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 ◽  
...  

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.

2021 ◽  
Author(s):  
Paulina Pawlica ◽  
Therese A. Yario ◽  
Sylvia White ◽  
Jianhui Wang ◽  
Walter N. Moss ◽  
...  

AbstractSevere 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 vmiR-5p (for viral miRNA), derived from the SARS-CoV-2 ORF7a transcript. Its abundance ranges from low to moderate as compared to host miRNAs. vmiR-5p functionally associates with Argonaute proteins — core components of the RNA interference pathway — leading to downregulation of host transcripts. One such host messenger RNA encodes Basic Leucine Zipper ATF-Like Transcription Factor 2 (BATF2), which is linked to interferon signaling. We demonstrate that vmiR-5p 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.Significance statementWe discovered that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) expresses a small viral non-coding RNA, named vmiR-5p (for viral miRNA), derived from the ORF7a transcript. vmiR-5p associates with the cellular RNA interference machinery to regulate host transcripts likely via target silencing. The production of vmiR-5p relies on cellular machinery and the formation of a strong hairpin within ORF7a sequences. This newly-described vmiR-5p may contribute to SARS-CoV-2 pathogenesis and could become a target for therapeutic intervention.


2020 ◽  
Vol 11 ◽  
Author(s):  
Manuel Soto ◽  
Laura Ramírez ◽  
José Carlos Solana ◽  
Emma C. L. Cook ◽  
Elena Hernández-García ◽  
...  

Unveiling the protective immune response to visceral leishmaniasis is critical for a rational design of vaccines aimed at reducing the impact caused by this fatal, if left untreated, vector-borne disease. In this study we sought to determine the role of the basic leucine zipper transcription factor ATF-like 3 (Batf3) in the evolution of infection with Leishmania infantum, the causative agent of human visceral leishmaniasis in the Mediterranean Basin and Latin America. For that, Batf3-deficient mice in C57BL/6 background were infected with an L. infantum strain expressing the luciferase gene. Bioluminescent imaging, as well as in vitro parasite titration, demonstrated that Batf3-deficient mice were unable to control hepatic parasitosis as opposed to wild-type C57BL/6 mice. The impaired microbicide capacities of L. infantum-infected macrophages from Batf3-deficient mice mainly correlated with a reduction of parasite-specific IFN-γ production. Our results reinforce the implication of Batf3 in the generation of type 1 immunity against infectious diseases.


2004 ◽  
Vol 71 ◽  
pp. 157-176 ◽  
Author(s):  
Joanne Mathers ◽  
Jennifer A. Fraser ◽  
Michael McMahon ◽  
Robert D. C. Saunders ◽  
John D. Hayes ◽  
...  

Aerobic cells produce reactive oxygen species as a consequence of normal cellular metabolism, and an array of antioxidant systems are in place to maintain the redox balance. When the redox equilibrium of the cell is upset by pro-oxidant environmental stimuli, adaptive responses to the redox stress take place, which can result in up-regulation of antioxidant proteins and detoxification enzymes. Over the past few years, it has become apparent that members of the CNC (cap 'n' collar)-basic leucine zipper family of transcription factors are principal mediators of defensive responses to redox stress. In mammals, the CNC family members nuclear factor-erythroid 2 p45-related factors 1 and 2 (Nrf1 and Nrf2) have been shown to be involved in the transcriptional up-regulation of cytoprotective genes including those encoding glutamate cysteine ligase, NAD(P)H:quinone oxidoreductase, glutathione S-transferases and aldo-keto reductases. An evolutionarily conserved system exists in Caenorhabditis elegans, and it is possible that Drosophila melanogaster may also utilize CNC transcription factors to induce antioxidant genes in response to pro-oxidant chemicals. The advent of microarray and proteomic technologies has advanced our understanding of the gene batteries regulated by oxidative insult, but has highlighted the complexity of gene regulation by environmental factors. This review focuses on the antioxidant response to environmental stress, and the impact that microarrays and proteomics have made in this field.


