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Xu W, Liu X, Li J, Sun C, Chen L, Zhou J, Li K, Li Q, Meng A, Sun Q. ULI-ssDRIP-seq revealed R-loop dynamics during vertebrate early embryogenesis. CELL INSIGHT 2024; 3:100179. [PMID: 38974143 PMCID: PMC11225018 DOI: 10.1016/j.cellin.2024.100179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/29/2024] [Accepted: 05/29/2024] [Indexed: 07/09/2024]
Abstract
R-loop, a chromatin structure containing one RNA:DNA hybrid and one unpaired single-stranded DNA, plays multiple biological roles. However, due to technical limitations, the landscapes and potential functions of R-loops during embryogenesis remain elusive. Here, we developed a quantitative and high-resolution ultra-low input R-loop profiling method, named ULI-ssDRIP-seq, which can map global R-loops with as few as 1000 cells. By using ULI-ssDRIP-seq, we reveal the R-loop dynamics in the zebrafish from gametes to early embryos. In oocytes, the R-loop level is relatively low in most regions of the nuclear genome, except maternal-inherited rDNA and mitochondrial genome. The correlation between R-loop and CG methylation dynamics during early development is relatively weak. Furthermore, either up- or down-regulation of global R-loops by knockdown or overexpression of RNase H1 causes a delay of embryonic development with dramatic expression changes in zygotic and maternal genes. This study provides comprehensive R-loop landscapes during early vertebrate embryogenesis and demonstrates the implication of R-loops in embryonic development.
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Affiliation(s)
- Wei Xu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Xin Liu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Jinjin Li
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Changbin Sun
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Luxi Chen
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Jincong Zhou
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Kuan Li
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Qin Li
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Anming Meng
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Qianwen Sun
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
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2
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Li Z, Liu J, Liang M, Guo Y, Chen X, Wu H, Jin S. De novo assembly of the complete mitochondrial genome of pepino (Solanum muricatum) using PacBio HiFi sequencing: insights into structure, phylogenetic implications, and RNA editing. BMC PLANT BIOLOGY 2024; 24:361. [PMID: 38702620 PMCID: PMC11069145 DOI: 10.1186/s12870-024-04978-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 04/02/2024] [Indexed: 05/06/2024]
Abstract
BACKGROUND Solanum muricatum is an emerging horticultural fruit crop with rich nutritional and antioxidant properties. Although the chromosome-scale genome of this species has been sequenced, its mitochondrial genome sequence has not been reported to date. RESULTS PacBio HiFi sequencing was used to assemble the circular mitogenome of S. muricatum, which was 433,466 bp in length. In total, 38 protein-coding, 19 tRNA, and 3 rRNA genes were annotated. The reticulate mitochondrial conformations with multiple junctions were verified by polymerase chain reaction, and codon usage, sequence repeats, and gene migration from chloroplast to mitochondrial genome were determined. A collinearity analysis of eight Solanum mitogenomes revealed high structural variability. Overall, 585 RNA editing sites in protein coding genes were identified based on RNA-seq data. Among them, mttB was the most frequently edited (52 times), followed by ccmB (46 times). A phylogenetic analysis based on the S. muricatum mitogenome and those of 39 other taxa (including 25 Solanaceae species) revealed the evolutionary and taxonomic status of S. muricatum. CONCLUSIONS We provide the first report of the assembled and annotated S. muricatum mitogenome. This information will help to lay the groundwork for future research on the evolutionary biology of Solanaceae species. Furthermore, the results will assist the development of molecular breeding strategies for S. muricatum based on the most beneficial agronomic traits of this species.
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Affiliation(s)
- Ziwei Li
- Yunnan Agricultural University, Kunming, Yunnan, 650201, China
| | - Jiaxun Liu
- Horticultural Research Institute Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, 650205, China
| | - Mingtai Liang
- Horticultural Research Institute Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, 650205, China
| | - Yanbing Guo
- Yunnan Agricultural University, Kunming, Yunnan, 650201, China
| | - Xia Chen
- Horticultural Research Institute Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, 650205, China
| | - Hongzhi Wu
- Yunnan Agricultural University, Kunming, Yunnan, 650201, China.
| | - Shoulin Jin
- Yunnan Agricultural University, Kunming, Yunnan, 650201, China.
