101
|
Luo Z, Hoffmann SA, Jiang S, Cai Y, Dai J. Probing eukaryotic genome functions with synthetic chromosomes. Exp Cell Res 2020; 390:111936. [PMID: 32165165 DOI: 10.1016/j.yexcr.2020.111936] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 02/25/2020] [Accepted: 02/29/2020] [Indexed: 02/07/2023]
Abstract
The ability to redesign and reconstruct a cell at whole-genome level provides new platforms for biological study. The international synthetic yeast genome project-Sc2.0, designed by interrogating knowledge amassed by the yeast community to date, exemplifies how a classical synthetic biology "design-build-test-learn" engineering cycle can effectively test hypotheses about various genome fundamentals. The genome reshuffling SCRaMbLE system implemented in synthetic yeast strains also provides unprecedented diversified resources for genotype-phenotype study and yeast metabolic engineering. Further development of genome synthesis technology will shed new lights on complex biological processes in higher eukaryotes.
Collapse
Affiliation(s)
- Zhouqing Luo
- Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Key Laboratory of Synthetic Genomics, Center for Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Stefan A Hoffmann
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, M1 7DN, Manchester, UK
| | - Shuangying Jiang
- Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Key Laboratory of Synthetic Genomics, Center for Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Yizhi Cai
- Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Key Laboratory of Synthetic Genomics, Center for Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China; Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, M1 7DN, Manchester, UK.
| | - Junbiao Dai
- Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Key Laboratory of Synthetic Genomics, Center for Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China; College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518055, China.
| |
Collapse
|
102
|
Plant 22-nt siRNAs mediate translational repression and stress adaptation. Nature 2020; 581:89-93. [PMID: 32376953 DOI: 10.1038/s41586-020-2231-y] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 02/25/2020] [Indexed: 11/08/2022]
Abstract
Small interfering RNAs (siRNAs) are essential for proper development and immunity in eukaryotes1. Plants produce siRNAs with lengths of 21, 22 or 24 nucleotides. The 21- and 24-nucleotide species mediate cleavage of messenger RNAs and DNA methylation2,3, respectively, but the biological functions of the 22-nucleotide siRNAs remain unknown. Here we report the identification and characterization of a group of endogenous 22-nucleotide siRNAs that are generated by the DICER-LIKE 2 (DCL2) protein in plants. When cytoplasmic RNA decay and DCL4 are deficient, the resulting massive accumulation of 22-nucleotide siRNAs causes pleiotropic growth disorders, including severe dwarfism, meristem defects and pigmentation. Notably, two genes that encode nitrate reductases-NIA1 and NIA2-produce nearly half of the 22-nucleotide siRNAs. Production of 22-nucleotide siRNAs triggers the amplification of gene silencing and induces translational repression both gene specifically and globally. Moreover, these 22-nucleotide siRNAs preferentially accumulate upon environmental stress, especially those siRNAs derived from NIA1/2, which act to restrain translation, inhibit plant growth and enhance stress responses. Thus, our research uncovers the unique properties of 22-nucleotide siRNAs, and reveals their importance in plant adaptation to environmental stresses.
Collapse
|
103
|
Fonseca PLC, Badotti F, De-Paula RB, Araújo DS, Bortolini DE, Del-Bem LE, Azevedo VA, Brenig B, Aguiar ERGR, Góes-Neto A. Exploring the Relationship Among Divergence Time and Coding and Non-coding Elements in the Shaping of Fungal Mitochondrial Genomes. Front Microbiol 2020; 11:765. [PMID: 32411111 PMCID: PMC7202290 DOI: 10.3389/fmicb.2020.00765] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/30/2020] [Indexed: 12/24/2022] Open
Abstract
The order Hypocreales (Ascomycota) is composed of ubiquitous and ecologically diverse fungi such as saprobes, biotrophs, and pathogens. Despite their phylogenetic relationship, these species exhibit high variability in biomolecules production, lifestyle, and fitness. The mitochondria play an important role in the fungal biology, providing energy to the cells and regulating diverse processes, such as immune response. In spite of its importance, the mechanisms that shape fungal mitogenomes are still poorly understood. Herein, we investigated the variability and evolution of mitogenomes and its relationship with the divergence time using the order Hypocreales as a study model. We sequenced and annotated for the first time Trichoderma harzianum mitochondrial genome (mtDNA), which was compared to other 34 mtDNAs species that were publicly available. Comparative analysis revealed a substantial structural and size variation on non-coding mtDNA regions, despite the conservation of copy number, length, and structure of protein-coding elements. Interestingly, we observed a highly significant correlation between mitogenome length, and the number and size of non-coding sequences in mitochondrial genome. Among the non-coding elements, group I and II introns and homing endonucleases genes (HEGs) were the main contributors to discrepancies in mitogenomes structure and length. Several intronic sequences displayed sequence similarity among species, and some of them are conserved even at gene position, and were present in the majority of mitogenomes, indicating its origin in a common ancestor. On the other hand, we also identified species-specific introns that advocate for the origin by different mechanisms. Investigation of mitochondrial gene transfer to the nuclear genome revealed that nuclear copies of the nad5 are the most frequent while atp8, atp9, and cox3 could not be identified in any of the nuclear genomes analyzed. Moreover, we also estimated the divergence time of each species and investigated its relationship with coding and non-coding elements as well as with the length of mitogenomes. Altogether, our results demonstrated that introns and HEGs are key elements on mitogenome shaping and its presence on fast-evolving mtDNAs could be mostly explained by its divergence time, although the intron sharing profile suggests the involvement of other mechanisms on the mitochondrial genome evolution, such as horizontal transference.
