s)
- Carol J Wilusz
- Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO, USA.
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22
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Johnson SJ, Jackson RN. Ski2-like RNA helicase structures: common themes and complex assemblies. RNA Biol 2012; 10:33-43. [PMID: 22995828 DOI: 10.4161/rna.22101] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Ski2-like RNA helicases are large multidomain proteins involved in a variety of RNA processing and degradation events. Recent structures of Mtr4, Ski2 and Brr2 provide our first view of these intricate helicases. Here we review these structures, which reveal a conserved ring-like architecture that extends beyond the canonical RecA domains to include a winged helix and ratchet domain. Comparison of apo- and RNA-bound Mtr4 structures suggests a role for the winged helix domain as a molecular hub that coordinates RNA interacting events throughout the helicase. Unique accessory domains provide expanded diversity and functionality to each Ski2-like family member. A common theme is the integration of Ski2-like RNA helicases into larger protein assemblies. We describe the central role of Mtr4 and Ski2 in formation of complexes that activate RNA decay by the eukaryotic exosome. The current structures provide clues into what promises to be a fascinating view of these dynamic assemblies.
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Affiliation(s)
- Sean J Johnson
- Department of Chemistry & Biochemistry, Utah State University, Logan, UT, USA.
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23
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Yeast Gene Expression. Yeast 2012. [DOI: 10.1002/9783527659180.ch9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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24
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Exo- and endoribonucleolytic activities of yeast cytoplasmic and nuclear RNA exosomes are dependent on the noncatalytic core and central channel. Mol Cell 2012; 48:133-44. [PMID: 22902556 DOI: 10.1016/j.molcel.2012.07.012] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 06/20/2012] [Accepted: 07/10/2012] [Indexed: 11/21/2022]
Abstract
The RNA exosome is an essential multisubunit ribonuclease (RNase) that contributes to cytoplasmic and nuclear RNA decay and quality control. The 9-subunit exosome core (Exo9) features a prominent central channel formed by stacked asymmetric rings of six RNase PH-like proteins and three S1/KH domain proteins. Exo9 is catalytically inert but associates with Rrp44, an endoribonuclease and processive 3'→5' exoribonuclease, and Rrp6, a distributive 3'→5' exoribonuclease. We show that Exo9 and its central channel modulate all three yeast exosome RNase activities because channel occlusion attenuates RNA binding and RNase activities in vitro and fails to complement exosome functions in vivo. We find that Rrp6 stimulates Rrp44 RNase activities and that Rrp6 is inhibited by a mutation in the Rrp44 exoribonuclease active site in 11-subunit nuclear exosomes. These results suggest the exosome core and central channel is essential because it modulates each of the known RNase activities of the yeast RNA exosome.
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25
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Wolin SL, Sim S, Chen X. Nuclear noncoding RNA surveillance: is the end in sight? Trends Genet 2012; 28:306-13. [PMID: 22475369 DOI: 10.1016/j.tig.2012.03.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 03/05/2012] [Accepted: 03/07/2012] [Indexed: 12/13/2022]
Abstract
Nuclear noncoding RNA (ncRNA) surveillance pathways play key roles in shaping the steady-state transcriptomes of eukaryotic cells. Defective and unneeded ncRNAs are primarily degraded by exoribonucleases that rely on protein cofactors to identify these RNAs. Recent studies have begun to elucidate both the mechanisms by which these cofactors recognize aberrant RNAs and the features that mark RNAs for degradation. One crucial RNA determinant is the presence of an accessible end; in addition, the failure of aberrant RNAs to fold into compact structures and assemble with specific binding proteins probably also contributes to their recognition and subsequent degradation. To date, ncRNA surveillance has been most extensively studied in budding yeast. However, mammalian cells possess nucleases and cofactors that have no known yeast counterparts, indicating that RNA surveillance pathways may be more complex in metazoans. Importantly, there is evidence that the failure of ncRNA surveillance pathways contributes to human disease.
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Affiliation(s)
- Sandra L Wolin
- Department of Cell Biology, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.
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26
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Lubas M, Chlebowski A, Dziembowski A, Jensen TH. Biochemistry and Function of RNA Exosomes. EUKARYOTIC RNASES AND THEIR PARTNERS IN RNA DEGRADATION AND BIOGENESIS, PART A 2012; 31:1-30. [DOI: 10.1016/b978-0-12-404740-2.00001-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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27
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Lin CL, Wang YT, Yang WZ, Hsiao YY, Yuan HS. Crystal structure of human polynucleotide phosphorylase: insights into its domain function in RNA binding and degradation. Nucleic Acids Res 2011; 40:4146-57. [PMID: 22210891 PMCID: PMC3351181 DOI: 10.1093/nar/gkr1281] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Human polynucleotide phosphorylase (hPNPase) is a 3′-to-5′ exoribonuclease that degrades specific mRNA and miRNA, and imports RNA into mitochondria, and thus regulates diverse physiological processes, including cellular senescence and homeostasis. However, the RNA-processing mechanism by hPNPase, particularly how RNA is bound via its various domains, remains obscure. Here, we report the crystal structure of an S1 domain-truncated hPNPase at a resolution of 2.1 Å. The trimeric hPNPase has a hexameric ring-like structure formed by six RNase PH domains, capped with a trimeric KH pore. Our biochemical and mutagenesis studies suggest that the S1 domain is not critical for RNA binding, and conversely, that the conserved GXXG motif in the KH domain directly participates in RNA binding in hPNPase. Our studies thus provide structural and functional insights into hPNPase, which uses a KH pore to trap a long RNA 3′ tail that is further delivered into an RNase PH channel for the degradation process. Structural RNA with short 3′ tails are, on the other hand, transported but not digested by hPNPase.
