scholarly journals The origin and evolution of loqs2: a gene encoding an antiviral dsRNA binding protein in Aedes mosquitoes

2021 ◽  
Author(s):  
Carlos F. Estevez-Castro ◽  
Murillo F. Rodrigues ◽  
Antinéa Babarit ◽  
Flávia Viana Ferreira ◽  
Eric Marois ◽  
...  
Keyword(s):  
Rna Binding ◽  
Binding Protein ◽  
Mosquito Species ◽  
Rnai Pathway ◽  
Gene Encoding ◽  
Origin And Evolution ◽  
Larval Stages ◽  
Dsrna Binding ◽  
Dsrna Binding Protein ◽  
Antiviral Gene

Mosquito borne viruses such as dengue, Zika, yellow fever and Chikungunya cause millions of infections every year. These viruses are mostly transmitted by two urban-adapted mosquito species, Aedes aegypti and Aedes albopictus, that appear to be more permissive to arbovirus infections compared to closely related species. Although mechanistic understanding remains, Aedes mosquitoes may have evolved specialized antiviral mechanisms that potentially contribute to the low impact of viral infection. Recently, we reported the identification of an Aedes specific double-stranded RNA binding protein (dsRBP), named Loqs2, that is involved in the control of infection by dengue and Zika viruses in Ae. aegypti. Loqs2 interacts with two important co-factors of the RNA interference (RNAi) pathway, Loquacious (Loqs) and R2D2, and seems to be a strong regulator of the antiviral defense. However, the origin and evolution of loqs2 remains unclear. Here, we describe that loqs2 likely originated from two independent duplications of the first dsRNA binding domain (dsRBD) of loquacious that occurred before the radiation of the Aedes Stegomya subgenus. After its origin, our analyses suggest that loqs2 evolved by relaxed positive selection towards neofunctionalization. In fact, loqs2 is evolving at a faster pace compared to other RNAi components such as loquacious, r2d2 and Dicer-2 in Aedes mosquitoes. Unlike loquacious, transcriptomic analysis showed that loqs2 expression is tightly regulated, almost restricted to reproductive tissues in Ae. aegypti and Ae. albopictus. Transgenic mosquitoes engineered to ubiquitously express loqs2 show massive dysregulation of stress response genes and undergo developmental arrest at larval stages. Overall, our results uncover the possible origin and neofunctionalization of a novel antiviral gene, loqs2, in Aedes mosquitoes that ultimately may contribute to their effectiveness as vectors for arboviruses.

scholarly journals Double-Stranded-RNA-Binding Protein 2 Participates in Antiviral Defense

2020 ◽  
Vol 94 (11) ◽  
Author(s):  
Károly Fátyol ◽  
Katalin Anna Fekete ◽  
Márta Ludman
Keyword(s):  
Rna Interference ◽  
Virus Infection ◽  
Nicotiana Benthamiana ◽  
Rna Binding ◽  
Binding Protein ◽  
Systemic Necrosis ◽  
Double Stranded Rna ◽  
Content Type ◽  
Dsrna Binding ◽  
Dsrna Binding Protein

ABSTRACT Double-stranded RNA (dsRNA) is a common pattern formed during the replication of both RNA and DNA viruses. Perception of virus-derived dsRNAs by specialized receptor molecules leads to the activation of various antiviral measures. In plants, these defensive processes include the adaptive RNA interference (RNAi) pathway and innate pattern-triggered immune (PTI) responses. While details of the former process have been well established in recent years, the latter are still only partially understood at the molecular level. Nonetheless, emerging data suggest extensive cross talk between the different antiviral mechanisms. Here, we demonstrate that dsRNA-binding protein 2 (DRB2) of Nicotiana benthamiana plays a direct role in potato virus X (PVX)-elicited systemic necrosis. These results establish that DRB2, a known component of RNAi, is also involved in a virus-induced PTI response. In addition, our findings suggest that RNA-dependent polymerase 6 (RDR6)-dependent dsRNAs play an important role in the triggering of PVX-induced systemic necrosis. Based on our data, a model is formulated whereby competition between different DRB proteins for virus-derived dsRNAs helps establish the dominant antiviral pathways that are activated in response to virus infection. IMPORTANCE Plants employ multiple defense mechanisms to restrict viral infections, among which RNA interference is the best understood. The activation of innate immunity often leads to both local and systemic necrotic responses, which confine the virus to the infected cells and can also provide resistance to distal, noninfected parts of the organism. Systemic necrosis, which is regarded as a special form of the local hypersensitive response, results in necrosis of the apical stem region, usually causing the death of the plant. Here, we provide evidence that the dsRNA-binding protein 2 of Nicotiana benthamiana plays an important role in virus-induced systemic necrosis. Our findings are not only compatible with the recent hypothesis that DRB proteins act as viral invasion sensors but also extends it by proposing that DRBs play a critical role in establishing the dominant antiviral measures that are triggered during virus infection.

scholarly journals Double-Stranded RNA Binding May Be a General Plant RNA Viral Strategy To Suppress RNA Silencing