Collapse
Affiliation(s)
- Paula L. C. Fonseca
- Molecular and Computational Biology of Fungi Laboratory, Department of Microbiology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Fernanda Badotti
- Department of Chemistry, Centro Federal de Educação Tecnológica de Minas Gerais, Belo Horizonte, Brazil
| | - Ruth B. De-Paula
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Daniel S. Araújo
- Molecular and Computational Biology of Fungi Laboratory, Department of Microbiology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Dener E. Bortolini
- Program of Bioinformatics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Luiz-Eduardo Del-Bem
- Program of Bioinformatics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Department of Botany, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Vasco A. Azevedo
- Program of Bioinformatics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Bertram Brenig
- Institute of Veterinary Medicine, Burckhardtweg, University of Göttingen, Göttingen, Germany
| | - Eric R. G. R. Aguiar
- Program of Bioinformatics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Aristóteles Góes-Neto
- Molecular and Computational Biology of Fungi Laboratory, Department of Microbiology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Program of Bioinformatics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| |
Collapse
|
104
|
Villalta O, Callahan K, Myres J, Ashton J. Transcriptome analysis of Rrp6p’s role in intron retention during the stationary phase of
Saccharomyces cerevisiae. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.05895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
105
|
Roy KR, Chanfreau GF. Robust mapping of polyadenylated and non-polyadenylated RNA 3' ends at nucleotide resolution by 3'-end sequencing. Methods 2020; 176:4-13. [PMID: 31128237 PMCID: PMC6874744 DOI: 10.1016/j.ymeth.2019.05.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/10/2019] [Accepted: 05/20/2019] [Indexed: 10/26/2022] Open
Abstract
3'-end poly(A)+ sequencing is an efficient and economical method for global measurement of mRNA levels and alternative poly(A) site usage. A common method involves oligo(dT)19V reverse-transcription (RT)-based library preparation and high-throughput sequencing with a custom primer ending in (dT)19. While the majority of library products have the first sequenced nucleotide reflect the bona fide poly(A) site (pA), a substantial fraction of sequencing reads arise from various mis-priming events. These can result in incorrect pA site calls anywhere from several nucleotides downstream to several kilobases upstream from the bona fide pA site. While these mis-priming events can be mitigated by increasing annealing stringency (e.g. increasing temperature from 37 °C to 42 °C), they still persist at an appreciable level (∼10%) and computational methods must be used to prevent artifactual calls. Here we present a bioinformatics workflow for precise mapping of poly(A)+ 3' ends and handling of artifacts due to oligo(dT) mis-priming and sample polymorphisms. We test pA site calling with three different read mapping programs (STAR, BWA, and BBMap), and show that the way in which each handles terminal mismatches and soft clipping has a substantial impact on identifying correct pA sites, with BWA requiring the least post-processing to correct artifacts. We demonstrate the use of this pipeline for mapping pA sites in the model eukaryote S. cerevisiae, and further apply this technology to non-polyadenylated transcripts by employing in vitro polyadenylation prior to library prep (IVP-seq). As proof of principle, we show that a fraction of tRNAs harbor CCU 3' tails instead of the canonical CCA tail, and globally identify 3' ends of splicing intermediates arising from inefficiently spliced transcripts.
Collapse
Affiliation(s)
- Kevin R Roy
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-1569, United States; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095-1570, United States
| | - Guillaume F Chanfreau
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-1569, United States; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095-1570, United States.
| |
Collapse
|
106
|
Hou Y, Qi F, Bai X, Ren T, Shen X, Chu Q, Zhang X, Lu X. Genome-wide analysis reveals molecular convergence underlying domestication in 7 bird and mammals. BMC Genomics 2020; 21:204. [PMID: 32131728 PMCID: PMC7057487 DOI: 10.1186/s12864-020-6613-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 02/24/2020] [Indexed: 12/19/2022] Open
Abstract
Background In response to ecological niche of domestication, domesticated mammals and birds developed adaptively phenotypic homoplasy in behavior modifications like fearlessness, altered sociability, exploration and cognition, which partly or indirectly result in consequences for economic productivity. Such independent adaptations provide an excellent model to investigate molecular mechanisms and patterns of evolutionary convergence driven by artificial selection. Results First performing population genomic and brain transcriptional comparisons in 68 wild and domesticated chickens, we revealed evolutionary trajectories, genetic architectures and physiologic bases of adaptively behavioral alterations. To extensively decipher molecular convergence on behavioral changes thanks to domestication, we investigated selection signatures in hundreds of genomes and brain transcriptomes across chicken and 6 other domesticated mammals. Although no shared substitution was detected, a common enrichment of the adaptive mutations in regulatory sequences was observed, presenting significance to drive adaptations. Strong convergent pattern emerged at levels of gene, gene family, pathway and network. Genes implicated in neurotransmission, semaphorin, tectonic protein and modules regulating neuroplasticity were central focus of selection, supporting molecular repeatability of homoplastic behavior reshapes. Genes at nodal positions in trans-regulatory networks were preferably targeted. Consistent down-regulation of majority brain genes may be correlated with reduced brain size during domestication. Up-regulation of splicesome genes in chicken rather mammals highlights splicing as an efficient way to evolve since avian-specific genomic contraction of introns and intergenics. Genetic burden of domestication elicits a general hallmark. The commonly selected genes were relatively evolutionary conserved and associated with analogous neuropsychiatric disorders in human, revealing trade-off between adaption to life with human at the cost of neural changes affecting fitness in wild. Conclusions After a comprehensive investigation on genomic diversity and evolutionary trajectories in chickens, we revealed basis, pattern and evolutionary significance of molecular convergence in domesticated bird and mammals, highlighted the genetic basis of a compromise on utmost adaptation to the lives with human at the cost of high risk of neurophysiological changes affecting animals’ fitness in wild.
