Argonaute proteins: structures and their endonuclease activity

2021 ◽  
Author(s):  
Shujuan Jin ◽  
Jian Zhan ◽  
Yaoqi Zhou
Keyword(s):  
Endonuclease Activity ◽  
Argonaute Proteins

scholarly journals The stepwise endonuclease activity of a thermophilic Argonaute protein

2019 ◽  
Author(s):  
Guanhua Xun ◽  
Qian Liu ◽  
Yuesheng Chong ◽  
Zhonglei Li ◽  
Xiang Guo ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Dna Cleavage ◽  
Pyrococcus Furiosus ◽  
Dna Amplification ◽  
Endonuclease Activity ◽  
Gene Detection ◽  
Complementary Sequences ◽  
Argonaute Proteins ◽  
Target Dna ◽  
Single Reaction

AbstractThermophilic Argonaute proteins (Agos) can function as endonucleases via specific guide-target base-pairing cleavage for host defense. The ability to cleave target DNA sequences at any arbitrary sites endows them with reprogramed DNA capacity. Here, we identify that an Ago from the hyperthermophilic archaeon Pyrococcus furiosus (PfAgo) shows a stepwise endonuclease activity, which is demonstrated by the double strand DNA cleavage directed by a single guide DNA rather than canonical one pair of guide DNAs. We reveal that the cleavage products with 5’-phosphorylated ends can used as the renewed guide which is capable to induce next round of cleavage to complementary sequences of target DNA. By combining the PfAgo stepwise endonuclease activity followed by target DNA amplification, we establish a rapid and specific platform for the unambiguously multiplex gene detection, termed RADAR (Renewed-gDNA Assisted DNA-cleavage by Argonaute). In the end, RADAR was applied to distinguish of human papillomavirus of serotypes in patient samples in a single reaction, suggesting that our technique would be adopted for diagnosing application.

scholarly journals EXTENDED TUDOR-DOMAINS of the piRNA BIOGENESIS PATHWAY HAVE RNA-SPECIFIC NUCLEASE ACTIVITY

2021 ◽  
Author(s):  
Neha Dhimole ◽  
Susanne Zur Lage ◽  
Wilfried Klug ◽  
Teresa Carlomagno
Keyword(s):  
Nuclease Activity ◽  
Protein Fold ◽  
Endonuclease Activity ◽  
Deleterious Mutations ◽  
The Core ◽  
Argonaute Proteins ◽  
Biochemical Assays ◽  
Tightly Coupled ◽  
Amplification Loop ◽  
Prime End

piRNAs are essential for transposon repression and protecting the germline from deleterious mutations. piRNA biogenesis comprises a primary and secondary pathway, and involves PIWI clade argonaute proteins and ancillary factors. Secondary piRNA biogenesis is tightly coupled to transposon repression. It requires processing of the 3-prime end of pre-piRNA during an amplification loop by an as yet unidentified endonuclease. Here, using crystallography, and biochemical assays, we discover that the Drosophila Qin protein, which is a critical member of the core amplification complex, has endonuclease activity. Qin contains five extended Tudor domains, which had been proposed to recognize methylated ligands. Instead, we show that these domains act as RNA-specific nucleases. This supports a role for Qin in the 3-prime end processing of Ago3-bound pre-piRNAs. Extended Tudor domains are frequent in piRNA-processing proteins, suggesting that the uncovered nuclease activity of this protein fold may be key to understanding the piRNA biogenesis.

scholarly journals The Non-Canonical Aspects of MicroRNAs: Many Roads to Gene Regulation

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1465 ◽  
Author(s):  
Christiaan J. Stavast ◽  
Stefan J. Erkeland
Keyword(s):  
Rna Polymerase Ii ◽  
Transcriptional Activation ◽  
Small Rnas ◽  
Target Genes ◽  
Biological Functions ◽  
Rnase Iii ◽  
Mrna Targets ◽  
Argonaute Proteins ◽  
Epigenetic Modifiers ◽  
Encoding Genes

MicroRNAs (miRNAs) are critical regulators of gene expression. As miRNAs are frequently deregulated in many human diseases, including cancer and immunological disorders, it is important to understand their biological functions. Typically, miRNA-encoding genes are transcribed by RNA Polymerase II and generate primary transcripts that are processed by RNase III-endonucleases DROSHA and DICER into small RNAs of approximately 21 nucleotides. All miRNAs are loaded into Argonaute proteins in the RNA-induced silencing complex (RISC) and act as post-transcriptional regulators by binding to the 3′- untranslated region (UTR) of mRNAs. This seed-dependent miRNA binding inhibits the translation and/or promotes the degradation of mRNA targets. Surprisingly, recent data presents evidence for a target-mediated decay mechanism that controls the level of specific miRNAs. In addition, several non-canonical miRNA-containing genes have been recently described and unexpected functions of miRNAs have been identified. For instance, several miRNAs are located in the nucleus, where they are involved in the transcriptional activation or silencing of target genes. These epigenetic modifiers are recruited by RISC and guided by miRNAs to specific loci in the genome. Here, we will review non-canonical aspects of miRNA biology, including novel regulators of miRNA expression and functions of miRNAs in the nucleus.