2006 ◽  
Vol 80 (12) ◽  
pp. 5747-5756 ◽  
Author(s):  
Zsuzsanna Mérai ◽  
Zoltán Kerényi ◽  
Sándor Kertész ◽  
Melinda Magna ◽  
Lóránt Lakatos ◽  
...  
Keyword(s):  
Rna Silencing ◽  
Rna Binding ◽  
Binding Protein ◽  
Turnip Crinkle Virus ◽  
Double Stranded Rna ◽  
Dsrna Binding ◽  
Beet Yellows Virus ◽  
Dsrna Binding Protein ◽  
Silencing Suppression ◽  
Suppression Strategy

ABSTRACT In plants, RNA silencing (RNA interference) is an efficient antiviral system, and therefore successful virus infection requires suppression of silencing. Although many viral silencing suppressors have been identified, the molecular basis of silencing suppression is poorly understood. It is proposed that various suppressors inhibit RNA silencing by targeting different steps. However, as double-stranded RNAs (dsRNAs) play key roles in silencing, it was speculated that dsRNA binding might be a general silencing suppression strategy. Indeed, it was shown that the related aureusvirus P14 and tombusvirus P19 suppressors are dsRNA-binding proteins. Interestingly, P14 is a size-independent dsRNA-binding protein, while P19 binds only 21-nucleotide ds-sRNAs (small dsRNAs having 2-nucleotide 3′ overhangs), the specificity determinant of the silencing system. Much evidence supports the idea that P19 inhibits silencing by sequestering silencing-generated viral ds-sRNAs. In this study we wanted to test the hypothesis that dsRNA binding is a general silencing suppression strategy. Here we show that many plant viral silencing suppressors bind dsRNAs. Beet yellows virus Peanut P21, clump virus P15, Barley stripe mosaic virus γB, and Tobacco etch virus HC-Pro, like P19, bind ds-sRNAs size-selectively, while Turnip crinkle virus CP is a size-independent dsRNA-binding protein, which binds long dsRNAs as well as ds-sRNAs. We propose that size-selective ds-sRNA-binding suppressors inhibit silencing by sequestering viral ds-sRNAs, whereas size-independent dsRNA-binding suppressors inactivate silencing by sequestering long dsRNA precursors of viral sRNAs and/or by binding ds-sRNAs. The findings that many unrelated silencing suppressors bind dsRNA suggest that dsRNA binding is a general silencing suppression strategy which has evolved independently many times.

scholarly journals Double-Stranded RNA Binding by a Heterodimeric Complex of Murine Cytomegalovirus m142 and m143 Proteins

2006 ◽  
Vol 80 (20) ◽  
pp. 10173-10180 ◽  
Author(s):  
Stephanie J. Child ◽  
Laura K. Hanson ◽  
Crystal E. Brown ◽  
Deanna M. Janzen ◽  
Adam P. Geballe
Keyword(s):  
Protein Synthesis ◽  
Human Cytomegalovirus ◽  
Binding Proteins ◽  
Rna Binding ◽  
Binding Protein ◽  
Murine Cytomegalovirus ◽  
Oligoadenylate Synthetase ◽  
Dsrna Binding ◽  
Dsrna Binding Protein ◽  
Heterodimeric Complex

ABSTRACT In response to viral infection, cells activate a variety of antiviral responses, including several that are triggered by double-stranded (ds) RNA. Among these are the protein kinase R and oligoadenylate synthetase/RNase L pathways, both of which result in the shutoff of protein synthesis. Many viruses, including human cytomegalovirus, encode dsRNA-binding proteins that prevent the activation of these pathways and thereby enable continued protein synthesis and viral replication. We have extended these analyses to another member of the β subfamily of herpesviruses, murine cytomegalovirus (MCMV), and now report that products of the m142 and m143 genes together bind dsRNA. Coimmunoprecipitation experiments demonstrate that these two proteins interact in infected cells, consistent with their previously reported colocalization. Jointly, but not individually, the proteins rescue replication of a vaccinia virus mutant with a deletion of the dsRNA-binding protein gene E3L (VVΔE3L). Like the human cytomegalovirus dsRNA-binding protein genes TRS1 and IRS1, m142 and m143 are members of the US22 gene family. We also found that two other members of the MCMV US22 family, M23 and M24, encode dsRNA-binding proteins, but they do not rescue VVΔE3L replication. These results reveal that MCMV, like many other viruses, encodes dsRNA-binding proteins, at least two of which can inhibit dsRNA-activated antiviral pathways. However, unlike other well-studied examples, the MCMV proteins appear to act in a heterodimeric complex.

scholarly journals AUH, a gene encoding an AU-specific RNA binding protein with intrinsic enoyl-CoA hydratase activity.

1995 ◽  
Vol 92 (6) ◽  
pp. 2051-2055 ◽  
Author(s):  
J. Nakagawa ◽  
H. Waldner ◽  
S. Meyer-Monard ◽  
J. Hofsteenge ◽  
P. Jeno ◽  
...  
Keyword(s):  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Gene Encoding ◽  
Hydratase Activity ◽  
Enoyl Coa Hydratase

scholarly journals Dodging two bullets with one dsRNA-binding protein

Cell Cycle ◽  
2013 ◽  
Vol 13 (3) ◽  
pp. 345-346 ◽  
Author(s):  
Reyad A Elbarbary ◽  
Lynne E Maquat
Keyword(s):  
Binding Protein ◽  
Dsrna Binding ◽  
Dsrna Binding Protein
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