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Yan Y, Guo H, Li W. Endoribonuclease DNE1 Promotes Ethylene Response by Modulating EBF1/2 mRNA Processing in Arabidopsis. Int J Mol Sci 2024; 25:2138. [PMID: 38396815 PMCID: PMC10888710 DOI: 10.3390/ijms25042138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 02/04/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
The gaseous phytohormone ethylene plays a crucial role in plant growth, development, and stress responses. In the ethylene signal transduction cascade, the F-box proteins EIN3-BINDING F-BOX 1 (EBF1) and EBF2 are identified as key negative regulators governing ethylene sensitivity. The translation and processing of EBF1/2 mRNAs are tightly controlled, and their 3' untranslated regions (UTRs) are critical in these regulations. However, despite their significance, the exact mechanisms modulating the processing of EBF1/2 mRNAs remain poorly understood. In this work, we identified the gene DCP1-ASSOCIATED NYN ENDORIBONUCLEASE 1 (DNE1), which encodes an endoribonuclease and is induced by ethylene treatment, as a positive regulator of ethylene response. The loss of function mutant dne1-2 showed mild ethylene insensitivity, highlighting the importance of DNE1 in ethylene signaling. We also found that DNE1 colocalizes with ETHYLENE INSENSITIVE 2 (EIN2), the core factor manipulating the translation of EBF1/2, and targets the P-body in response to ethylene. Further analysis revealed that DNE1 negatively regulates the abundance of EBF1/2 mRNAs by recognizing and cleaving their 3'UTRs, and it also represses their translation. Moreover, the dne1 mutant displays hypersensitivity to 1,4-dithiothreitol (DTT)-induced ER stress and oxidative stress, indicating the function of DNE1 in stress responses. This study sheds light on the essential role of DNE1 as a modulator of ethylene signaling through regulation of EBF1/2 mRNA processing. Our findings contribute to the understanding of the intricate regulatory process of ethylene signaling and provide insights into the significance of ribonuclease in stress responses.
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Affiliation(s)
- Yan Yan
- Harbin Institute of Technology, Harbin 150001, China;
- Department of Biology, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory, Guangdong Higher Education Institute, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hongwei Guo
- Department of Biology, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory, Guangdong Higher Education Institute, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Wenyang Li
- Department of Biology, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory, Guangdong Higher Education Institute, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
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4
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Ha YH, Chang KS, Gil HY. Characteristics of chloroplast and mitochondrial genomes and intracellular gene transfer in the Korean endemic shrub, Sophora koreensis Nakai (Fabaceae). Gene 2024; 894:147963. [PMID: 37926173 DOI: 10.1016/j.gene.2023.147963] [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: 08/22/2023] [Revised: 10/24/2023] [Accepted: 11/01/2023] [Indexed: 11/07/2023]
Abstract
Sophora koreensis Nakai, an endemic species distributed only in the Korean Peninsula, is of great geographical, economic, and taxonomic importance. Although its complete chloroplast (cp) genome sequence has been reported, its mitochondrial (mt) genome sequence has not yet been studied. Therefore, in this study, we aimed to investigate its mt genome sequence and compare it with those reported for other Fabaceae species. Total genomic DNA was extracted from fresh S. koreensis leaves collected from natural habitats in Gangwon-do Province, South Korea. This was followed by polymerase chain reaction (PCR) amplification of cpDNA insertions in the mt genome and the detection of microsatellites and dispersed repeats in the cp and mt genomes. Finally, the cp and mt genomes of S. koreensis were compared with those reported for other Fabaceae species. The cp sequence of S. koreensis showed identical gene orders and contents as those previously reported. Only six substitutions and one deletion were detected with 99 % homology. Conversely, the complete mt genome sequence, which was 517,845 bp in length and encoded 61 genes, including 43 protein-coding, 15 transfer RNAs, and 3 ribosomal RNA genes, was considerably different from that of S. japonica in terms of gene order and composition. Further, the mt genome of S. koreensis included ca. 7 and 3 kb insertions, representing an intracellular gene transfer (IGT) event, and the regions with these insertions were determined to be originally present in the cp genome. This IGT event was also confirmed via PCR amplification. IGT events can be induced via biological gene expression control or the use of repetitive sequences, and they provide important insights into the evolutionary lineage of S. koreensis. However, further studies are needed to clarify the gene transfer mechanisms between the two organelles.
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Affiliation(s)
- Young-Ho Ha
- Division of Forest Biodiversity, Korea National Arboretum, Pocheon-si, Gyeonggi-do 11186, Republic of Korea
| | - Kae Sun Chang
- DMZ Botanic Garden, Korea National Arboretum, Yanggu-gun, Gangwon-do 24564, Republic of Korea
| | - Hee-Young Gil
- Division of Forest Biodiversity, Korea National Arboretum, Pocheon-si, Gyeonggi-do 11186, Republic of Korea.
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5
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Zhang W, Yang Z, Wang W, Sun Q. Primase promotes the competition between transcription and replication on the same template strand resulting in DNA damage. Nat Commun 2024; 15:73. [PMID: 38168108 PMCID: PMC10761990 DOI: 10.1038/s41467-023-44443-0] [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: 06/20/2023] [Accepted: 12/13/2023] [Indexed: 01/05/2024] Open
Abstract
Transcription-replication conflicts (TRCs), especially Head-On TRCs (HO-TRCs) can introduce R-loops and DNA damage, however, the underlying mechanisms are still largely unclear. We previously identified a chloroplast-localized RNase H1 protein AtRNH1C that can remove R-loops and relax HO-TRCs for genome integrity. Through the mutagenesis screen, we identify a mutation in chloroplast-localized primase ATH that weakens the binding affinity of DNA template and reduces the activities of RNA primer synthesis and delivery. This slows down DNA replication, and reduces competition of transcription-replication, thus rescuing the developmental defects of atrnh1c. Strand-specific DNA damage sequencing reveals that HO-TRCs cause DNA damage at the end of the transcription unit in the lagging strand and overexpression of ATH can boost HO-TRCs and exacerbates DNA damage. Furthermore, mutation of plastid DNA polymerase Pol1A can similarly rescue the defects in atrnh1c mutants. Taken together these results illustrate a potentially conserved mechanism among organisms, of which the primase activity can promote the occurrence of transcription-replication conflicts leading to HO-TRCs and genome instability.