Collapse
Affiliation(s)
- Yali Hou
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China. .,China National Center for Bioinformation, Beijing, People's Republic of China.
| | - Furong Qi
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China.,China National Center for Bioinformation, Beijing, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Xue Bai
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China.,China National Center for Bioinformation, Beijing, People's Republic of China
| | - Tong Ren
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Xu Shen
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Qin Chu
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, People's Republic of China
| | - Xiquan Zhang
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, South China Agricultural University, Guangzhou, People's Republic of China.
| | - Xuemei Lu
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China. .,University of Chinese Academy of Sciences, Beijing, People's Republic of China. .,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, People's Republic of China.
| |
Collapse
|
107
|
Espinas NA, Tu LN, Furci L, Shimajiri Y, Harukawa Y, Miura S, Takuno S, Saze H. Transcriptional regulation of genes bearing intronic heterochromatin in the rice genome. PLoS Genet 2020; 16:e1008637. [PMID: 32187179 PMCID: PMC7145194 DOI: 10.1371/journal.pgen.1008637] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 04/09/2020] [Accepted: 01/28/2020] [Indexed: 11/18/2022] Open
Abstract
Intronic regions of eukaryotic genomes accumulate many Transposable Elements (TEs). Intronic TEs often trigger the formation of transcriptionally repressive heterochromatin, even within transcription-permissive chromatin environments. Although TE-bearing introns are widely observed in eukaryotic genomes, their epigenetic states, impacts on gene regulation and function, and their contributions to genetic diversity and evolution, remain poorly understood. In this study, we investigated the genome-wide distribution of intronic TEs and their epigenetic states in the Oryza sativa genome, where TEs comprise 35% of the genome. We found that over 10% of rice genes contain intronic heterochromatin, most of which are associated with TEs and repetitive sequences. These heterochromatic introns are longer and highly enriched in promoter-proximal positions. On the other hand, introns also accumulate hypomethylated short TEs. Genes with heterochromatic introns are implicated in various biological functions. Transcription of genes bearing intronic heterochromatin is regulated by an epigenetic mechanism involving the conserved factor OsIBM2, mutation of which results in severe developmental and reproductive defects. Furthermore, we found that heterochromatic introns evolve rapidly compared to non-heterochromatic introns. Our study demonstrates that heterochromatin is a common epigenetic feature associated with actively transcribed genes in the rice genome.
Collapse
Affiliation(s)
- Nino A. Espinas
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
- Plant Immunity Research Group, RIKEN Center for Sustainable Resource Science (CSRS), Yokohama city, Kanagawa, Japan
| | - Le Ngoc Tu
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Leonardo Furci
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Yasuka Shimajiri
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
- EditForce, Fukuoka, Japan
| | - Yoshiko Harukawa
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Saori Miura
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Shohei Takuno
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, Japan
| | - Hidetoshi Saze
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| |
Collapse
|
108
|
Abstract
High-throughput sequencing-based methods and their applications in the study of transcriptomes have revolutionized our understanding of alternative splicing. Networks of functionally coordinated and biologically important alternative splicing events continue to be discovered in an ever-increasing diversity of cell types in the context of physiologically normal and disease states. These studies have been complemented by efforts directed at defining sequence codes governing splicing and their cognate trans-acting factors, which have illuminated important combinatorial principles of regulation. Additional studies have revealed critical roles of position-dependent, multivalent protein-RNA interactions that direct splicing outcomes. Investigations of evolutionary changes in RNA binding proteins, splice variants, and associated cis elements have further shed light on the emergence, mechanisms, and functions of splicing networks. Progress in these areas has emphasized the need for a coordinated, community-based effort to systematically address the functions of individual splice variants associated with normal and disease biology.
