rna cleavage
Recently Published Documents


TOTAL DOCUMENTS

310
(FIVE YEARS 47)

H-INDEX

50
(FIVE YEARS 7)

2021 ◽  
Vol 2 (4) ◽  
pp. 101001
Author(s):  
Catia Andreassi ◽  
Antonella Riccio

2021 ◽  
Author(s):  
Longyu Wang ◽  
Xiaochen Xie ◽  
Yang Liu ◽  
Wenqiang Li ◽  
Bin Lv ◽  
...  

ABSTRACTArgonaute proteins are widespread in prokaryotes and eukaryotes. Most prokaryotic Argonaute proteins (pAgos) use 5’P-gDNA to target complementary DNA. However, more and more studies on the properties of pAgos make their functions more diversified. Previously reported pAgos only possess several forms of high activity in all eight cleavage patterns, which limits their practical applications. Here, we described a unique pAgo from Marinitoga hydrogenitolerans (MhAgo) with eight cleavage activities. MhAgo can utilize all four types of guides (5’OH-gDNA, 5’P-gDNA, 5’OH-gRNA, and 5’P-gRNA) for ssDNA and RNA cleavage. Further studies demonstrated that MhAgo had high activities with 16-21 nt guides and no obvious preferences for the 5’-end nucleotides of 5’OH-guides. Unexpectedly, MhAgo had different preferences for the 5’-end nucleotides of 5’P-guides depending on the types of targets. Although the specificity of MhAgo was related to the types of guides, single mismatches in the central and 3’-supplementary regions of guides greatly reduced the cleavage efficiency. Additionally, the electrophoretic mobility shift assay (EMSA) demonstrated MhAgo had the weakest affinity for 5’P-gRNA:tRNA duplex, which was consistent with its cleavage efficiency. In conclusion, MhAgo is highly active under a wide range of conditions and can be used for programmable endonucleolytic cleavage of both ssDNA and RNA substrates. The abundant biochemical characteristics of MhAgo broaden our understanding of pAgos and expand the potential application in nucleic acids manipulations.


2021 ◽  
Author(s):  
Min-Han Lin ◽  
Madeline K Jensen ◽  
Nathan D Elrod ◽  
Kai-Lieh Huang ◽  
Eric J Wagner ◽  
...  

Integrator has critical roles in noncoding RNA 3'-end processing as well as transcription attenuation of selected mRNAs. IntS11 is the endonuclease for RNA cleavage, as a part of the IntS4-IntS9-IntS11 complex (Integrator cleavage module, ICM). Our structure of the Drosophila ICM, determined by cryo-electron microscopy at 2.74 A resolution, unexpectedly revealed the stable association of an inositol hexakisphosphate (IP6) molecule. The binding site is located in a highly electropositive pocket at an interface among all three subunits of ICM, 55 A away from the IntS11 active site and generally conserved in other ICMs. IP6 binding is also confirmed in human ICM. Mutations of residues in this binding site or disruption of IP6 biosynthesis significantly reduced Integrator assembly and activity in snRNA 3'-end processing. Our structural and functional studies reveal that Integrator is subject to intricate cellular control and IP6 is a critical regulator of Integrator assembly and function in Drosophila, humans, and likely other organisms.


Author(s):  
Arjun Bhatta ◽  
Christian Dienemann ◽  
Patrick Cramer ◽  
Hauke S. Hillen

AbstractHuman mitochondrial transcripts contain messenger and ribosomal RNAs flanked by transfer RNAs (tRNAs), which are excised by mitochondrial RNase (mtRNase) P and Z to liberate all RNA species. In contrast to nuclear or bacterial RNase P, mtRNase P is not a ribozyme but comprises three protein subunits that carry out RNA cleavage and methylation by unknown mechanisms. Here, we present the cryo-EM structure of human mtRNase P bound to precursor tRNA, which reveals a unique mechanism of substrate recognition and processing. Subunits TRMT10C and SDR5C1 form a subcomplex that binds conserved mitochondrial tRNA elements, including the anticodon loop, and positions the tRNA for methylation. The endonuclease PRORP is recruited and activated through interactions with its PPR and nuclease domains to ensure precise pre-tRNA cleavage. The structure provides the molecular basis for the first step of RNA processing in human mitochondria.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Daishin Ueno ◽  
Harunori Kawabe ◽  
Shotaro Yamasaki ◽  
Taku Demura ◽  
Ko Kato