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Affiliation(s)
- Weifeng Zhang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
- Tsinghua-Peking Center for Life Sciences, 100084, Beijing, China
| | - Zhuo Yang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
- Tsinghua-Peking Center for Life Sciences, 100084, Beijing, China
| | - Wenjie Wang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
- Tsinghua-Peking Center for Life Sciences, 100084, Beijing, China
| | - Qianwen Sun
- Center for Plant Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China.
- Tsinghua-Peking Center for Life Sciences, 100084, Beijing, China.
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He Z, Li M, Pan X, Peng Y, Shi Y, Han Q, Shi M, She L, Borovskii G, Chen X, Gu X, Cheng X, Zhang W. R-loops act as regulatory switches modulating transcription of COLD-responsive genes in rice. THE NEW PHYTOLOGIST 2024; 241:267-282. [PMID: 37849024 DOI: 10.1111/nph.19315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 09/22/2023] [Indexed: 10/19/2023]
Abstract
COLD is a major naturally occurring stress that usually causes complex symptoms and severe yield loss in crops. R-loops function in various cellular processes, including development and stress responses, in plants. However, how R-loops function in COLD responses is largely unknown in COLD susceptible crops like rice (Oryza sativa L.). We conducted DRIP-Seq along with other omics data (RNA-Seq, DNase-Seq and ChIP-Seq) in rice with or without COLD treatment. COLD treatment caused R-loop reprogramming across the genome. COLD-biased R-loops had higher GC content and novel motifs for the binding of distinct transcription factors (TFs). Moreover, R-loops can directly/indirectly modulate the transcription of a subset of COLD-responsive genes, which can be mediated by R-loop overlapping TF-centered or cis-regulatory element-related regulatory networks and lncRNAs, accounting for c. 60% of COLD-induced expression of differential genes in rice, which is different from the findings in Arabidopsis. We validated two R-loop loci with contrasting (negative/positive) roles in the regulation of two individual COLD-responsive gene expression, as potential targets for enhanced COLD resistance. Our study provides detailed evidence showing functions of R-loop reprogramming during COLD responses and provides some potential R-loop loci for genetic and epigenetic manipulation toward breeding of rice varieties with enhanced COLD tolerance.
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Affiliation(s)
- Zexue He
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Mengqi Li
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Xiucai Pan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
- Xiangyang Academy of Agricultural Sciences, Xiangyang, Hubei Province, 441057, China
| | - Yulian Peng
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Yining Shi
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Qi Han
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Manli Shi
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Linwei She
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Gennadii Borovskii
- Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch of Russian Academy of Sciences (SB RAS) Irkutsk, Lermontova, 664033, Russia
| | - Xiaojun Chen
- Key Lab of Agricultural Biotechnology of Ningxia, Ningxia Academy of Agriculture and Forestry Sciences, YinChuan, 750002, China
| | - Xiaofeng Gu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xuejiao Cheng
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Wenli Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry (CIC-MCP), Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
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7
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Tripathi D, Oldenburg DJ, Bendich AJ. Ribonucleotide and R-Loop Damage in Plastid DNA and Mitochondrial DNA during Maize Development. PLANTS (BASEL, SWITZERLAND) 2023; 12:3161. [PMID: 37687407 PMCID: PMC10489836 DOI: 10.3390/plants12173161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023]
Abstract
Although the temporary presence of ribonucleotides in DNA is normal, their persistence represents a form of DNA damage. Here, we assess such damage and damage defense to DNA in plastids and mitochondria of maize. Shoot development proceeds from meristematic, non-pigmented cells containing proplastids and promitochondria at the leaf base to non-dividing green cells in the leaf blade containing mature organelles. The organellar DNAs (orgDNAs) become fragmented during this transition. Previously, orgDNA damage and damage defense of two types, oxidative and glycation, was described in maize, and now a third type, ribonucleotide damage, is reported. We hypothesized that ribonucleotide damage changes during leaf development and could contribute to the demise of orgDNAs. The levels of ribonucleotides and R-loops in orgDNAs and of RNase H proteins in organelles were measured throughout leaf development and in leaves grown in light and dark conditions. The data reveal that ribonucleotide damage to orgDNAs increased by about 2- to 5-fold during normal maize development from basal meristem to green leaf and when leaves were grown in normal light conditions compared to in the dark. During this developmental transition, the levels of the major agent of defense, RNase H, declined. The decline in organellar genome integrity during maize development may be attributed to oxidative, glycation, and ribonucleotide damages that are not repaired.