Collapse
|
109
|
Wang F, Ren D, Liang X, Ke S, Zhang B, Hu B, Song X, Wang X. A long noncoding RNA cluster-based genomic locus maintains proper development and visual function. Nucleic Acids Res 2020; 47:6315-6329. [PMID: 31127312 PMCID: PMC6614851 DOI: 10.1093/nar/gkz444] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 04/29/2019] [Accepted: 05/10/2019] [Indexed: 01/07/2023] Open
Abstract
Long noncoding RNAs (lncRNAs) represent a group of regulatory RNAs that play critical roles in numerous cellular events, but their functional importance in development remains largely unexplored. Here, we discovered a series of previously unidentified gene clusters harboring conserved lncRNAs at the nonimprinting regions in brain (CNIBs). Among the seven identified CNIBs, human CNIB1 locus is located at Chr 9q33.3 and conserved from Danio rerio to Homo sapiens. Chr 9q33.3-9q34.11 microdeletion has previously been linked to human nail-patella syndrome (NPS) which is frequently accompanied by developmental and visual deficiencies. By generating CNIB1 deletion alleles in zebrafish, we demonstrated the requirement of CNIB1 for proper growth and development, and visual activities. Furthermore, we found that the role of CNIB1 on visual activity is mediated through a regulator of ocular development-lmx1bb. Collectively, our study shows that CNIB1 lncRNAs are important for zebrafish development and provides an lncRNA cluster-mediated pathophysiological mechanism for human Chr 9q33.3-9q34.11 microdeletion syndrome.
Collapse
Affiliation(s)
- Fei Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Dalong Ren
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaolin Liang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shengwei Ke
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Bowen Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Bing Hu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaoyuan Song
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiangting Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| |
Collapse
|
110
|
Liu G, Xia R, Wang Q, Wang Z, Ying B, Yan H. Significance of LncRNA CASC8 genetic polymorphisms on the tuberculosis susceptibility in Chinese population. J Clin Lab Anal 2020; 34:e23234. [PMID: 32034808 PMCID: PMC7307370 DOI: 10.1002/jcla.23234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 12/29/2019] [Accepted: 01/21/2020] [Indexed: 02/05/2023] Open
Abstract
Background Tuberculosis remains an important disease threatening the security of public health, and no effective targets have been found for the immunological diagnosis or therapy of tuberculosis. The aim of this study was to explore the associations between lncRNA CASC8 genetic polymorphism and tuberculosis risk. Method A total of 900 tuberculosis patients and 1534 healthy individuals in the Western Chinese Han population were recruited for our study. Candidate SNPs of CASC8 were initially filtered by importing the 1000 genomes database into Haploview, and subsequently genotyped using modified multiplex ligation detection reactions. Results The lncRNA CASC8 genetic variant rs7836840 was associated with an increased tuberculosis risk with a P‐value of .034, but .134 after Bonferroni correction. Using subtype analysis, the C allele in rs7836840 showed a significant association with tuberculosis susceptibility (OR = 1.196, 95% CI = 1.05‐1.362, P = .02739 after Bonferroni correction). Patients carrying genotype AG and GG of rs7825118 and rs9297758 exhibited lower Hb concentrations (P = .006) and neutrophil counts (P = .015), respectively, while genotype AG and AA in rs6981424 demonstrated higher levels of ALT (P = .005) and AST (P = .033) in a dominant model, which were consistent with a tendency toward increased TB risk. Conclusions This study was the first to explore the association between lncRNA CASC8 polymorphisms and TB infection risk and clinical manifestations. Our results provide evidence that CASC8 may act as a biomarker for the progression of clinical tuberculosis.
Collapse
Affiliation(s)
- Guoye Liu
- Department of Laboratory medicine, Affiliated Brain Hospital of Nanjing Medical University (Chest Branch), Nanjing, China
| | - Rui Xia
- Department of Laboratory medicine, Affiliated Brain Hospital of Nanjing Medical University (Chest Branch), Nanjing, China
| | - Qian Wang
- Department of Laboratory medicine, Affiliated Brain Hospital of Nanjing Medical University (Chest Branch), Nanjing, China
| | - Zhiqiang Wang
- Department of Laboratory medicine, Affiliated Brain Hospital of Nanjing Medical University (Chest Branch), Nanjing, China
| | - Binwu Ying
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Hong Yan
- Department of Laboratory medicine, Affiliated Brain Hospital of Nanjing Medical University (Chest Branch), Nanjing, China
| |
Collapse
|
111
|
Yao RW, Liu CX, Chen LL. Linking RNA Processing and Function. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2020; 84:67-82. [PMID: 32019863 DOI: 10.1101/sqb.2019.84.039495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
RNA processing is critical for eukaryotic mRNA maturation and function. It appears there is no exception for other types of RNAs. Long noncoding RNAs (lncRNAs) represent a subclass of noncoding RNAs, have sizes of >200 nucleotides (nt), and participate in various aspects of gene regulation. Although many lncRNAs are capped, polyadenylated, and spliced just like mRNAs, others are derived from primary transcripts of RNA polymerase II and stabilized by forming circular structures or by ending with small nucleolar RNA-protein complexes. Here we summarize the recent progress in linking the processing and function of these unconventionally processed lncRNAs; we also discuss how directional RNA movement is achieved using the radial flux movement of nascent precursor ribosomal RNA (pre-rRNA) in the human nucleolus as an example.