Abstract Background RNA degradation is important for the regulation of gene expression. Despite the identification of proteins and sequences related to deadenylation-dependent RNA degradation in plants, endonucleolytic cleavage-dependent RNA degradation has not been studied in detail. Here, we developed truncated RNA end sequencing in Arabidopsis thaliana to identify cleavage sites and evaluate the efficiency of cleavage at each site. Although several features are related to RNA cleavage efficiency, the effect of each feature on cleavage efficiency has not been evaluated by considering multiple putative determinants in A. thaliana. Results Cleavage site information was acquired from a previous study, and cleavage efficiency at the site level (CSsite value), which indicates the number of reads at each cleavage site normalized to RNA abundance, was calculated. To identify features related to cleavage efficiency at the site level, multiple putative determinants (features) were used to perform feature selection using the Least Absolute Shrinkage and Selection Operator (LASSO) regression model. The results indicated that whole RNA features were important for the CSsite value, in addition to features around cleavage sites. Whole RNA features related to the translation process and nucleotide frequency around cleavage sites were major determinants of cleavage efficiency. The results were verified in a model constructed using only sequence features, which showed that the prediction accuracy was similar to that determined using all features including the translation process, suggesting that cleavage efficiency can be predicted using only sequence information. The LASSO regression model was validated in exogenous genes, which showed that the model constructed using only sequence information can predict cleavage efficiency in both endogenous and exogenous genes. Conclusions Feature selection using the LASSO regression model in A. thaliana identified 155 features. Correlation coefficients revealed that whole RNA features are important for determining cleavage efficiency in addition to features around the cleavage sites. The LASSO regression model can predict cleavage efficiency in endogenous and exogenous genes using only sequence information. The model revealed the significance of the effect of multiple determinants on cleavage efficiency, suggesting that sequence features are important for RNA degradation mechanisms in A. thaliana.


2021 ◽  
Author(s):  
Peter H Culviner ◽  
Isabel Nocedal ◽  
Sarah Fortune ◽  
Michael T Laub

Toxin-antitoxin systems are widely distributed genetic modules typically featuring toxins that can inhibit bacterial growth and antitoxins that can reverse inhibition. Although Escherichia coli encodes 11 toxins with known or putative endoribonuclease activity, the target of most of these toxins remain poorly characterized. Using a new RNA-seq pipeline that enables the mapping and quantification of RNA cleavage with single-nucleotide resolution, we characterize the targets and specificities of 9 endoribonuclease toxins from E. coli. We find that these toxins use low-information cleavage motifs to cut a significant proportion of mRNAs in E. coli, but not tRNAs or the rRNAs from mature ribosomes. However, all the toxins, including those that are ribosome-dependent and cleave only translated RNA, inhibit ribosome biogenesis. This inhibition likely results from the cleavage of ribosomal protein transcripts, which disrupts the stoichiometry and biogenesis of new ribosomes and causes the accumulation of aberrant ribosome precursors. Collectively, our results provide a comprehensive, global analysis of endoribonuclease-based toxin-antitoxin systems in E. coli and support the conclusion that, despite their diversity, each disrupts translation and ribosome biogenesis.


2021 ◽  
Author(s):  
Rebecca Guth-Metzler ◽  
Ahmad Mohyeldin Mohamed ◽  
Elizabeth T Cowan ◽  
Moran Frenkel-Pinter ◽  
Roger Wartell ◽  
...  

Mg2+, the most abundant divalent cation in cells, catalyzes RNA cleavage but can also promote RNA folding. Because folding can protect RNA from cleavage, we predicted a "Goldilocks zone", which is a local maximum in RNA lifetime at the minimum Mg2+ concentration required for folding. By simulation and experiment, we characterized the RNA Goldilocks zone and its dependence on cleavage parameters and extent of folding. We show experimentally that yeast tRNAPhe can inhabit a Goldilocks zone. The Goldilocks phenomena appears to be robust and is tunable by changes in magnesium affinity, and a variety of other factors. Goldilocks behavior can be more pronounced for RNAs with intermediate folding states. Goldilocks behavior allows ultrafine control of RNA chemical lifetime. A subset of RNAs in vivo are expected to occupy the Goldilocks zone. In evolutionary context, Goldilocks behavior may have shaped RNA in an early Earth environment containing Mg2+ and other metals. RNAs that do not fold cannot access a Goldilocks zone.


