1
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Scheepbouwer C, Aparicio-Puerta E, Gómez-Martin C, van Eijndhoven MA, Drees EE, Bosch L, de Jong D, Wurdinger T, Zijlstra JM, Hackenberg M, Gerber A, Pegtel DM. Full-length tRNAs lacking a functional CCA tail are selectively sorted into the lumen of extracellular vesicles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.12.593148. [PMID: 38765958 PMCID: PMC11100784 DOI: 10.1101/2024.05.12.593148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Small extracellular vesicles (sEVs) are heterogenous lipid membrane particles typically less than 200 nm in size and secreted by most cell types either constitutively or upon activation signals. sEVs isolated from biofluids contain RNAs, including small non-coding RNAs (ncRNAs), that can be either encapsulated within the EV lumen or bound to the EV surface. EV-associated microRNAs (miRNAs) are, despite a relatively low abundance, extensively investigated for their selective incorporation and their role in cell-cell communication. In contrast, the sorting of highly-structured ncRNA species is understudied, mainly due to technical limitations of traditional small RNA sequencing protocols. Here, we adapted ALL-tRNAseq to profile the relative abundance of highly structured and potentially methylated small ncRNA species, including transfer RNAs (tRNAs), small nucleolar RNAs (snoRNAs), and Y RNAs in bulk EV preparations. We determined that full-length tRNAs, typically 75 to 90 nucleotides in length, were the dominant small ncRNA species (>60% of all reads in the 18-120 nucleotides size-range) in all cell culture-derived EVs, as well as in human plasma-derived EV samples, vastly outnumbering 21 nucleotides-long miRNAs. Nearly all EV-associated tRNAs were protected from external RNAse treatment, indicating a location within the EV lumen. Strikingly, the vast majority of luminal-sorted, full-length, nucleobase modification-containing EV-tRNA sequences, harbored a dysfunctional 3' CCA tail, 1 to 3 nucleotides truncated, rendering them incompetent for amino acid loading. In contrast, in non-EV associated extracellular particle fractions (NVEPs), tRNAs appeared almost exclusively fragmented or 'nicked' into tRNA-derived small RNAs (tsRNAs) with lengths between 18 to 35 nucleotides. We propose that in mammalian cells, tRNAs that lack a functional 3' CCA tail are selectively sorted into EVs and shuttled out of the producing cell, offering a new perspective into the physiological role of secreted EVs and luminal cargo-selection.
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Affiliation(s)
- Chantal Scheepbouwer
- Department of Neurosurgery, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
- Cancer Center Amsterdam, Cancer Biology, Amsterdam, Netherlands
- Department of Pathology, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
| | - Ernesto Aparicio-Puerta
- Department of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, NY, USA
| | - Cristina Gómez-Martin
- Department of Pathology, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, Netherlands
| | - Monique A.J. van Eijndhoven
- Department of Pathology, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, Netherlands
| | - Esther E.E. Drees
- Department of Pathology, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, Netherlands
- Department of Hematology, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
| | - Leontien Bosch
- Department of Pathology, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, Netherlands
| | - Daphne de Jong
- Department of Pathology, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, Netherlands
| | - Thomas Wurdinger
- Department of Neurosurgery, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
- Cancer Center Amsterdam, Cancer Biology, Amsterdam, Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, Netherlands
| | - Josée M. Zijlstra
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, Netherlands
- Department of Hematology, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
| | - Michael Hackenberg
- Bioinformatics Laboratory, Biomedical Research Centre (CIBM), Biotechnology Institute, PTS, Avda. del Conocimiento s/n, 18100 Granada, Spain
- Genetics Department, Faculty of Science, Universidad de Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain
- Excellence Research Unit “Modeling Nature” (MNat), University of Granada, Spain
- Instituto de Investigación Biosanitaria ibs. Granada, University Hospitals of Granada-University of Granada, Spain; Conocimiento s/n 18100, Granada. Spain
| | - Alan Gerber
- Department of Neurosurgery, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
- Cancer Center Amsterdam, Cancer Biology, Amsterdam, Netherlands
| | - D. Michiel Pegtel
- Department of Pathology, Cancer Center Amsterdam, Amsterdam University Medical Center, VU University, Amsterdam, Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, Netherlands
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2
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Khomarbaghi Z, Ngan WY, Ayan GB, Lim S, Dechow-Seligmann G, Nandy P, Gallie J. Large-scale duplication events underpin population-level flexibility in tRNA gene copy number in Pseudomonas fluorescens SBW25. Nucleic Acids Res 2024; 52:2446-2462. [PMID: 38296823 PMCID: PMC10954465 DOI: 10.1093/nar/gkae049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/10/2024] [Accepted: 01/15/2024] [Indexed: 02/02/2024] Open
Abstract
The complement of tRNA genes within a genome is typically considered to be a (relatively) stable characteristic of an organism. Here, we demonstrate that bacterial tRNA gene set composition can be more flexible than previously appreciated, particularly regarding tRNA gene copy number. We report the high-rate occurrence of spontaneous, large-scale, tandem duplication events in laboratory populations of the bacterium Pseudomonas fluorescens SBW25. The identified duplications are up to ∼1 Mb in size (∼15% of the wildtype genome) and are predicted to change the copy number of up to 917 genes, including several tRNA genes. The observed duplications are inherently unstable: they occur, and are subsequently lost, at extremely high rates. We propose that this unusually plastic type of mutation provides a mechanism by which tRNA gene set diversity can be rapidly generated, while simultaneously preserving the underlying tRNA gene set in the absence of continued selection. That is, if a tRNA set variant provides no fitness advantage, then high-rate segregation of the duplication ensures the maintenance of the original tRNA gene set. However, if a tRNA gene set variant is beneficial, the underlying duplication fragment(s) may persist for longer and provide raw material for further, more stable, evolutionary change.
