scholarly journals Inhibition of Arginyl-tRNA Synthetase Promotes the Protection of Neuronal Ischemic Tolerance in Vitro Author Imformation

2021 ◽  
Author(s):  
Lizhi ZHANG ◽  
Rong FU
Keyword(s):  
Energy Consumption ◽  
Gene Silencing ◽  
Adenoviral Vector ◽  
Viral Vector ◽  
Protein Translation ◽  
Trna Synthetase ◽  
Adenoviral Vectors ◽  
Ischemic Tolerance ◽  
C Elegans ◽  
Time Point

Abstract BackgroundsStudies have shown that the metabolic rate of mammals decreases during hibernation, suggesting that effective reduction of the energy consumption of ischemic cells may be the basis of the protective effect of ischemic tolerance. Anderson et al. reported after inhibition of the gene encoding arginyl-tRNA synthetase, the protein translation and mortality in C. elegans under anoxic conditions decreased significantly.PurposesWhether inhibition of arginyl-tRNA synthetase (RARS), in addition to combating hypoxic injury in C. elegans, protects rat neurons from ischemic damage remains unknown. The aim of this study is to determine whether knockdown of arginyl-tRNA synthetase improves the tolerance of primary cultured rat neurons to ischemic anoxia. Methods For the primary neuronal cutlure, cerebral cortex tissues were collected from newborn 24 hours Sprague-Dawley rats. Different viral vectors were transfected into cultured primary neurons, and the optimal viral vector and time points for gene silencing were determined by detecting the expression of RARS gene and protein. The adenovirus vector expressing shRNA-RARS with the highest silencing efficiency was transfected into rat primary cultured cortical neurons. The time point at which the viral vector exhibits optimal gene silencing efficiency was selected as the detection time point for subsequent experiments. The neurons after OGD treatment were divided into 2 groups: the experimental group and the control group. Each group was divided into 3 subgroups: the normal group, the control shRNA group and the shRNA-RARS group. After 3 hours of OGD treatment, cell survival, ATP levels and RARS protein expression were evaluated , and the data was analyzed. ResultsPrimary cultured neurons were identified and purified. The adenoviral vector expressing RARS-RNAi (27394-1) exhibited the highest silencing efficiency of the three adenoviral vectors, and 3 days after transfection of the adenoviral vector was selected as the optimal time point for gene silencing. Transfection of adenoviral vectors expressing shRNA-RARS reduced RARS protein expression, ATP consumption and neuronal death, and increased CCK8 activity in neurons after OGD insult.Conclusions Our work revealed neurons transfected with adenoviral vectors expressing shRNA-RARS exhibited stronger tolerance to ischemia and hypoxia, which was due to the inhibition of RARS activity andreduced cell energy metabolism rate. These results suggested that RARS inhibition reduced protein translation and energy consumption, and played a protective role in ischemic tolerance.

scholarly journals A cassava common mosaic virus vector for virus-induced gene silencing in cassava

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Decai Tuo ◽  
Peng Zhou ◽  
Pu Yan ◽  
Hongguang Cui ◽  
Yang Liu ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Mosaic Virus ◽  
Gene Function ◽  
Viral Vector ◽  
Function Analysis ◽  
Systemic Infection ◽  
Cdna Clones ◽  
Virus Induced Gene Silencing ◽  
Efficient Gene ◽  
Gene Function Analysis

Abstract Background Cassava is an important crop for food security and industry in the least-developed and developing countries. The completion of the cassava genome sequence and identification of large numbers of candidate genes by next-generation sequencing provide extensive resources for cassava molecular breeding and increase the need for rapid and efficient gene function analysis systems in cassava. Several plant virus-induced gene silencing (VIGS) systems have been developed as reverse genetic tools for rapid gene function analysis in cassava. However, these VIGS vectors could cause severe viral symptoms or inefficient gene silencing. Results In this study, we constructed agroinfection-compatible infectious cDNA clones of cassava common mosaic virus isolate CM (CsCMV-CM, genus Potexvirus, family Alphaflexiviridae) that causes systemic infection with mild symptoms in cassava. CsCMV-CM was then modified to a viral vector carrying the Nimble cloning frame, which facilitates the rapid and high-throughput cloning of silencing fragments into the viral genome. The CsCMV-based vector successfully silenced phytoene desaturase (PDS) and magnesium chelatase subunit I (ChlI) in different cassava varieties and Nicotiana benthamiana. The silencing of the ChlI gene could persist for more than two months. Conclusions This CsCMV-based VIGS system provides a new tool for rapid and efficient gene function studies in cassava.