Collapse
Affiliation(s)
- Run-Wen Yao
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Chu-Xiao Liu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ling-Ling Chen
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| |
Collapse
|
112
|
Ninomiya K, Adachi S, Natsume T, Iwakiri J, Terai G, Asai K, Hirose T. LncRNA-dependent nuclear stress bodies promote intron retention through SR protein phosphorylation. EMBO J 2020; 39:e102729. [PMID: 31782550 PMCID: PMC6996502 DOI: 10.15252/embj.2019102729] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 10/17/2019] [Accepted: 10/29/2019] [Indexed: 12/19/2022] Open
Abstract
A number of long noncoding RNAs (lncRNAs) are induced in response to specific stresses to construct membrane-less nuclear bodies; however, their function remains poorly understood. Here, we report the role of nuclear stress bodies (nSBs) formed on highly repetitive satellite III (HSATIII) lncRNAs derived from primate-specific satellite III repeats upon thermal stress exposure. A transcriptomic analysis revealed that depletion of HSATIII lncRNAs, resulting in elimination of nSBs, promoted splicing of 533 retained introns during thermal stress recovery. A HSATIII-Comprehensive identification of RNA-binding proteins by mass spectrometry (ChIRP-MS) analysis identified multiple splicing factors in nSBs, including serine and arginine-rich pre-mRNA splicing factors (SRSFs), the phosphorylation states of which affect splicing patterns. SRSFs are rapidly de-phosphorylated upon thermal stress exposure. During stress recovery, CDC like kinase 1 (CLK1) was recruited to nSBs and accelerated the re-phosphorylation of SRSF9, thereby promoting target intron retention. Our findings suggest that HSATIII-dependent nSBs serve as a conditional platform for phosphorylation of SRSFs by CLK1 to promote the rapid adaptation of gene expression through intron retention following thermal stress exposure.
Collapse
Grants
- JP26113002 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP16H06279 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP17H03630 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP17K19335 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP19K06478 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- Tokyo Biochemical Research Foundation (TBRF)
- Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- Tokyo Biochemical Research Foundation (TBRF)
Collapse
Affiliation(s)
| | - Shungo Adachi
- Molecular Profiling Research CenterNational Institute for Advanced Industrial Science and Technology (AIST)TokyoJapan
| | - Tohru Natsume
- Molecular Profiling Research CenterNational Institute for Advanced Industrial Science and Technology (AIST)TokyoJapan
| | - Junichi Iwakiri
- Graduate School of Frontier SciencesUniversity of TokyoKashiwaJapan
| | - Goro Terai
- Graduate School of Frontier SciencesUniversity of TokyoKashiwaJapan
| | - Kiyoshi Asai
- Graduate School of Frontier SciencesUniversity of TokyoKashiwaJapan
| | - Tetsuro Hirose
- Institute for Genetic MedicineHokkaido UniversitySapporoJapan
| |
Collapse
|
113
|
Bhadra M, Howell P, Dutta S, Heintz C, Mair WB. Alternative splicing in aging and longevity. Hum Genet 2019; 139:357-369. [PMID: 31834493 DOI: 10.1007/s00439-019-02094-6] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 11/24/2019] [Indexed: 12/13/2022]
Abstract
Alternative pre-mRNA splicing increases the complexity of the proteome that can be generated from the available genomic coding sequences. Dysregulation of the splicing process has been implicated in a vast repertoire of diseases. However, splicing has recently been linked to both the aging process itself and pro-longevity interventions. This review focuses on recent research towards defining RNA splicing as a new hallmark of aging. We highlight dysfunctional alternative splicing events that contribute to the aging phenotype across multiple species, along with recent efforts toward deciphering mechanistic roles for RNA splicing in the regulation of aging and longevity. Further, we discuss recent research demonstrating a direct requirement for specific splicing factors in pro-longevity interventions, and specifically how nutrient signaling pathways interface to splicing factor regulation and downstream splicing targets. Finally, we review the emerging potential of using splicing profiles as a predictor of biological age and life expectancy. Understanding the role of RNA splicing components and downstream targets altered in aging may provide opportunities to develop therapeutics and ultimately extend healthy lifespan in humans.
Collapse
Affiliation(s)
- Malini Bhadra
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Porsha Howell
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Sneha Dutta
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Caroline Heintz
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - William B Mair
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA.
| |
Collapse
|
114
|
van der Feltz C, Hoskins AA. Structural and functional modularity of the U2 snRNP in pre-mRNA splicing. Crit Rev Biochem Mol Biol 2019; 54:443-465. [PMID: 31744343 DOI: 10.1080/10409238.2019.1691497] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The U2 small nuclear ribonucleoprotein (snRNP) is an essential component of the spliceosome, the cellular machine responsible for removing introns from precursor mRNAs (pre-mRNAs) in all eukaryotes. U2 is an extraordinarily dynamic splicing factor and the most frequently mutated in cancers. Cryo-electron microscopy (cryo-EM) has transformed our structural and functional understanding of the role of U2 in splicing. In this review, we synthesize these and other data with respect to a view of U2 as an assembly of interconnected functional modules. These modules are organized by the U2 small nuclear RNA (snRNA) for roles in spliceosome assembly, intron substrate recognition, and protein scaffolding. We describe new discoveries regarding the structure of U2 components and how the snRNP undergoes numerous conformational and compositional changes during splicing. We specifically highlight large scale movements of U2 modules as the spliceosome creates and rearranges its active site. U2 serves as a compelling example for how cellular machines can exploit the modular organization and structural plasticity of an RNP.