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Affiliation(s)
- Zahra Khomarbaghi
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Wing Y Ngan
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Gökçe B Ayan
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Sungbin Lim
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Gunda Dechow-Seligmann
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Pabitra Nandy
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Jenna Gallie
- Microbial Evolutionary Dynamics Research Group, Department of Theoretical Biology, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
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3
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Cabrelle C, Giorgi FM, Mercatelli D. Quantitative and qualitative detection of tRNAs, tRNA halves and tRFs in human cancer samples: Molecular grounds for biomarker development and clinical perspectives. Gene 2024; 898:148097. [PMID: 38128792 DOI: 10.1016/j.gene.2023.148097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 12/04/2023] [Accepted: 12/18/2023] [Indexed: 12/23/2023]
Abstract
Transfer RNAs (tRNAs) are small non-coding RNAs playing a central role during protein synthesis. Besides translation, growing evidence suggests that in many contexts, precursor or mature tRNAs can also be processed into smaller fragments playing many non-canonical regulatory roles in different biological pathways with oncogenic relevance. Depending on the source, these molecules can be classified as tRNA halves (also known as tiRNAs) or tRNA-derived fragments (tRFs), and furtherly divided into 5'-tRNA and 3'-tRNA halves, or tRF-1, tRF-2, tRF-3, tRF-5, and i-tRF, respectively. Unlike DNA and mRNA, high-throughput sequencing of tRNAs is challenging, because of technical limitations of currently developed sequencing methods. In recent years, different sequencing approaches have been proposed allowing the quantification and identification of an increasing number of tRNA fragments with critical functions in distinct physiological and pathophysiological processes. In the present review, we discussed pros and cons of recent advances in different sequencing methods, also introducing the expanding repertoire of bioinformatics tool and resources specifically focused on tRNA research and discussing current issues in the study of these small RNA molecules. Furthermore, we discussed the potential value of tRNA fragments as diagnostic and prognostic biomarkers for different types of cancers.
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Affiliation(s)
- Chiara Cabrelle
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy.
| | | | - Daniele Mercatelli
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy.
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4
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Padhiar NH, Katneni U, Komar AA, Motorin Y, Kimchi-Sarfaty C. Advances in methods for tRNA sequencing and quantification. Trends Genet 2024; 40:276-290. [PMID: 38123442 DOI: 10.1016/j.tig.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 12/23/2023]
Abstract
In the past decade tRNA sequencing (tRNA-seq) has attracted considerable attention as an important tool for the development of novel approaches to quantify highly modified tRNA species and to propel tRNA research aimed at understanding the cellular physiology and disease and development of tRNA-based therapeutics. Many methods are available to quantify tRNA abundance while accounting for modifications and tRNA charging/acylation. Advances in both library preparation methods and bioinformatic workflows have enabled developments in next-generation sequencing (NGS) workflows. Other approaches forgo NGS applications in favor of hybridization-based approaches. In this review we provide a brief comparative overview of various tRNA quantification approaches, focusing on the advantages and disadvantages of these methods, which together facilitate reliable tRNA quantification.