Ketogenic Diet for KARS-Related Mitochondrial Dysfunction and Progressive Leukodystrophy

2021 ◽  
Author(s):  
Yuka Murofushi ◽  
Itaru Hayakawa ◽  
Yuichi Abe ◽  
Tatsuyuki Ohto ◽  
Kei Murayama ◽  
...  
Keyword(s):  
Mitochondrial Dysfunction ◽  
Ketogenic Diet ◽  
Early Report ◽  
Mitochondrial Protein ◽  
Protein Translation ◽  
Trna Synthetase ◽  
Vitamin Supplementation ◽  
Low Oxygen ◽  
Disease Modifying Therapy ◽  
Disease Modifying

Abstract KARS encodes lysyl-tRNA synthetase, which is essential for protein translation. KARS mutations sometimes cause impairment of cytoplasmic and mitochondrial protein synthesis, and sometimes lead to progressive leukodystrophies with mitochondrial signature and psychomotor regression, and follow a rapid regressive course to premature death. There has been no disease-modifying therapy beyond supportive treatment. We present a 5-year-old male patient with an asymmetrical leukodystrophy who showed overt evidence of mitochondrial dysfunction, including elevation of lactate on brain MR spectroscopy and low oxygen consumption rate in fibroblasts. We diagnosed this patient's condition as KARS-related leukodystrophy with cerebral calcification, congenital deafness, and evidence of mitochondrial dysfunction. We employed a ketogenic diet as well as multiple vitamin supplementation with the intention to alleviate mitochondrial dysfunction. The patient showed alleviation of his psychomotor regression and even partial restoration of his abilities within 4 months. This is an early report of a potential disease-modifying therapy for KARS-related progressive leukodystrophy without appreciable adverse effects.

Protein translation components are colocalized in granules in oligodendrocytes

1995 ◽  
Vol 108 (8) ◽  
pp. 2781-2790 ◽  
Author(s):  
E. Barbarese ◽  
D.E. Koppel ◽  
M.P. Deutscher ◽  
C.L. Smith ◽  
K. Ainger ◽  
...  
Keyword(s):  
Myelin Basic Protein ◽  
Ribosomal Rna ◽  
Spatial Organization ◽  
Basic Protein ◽  
Elongation Factor ◽  
Protein Translation ◽  
Trna Synthetase ◽  
Laser Scanning Microscopy ◽  
Dual Channel ◽  
Cross Correlation Analysis

The intracellular distribution of various components of the protein translational machinery was visualized in mouse oligodendrocytes in culture using high resolution fluorescence in situ hybridization and immunofluorescence in conjunction with dual channel confocal laser scanning microscopy. Arginyl-tRNA synthetase, elongation factor 1a, ribosomal RNA, and myelin basic protein mRNA were all co-localized in granules in the processes, veins and membrane sheets of the cell. Colocalization was evaluated by dual channel cross correlation analysis to determine the correlation index (% colocalization) and correlation distance (granule radius), and by single granule ratiometric analysis to determine the distribution of the different components in individual granules. Most granules contained synthetase, elongation factor, ribosomal RNA and myelin basic protein mRNA. These results indicate that several different components of the protein synthetic machinery, including aminoacyl-tRNA synthetases, elongation factors, ribosomes and mRNAs, are colocalized in granules in oligodendrocytes. We propose that these granules are supramolecular complexes containing all of the necessary macromolecular components for protein translation and that they represent a heretofore undescribed subcellular organization of the protein synthetic machinery. This spatial organization may increase the efficiency of protein synthesis and may also provide a vehicle for transport and localization of specific mRNAs within the cell.

scholarly journals Genetic Validation of Leishmania donovani Lysyl-tRNA Synthetase Shows that It Is Indispensable for Parasite Growth and Infectivity

mSphere ◽  
2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Sanya Chadha ◽  
N. Arjunreddy Mallampudi ◽  
Debendra K. Mohapatra ◽  
Rentala Madhubala
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Essential Gene ◽  
Protozoan Parasite ◽  
Protein Translation ◽  
Trna Synthetase ◽  
Parasite Growth ◽  
Coding Sequences ◽  
Trna Synthetases ◽  
Aminoacyl Trna Synthetases

