scholarly journals The Mechanism Selecting the Guide Strand from Small RNA Duplexes is Different Among Argonaute Proteins

2008 ◽  
Vol 49 (4) ◽  
pp. 493-500 ◽  
Author(s):  
Atsushi Takeda ◽  
Shintaro Iwasaki ◽  
Toshiaki Watanabe ◽  
Maki Utsumi ◽  
Yuichiro Watanabe
Keyword(s):  
Small Rna ◽  
Guide Strand ◽  
Argonaute Proteins ◽  
Rna Duplexes

scholarly journals A bacterial Argonaute with noncanonical guide RNA specificity

2016 ◽  
Vol 113 (15) ◽  
pp. 4057-4062 ◽  
Author(s):  
Emine Kaya ◽  
Kevin W. Doxzen ◽  
Kilian R. Knoll ◽  
Ross C. Wilson ◽  
Steven C. Strutt ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Binding Site ◽  
Sequence Alignment ◽  
Small Rna ◽  
Guide Strand ◽  
Guide Rna ◽  
Guide Rnas ◽  
Mrna Targets ◽  
Argonaute Proteins ◽  
Rna Complex

Eukaryotic Argonaute proteins induce gene silencing by small RNA-guided recognition and cleavage of mRNA targets. Although structural similarities between human and prokaryotic Argonautes are consistent with shared mechanistic properties, sequence and structure-based alignments suggested that Argonautes encoded within CRISPR-cas [clustered regularly interspaced short palindromic repeats (CRISPR)-associated] bacterial immunity operons have divergent activities. We show here that the CRISPR-associated Marinitoga piezophila Argonaute (MpAgo) protein cleaves single-stranded target sequences using 5′-hydroxylated guide RNAs rather than the 5′-phosphorylated guides used by all known Argonautes. The 2.0-Å resolution crystal structure of an MpAgo–RNA complex reveals a guide strand binding site comprising residues that block 5′ phosphate interactions. Using structure-based sequence alignment, we were able to identify other putative MpAgo-like proteins, all of which are encoded within CRISPR-cas loci. Taken together, our data suggest the evolution of an Argonaute subclass with noncanonical specificity for a 5′-hydroxylated guide.

scholarly journals Protease-mediated processing of Argonaute proteins controls small RNA association

2021 ◽  
Author(s):  
Rajani Kanth Gudipati ◽  
Kathrin Braun ◽  
Foivos Gypas ◽  
Daniel Hess ◽  
Jan Schreier ◽  
...  
Keyword(s):  
Small Rna ◽  
Argonaute Proteins

scholarly journals SARS-CoV-2 expresses a microRNA-like small RNA able to selectively repress host genes

2021 ◽  
Vol 118 (52) ◽  
pp. e2116668118
Author(s):  
Paulina Pawlica ◽  
Therese A. Yario ◽  
Sylvia White ◽  
Jianhui Wang ◽  
Walter N. Moss ◽  
...  
Keyword(s):  
Small Rna ◽  
Leucine Zipper ◽  
Health Concern ◽  
Interferon Signaling ◽  
Basic Leucine Zipper ◽  
Argonaute Proteins ◽  
Evolutionarily Conserved ◽  
Core Components ◽  
Cellular Machinery ◽  
The Impact

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease (COVID-19), continues to be a pressing health concern. In this study, we investigated the impact of SARS-CoV-2 infection on host microRNA (miRNA) populations in three human lung-derived cell lines, as well as in nasopharyngeal swabs from SARS-CoV-2–infected individuals. We did not detect any major and consistent differences in host miRNA levels after SARS-CoV-2 infection. However, we unexpectedly discovered a viral miRNA-like small RNA, named CoV2-miR-O7a (for SARS-CoV-2 miRNA-like ORF7a-derived small RNA). Its abundance ranges from low to moderate as compared to host miRNAs and it associates with Argonaute proteins—core components of the RNA interference pathway. We identify putative targets for CoV2-miR-O7a, including Basic Leucine Zipper ATF-Like Transcription Factor 2 (BATF2), which participates in interferon signaling. We demonstrate that CoV2-miR-O7a production relies on cellular machinery, yet is independent of Drosha protein, and is enhanced by the presence of a strong and evolutionarily conserved hairpin formed within the ORF7a sequence.

scholarly journals Protease-mediated processing of Argonaute proteins controls small RNA association

2020 ◽  
Author(s):  
Rajani Kanth Gudipati ◽  
Kathrin Braun ◽  
Foivos Gypas ◽  
Daniel Hess ◽  
Jan Schreier ◽  
...  
Keyword(s):  
Small Rna ◽  
Small Rnas ◽  
Proteolytic Processing ◽  
Genome Integrity ◽  
Wild Type ◽  
Selfish Genetic Elements ◽  
Argonaute Proteins ◽  
Processing Activity ◽  
Rna Pathways

SummarySmall RNA pathways defend the germlines of animals against selfish genetic elements and help to maintain genomic integrity. At the same time, their activity needs to be well-controlled to prevent silencing of ‘self’ genes. Here, we reveal a proteolytic mechanism that controls endogenous small interfering (22G) RNA activity in the Caenorhabditis elegans germline to protect genome integrity and maintain fertility. We find that WAGO-1 and WAGO-3 Argonaute (Ago) proteins are matured through proteolytic processing of their unusually proline-rich N-termini. In the absence of DPF-3, a P-granule-localized N-terminal dipeptidase orthologous to mammalian DPP8/9, processing fails, causing a change of identity of 22G RNAs bound to these WAGO proteins. Desilencing of repeat- and transposon-derived transcripts, DNA damage and acute sterility ensue. These phenotypes are recapitulated when WAGO-1 and WAGO-3 are rendered resistant to DFP-3-mediated processing, identifying them as critical substrates of DPF-3. We conclude that N-terminal processing of Ago proteins regulates their activity and promotes discrimination of self from non-self by ensuring association with the proper complement of small RNAs.Graphical Abstract: The role of DPF-3 in the fertility of the animalsIn wild type animals, the WAGO-1 and WAGO-3 Argonaute proteins are produced as immature pro-proteins with N-termini (N) that are unusually rich in prolines (P). N-terminal processing by DPF-3 is required for loading of the proper small RNA cargo and stabilization of WAGO-3. Accordingly, loss of this processing activity causes desilencing of transposable elements (TE), cell death and sterility.

scholarly journals Dicer-independent processing of small RNA duplexes: mechanistic insights and applications

2017 ◽  
Vol 45 (18) ◽  
pp. 10369-10379 ◽  
Author(s):  
Elena Herrera-Carrillo ◽  
Ben Berkhout
Keyword(s):  
Small Rna ◽  
Rna Duplexes
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