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Affiliation(s)
- Nigam H Padhiar
- Hemostasis Branch 1, Division of Hemostasis, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
| | - Upendra Katneni
- Hemostasis Branch 1, Division of Hemostasis, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
| | - Anton A Komar
- Department of Biological, Geological, and Environmental Sciences, Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH, USA
| | - Yuri Motorin
- CNRS-Université de Lorraine, UAR 2008, IBSLor UMR 7365 IMoPA, Nancy, France.
| | - Chava Kimchi-Sarfaty
- Hemostasis Branch 1, Division of Hemostasis, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA.
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5
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Nakano Y, Gamper H, McGuigan H, Maharjan S, Sun Z, Krishnan K, Yigit E, Li NS, Piccirilli JA, Kleiner R, Nichols N, Hou YM. Genome-Wide Profiling of tRNA Using an Unexplored Reverse Transcriptase with High Processivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.09.569604. [PMID: 38106225 PMCID: PMC10723452 DOI: 10.1101/2023.12.09.569604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Monitoring the dynamic changes of cellular tRNA pools is challenging, due to the extensive post-transcriptional modifications of individual species. The most critical component in tRNAseq is a processive reverse transcriptase (RT) that can read through each modification with high efficiency. Here we show that the recently developed group-II intron RT Induro has the processivity and efficiency necessary to profile tRNA dynamics. Using our Induro-tRNAseq, simpler and more comprehensive than the best methods to date, we show that Induro progressively increases readthrough of tRNA over time and that the mechanism of increase is selective removal of RT stops, without altering the misincorporation frequency. We provide a parallel dataset of the misincorporation profile of Induro relative to the related TGIRT RT to facilitate the prediction of non-annotated modifications. We report an unexpected modification profile among human proline isoacceptors, absent from mouse and lower eukaryotes, that indicates new biology of decoding proline codons.
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6
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van Breugel ME, van Kruijsbergen I, Mittal C, Lieftink C, Brouwer I, van den Brand T, Kluin RJC, Hoekman L, Menezes RX, van Welsem T, Del Cortona A, Malik M, Beijersbergen RL, Lenstra TL, Verstrepen KJ, Pugh BF, van Leeuwen F. Locus-specific proteome decoding reveals Fpt1 as a chromatin-associated negative regulator of RNA polymerase III assembly. Mol Cell 2023; 83:4205-4221.e9. [PMID: 37995691 DOI: 10.1016/j.molcel.2023.10.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 09/27/2023] [Accepted: 10/26/2023] [Indexed: 11/25/2023]
Abstract
Transcription of tRNA genes by RNA polymerase III (RNAPIII) is tuned by signaling cascades. The emerging notion of differential tRNA gene regulation implies the existence of additional regulatory mechanisms. However, tRNA gene-specific regulators have not been described. Decoding the local chromatin proteome of a native tRNA gene in yeast revealed reprogramming of the RNAPIII transcription machinery upon nutrient perturbation. Among the dynamic proteins, we identified Fpt1, a protein of unknown function that uniquely occupied RNAPIII-regulated genes. Fpt1 binding at tRNA genes correlated with the efficiency of RNAPIII eviction upon nutrient perturbation and required the transcription factors TFIIIB and TFIIIC but not RNAPIII. In the absence of Fpt1, eviction of RNAPIII was reduced, and the shutdown of ribosome biogenesis genes was impaired upon nutrient perturbation. Our findings provide support for a chromatin-associated mechanism required for RNAPIII eviction from tRNA genes and tuning the physiological response to changing metabolic demands.
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Affiliation(s)
- Maria Elize van Breugel
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands
| | - Ila van Kruijsbergen
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands
| | - Chitvan Mittal
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA; Department of Molecular Biology and Genetics, Biotechnology Building, Cornell University, Ithaca, NY 14853, USA
| | - Cor Lieftink
- Division of Molecular Carcinogenesis and Robotics and Screening Center, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands
| | - Ineke Brouwer
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands; Division of Gene Regulation, Netherlands Cancer Institute, Oncode Institute, Amsterdam 1066 CX, the Netherlands
| | - Teun van den Brand
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands
| | - Roelof J C Kluin
- Genomics Core Facility, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands
| | - Liesbeth Hoekman
- Proteomics Facility, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands
| | - Renée X Menezes
- Biostatistics Centre and Division of Psychosocial Research and Epidemiology, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands
| | - Tibor van Welsem
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands
| | - Andrea Del Cortona
- VIB-KU Leuven Center for Microbiology, KU Leuven, 3001 Heverlee-Leuven, Belgium
| | - Muddassir Malik
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands
| | - Roderick L Beijersbergen
- Division of Molecular Carcinogenesis and Robotics and Screening Center, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands; Genomics Core Facility, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands
| | - Tineke L Lenstra
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands; Division of Gene Regulation, Netherlands Cancer Institute, Oncode Institute, Amsterdam 1066 CX, the Netherlands
| | - Kevin J Verstrepen
- VIB-KU Leuven Center for Microbiology, KU Leuven, 3001 Heverlee-Leuven, Belgium
| | - B Franklin Pugh
- Department of Molecular Biology and Genetics, Biotechnology Building, Cornell University, Ithaca, NY 14853, USA
| | - Fred van Leeuwen
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam 1066 CX, the Netherlands; Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam 1105 AZ, the Netherlands.