ABSTRACT Leishmania donovani is a protozoan parasite that causes visceral leishmaniasis. Increasing resistance and severe side effects of existing drugs have led to the need to identify new chemotherapeutic targets. Aminoacyl-tRNA synthetases (aaRSs) are ubiquitous and are required for protein synthesis. aaRSs are known drug targets for bacterial and fungal pathogens. Here, we have characterized and evaluated the essentiality of L. donovani lysyl-tRNA synthetase (LdLysRS). Two different coding sequences for lysyl-tRNA synthetases are annotated in the Leishmania genome database. LdLysRS-1 (LdBPK_150270.1), located on chromosome 15, is closer to apicomplexans and eukaryotes, whereas LdLysRS-2 (LdBPK_300130.1), present on chromosome 30, is closer to bacteria. In the present study, we have characterized LdLysRS-1. Recombinant LdLysRS-1 displayed aminoacylation activity, and the protein localized to the cytosol. The LdLysRS-1 heterozygous mutants had a restrictive growth phenotype and attenuated infectivity. LdLysRS-1 appears to be an essential gene, as a chromosomal knockout of LdLysRS-1 could be generated when the gene was provided on a rescuing plasmid. Cladosporin, a fungal secondary metabolite and a known inhibitor of LysRS, was more potent against promastigotes (50% inhibitory concentration [IC50], 4.19 µM) and intracellular amastigotes (IC50, 1.09 µM) than were isomers of cladosporin (3-epi-isocladosporin and isocladosporin). These compounds exhibited low toxicity to mammalian cells. The specificity of inhibition of parasite growth caused by these inhibitors was further assessed using LdLysRS-1 heterozygous mutant strains and rescue mutant promastigotes. These inhibitors inhibited the aminoacylation activity of recombinant LdLysRS. Our data provide a framework for the development of a new class of drugs against this parasite. IMPORTANCE Aminoacyl-tRNA synthetases are housekeeping enzymes essential for protein translation, providing charged tRNAs for the proper construction of peptide chains. These enzymes provide raw materials for protein translation and also ensure fidelity of translation. L. donovani is a protozoan parasite that causes visceral leishmaniasis. It is a continuously proliferating parasite that depends heavily on efficient protein translation. Lysyl-tRNA synthetase is one of the aaRSs which charges lysine to its cognate tRNA. Two different coding sequences for lysyl-tRNA synthetases (LdLysRS) are present in this parasite. LdLysRS-1 is closer to apicomplexans and eukaryotes, whereas LdLysRS-2 is closer to bacteria. Here, we have characterized LdLysRS-1 of L. donovani. LdLysRS-1 appears to be an essential gene, as the chromosomal null mutants did not survive. The heterozygous mutants showed slower growth kinetics and exhibited attenuated virulence. This study also provides a platform to explore LdLysRS-1 as a potential drug target.

scholarly journals Bacterial carotenoids suppress Caenorhabditis elegans surveillance and defense of translational dysfunction

2020 ◽  
Author(s):  
J. Amaranath Govindan ◽  
Elamparithi Jayamani ◽  
Victor Lelyveld ◽  
Jack Szostak ◽  
Gary Ruvkun
Keyword(s):  
Caenorhabditis Elegans ◽  
Protein Translation ◽  
Food Aversion ◽  
Eukaryotic Translation ◽  
C Elegans ◽  
Surveillance And Response ◽  
Carotenoid Mutants ◽  
Human Immune ◽  
Microbial Toxins ◽  
Kocuria Rhizophila

AbstractMicrobial toxins and virulence factors often target the eukaryotic translation machinery. Caenorhabditis elegans surveils for such microbial attacks by monitoring translational competence, and if a deficit is detected, particular drug detoxification and bacterial defense genes are induced. The bacteria Kocuria rhizophila has evolved countermeasures to animal translational surveillance and defense pathways. Here, we used comprehensive genetic analysis of Kocuria rhizophila to identify the bacterial genetic pathways that inhibit C. elegans translational toxin surveillance and defense. Kocuria rhizophila mutations that disrupt its ability to disable animal immunity and defense map to multiple steps in the biosynthesis of a 50-carbon bacterial carotenoid from 5 carbon precursors. Extracts of the C50 carotenoid from wild type K. rhizophila could restore this bacterial anti-immunity activity to K. rhizophila carotenoid biosynthetic mutant. Corynebacterium glutamicum, also inhibits the C. elegans translation detoxification response by producing the C50 carotenoid decaprenoxanthin, and C. glutamicum carotenoid mutants are defective in this suppression of C. elegans detoxification. Consistent with the salience of these bacterial countermeasures to animal drug responses, bacterial carotenoids sensitize C. elegans to drugs that target translation and inhibit food aversion behaviors normally induced by protein translation toxins or mutations. The surveillance and response to toxins is mediated by signaling pathways conserved across animal phylogeny, suggesting that these bacterial carotenoids may also suppress such human immune and toxin responses.

scholarly journals Progress in Adenoviral Capsid-Display Vaccines

Biomedicines ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 81 ◽  
Author(s):  
Marija Vujadinovic ◽  
Jort Vellinga
Keyword(s):  
Immune Responses ◽  
Adenoviral Vector ◽  
Vaccine Development ◽  
Adenoviral Vectors ◽  
Manufacturing Costs ◽  
Genetic Vaccine ◽  
Immunogenic Peptides ◽  
T Cell Immune Responses ◽  
Protein Ix ◽  
Capsid Display