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Affiliation(s)
| | | | - Arnold J. Bendich
- Department of Biology, University of Washington, Seattle, WA 98195, USA; (D.T.); (D.J.O.)
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8
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Manavella PA, Godoy Herz MA, Kornblihtt AR, Sorenson R, Sieburth LE, Nakaminami K, Seki M, Ding Y, Sun Q, Kang H, Ariel FD, Crespi M, Giudicatti AJ, Cai Q, Jin H, Feng X, Qi Y, Pikaard CS. Beyond transcription: compelling open questions in plant RNA biology. THE PLANT CELL 2023; 35:1626-1653. [PMID: 36477566 PMCID: PMC10226580 DOI: 10.1093/plcell/koac346] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/14/2022] [Accepted: 12/06/2022] [Indexed: 05/30/2023]
Abstract
The study of RNAs has become one of the most influential research fields in contemporary biology and biomedicine. In the last few years, new sequencing technologies have produced an explosion of new and exciting discoveries in the field but have also given rise to many open questions. Defining these questions, together with old, long-standing gaps in our knowledge, is the spirit of this article. The breadth of topics within RNA biology research is vast, and every aspect of the biology of these molecules contains countless exciting open questions. Here, we asked 12 groups to discuss their most compelling question among some plant RNA biology topics. The following vignettes cover RNA alternative splicing; RNA dynamics; RNA translation; RNA structures; R-loops; epitranscriptomics; long non-coding RNAs; small RNA production and their functions in crops; small RNAs during gametogenesis and in cross-kingdom RNA interference; and RNA-directed DNA methylation. In each section, we will present the current state-of-the-art in plant RNA biology research before asking the questions that will surely motivate future discoveries in the field. We hope this article will spark a debate about the future perspective on RNA biology and provoke novel reflections in the reader.
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Affiliation(s)
- Pablo A Manavella
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe 3000, Argentina
| | - Micaela A Godoy Herz
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Universidad de Buenos Aires (UBA), Buenos Aires C1428EHA, Argentina
| | - Alberto R Kornblihtt
- Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Universidad de Buenos Aires (UBA), Buenos Aires C1428EHA, Argentina
| | - Reed Sorenson
- School of Biological Sciences, University of UtahSalt Lake City 84112, USA
| | - Leslie E Sieburth
- School of Biological Sciences, University of UtahSalt Lake City 84112, USA
| | - Kentaro Nakaminami
- Center for Sustainable Resource Science, RIKEN, Kanagawa 230-0045, Japan
| | - Motoaki Seki
- Center for Sustainable Resource Science, RIKEN, Kanagawa 230-0045, Japan
- Cluster for Pioneering Research, RIKEN, Saitama 351-0198, Japan
- Kihara Institute for Biological Research, Yokohama City University, Kanagawa 244-0813, Japan
| | - Yiliang Ding
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Qianwen Sun
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Hunseung Kang
- Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea
| | - Federico D Ariel
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe 3000, Argentina
| | - Martin Crespi
- Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Université Evry, Université Paris-Saclay, Bâtiment 630, Orsay 91405, France
- Institute of Plant Sciences Paris-Saclay IPS2, Université de Paris, Bâtiment 630, Orsay 91405, France
| | - Axel J Giudicatti
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe 3000, Argentina
| | - Qiang Cai
- State Key Laboratory of Hybrid Rice, College of Life Science, Wuhan University, Wuhan 430072, China
| | - Hailing Jin
- Department of Microbiology and Plant Pathology and Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, California 92507, USA
| | - Xiaoqi Feng
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Yijun Qi
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Craig S Pikaard
- Howard Hughes Medical Institute, Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
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9
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Zhao Y, Simon M, Seluanov A, Gorbunova V. DNA damage and repair in age-related inflammation. Nat Rev Immunol 2023; 23:75-89. [PMID: 35831609 PMCID: PMC10106081 DOI: 10.1038/s41577-022-00751-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2022] [Indexed: 02/07/2023]
Abstract
Genomic instability is an important driver of ageing. The accumulation of DNA damage is believed to contribute to ageing by inducing cell death, senescence and tissue dysfunction. However, emerging evidence shows that inflammation is another major consequence of DNA damage. Inflammation is a hallmark of ageing and the driver of multiple age-related diseases. Here, we review the evidence linking DNA damage, inflammation and ageing, highlighting how premature ageing syndromes are associated with inflammation. We discuss the mechanisms by which DNA damage induces inflammation, such as through activation of the cGAS-STING axis and NF-κB activation by ATM. The triggers for activation of these signalling cascades are the age-related accumulation of DNA damage, activation of transposons, cellular senescence and the accumulation of persistent R-loops. We also discuss how epigenetic changes triggered by DNA damage can lead to inflammation and ageing via redistribution of heterochromatin factors. Finally, we discuss potential interventions against age-related inflammation.