Collapse
Affiliation(s)
| | - Aaron A Hoskins
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| |
Collapse
|
115
|
Tatip S, Taggart J, Wang Y, MacDiarmid CW, Eide DJ. Changes in transcription start sites of Zap1-regulated genes during zinc deficiency: Implications for HNT1 gene regulation. Mol Microbiol 2019; 113:285-296. [PMID: 31692084 DOI: 10.1111/mmi.14416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2019] [Indexed: 12/01/2022]
Abstract
Changes in RNA are often poor predictors of protein accumulation. One factor disrupting this relationship are changes in transcription start sites (TSSs). Therefore, we explored how alterations in TSS affected expression of genes regulated by the Zap1 transcriptional activator of Saccharomyces cerevisiae. Zap1 controls their response to zinc deficiency. Among over 80 known Zap1-regulated genes, several produced long leader transcripts (LLTs) in one zinc status condition and short leader transcripts (SLTs) in the other. Fusing LLT and SLT transcript leaders to green fluorescent protein indicated that for five genes, the start site shift likely has little effect on protein synthesis. For four genes, however, the different transcript leaders greatly affected translation. We focused on the HNT1 gene. Zap1 caused a shift from SLT HNT1 RNA in zinc-replete cells to LLT HNT1 RNA in deficient cells. This shift correlated with decreased protein production despite increased RNA. The LLT RNA contains multiple upstream open reading frames that can inhibit translation. Expression of the LLT HNT1 RNA was dependent on Zap1. However, expression of the long transcript was not required to decrease SLT HNT1 mRNA. Our results suggest that the Zap1-activated LLT RNA is a "fail-safe" mechanism to ensure decreased Hnt1 protein in zinc deficiency.
Collapse
Affiliation(s)
- Supinda Tatip
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Janet Taggart
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Yirong Wang
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Colin W MacDiarmid
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - David J Eide
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| |
Collapse
|
116
|
Neil CR, Fairbrother WG. Intronic RNA: Ad'junk' mediator of post-transcriptional gene regulation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194439. [PMID: 31682938 DOI: 10.1016/j.bbagrm.2019.194439] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 09/30/2019] [Indexed: 01/23/2023]
Abstract
RNA splicing, the process through which intervening segments of noncoding RNA (introns) are excised from pre-mRNAs to allow for the formation of a mature mRNA product, has long been appreciated for its capacity to add complexity to eukaryotic proteomes. However, evidence suggests that the utility of this process extends beyond protein output and provides cells with a dynamic tool for gene regulation. In this review, we aim to highlight the role that intronic RNA plays in mediating specific splicing outcomes in pre-mRNA processing, as well as explore an emerging class of stable intronic sequences that have been observed to act in gene expression control. Building from underlying flexibility in both sequence and structure, intronic RNA provides mechanisms for post-transcriptional gene regulation that are amenable to the tissue and condition specific needs of eukaryotic cells. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
Collapse
Affiliation(s)
- Christopher R Neil
- Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, United States of America
| | - William G Fairbrother
- Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, United States of America; Center for Computational Molecular Biology, Brown University, Providence, RI, United States of America.
| |
Collapse
|
117
|
Parenteau J, Abou Elela S. Introns: Good Day Junk Is Bad Day Treasure. Trends Genet 2019; 35:923-934. [PMID: 31668856 DOI: 10.1016/j.tig.2019.09.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/28/2019] [Accepted: 09/19/2019] [Indexed: 02/01/2023]
Abstract
Introns are ubiquitous in eukaryotic transcripts. They are often viewed as junk RNA but the huge energetic burden of transcribing, removing, and degrading them suggests a significant evolutionary advantage. Ostensibly, an intron functions within the host pre-mRNA to regulate its splicing, transport, and degradation. However, recent studies have revealed an entirely new class of trans-acting functions where the presence of intronic RNA in the cell impacts the expression of other genes in trans. Here, we review possible new mechanisms of intron functions, with a focus on the role of yeast introns in regulating the cell growth response to starvation.
