Small RNA Silencing Pathways

2007 ◽  
pp. 75-88
Author(s):  
Phillip Zamore ◽  
Alla Sigova
Keyword(s):  
Small Rna ◽  
Rna Silencing ◽  
Silencing Pathways

scholarly journals tRNA 2′-O-methylation by a duo of TRM7/FTSJ1 proteins modulates small RNA silencing in Drosophila

2020 ◽  
Vol 48 (4) ◽  
pp. 2050-2072 ◽  
Author(s):  
Margarita T Angelova ◽  
Dilyana G Dimitrova ◽  
Bruno Da Silva ◽  
Virginie Marchand ◽  
Caroline Jacquier ◽  
...  
Keyword(s):  
Small Rna ◽  
Rna Structure ◽  
Rna Silencing ◽  
Defense Mechanisms ◽  
Rna Virus ◽  
Virus Infections ◽  
Self Recognition ◽  
Silencing Pathways ◽  
Rna Pathways ◽  
And Function

Abstract 2′-O-Methylation (Nm) represents one of the most common RNA modifications. Nm affects RNA structure and function with crucial roles in various RNA-mediated processes ranging from RNA silencing, translation, self versus non-self recognition to viral defense mechanisms. Here, we identify two Nm methyltransferases (Nm-MTases) in Drosophila melanogaster (CG7009 and CG5220) as functional orthologs of yeast TRM7 and human FTSJ1. Genetic knockout studies together with MALDI-TOF mass spectrometry and RiboMethSeq mapping revealed that CG7009 is responsible for methylating the wobble position in tRNAPhe, tRNATrp and tRNALeu, while CG5220 methylates position C32 in the same tRNAs and also targets additional tRNAs. CG7009 or CG5220 mutant animals were viable and fertile but exhibited various phenotypes such as lifespan reduction, small RNA pathways dysfunction and increased sensitivity to RNA virus infections. Our results provide the first detailed characterization of two TRM7 family members in Drosophila and uncover a molecular link between enzymes catalyzing Nm at specific tRNAs and small RNA-induced gene silencing pathways.

scholarly journals Distinctive profiles of small RNA couple inverted repeat-induced post-transcriptional gene silencing with endogenous RNA silencing pathways inArabidopsis

RNA ◽  
2014 ◽  
Vol 20 (12) ◽  
pp. 1987-1999 ◽  
Author(s):  
Tadeusz Wroblewski ◽  
Marta Matvienko ◽  
Urszula Piskurewicz ◽  
Huaqin Xu ◽  
Belinda Martineau ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Small Rna ◽  
Inverted Repeat ◽  
Rna Silencing ◽  
Transcriptional Gene Silencing ◽  
Post Transcriptional Gene Silencing ◽  
Silencing Pathways

scholarly journals Pan-arthropod analysis reveals somatic piRNAs as an ancestral defence against transposable elements

2017 ◽  
Author(s):  
Samuel H. Lewis ◽  
Kaycee A. Quarles ◽  
Yujing Yang ◽  
Melanie Tanguy ◽  
Lise Frézal ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Small Rna ◽  
Rna Silencing ◽  
Individual Species ◽  
Rna Molecules ◽  
Horseshoe Crabs ◽  
Silencing Pathways ◽  
Pirna Pathway ◽  
Interference Mechanism

AbstractIn animals, small RNA molecules termed PIWI-interacting RNAs (piRNAs) silence transposable elements (TEs), protecting the germline from genomic instability and mutation. piRNAs have been detected in the soma in a few animals, but these are believed to be specific adaptations of individual species. Here, we report that somatic piRNAs were likely present in the ancestral arthropod more than 500 million years ago. Analysis of 20 species across the arthropod phylum suggests that somatic piRNAs targeting TEs and mRNAs are common among arthropods. The presence of an RNA-dependent RNA polymerase in chelicerates (horseshoe crabs, spiders, scorpions) suggests that arthropods originally used a plant-like RNA interference mechanism to silence TEs. Our results call into question the view that the ancestral role of the piRNA pathway was to protect the germline and demonstrate that small RNA silencing pathways have been repurposed for both somatic and germline functions throughout arthropod evolution.

scholarly journals Phytophthora effector targets a novel component of small RNA pathway in plants to promote infection

2015 ◽  
Vol 112 (18) ◽  
pp. 5850-5855 ◽  
Author(s):  
Yongli Qiao ◽  
Jinxia Shi ◽  
Yi Zhai ◽  
Yingnan Hou ◽  
Wenbo Ma
Keyword(s):  
Small Rna ◽  
Rna Silencing ◽  
Effector Proteins ◽  
Helicase Domain ◽  
Small Interfering Rnas ◽  
Developmental Defects ◽  
Interacting Protein ◽  
Homologous Genes ◽  
Unidentified Component ◽  
Virulence Target

A broad range of parasites rely on the functions of effector proteins to subvert host immune response and facilitate disease development. The notorious Phytophthora pathogens evolved effectors with RNA silencing suppression activity to promote infection in plant hosts. Here we report that the Phytophthora Suppressor of RNA Silencing 1 (PSR1) can bind to an evolutionarily conserved nuclear protein containing the aspartate–glutamate–alanine–histidine-box RNA helicase domain in plants. This protein, designated PSR1-Interacting Protein 1 (PINP1), regulates the accumulation of both microRNAs and endogenous small interfering RNAs in Arabidopsis. A null mutation of PINP1 causes embryonic lethality, and silencing of PINP1 leads to developmental defects and hypersusceptibility to Phytophthora infection. These phenotypes are reminiscent of transgenic plants expressing PSR1, supporting PINP1 as a direct virulence target of PSR1. We further demonstrate that the localization of the Dicer-like 1 protein complex is impaired in the nucleus of PINP1-silenced or PSR1-expressing cells, indicating that PINP1 may facilitate small RNA processing by affecting the assembly of dicing complexes. A similar function of PINP1 homologous genes in development and immunity was also observed in Nicotiana benthamiana. These findings highlight PINP1 as a previously unidentified component of RNA silencing that regulates distinct classes of small RNAs in plants. Importantly, Phytophthora has evolved effectors to target PINP1 in order to promote infection.

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