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Affiliation(s)
- Yang Zhao
- Department of Biology, University of Rochester, Rochester, NY, USA.,Department of Physiology, Zhejiang University School of Medicine, Hangzhou, China.,Department of Hepatobiliary and Pancreatic Surgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Matthew Simon
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Andrei Seluanov
- Department of Biology, University of Rochester, Rochester, NY, USA. .,Department of Medicine, University of Rochester, Rochester, NY, USA.
| | - Vera Gorbunova
- Department of Biology, University of Rochester, Rochester, NY, USA. .,Department of Medicine, University of Rochester, Rochester, NY, USA.
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10
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Guo S, Zhu X, Huang Z, Wei C, Yu J, Zhang L, Feng J, Li M, Li Z. Genomic instability drives tumorigenesis and metastasis and its implications for cancer therapy. Biomed Pharmacother 2023; 157:114036. [PMID: 36436493 DOI: 10.1016/j.biopha.2022.114036] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/19/2022] [Indexed: 11/27/2022] Open
Abstract
Genetic instability can be caused by external factors and may also be associated with intracellular damage. At the same time, there is a large body of research investigating the mechanisms by which genetic instability occurs and demonstrating the relationship between genomic stability and tumors. Nowadays, tumorigenesis development is one of the hottest research areas. It is a vital factor affecting tumor treatment. Mechanisms of genomic stability and tumorigenesis development are relatively complex. Researchers have been working on these aspects of research. To explore the research progress of genomic stability and tumorigenesis, development, and treatment, the authors searched PubMed with the keywords "genome instability" "chromosome instability" "DNA damage" "tumor spread" and "cancer treatment". This extracts the information relevant to this study. Results: This review introduces genomic stability, drivers of tumor development, tumor cell characteristics, tumor metastasis, and tumor treatment. Among them, immunotherapy is more important in tumor treatment, which can effectively inhibit tumor metastasis and kill tumor cells. Breakthroughs in tumorigenesis development studies and discoveries in tumor metastasis will provide new therapeutic techniques. New tumor treatment methods can effectively prevent tumor metastasis and improve the cure rate of tumors.
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Affiliation(s)
- Shihui Guo
- Computational Oncology Lab, The Marine Biomedical Research Institute, Guangdong Medical University, Zhanjiang 524023, China
| | - Xiao Zhu
- Computational Oncology Lab, The Marine Biomedical Research Institute, Guangdong Medical University, Zhanjiang 524023, China
| | - Ziyuan Huang
- Computational Oncology Lab, The Marine Biomedical Research Institute, Guangdong Medical University, Zhanjiang 524023, China
| | - Chuzhong Wei
- Computational Oncology Lab, The Marine Biomedical Research Institute, Guangdong Medical University, Zhanjiang 524023, China
| | - Jiaao Yu
- Computational Oncology Lab, The Marine Biomedical Research Institute, Guangdong Medical University, Zhanjiang 524023, China
| | - Lin Zhang
- Computational Oncology Lab, The Marine Biomedical Research Institute, Guangdong Medical University, Zhanjiang 524023, China
| | - Jinghua Feng
- Computational Oncology Lab, The Marine Biomedical Research Institute, Guangdong Medical University, Zhanjiang 524023, China
| | - Mingdong Li
- Department of Gastroenterology, Zibo Central Hospital, Zibo 255000, China.
| | - Zesong Li
- Guangdong Provincial Key Laboratory of Systems Biology and Synthetic Biology for Urogenital Tumors, Shenzhen Key Laboratory of Genitourinary Tumor, Department of Urology, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital (Shenzhen Institute of Translational Medicine), Shenzhen, China.
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11
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Zhou J, Zhang W, Sun Q. R-loop: The new genome regulatory element in plants. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:2275-2289. [PMID: 36223078 DOI: 10.1111/jipb.13383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
An R-loop is a three-stranded chromatin structure that consists of a displaced single strand of DNA and an RNA:DNA hybrid duplex, which was thought to be a rare by-product of transcription. However, recent genome-wide data have shown that R-loops are widespread and pervasive in a variety of genomes, and a growing body of experimental evidence indicates that R-loops have both beneficial and harmful effects on an organism. To maximize benefit and avoid harm, organisms have evolved several means by which they tightly regulate R-loop levels. Here, we summarize our current understanding of the biogenesis and effects of R-loops, the mechanisms that regulate them, and methods of R-loop profiling, reviewing recent research advances on R-loops in plants. Furthermore, we provide perspectives on future research directions for R-loop biology in plants, which might lead to a more comprehensive understanding of R-loop functions in plant genome regulation and contribute to future agricultural improvements.