Collapse
Affiliation(s)
- Julie Parenteau
- Département de microbiologie et d'infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada
| | - Sherif Abou Elela
- Département de microbiologie et d'infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada.
| |
Collapse
|
118
|
Milković L, Tomljanović M, Čipak Gašparović A, Novak Kujundžić R, Šimunić D, Konjevoda P, Mojzeš A, Đaković N, Žarković N, Gall Trošelj K. Nutritional Stress in Head and Neck Cancer Originating Cell Lines: The Sensitivity of the NRF2-NQO1 Axis. Cells 2019; 8:cells8091001. [PMID: 31470592 PMCID: PMC6769674 DOI: 10.3390/cells8091001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 12/18/2022] Open
Abstract
Nutritional stress disturbs the cellular redox-status, which is characterized by the increased generation of reactive oxygen species (ROS). The NRF2-NQO1 axis represents a protective mechanism against ROS. Its strength is cell type-specific. FaDu, Cal 27 and Detroit 562 cells differ with respect to basal NQO1 activity. These cells were grown for 48 hours in nutritional conditions (NC): (a) Low glucose-NC2, (b) no glucose, no glutamine-NC3, (c) no glucose with glutamine-NC4. After determining the viability, proliferation and ROS generation, NC2 and NC3 were chosen for further exploration. These conditions were also applied to IMR-90 fibroblasts. The transcripts/transcript variants of NRF2 and NQO1 were quantified and transcript variants were characterized. The proteins (NRF2, NQO1 and TP53) were analyzed by a western blot in both cellular fractions. Under NC2, the NRF2-NQO1 axis did not appear activated in the cancer cell lines. Under NC3, the NRF2-NQO1axis appeared slightly activated in Detroit 562. There are opposite trends with respect to TP53 nuclear signal when comparing Cal 27 and Detroit 562 to FaDu, under NC2 and NC3. The strong activation of the NRF2-NQO1 axis in IMR-90 resulted in an increased expression of catalytically deficient NQO1, due to NQO1*2/*2 polymorphism (rs1800566). The presented results call for a comprehensive exploration of the stress response in complex biological systems.
Collapse
Affiliation(s)
- Lidija Milković
- Laboratory for Oxidative Stress, Division of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Marko Tomljanović
- Laboratory for Epigenomics, Division of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Ana Čipak Gašparović
- Laboratory for Oxidative Stress, Division of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Renata Novak Kujundžić
- Laboratory for Epigenomics, Division of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Dina Šimunić
- Laboratory for Epigenomics, Division of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Paško Konjevoda
- Laboratory for Epigenomics, Division of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Anamarija Mojzeš
- Laboratory for Epigenomics, Division of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Nikola Đaković
- University Hospital Centre Sisters of Charity, Institute for Clinical Medical Research and Education, 10000 Zagreb, Croatia
- Department of Clinical Oncology, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Neven Žarković
- Laboratory for Oxidative Stress, Division of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Koraljka Gall Trošelj
- Laboratory for Epigenomics, Division of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia.
| |
Collapse
|
119
|
Janapala Y, Preiss T, Shirokikh NE. Control of Translation at the Initiation Phase During Glucose Starvation in Yeast. Int J Mol Sci 2019; 20:E4043. [PMID: 31430885 PMCID: PMC6720308 DOI: 10.3390/ijms20164043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/10/2019] [Accepted: 08/15/2019] [Indexed: 12/13/2022] Open
Abstract
Glucose is one of the most important sources of carbon across all life. Glucose starvation is a key stress relevant to all eukaryotic cells. Glucose starvation responses have important implications in diseases, such as diabetes and cancer. In yeast, glucose starvation causes rapid and dramatic effects on the synthesis of proteins (mRNA translation). Response to glucose deficiency targets the initiation phase of translation by different mechanisms and with diverse dynamics. Concomitantly, translationally repressed mRNAs and components of the protein synthesis machinery may enter a variety of cytoplasmic foci, which also form with variable kinetics and may store or degrade mRNA. Much progress has been made in understanding these processes in the last decade, including with the use of high-throughput/omics methods of RNA and RNA:protein detection. This review dissects the current knowledge of yeast reactions to glucose starvation systematized by the stage of translation initiation, with the focus on rapid responses. We provide parallels to mechanisms found in higher eukaryotes, such as metazoans, for the most critical responses, and point out major remaining gaps in knowledge and possible future directions of research on translational responses to glucose starvation.
Collapse
Affiliation(s)
- Yoshika Janapala
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Thomas Preiss
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia.
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.
| | - Nikolay E Shirokikh
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia.
| |
Collapse
|
120
|
Tomaska L, Nosek J, Kar A, Willcox S, Griffith JD. A New View of the T-Loop Junction: Implications for Self-Primed Telomere Extension, Expansion of Disease-Related Nucleotide Repeat Blocks, and Telomere Evolution. Front Genet 2019; 10:792. [PMID: 31475042 PMCID: PMC6702307 DOI: 10.3389/fgene.2019.00792] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/26/2019] [Indexed: 12/12/2022] Open
Abstract
Telomere loops (t-loops) are formed at the ends of chromosomes in species ranging from humans to worms, plants, and with genetic manipulation, some yeast. Recent in vitro studies demonstrated that transcription of telomeric DNA leads to highly efficient t-loop formation. It was also shown that both DNA termini are inserted into the preceding DNA to generate a highly stable t-loop junction. Furthermore, some telomeric RNA remains present at the junction, potentially acting as a plug to further protect and stabilize the t-loop. Modeling the loop junction reveals two mechanisms by which the canonical chromosomal replication factors could extend the telomere in the absence of telomerase. One mechanism would utilize the annealed 3’ terminus as a de novo replication origin. In vitro evidence for the ability of the t-loop to prime telomere extension using the T7 replication factors is presented. A second mechanism would involve resolution of the Holliday junction present in the t-loop bubble by factors such as GEN1 to generate a rolling circle template at the extreme terminus of the telomere. This could lead to large expansions of the telomeric tract. Here, we propose that telomeres evolved as terminal elements containing long arrays of short nucleotide repeats due to the ability of such arrays to fold back into loops and self-prime their replicative extension. In this view, telomerase may have evolved later to provide a more precise mechanism of telomere maintenance. Both pathways have direct relevance to the alternative lengthening of telomeres (ALT) pathway. This view also provides a possible mechanism for the very large repeat expansions observed in nucleotide repeat diseases such as Fragile X syndrome, myotonic dystrophy, familial amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD). The evolution of telomeres is discussed in the framework of these models.