2021 ◽  
Author(s):  
Alexander J Meeske ◽  
Matthew C Johnson ◽  
Logan T Hille ◽  
Benjamin P Kleinstiver ◽  
Joseph Bondy-Denomy

CRISPR systems are prokaryotic adaptive immune systems that use RNA-guided Cas nucleases to recognize and destroy foreign genetic elements, like bacteriophages and plasmids. To overcome CRISPR immunity, phages have evolved diverse families of anti-CRISPR proteins (Acrs), each of which inhibits the nucleic acid binding or cleavage activities of specific Cas protein families. Recently, Lin et al. (2020) described the discovery and characterization of 7 different Acr families (AcrVIA1-7) that inhibit type VI-A CRISPR systems, which use the nuclease Cas13a to perform RNA-guided RNA cleavage. In this Matters Arising article, we detail several inconsistencies that question the results reported in the Lin et al. (2020) study. These include inaccurate bioinformatics analyses, as well as reported experiments involving bacterial strains that are impossible to construct. The authors were unable to provide their published strains with which we might reproduce their experiments. We independently tested the Acr sequences described in Lin et al. (2020) in two different Cas13 inhibition assays, but could not detect anti-CRISPR activity. Taken together, our data and analyses prompt us to question the claim that AcrVIA1-7 reported in Lin et al. are bona fide type VI anti-CRISPR proteins.


Author(s):  
Jagadeesh Kumar Uppala ◽  
Sankhajit Bhattacharjee ◽  
Madhusudan Dey

In the budding yeast Saccharomyces cerevisiae an mRNA, called HAC1, exists in a translationally repressed form in the cytoplasm. Under conditions of cellular stress, such as when unfolded proteins accumulate inside the endoplasmic reticulum (ER), an RNase Ire1 removes an intervening sequence (intron) from the HAC1 mRNA by non-conventional cytosolic splicing. Removal of the intron results in translational de-repression of HAC1 mRNA and production of a transcription factor that activates expressions of many enzymes and chaperones to increase the protein-folding capacity of the cell. Here, we show that Ire1-mediated RNA cleavage requires Watson-Crick base pairs in two RNA hairpins, which are located at the HAC1 mRNA exon-intron junctions. Then, we show that the translational de-repression of HAC1 mRNA can occur independent of cytosolic splicing. These results are obtained from HAC1 variants that translated an active Hac1 protein from the un-spliced mRNA. Additionally, we show that the phosphatidylinositol-3-kinase Vps34 and the nutrient-sensing kinases TOR and GCN2 are key regulators of HAC1 mRNA translation and consequently the ER stress responses. Collectively, our data suggest that the cytosolic splicing and the translational de-repression of HAC1 mRNA are coordinated by unique and parallel networks of signaling pathways.


2021 ◽  
Author(s):  
Daishin Ueno ◽  
Shotaro Yamasaki ◽  
Yuta Sadakiyo ◽  
Takumi Teruyama ◽  
Taku Demura ◽  
...  

ABSTRACTRNA degradation is critical for control of gene expression, and endonucleolytic cleavage– dependent RNA degradation is conserved among eukaryotes. Some cleavage sites are secondarily capped in the cytoplasm and identified using the CAGE method. Although uncapped cleavage sites are widespread in eukaryotes, comparatively little information has been obtained about these sites using CAGE-based degradome analysis. Previously, we developed the truncated RNA-end sequencing (TREseq) method in plant species and used it to acquire comprehensive information about uncapped cleavage sites; we observed G-rich sequences near cleavage sites. However, it remains unclear whether this finding is general to other eukaryotes. In this study, we conducted TREseq analyses in fruit flies (Drosophila melanogaster) and budding yeast (Saccharomyces cerevisiae). The results revealed specific sequence features related to RNA cleavage in D. melanogaster and S. cerevisiae that were similar to sequence patterns in Arabidopsis thaliana. Although previous studies suggest that ribosome movements are important for determining cleavage position, feature selection using a random forest classifier showed that sequences around cleavage sites were major determinant for cleaved or uncleaved sites. Together, our results suggest that sequence features around cleavage sites are critical for determining cleavage position, and that sequence-specific endonucleolytic cleavage–dependent RNA degradation is highly conserved across eukaryotes.


Sign in / Sign up

Export Citation Format

Share Document