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7
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Kuhle B, Chen Q, Schimmel P. tRNA renovatio: Rebirth through fragmentation. Mol Cell 2023; 83:3953-3971. [PMID: 37802077 PMCID: PMC10841463 DOI: 10.1016/j.molcel.2023.09.016] [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: 05/23/2023] [Revised: 08/15/2023] [Accepted: 09/12/2023] [Indexed: 10/08/2023]
Abstract
tRNA function is based on unique structures that enable mRNA decoding using anticodon trinucleotides. These structures interact with specific aminoacyl-tRNA synthetases and ribosomes using 3D shape and sequence signatures. Beyond translation, tRNAs serve as versatile signaling molecules interacting with other RNAs and proteins. Through evolutionary processes, tRNA fragmentation emerges as not merely random degradation but an act of recreation, generating specific shorter molecules called tRNA-derived small RNAs (tsRNAs). These tsRNAs exploit their linear sequences and newly arranged 3D structures for unexpected biological functions, epitomizing the tRNA "renovatio" (from Latin, meaning renewal, renovation, and rebirth). Emerging methods to uncover full tRNA/tsRNA sequences and modifications, combined with techniques to study RNA structures and to integrate AI-powered predictions, will enable comprehensive investigations of tRNA fragmentation products and new interaction potentials in relation to their biological functions. We anticipate that these directions will herald a new era for understanding biological complexity and advancing pharmaceutical engineering.
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Affiliation(s)
- Bernhard Kuhle
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA; Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Qi Chen
- Molecular Medicine Program, Department of Human Genetics, and Division of Urology, Department of Surgery, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Paul Schimmel
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.
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Chen Q, Zhou T. Emerging functional principles of tRNA-derived small RNAs and other regulatory small RNAs. J Biol Chem 2023; 299:105225. [PMID: 37673341 PMCID: PMC10562873 DOI: 10.1016/j.jbc.2023.105225] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 08/22/2023] [Accepted: 08/28/2023] [Indexed: 09/08/2023] Open
Abstract
Recent advancements in small RNA sequencing have unveiled a previously hidden world of regulatory small noncoding RNAs (sncRNAs) that extend beyond the well-studied small interfering RNAs, microRNAs, and piwi-interacting RNAs. This exploration, starting with tRNA-derived small RNAs, has led to the discovery of a diverse universe of sncRNAs derived from various longer structured RNAs such as rRNAs, small nucleolar RNAs, small nuclear RNAs, Y RNAs, and vault RNAs, with exciting uncharted functional possibilities. In this perspective, we discuss the emerging functional principles of sncRNAs beyond the well-known RNAi-like mechanisms, focusing on those that operate independent of linear sequence complementarity but rather function in an aptamer-like fashion. Aptamers use 3D structure for specific interactions with ligands and are modulated by RNA modifications and subcellular environments. Given that aptamer-like sncRNA functions are widespread and present in species lacking RNAi, they may represent an ancient functional principle that predates RNAi. We propose a rethinking of the origin of RNAi and its relationship with these aptamer-like functions in sncRNAs and how these complementary mechanisms shape biological processes. Lastly, the aptamer-like function of sncRNAs highlights the need for caution in using small RNA mimics in research and therapeutics, as their specificity is not restricted solely to linear sequence.
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Affiliation(s)
- Qi Chen
- Molecular Medicine Program, University of Utah School of Medicine, Salt Lake City, Utah, USA; Division of Urology, Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah, USA; Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, USA.
| | - Tong Zhou
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada, USA.