Adenoviral vectored vaccines against infectious diseases are currently in clinical trials due to their capacity to induce potent antigen-specific B- and T-cell immune responses. Heterologous prime-boost vaccination with adenoviral vector and, for example, adjuvanted protein-based vaccines can further enhance antigen-specific immune responses. Although leading to potent immune responses, these heterologous prime-boost regimens may be complex and impact manufacturing costs limiting efficient implementation. Typically, adenoviral vectors are engineered to genetically encode a transgene in the E1 region and utilize the host cell machinery to express the encoded antigen and thereby induce immune responses. Similarly, adenoviral vectors can be engineered to display foreign immunogenic peptides on the capsid-surface by insertion of antigens in capsid proteins hexon, fiber and protein IX. The ability to use adenoviral vectors as antigen-display particles, with or without using the genetic vaccine function, greatly increases the versatility of the adenoviral vector for vaccine development. This review describes the application of adenoviral capsid antigen-display vaccine vectors by focusing on their distinct advantages and possible limitations in vaccine development.

scholarly journals Intronic MicroRNA (miRNA)

2006 ◽  
Vol 2006 ◽  
pp. 1-13 ◽  
Author(s):  
Shi-Lung Lin ◽  
Joseph D. Miller ◽  
Shao-Yao Ying
Keyword(s):  
Rna Interference ◽  
Gene Silencing ◽  
Regulatory System ◽  
Fine Tuning ◽  
Messenger Rnas ◽  
Noncoding Dna ◽  
Protein Coding ◽  
C Elegans ◽  
Adult Mice

Nearly 97% of the human genome is composed of noncoding DNA, which varies from one species to another. Changes in these sequences often manifest themselves in clinical and circumstantial malfunction. Numerous genes in these non-protein-coding regions encode microRNAs, which are responsible for RNA-mediated gene silencing through RNA interference (RNAi)-like pathways. MicroRNAs (miRNAs), small single-stranded regulatory RNAs capable of interfering with intracellular messenger RNAs (mRNAs) with complete or partial complementarity, are useful for the design of new therapies against cancer polymorphisms and viral mutations. Currently, many varieties of miRNA are widely reported in plants, animals, and even microbes. Intron-derived microRNA (Id-miRNA) is a new class of miRNA derived from the processing of gene introns. The intronic miRNA requires type-II RNA polymerases (Pol-II) and spliceosomal components for their biogenesis. Several kinds of Id-miRNA have been identified inC elegans, mouse, and human cells; however, neither function nor application has been reported. Here, we show for the first time that intron-derived miRNAs are able to induce RNA interference in not only human and mouse cells, but in also zebrafish, chicken embryos, and adult mice, demonstrating the evolutionary preservation of intron-mediated gene silencing via functional miRNA in cell and in vivo. These findings suggest an intracellular miRNA-mediated gene regulatory system, fine-tuning the degradation of protein-coding messenger RNAs.

scholarly journals poly(UG)-tailed RNAs in Genome Protection and Epigenetic Inheritance

2019 ◽  
Author(s):  
Aditi Shukla ◽  
Jenny Yan ◽  
Daniel J. Pagano ◽  
Anne E. Dodson ◽  
Yuhan Fei ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Epigenetic Inheritance ◽  
Genome Integrity ◽  
Small Interfering Rnas ◽  
Genetic Elements ◽  
C Elegans ◽  
Transposon Silencing ◽  
Rna Fragments ◽  
Heterologous Expression Systems ◽  
Genome Protection

AbstractMobile genetic elements threaten genome integrity in all organisms. MUT-2/RDE-3 is a ribonucleotidyltransferase required for transposon silencing and RNA interference (RNAi) in C. elegans. When tethered to RNAs in heterologous expression systems, RDE-3 can add long stretches of alternating non-templated uridine (U) and guanosine (G) ribonucleotides to the 3’ termini of these RNAs (polyUG or pUG tails). Here, we show that, in its natural context in C. elegans, RDE-3 adds pUG tails to transposon RNAs, as well as to targets of RNAi. pUG tails with more than 16 perfectly alternating 3’ U and G nucleotides convert otherwise inert RNA fragments into agents of gene silencing. pUG tails promote gene silencing by recruiting RNA-dependent RNA Polymerases (RdRPs), which use pUG-tailed RNAs as templates to synthesize small interfering RNAs (siRNAs). Cycles of pUG RNA-templated siRNA synthesis and siRNA-directed mRNA pUGylation underlie dsRNA-directed transgenerational epigenetic inheritance in the C. elegans germline. Our results show that pUG tails convert RNAs into transgenerational memories of past gene silencing events, which, we speculate, allow parents to inoculate progeny against the expression of unwanted or parasitic genetic elements.

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