tRNA-Like Structures: Possible Role of Ancestral tRNAs in Viral RNA Genome Formation

1981 ◽  
pp. 153-159
Author(s):  
François Chapeville
Keyword(s):  
Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1005 ◽  
Author(s):  
Jennifer L. Elliott ◽  
Sebla B. Kutluay

The HIV-1 integrase enzyme (IN) plays a critical role in the viral life cycle by integrating the reverse-transcribed viral DNA into the host chromosome. This function of IN has been well studied, and the knowledge gained has informed the design of small molecule inhibitors that now form key components of antiretroviral therapy regimens. Recent discoveries unveiled that IN has an under-studied yet equally vital second function in human immunodeficiency virus type 1 (HIV-1) replication. This involves IN binding to the viral RNA genome in virions, which is necessary for proper virion maturation and morphogenesis. Inhibition of IN binding to the viral RNA genome results in mislocalization of the viral genome inside the virus particle, and its premature exposure and degradation in target cells. The roles of IN in integration and virion morphogenesis share a number of common elements, including interaction with viral nucleic acids and assembly of higher-order IN multimers. Herein we describe these two functions of IN within the context of the HIV-1 life cycle, how IN binding to the viral genome is coordinated by the major structural protein, Gag, and discuss the value of targeting the second role of IN in virion morphogenesis.


2021 ◽  
Author(s):  
Yasuo Ariumi

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has largest RNA genome of approximately 30kb among RNA viruses. The DDX DEAD-box RNA helicase is a multifunctional protein involved in all aspects of RNA metabolism. Therefore, host RNA helicases may regulate and maintain such large viral RNA genome. In this study, I investigated the potential role of several host cellular RNA helicases in SARS-CoV-2 infection. Notably, DDX21 knockdown markedly accumulated intracellular viral RNA and viral production, as well as viral infectivity of SARS-CoV-2, indicating that DDX21 strongly restricts the SARS-CoV-2 infection. As well, MOV10 RNA helicase also suppressed the SARS-CoV-2 infection. In contrast, DDX1, DDX5, and DDX6 RNA helicases were required for SARS-CoV-2 replication. Indeed, SARS-CoV-2 infection dispersed the P-body formation of DDX6 and MOV10 RNA helicases as well as XRN1 exonuclease, while the viral infection did not induce stress granule formation. Accordingly, the SARS-CoV-2 nucleocapsid (N) protein interacted with DDX6, DDX21, and MOV10 and disrupted the P-body formation, suggesting that SARS-CoV-2 N hijacks DDX6 to utilize own viral replication and overcomes their anti-viral effect of DDX21 and MOV10 through as interaction with host cellular RNA helicase. Altogether, host cellular RNA helicases seem to regulate the SARS-CoV-2 infection.


1997 ◽  
Vol 44 (4) ◽  
pp. 827-837 ◽  
Author(s):  
A L Haenni ◽  
F Chapeville

The first demonstration on the aminoacylation capacity of the RNA genome of a plant virus appeared more than 25 years ago. Shortly thereafter, aminoacylation of the RNA genome of a number of other plant viruses was observed. This led to considerable work on the tRNA-like region of these viral RNAs, and to the first demonstration of the presence of pseudoknots in their folding pattern. In spite of the vast amount of efforts put into trying to understand the reason for the aminoacylation capacity of certain viral RNA genomes, as yet no clear general conclusion emerges. It rather looks as though the reason for aminoacylation may be different for different viruses, and that aminoacylation may operate at different levels in the virus life cycle. Given that certain RNA viruses possess structures which resemble that of tRNAs at their 5'- or 3'-termini, it is most likely that convergent evolution may have dominated the appearance of such structures in the virus world.


Author(s):  
Lev Levintov ◽  
Harish Vashisth

Ribonucleic acid (RNA) molecules are known to undergo conformational changes in response to various environmental stimuli including temperature, pH, and ligands. In particular, viral RNA molecules are a key example...


Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 501
Author(s):  
Mohd Ridzuan Mohd Abd Razak ◽  
Nor Azrina Norahmad ◽  
Nur Hana Md Jelas ◽  
Adlin Afzan ◽  
Norazlan Mohmad Misnan ◽  
...  

The role of Carica papaya L. leaf juice in immune dysregulation caused by dengue virus infection remains unclear. This study aimed to investigate the immunomodulatory activities of the freeze-dried C. papaya leaf juice (FCPLJ) on AG129 mice infected with a clinical DENV-2 (DMOF015) isolate. The infected AG129 mice were orally treated with 500 and 1000 mg/kg/day of FCPLJ, for three days. Platelet, leukocyte, lymphocyte and neutrophil counts were microscopically determined. The level of plasma proinflammatory cytokines was measured by multiplex immunoassay. The levels of intracellular cytokines and viral RNA were determined by RT-qPCR technique. The results showed that the FCPLJ treatment increased the total white blood cell and neutrophil counts in the infected mice. The FCPLJ treatment decreased the level of GM-CSF, GRO-alpha, IL-1 beta, IL-6, MCP-1 and MIP-1 beta in the plasma of the infected mice. The intracellular IL-6 and viral RNA levels in the liver of infected mice were decreased by the FCPLJ treatment. In conclusion, this study supports the potential immunomodulatory role of the FCPLJ in a non-lethal, symptomatic dengue mouse model. Further studies on the action mechanism of the C. papaya leaf juice and its possible use as adjunctive dengue immunotherapy are warranted.


2006 ◽  
Vol 80 (13) ◽  
pp. 6712-6715 ◽  
Author(s):  
Mark Seemanpillai ◽  
Rabab Elamawi ◽  
Christophe Ritzenthaler ◽  
Manfred Heinlein

ABSTRACT The movement protein (MP) of Tobacco mosaic virus interacts with microtubules during infection. Although this interaction is correlated with the function of MP in the cell-to-cell transport of viral RNA, a direct role of microtubules in the movement process was recently challenged by studies involving the treatment of plants with inhibitors of microtubule polymerization. Here, we report evidence suggesting that such treatments may not efficiently disrupt all microtubules. Thus, results obtained from studies using microtubule inhibitors may have to remain open to interpretation with regard to the involvement of microtubules in viral RNA trafficking.


2014 ◽  
pp. 247-253 ◽  
Author(s):  
Denise Egger ◽  
Rainer Gosert ◽  
Kurt Bienz

1984 ◽  
Vol 3 (2) ◽  
pp. 199-205
Author(s):  
Asaad N. Masoud ◽  
Moslih I. Al-Moslih ◽  
George R. Dubes

The RNA inactivator(s) synthesized from Cu2+ and hydroquinone reacts with ail four free bases: adenine, cytosine, guanine, and uracil. After 1 day at 23°C, losses of these bases averaged 66%, 39%, 97%, and 25%, respectively. In the controls with neither Cu2+ nor hydroquinone and with either one without the other, there was no significant loss of any of the bases, except for the possibly significant loss (14%) of adenine after incubation with Cu2+ without hydroquinone. L-Histidine, a chelator of Cu2+, protected all four bases against the inactivation. The hypothesis that the chemical target(s) for the inactivator(s) in monoribonucleotides and in the naked viral RNA genome is the base moiety(ies) is discussed.


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