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Affiliation(s)
- Jincong Zhou
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Weifeng Zhang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Qianwen Sun
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
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12
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Qian J, Zheng M, Wang L, Song Y, Yan J, Hsu YF. Arabidopsis mitochondrial single-stranded DNA-binding proteins SSB1 and SSB2 are essential regulators of mtDNA replication and homologous recombination. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:1952-1965. [PMID: 35925893 DOI: 10.1111/jipb.13338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
Faithful DNA replication is one of the most essential processes in almost all living organisms. However, the proteins responsible for organellar DNA replication are still largely unknown in plants. Here, we show that the two mitochondrion-targeted single-stranded DNA-binding (SSB) proteins SSB1 and SSB2 directly interact with each other and act as key factors for mitochondrial DNA (mtDNA) maintenance, as their single or double loss-of-function mutants exhibit severe germination delay and growth retardation. The mtDNA levels in mutants lacking SSB1 and/or SSB2 function were two- to four-fold higher than in the wild-type (WT), revealing a negative role for SSB1/2 in regulating mtDNA replication. Genetic analysis indicated that SSB1 functions upstream of mitochondrial DNA POLYMERASE IA (POLIA) or POLIB in mtDNA replication, as mutation in either gene restored the high mtDNA copy number of the ssb1-1 mutant back to WT levels. In addition, SSB1 and SSB2 also participate in mitochondrial genome maintenance by influencing mtDNA homologous recombination (HR). Additional genetic analysis suggested that SSB1 functions upstream of ORGANELLAR SINGLE-STRANDED DNA-BINDING PROTEIN1 (OSB1) during mtDNA replication, while SSB1 may act downstream of OSB1 and MUTS HOMOLOG1 for mtDNA HR. Overall, our results yield new insights into the roles of the plant mitochondrion-targeted SSB proteins and OSB1 in maintaining mtDNA stability via affecting DNA replication and DNA HR.
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Affiliation(s)
- Jie Qian
- School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Min Zheng
- School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Lingyu Wang
- School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Yu Song
- School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Jiawen Yan
- School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Yi-Feng Hsu
- School of Life Sciences, Southwest University, Chongqing, 400715, China
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13
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Sun M, Zhang M, Chen X, Liu Y, Liu B, Li J, Wang R, Zhao K, Wu J. Rearrangement and domestication as drivers of Rosaceae mitogenome plasticity. BMC Biol 2022; 20:181. [PMID: 35986276 PMCID: PMC9392253 DOI: 10.1186/s12915-022-01383-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 08/04/2022] [Indexed: 11/10/2022] Open
Abstract
Background The mitochondrion is an important cellular component in plants and that functions in producing vital energy for the cell. However, the evolution and structure of mitochondrial genomes (mitogenomes) remain unclear in the Rosaceae family. In this study, we assembled 34 Rosaceae mitogenomes and characterized genome variation, rearrangement rate, and selection signal variation within these mitogenomes. Results Comparative analysis of six genera from the Amygdaloideae and five from the Rosoideae subfamilies of Rosaceae revealed that three protein-coding genes were absent from the mitogenomes of five Rosoideae genera. Positive correlations between genome size and repeat content were identified in 38 Rosaceae mitogenomes. Twenty repeats with high recombination frequency (> 50%) provided evidence for predominant substoichiometric conformation of the mitogenomes. Variations in rearrangement rates were identified between eleven genera, and within the Pyrus, Malus, Prunus, and Fragaria genera. Based on population data, phylogenetic inferences from Pyrus mitogenomes supported two distinct maternal lineages of Asian cultivated pears. A Pyrus-specific deletion (DEL-D) in selective sweeps was identified based on the assembled genomes and population data. After the DEL-D sequence fragments originally arose, they may have experienced a subsequent doubling event via homologous recombination and sequence transfer in the Amygdaloideae; afterwards, this variant sequence may have significantly expanded to cultivated groups, thereby improving adaptation during the domestication process. Conclusions This study characterizes the variations in gene content, genome size, rearrangement rate, and the impact of domestication in Rosaceae mitogenomes and provides insights into their structural variation patterns and phylogenetic relationships. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01383-3.
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Regulation of Heat Stress in Physcomitrium (Physcomitrella) patens Provides Novel Insight into the Functions of Plant RNase H1s. Int J Mol Sci 2022; 23:ijms23169270. [PMID: 36012542 PMCID: PMC9409398 DOI: 10.3390/ijms23169270] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/02/2022] [Accepted: 08/13/2022] [Indexed: 11/17/2022] Open
Abstract
RNase H1s are associated with growth and development in both plants and animals, while the roles of RNase H1s in bryophytes have been rarely reported. Our previous data found that PpRNH1A, a member of the RNase H1 family, could regulate the development of Physcomitrium (Physcomitrella) patens by regulating the auxin. In this study, we further investigated the biological functions of PpRNH1A and found PpRNH1A may participate in response to heat stress by affecting the numbers and the mobilization of lipid droplets and regulating the expression of heat-related genes. The expression level of PpRNH1A was induced by heat stress (HS), and we found that the PpRNH1A overexpression plants (A-OE) were more sensitive to HS. At the same time, A-OE plants have a higher number of lipid droplets but with less mobility in cells. Consistent with the HS sensitivity phenotype in A-OE plants, transcriptomic analysis results indicated that PpRNH1A is involved in the regulation of expression of heat-related genes such as DNAJ and DNAJC. Taken together, these results provide novel insight into the functions of RNase H1s.