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Affiliation(s)
- Chia Liang Lin
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC
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Williams CW, Elmendorf HG. Identification and analysis of the RNA degrading complexes and machinery of Giardia lamblia using an in silico approach. BMC Genomics 2011; 12:586. [PMID: 22126454 PMCID: PMC3282835 DOI: 10.1186/1471-2164-12-586] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 11/29/2011] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND RNA degradation is critical to the survival of all cells. With increasing evidence for pervasive transcription in cells, RNA degradation has gained recognition as a means of regulating gene expression. Yet, RNA degradation machinery has been studied extensively in only a few eukaryotic organisms, including Saccharomyces cerevisiae and humans. Giardia lamblia is a parasitic protist with unusual genomic traits: it is binucleated and tetraploid, has a very compact genome, displays a theme of genomic minimalism with cellular machinery commonly comprised of a reduced number of protein components, and has a remarkably large population of long, stable, noncoding, antisense RNAs. RESULTS Here we use in silico approaches to investigate the major RNA degradation machinery in Giardia lamblia and compare it to a broad array of other parasitic protists. We have found key constituents of the deadenylation and decapping machinery and of the 5'-3' RNA degradation pathway. We have similarly found that all of the major 3'-5' RNA degradation pathways are present in Giardia, including both exosome-dependent and exosome-independent machinery. However, we observe significant loss of RNA degradation machinery genes that will result in important differences in the protein composition, and potentially functionality, of the various RNA degradation pathways. This is most apparent in the exosome, the central mediator of 3'-5' degradation, which apparently contains an altered core configuration in both Giardia and Plasmodium, with only four, instead of the canonical six, distinct subunits. Additionally the exosome in Giardia is missing both the Rrp6, Nab3, and Nrd1 proteins, known to be key regulators of noncoding transcript stability in other cells. CONCLUSIONS These findings suggest that although the full complement of the major RNA degradation mechanisms were present - and likely functional - early in eukaryotic evolution, the composition and function of the complexes is more variable than previously appreciated. We suggest that the missing components of the exosome complex provide an explanation for the stable abundance of sterile RNA species in Giardia.
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Affiliation(s)
| | - Heidi G Elmendorf
- Department of Biology, Georgetown University, Washington, DC 20057, USA
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Januszyk K, Liu Q, Lima CD. Activities of human RRP6 and structure of the human RRP6 catalytic domain. RNA (NEW YORK, N.Y.) 2011; 17:1566-77. [PMID: 21705430 PMCID: PMC3153979 DOI: 10.1261/rna.2763111] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 05/19/2011] [Indexed: 05/24/2023]
Abstract
The eukaryotic RNA exosome is a highly conserved multi-subunit complex that catalyzes degradation and processing of coding and noncoding RNA. A noncatalytic nine-subunit exosome core interacts with Rrp44 and Rrp6, two subunits that possess processive and distributive 3'-to-5' exoribonuclease activity, respectively. While both Rrp6 and Rrp44 are responsible for RNA processing in budding yeast, Rrp6 may play a more prominent role in processing, as it has been demonstrated to be inhibited by stable RNA secondary structure in vitro and because the null allele in budding yeast leads to the buildup of specific structured RNA substrates. Human RRP6, otherwise known as PM/SCL-100 or EXOSC10, shares sequence similarity to budding yeast Rrp6 and is proposed to catalyze 3'-to-5' exoribonuclease activity on a variety of nuclear transcripts including ribosomal RNA subunits, RNA that has been poly-adenylated by TRAMP, as well as other nuclear RNA transcripts destined for processing and/or destruction. To characterize human RRP6, we expressed the full-length enzyme as well as truncation mutants that retain catalytic activity, compared their activities to analogous constructs for Saccharomyces cerevisiae Rrp6, and determined the X-ray structure of a human construct containing the exoribonuclease and HRDC domains that retains catalytic activity. Structural data show that the human active site is more exposed when compared to the yeast structure, and biochemical data suggest that this feature may play a role in the ability of human RRP6 to productively engage and degrade structured RNA substrates more effectively than the analogous budding yeast enzyme.
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Affiliation(s)
- Kurt Januszyk
- Structural Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Quansheng Liu
- Structural Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Christopher D. Lima
- Structural Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
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