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9
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Guo LT, Pyle AM. End-to-end RT-PCR of long RNA and highly structured RNA. Methods Enzymol 2023; 691:3-15. [PMID: 37914451 DOI: 10.1016/bs.mie.2023.07.002] [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: 11/03/2023]
Abstract
RNA molecules play important roles in numerous normal cellular processes and disease states, from protein coding to gene regulation. RT-PCR, applying the power of polymerase chain reaction (PCR) to RNA by coupling reverse transcription with PCR, is one of the most important techniques to characterize RNA transcripts and monitor gene expression. The ability to analyze full-length RNA transcripts and detect their expression is critical to decipher their biological functions. However, due to the low processivity of retroviral reverse transcriptases (RTs), we can only monitor a small fraction of long RNA transcripts, especially those containing stable secondary and tertiary structures. The full-length sequences can only be deduced by computational analysis, which is often misleading. Group II intron-encoded RTs are a new type of RT enzymes. They have evolved specialized structural elements that unwind template structures and maintain close contact with the RNA template. Therefore, group II intron-encoded RTs are more processive than the retroviral RTs. The discovery, optimization and deployment of processive group II intron RTs provide us the opportunity to analyze RNA transcripts with single molecule resolution. MarathonRT, the most processive group II intron RT, has been extensively optimized for processive reverse transcription. In this chapter, we use MarathonRT to deliver a general protocol for long amplicon generation by RT-PCR, and also provide guidance for troubleshooting and further optimization.
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Affiliation(s)
- Li-Tao Guo
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, United States
| | - Anna Marie Pyle
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, United States; Department of Chemistry, Yale University, New Haven, CT, United States; Howard Hughes Medical Institute, Chevy Chase, MD, United States.
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10
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Scheepbouwer C, Hackenberg M, van Eijndhoven MAJ, Gerber A, Pegtel M, Gómez-Martín C. NORMSEQ: a tool for evaluation, selection and visualization of RNA-Seq normalization methods. Nucleic Acids Res 2023:7175338. [PMID: 37216599 DOI: 10.1093/nar/gkad429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/24/2023] [Accepted: 05/09/2023] [Indexed: 05/24/2023] Open
Abstract
RNA-sequencing has become one of the most used high-throughput approaches to gain knowledge about the expression of all different RNA subpopulations. However, technical artifacts, either introduced during library preparation and/or data analysis, can influence the detected RNA expression levels. A critical step, especially in large and low input datasets or studies, is data normalization, which aims at eliminating the variability in data that is not related to biology. Many normalization methods have been developed, each of them relying on different assumptions, making the selection of the appropriate normalization strategy key to preserve biological information. To address this, we developed NormSeq, a free web-server tool to systematically assess the performance of normalization methods in a given dataset. A key feature of NormSeq is the implementation of information gain to guide the selection of the best normalization method, which is crucial to eliminate or at least reduce non-biological variability. Altogether, NormSeq provides an easy-to-use platform to explore different aspects of gene expression data with a special focus on data normalization to help researchers, even without bioinformatics expertise, to obtain reliable biological inference from their data. NormSeq is freely available at: https://arn.ugr.es/normSeq.
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Affiliation(s)
- Chantal Scheepbouwer
- Department of Neurosurgery, Cancer Center Amsterdam, Amsterdam University Medical Center (UMC) location Vrije Universiteit Amsterdam, Amsterdam 1081HV, The Netherlands
- Cancer Center Amsterdam, Cancer Biology, Amsterdam, The Netherlands
- Department of Pathology, Cancer Center Amsterdam, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam 1081HV, The Netherlands
| | - Michael Hackenberg
- Genetics Genetics Department, Faculty of Science, Universidad de Granada, Campus de Fuentenueva s/n, 18071, Granada, Spain
- Bioinformatics Laboratory, Biomedical Research Centre (CIBM), Biotechnology Institute, PTS, Avda. del Conocimiento s/n, 18100 Granada, Spain
- Excellence Research Unit "Modeling Nature" (MNat), University of Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, University Hospitals of Granada-University of Granada, Spain, Conocimiento s/n, 18100, Granada, Spain
| | - Monique A J van Eijndhoven
- Department of Pathology, Cancer Center Amsterdam, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam 1081HV, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Alan Gerber
- Department of Neurosurgery, Cancer Center Amsterdam, Amsterdam University Medical Center (UMC) location Vrije Universiteit Amsterdam, Amsterdam 1081HV, The Netherlands
- Cancer Center Amsterdam, Cancer Biology, Amsterdam, The Netherlands
| | - Michiel Pegtel
- Department of Pathology, Cancer Center Amsterdam, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam 1081HV, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Cristina Gómez-Martín
- Department of Pathology, Cancer Center Amsterdam, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam 1081HV, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
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