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15
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Complex Physical Structure of Complete Mitochondrial Genome of Quercus acutissima (Fagaceae): A Significant Energy Plant. Genes (Basel) 2022; 13:genes13081321. [PMID: 35893058 PMCID: PMC9331829 DOI: 10.3390/genes13081321] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/19/2022] [Accepted: 07/22/2022] [Indexed: 02/06/2023] Open
Abstract
Quercus acutissima Carruth. is a Chinese important energy plant with high ecological and economic values. While the species chloroplast genome has been reported, its mitochondrial genome (mitogenome) is still unexplored. Here, we assembled and annotated the Q. acutissima mitogenome, and we compared its characteristic differences with several closely related species. The Q. acutissima mitogenome’s main structure is branched with three distinguished contigs (linear molecule 1, circular molecule 2, and circular molecule 3) with 448,982 bp total length and 45.72% GC content. The mitogenome contained 51 genes, including 32 protein-coding, 16 tRNA and 3 rRNA genes. We examined codon usage, repeated sequences, genome recombination, chloroplast to mitochondrion DNA transformation, RNA editing, and synteny in the Q. acutissima mitogenome. Phylogenetic trees based on 29 species mitogenomes clarified the species classification. Our results provided comprehensive information of Q. acutissima mitogenome, and they are expected to provide valuable information for Fagaceae evolutionary biology and to promote the species germplasm utilization.
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16
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Li J, Li J, Ma Y, Kou L, Wei J, Wang W. The complete mitochondrial genome of okra (Abelmoschus esculentus): using nanopore long reads to investigate gene transfer from chloroplast genomes and rearrangements of mitochondrial DNA molecules. BMC Genomics 2022; 23:481. [PMID: 35768783 PMCID: PMC9245263 DOI: 10.1186/s12864-022-08706-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/13/2022] [Indexed: 12/12/2022] Open
Abstract
Background Okra (Abelmoschus esculentus L. Moench) is an economically important crop and is known for its slimy juice, which has significant scientific research value. The A. esculentus chloroplast genome has been reported; however, the sequence of its mitochondrial genome is still lacking. Results We sequenced the plastid and mitochondrial genomes of okra based on Illumina short reads and Nanopore long reads and conducted a comparative study between the two organelle genomes. The plastid genome of okra is highly structurally conserved, but the mitochondrial genome of okra has been confirmed to have abundant subgenomic configurations. The assembly results showed that okra’s mitochondrial genome existed mainly in the form of two independent molecules, which could be divided into four independent molecules through two pairs of long repeats. In addition, we found that four pairs of short repeats could mediate the integration of the two independent molecules into one complete molecule at a low frequency. Subsequently, we also found extensive sequence transfer between the two organelles of okra, where three plastid-derived genes (psaA, rps7 and psbJ) remained intact in the mitochondrial genome. Furthermore, psbJ, psbF, psbE and psbL were integrated into the mitochondrial genome as a conserved gene cluster and underwent pseudogenization as nonfunctional genes. Only psbJ retained a relatively complete sequence, but its expression was not detected in the transcriptome data, and we speculate that it is still nonfunctional. Finally, we characterized the RNA editing events of protein-coding genes located in the organelle genomes of okra. Conclusions In the current study, our results not only provide high-quality organelle genomes for okra but also advance our understanding of the gene dialogue between organelle genomes and provide information to breed okra cultivars efficiently. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08706-2.
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Affiliation(s)
- Jihan Li
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Jingling Li
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Yubo Ma
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Lu Kou
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Juanjuan Wei
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China.,Key Laboratory of Horticulture Science for Southern Mountainous Regions from Ministry of Education, No.2 Tiansheng Road, Beibei District, Chongqing, 400716, China
| | - Weixing Wang
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China. .,Key Laboratory of Horticulture Science for Southern Mountainous Regions from Ministry of Education, No.2 Tiansheng Road, Beibei District, Chongqing, 400716, China.
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17
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How RNases Shape Mitochondrial Transcriptomes. Int J Mol Sci 2022; 23:ijms23116141. [PMID: 35682820 PMCID: PMC9181182 DOI: 10.3390/ijms23116141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 11/17/2022] Open
Abstract
Mitochondria are the power houses of eukaryote cells. These endosymbiotic organelles of prokaryote origin are considered as semi-autonomous since they have retained a genome and fully functional gene expression mechanisms. These pathways are particularly interesting because they combine features inherited from the bacterial ancestor of mitochondria with characteristics that appeared during eukaryote evolution. RNA biology is thus particularly diverse in mitochondria. It involves an unexpectedly vast array of factors, some of which being universal to all mitochondria and others being specific from specific eukaryote clades. Among them, ribonucleases are particularly prominent. They play pivotal functions such as the maturation of transcript ends, RNA degradation and surveillance functions that are required to attain the pool of mature RNAs required to synthesize essential mitochondrial proteins such as respiratory chain proteins. Beyond these functions, mitochondrial ribonucleases are also involved in the maintenance and replication of mitochondrial DNA, and even possibly in the biogenesis of mitochondrial ribosomes. The diversity of mitochondrial RNases is reviewed here, showing for instance how in some cases a bacterial-type enzyme was kept in some eukaryotes, while in other clades, eukaryote specific enzymes were recruited for the same function.