Collapse
Affiliation(s)
- Lubomir Tomaska
- Departments of Genetics and Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Jozef Nosek
- Departments of Genetics and Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Anirban Kar
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Smaranda Willcox
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jack D Griffith
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| |
Collapse
|
121
|
The Non-Coding RNA Journal Club: Highlights on Recent Papers-7. Noncoding RNA 2019; 5:ncrna5020040. [PMID: 31212658 PMCID: PMC6631633 DOI: 10.3390/ncrna5020040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 05/22/2019] [Indexed: 11/17/2022] Open
|
122
|
Chaudhary S, Jabre I, Reddy ASN, Staiger D, Syed NH. Perspective on Alternative Splicing and Proteome Complexity in Plants. TRENDS IN PLANT SCIENCE 2019; 24:496-506. [PMID: 30852095 DOI: 10.1016/j.tplants.2019.02.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/28/2019] [Accepted: 02/08/2019] [Indexed: 05/02/2023]
Abstract
Alternative splicing (AS) generates multiple transcripts from the same gene, however, AS contribution to proteome complexity remains elusive in plants. AS is prevalent under stress conditions in plants, but it is counterintuitive why plants would invest in protein synthesis under declining energy supply. We propose that plants employ AS not only to potentially increasing proteomic complexity, but also to buffer against the stress-responsive transcriptome to reduce the metabolic cost of translating all AS transcripts. To maximise efficiency under stress, plants may make fewer proteins with disordered domains via AS to diversify substrate specificity and maintain sufficient regulatory capacity. Furthermore, we suggest that chromatin state-dependent AS engenders short/long-term stress memory to mediate reproducible transcriptional response in the future.
Collapse
Affiliation(s)
- Saurabh Chaudhary
- School of Human and Life Sciences, Canterbury Christ Church University, Canterbury, CT1 1QU, UK; These authors contributed equally to this work
| | - Ibtissam Jabre
- School of Human and Life Sciences, Canterbury Christ Church University, Canterbury, CT1 1QU, UK; These authors contributed equally to this work
| | - Anireddy S N Reddy
- Department of Biology and Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO 80523-1878, USA
| | - Dorothee Staiger
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Naeem H Syed
- School of Human and Life Sciences, Canterbury Christ Church University, Canterbury, CT1 1QU, UK.
| |
Collapse
|
123
|
Grene R, Provart NJ, Pardo JM. Editorial: Resistance to Salinity and Water Scarcity in Higher Plants. Insights From Extremophiles and Stress-Adapted Plants: Tools, Discoveries and Future Prospects. FRONTIERS IN PLANT SCIENCE 2019; 10:373. [PMID: 31001299 PMCID: PMC6454212 DOI: 10.3389/fpls.2019.00373] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/11/2019] [Indexed: 06/09/2023]
Affiliation(s)
- Ruth Grene
- Department of Plant Pathology, Physiology, and Weed Science, College of Agriculture and Life Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Nicholas J. Provart
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - José M. Pardo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Seville, Spain
| |
Collapse
|
124
|
|
125
|
Marshall M. Cryptic DNA sequences may help cells survive starvation. Nature 2019:10.1038/d41586-019-00183-0. [PMID: 30657751 DOI: 10.1038/d41586-019-00183-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
126
|
Carrocci TJ, Neugebauer KM. Pre-mRNA Splicing in the Nuclear Landscape. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2019; 84:11-20. [PMID: 32493763 PMCID: PMC7384967 DOI: 10.1101/sqb.2019.84.040402] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Eukaryotic gene expression requires the cumulative activity of multiple molecular machines to synthesize and process newly transcribed pre-messenger RNA. Introns, the noncoding regions in pre-mRNA, must be removed by the spliceosome, which assembles on the pre-mRNA as it is transcribed by RNA polymerase II (Pol II). The assembly and activity of the spliceosome can be modulated by features including the speed of transcription elongation, chromatin, post-translational modifications of Pol II and histone tails, and other RNA processing events like 5'-end capping. Here, we review recent work that has revealed cooperation and coordination among co-transcriptional processing events and speculate on new avenues of research. We anticipate new mechanistic insights capable of unraveling the relative contribution of coupled processing to gene expression.
Collapse
Affiliation(s)
- Tucker J Carrocci
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| |
Collapse
|