scholarly journals Evaluation of a System to Screen for Stimulators of Non-Specific DNA Nicking by HIV-1 Integrase: Application to a Library of 50,000 Compounds

2011 ◽  
Vol 22 (2) ◽  
pp. 67-74 ◽  
Author(s):  
Malgorzata Sudol ◽  
Jennifer L Fritz ◽  
Melissa Tran ◽  
Gavin P Robertson ◽  
Julie B Ealy ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Solution Phase ◽  
The Novel ◽  
Endonuclease Activity ◽  
Viral Dna ◽  
Hit Rate ◽  
Dna Nicking ◽  
Hiv 1 ◽  
Stimulation Of

Background: In addition to activities needed to catalyse integration, retroviral integrases exhibit non-specific endonuclease activity that is enhanced by certain small compounds, suggesting that integrase could be stimulated to damage viral DNA before integration occurs. Methods: A non-radioactive, plate-based, solution phase, fluorescence assay was used to screen a library of 50,080 drug-like chemicals for stimulation of non-specific DNA nicking by HIV-1 integrase. Results: A semi-automated workflow was established and primary hits were readily identified from a graphic output. Overall, 0.6% of the chemicals caused a large increase in fluorescence (the primary hit rate) without also having visible colour that could have artifactually caused this result. None of the potential stimulators from this moderate-size library, however, passed a secondary test that included an inactive integrase mutant that assessed whether the increased fluorescence depended on the endonuclease activity of integrase. Conclusions: This first attempt at identifying integrase stimulator compounds establishes the necessary logistics and workflow required. The results from this study should encourage larger scale high-throughput screening to advance the novel antiviral strategy of stimulating integrase to damage retroviral DNA.

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 Argonaute proteins: Structural features, functions and emerging roles

2020 ◽  
Vol 24 ◽  
pp. 317-324 ◽  
Author(s):  
Jin'en Wu ◽  
Jing Yang ◽  
William C. Cho ◽  
Yadong Zheng
Keyword(s):  
Structural Features ◽  
Argonaute Proteins

scholarly journals Aurintricarboxylic acid rescues PC12 cells and sympathetic neurons from cell death caused by nerve growth factor deprivation: correlation with suppression of endonuclease activity.

1991 ◽  
Vol 115 (2) ◽  
pp. 461-471 ◽  
Author(s):  
A Batistatou ◽  
L A Greene
Keyword(s):  
Cell Death ◽  
Nerve Growth Factor ◽  
Pc12 Cells ◽  
Sympathetic Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Endonuclease Activity ◽  
Term Survival ◽  
Serum Free

Past studies have shown that serum-free cultures of PC12 cells are a useful model system for studying the neuronal cell death which occurs after neurotrophic factor deprivation. In this experimental paradigm, nerve growth factor (NGF) rescues the cells from death. It is reported here that serum-deprived PC12 cells manifest an endonuclease activity that leads to internucleosomal cleavage of their cellular DNA. This activity is detected within 3 h of serum withdrawal and several hours before any morphological sign of cell degeneration or death. NGF and serum, which promote survival of the cells, inhibit the DNA fragmentation. Aurintricarboxylic acid (ATA), a general inhibitor of nucleases in vitro, suppresses the endonuclease activity and promotes long-term survival of PC12 cells in serum-free cultures. This effect appears to be independent of macromolecular synthesis. In addition, ATA promotes long-term survival of cultured sympathetic neurons after NGF withdrawal. ATA neither promotes nor maintains neurite outgrowth. It is hypothesized that the activation of an endogenous endonuclease could be responsible for neuronal cell death after neurotrophic factor deprivation and that growth factors could promote survival by leading to inhibition of constitutively present endonucleases.

scholarly journals The C-terminal domains of human TNRC6A, TNRC6B, and TNRC6C silence bound transcripts independently of Argonaute proteins

RNA ◽  
2009 ◽  
Vol 15 (6) ◽  
pp. 1059-1066 ◽  
Author(s):  
D. Lazzaretti ◽  
I. Tournier ◽  
E. Izaurralde
Keyword(s):  
Argonaute Proteins ◽  
Terminal Domains
Sign in / Sign up

Export Citation Format

Share Document