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18
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Brickner JR, Garzon JL, Cimprich KA. Walking a tightrope: The complex balancing act of R-loops in genome stability. Mol Cell 2022; 82:2267-2297. [PMID: 35508167 DOI: 10.1016/j.molcel.2022.04.014] [Citation(s) in RCA: 81] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/28/2022] [Accepted: 04/10/2022] [Indexed: 12/14/2022]
Abstract
Although transcription is an essential cellular process, it is paradoxically also a well-recognized cause of genomic instability. R-loops, non-B DNA structures formed when nascent RNA hybridizes to DNA to displace the non-template strand as single-stranded DNA (ssDNA), are partially responsible for this instability. Yet, recent work has begun to elucidate regulatory roles for R-loops in maintaining the genome. In this review, we discuss the cellular contexts in which R-loops contribute to genomic instability, particularly during DNA replication and double-strand break (DSB) repair. We also summarize the evidence that R-loops participate as an intermediate during repair and may influence pathway choice to preserve genomic integrity. Finally, we discuss the immunogenic potential of R-loops and highlight their links to disease should they become pathogenic.
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Affiliation(s)
- Joshua R Brickner
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jada L Garzon
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Karlene A Cimprich
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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19
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Liao Z, Oyama T, Kitagawa Y, Katayanagi K, Morikawa K, Oda M. Pivotal role of a conserved histidine in Escherichia coli ribonuclease HI as proposed by X-ray crystallography. Acta Crystallogr D Struct Biol 2022; 78:390-398. [PMID: 35234152 PMCID: PMC8900815 DOI: 10.1107/s2059798322000870] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/24/2022] [Indexed: 11/10/2022] Open
Abstract
The ribonuclease (RNase) H family of enzymes catalyze the specific cleavage of RNA strands of RNA/DNA hybrid duplexes and play an important role in DNA replication and repair. Since the first report of the crystal structure of RNase HI, its catalytic mechanisms, which require metal ions, have been discussed based on numerous structural and functional analyses, including X-ray crystallography. In contrast, the function of the conserved histidine residue (His124 in Escherichia coli) in the flexible loop around the active site remains poorly understood, although an important role was suggested by NMR analyses. Here, novel high-resolution X-ray crystal structures of E. coli RNase HI are described, with a particular focus on the interactions of divalent cations with His124 oriented towards the active site. The enzyme–Mg2+ complex contains two metal ions in the active site, one of which has previously been observed. The second ion lies alongside the first and binds to His124 in an octahedral coordination scheme. In the enzyme–Zn2+ complex a single metal ion was found to bind to the active site, showing a tetrahedral coordination geometry with the surrounding atoms, including His124. These results provide structural evidence that His124 plays a crucial role in the catalytic activity of RNase HI by interacting weakly and transiently with metal ions in the catalytic center.
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20
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Chen S, Dong X, Yang Z, Hou X, Liu L. Regulation of the Development in Physcomitrium (Physcomitrella) patens implicates the functional differentiation of plant RNase H1s. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 313:111070. [PMID: 34763863 DOI: 10.1016/j.plantsci.2021.111070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/14/2021] [Accepted: 09/25/2021] [Indexed: 06/13/2023]
Abstract
R-loops, consisting of a DNA:RNA hybrid and a single-stranded DNA (ssDNA), form naturally as functional chromosome structures and are crucial in many vital biological processes. However, disrupted R-loop homeostasis will threat to the integrity and stability of genome. As the endonuclease, RNase H1 can efficiently recognize and remove excess R-loops to protect organisms from DNA damage induced by R-loop over-accumulation. Here, we investigated the function of RNase H1 in Physcomitrium (Physcomitrella) patens to illustrate its important role in the evolution of plants. We found that PpRNH1A dysfunction seriously affected shoot growth and branch formation in P. patens, revealing a noticeable functional difference between PpRNH1A and AtRNH1A of Arabidopsis. Furthermore, auxin signaling was significantly affected at the transcriptional level in PpRNH1A mutant plants, as a result of the accumulation of R-loops at several auxin-related genes. This study provides evidence that PpRNH1A regulates the development of P. patens by controlling R-loop formation at specific loci to modulate the transcription of auxin-related genes. It also highlights the interspecific functional differences between early land plants and vascular plants, despite crucial and conserved role of RNase H1 played in maintaining R-loop homeostasis.
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Affiliation(s)
- Silin Chen
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650204, China; University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiumei Dong
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650204, China
| | - Zhuo Yang
- Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Xin Hou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Li Liu
- Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, China.
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21
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Kizito O. Comparative study of proportions of post-operative sepsis _ maternity versus general surgical ward. COGENT MEDICINE 2021. [DOI: 10.1080/2331205x.2021.1889100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Affiliation(s)
- Omona Kizito
- Faculty of Health Sciences, Uganda Martyrs’ University, Uganda
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