2021 ◽  
Vol 22 (11) ◽  
pp. 5662
Author(s):  
Maria Hrmova ◽  
Syed Sarfraz Hussain

Transcription factors (TFs) play a significant role in signal transduction networks spanning the perception of a stress signal and the expression of corresponding stress-responsive genes. TFs are multi-functional proteins that may simultaneously control numerous pathways during stresses in plants—this makes them powerful tools for the manipulation of regulatory and stress-responsive pathways. In recent years, the structure-function relationships of numerous plant TFs involved in drought and associated stresses have been defined, which prompted devising practical strategies for engineering plants with enhanced stress tolerance. Vast data have emerged on purposely basic leucine zipper (bZIP), WRKY, homeodomain-leucine zipper (HD-Zip), myeloblastoma (MYB), drought-response elements binding proteins/C-repeat binding factor (DREB/CBF), shine (SHN), and wax production-like (WXPL) TFs that reflect the understanding of their 3D structure and how the structure relates to function. Consequently, this information is useful in the tailored design of variant TFs that enhances our understanding of their functional states, such as oligomerization, post-translational modification patterns, protein-protein interactions, and their abilities to recognize downstream target DNA sequences. Here, we report on the progress of TFs based on their interaction pathway participation in stress-responsive networks, and pinpoint strategies and applications for crops and the impact of these strategies for improving plant stress tolerance.


Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 290 ◽  
Author(s):  
Stefania Fochi ◽  
Vincenzo Ciminale ◽  
Elisabetta Trabetti ◽  
Umberto Bertazzoni ◽  
Donna M. D’Agostino ◽  
...  

The risk of developing adult T-cell leukemia/lymphoma (ATLL) in individuals infected with human T-cell lymphotropic virus 1 (HTLV-1) is about 3–5%. The mechanisms by which the virus triggers this aggressive cancer are still an area of intensive investigation. The viral protein Tax-1, together with additional regulatory proteins, in particular HTLV-1 basic leucine zipper factor (HBZ), are recognized as relevant viral factors required for both viral replication and transformation of infected cells. Tax-1 deregulates several cellular pathways affecting the cell cycle, survival, and proliferation. The effects of Tax-1 on the NF-κB pathway have been thoroughly studied. Recent studies also revealed the impact of Tax-1 and HBZ on microRNA expression. In this review, we summarize the recent progress in understanding the contribution of HTLV-1 Tax- and HBZ-mediated deregulation of NF-κB and the microRNA regulatory network to HTLV-1 pathogenesis.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Na Sang ◽  
Hui Liu ◽  
Bin Ma ◽  
Xianzhong Huang ◽  
Lu Zhuo ◽  
...  

Abstract Background In plants, 14-3-3 proteins, also called GENERAL REGULATORY FACTORs (GRFs), encoded by a large multigene family, are involved in protein–protein interactions and play crucial roles in various physiological processes. No genome-wide analysis of the GRF gene family has been performed in cotton, and their functions in flowering are largely unknown. Results In this study, 17, 17, 31, and 17 GRF genes were identified in Gossypium herbaceum, G. arboreum, G. hirsutum, and G. raimondii, respectively, by genome-wide analyses and were designated as GheGRFs, GaGRFs, GhGRFs, and GrGRFs, respectively. A phylogenetic analysis revealed that these proteins were divided into ε and non-ε groups. Gene structural, motif composition, synteny, and duplicated gene analyses of the identified GRF genes provided insights into the evolution of this family in cotton. GhGRF genes exhibited diverse expression patterns in different tissues. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that the GhGRFs interacted with the cotton FLOWERING LOCUS T homologue GhFT in the cytoplasm and nucleus, while they interacted with the basic leucine zipper transcription factor GhFD only in the nucleus. Virus-induced gene silencing in G. hirsutum and transgenic studies in Arabidopsis demonstrated that GhGRF3/6/9/15 repressed flowering and that GhGRF14 promoted flowering. Conclusions Here, 82 GRF genes were identified in cotton, and their gene and protein features, classification, evolution, and expression patterns were comprehensively and systematically investigated. The GhGRF3/6/9/15 interacted with GhFT and GhFD to form florigen activation complexs that inhibited flowering. However, GhGRF14 interacted with GhFT and GhFD to form florigen activation complex that promoted flowering. The results provide a foundation for further studies on the regulatory mechanisms of flowering.


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