SARS-CoV-2 nsp15 endoribonuclease antagonizes dsRNA-induced antiviral signaling

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Nov. 15, 2023

ABSTRACT Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has caused millions of deaths since emerging in 2019. Innate immune antagonism by lethal CoVs such as SARS-CoV-2 is crucial for optimal replication and pathogenesis. The conserved nonstructural protein 15 (nsp15) endoribonuclease (EndoU) limits activation double-stranded (ds)RNA-induced pathways, including interferon (IFN) signaling, kinase R (PKR), oligoadenylate synthetase/ribonuclease L (OAS/RNase L) during diverse CoV infections murine Middle East (MERS)-CoV. To determine how nsp15 functions infection, we constructed a mutant recombinant (nsp15 mut ) expressing catalytically inactive nsp15. Infection with led to increased the IFN signaling PKR pathways lung-derived epithelial cell lines primary nasal air-liquid interface (ALI) cultures well significant attenuation ALI compared wild-type (WT) virus. This defect was rescued when inhibited Janus activated (JAK) inhibitor ruxolitinib. Finally, assess function context minimal (MERS-CoV) or moderate (SARS-CoV-2) innate induction, previously described MERS-CoV mutants. Inactivation had more dramatic impact on than both Calu3 cells suggesting that can better tolerate responses. Taken together, potent dsRNA-induced response its necessary viral culture. SIGNIFICANCE causes spectrum disease ranging from asymptomatic severe pneumonia death. responses infection have been associated clinical severity, robust early epithelium reported be protective. Thus, elucidating mechanisms through which induces antagonizes host understanding encode various antagonists, contains an domain. We demonstrate EndoU antagonist, providing further evidence role antagonizing activation, thereby optimizing replication.

Language: Английский

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Mutation of a highly conserved isoleucine residue in loop 2 of several β-coronavirus macrodomains indicates that enhanced ADP-ribose binding is detrimental for replication

Journal of Virology, Journal Year: 2024, Volume and Issue: 98(11)

Published: Oct. 10, 2024

ABSTRACT All coronaviruses (CoVs) encode for a conserved macrodomain (Mac1) located in non-structural protein 3. Mac1 is an ADP-ribosylhydrolase that binds and hydrolyzes mono-ADP-ribose from target proteins. Previous work has shown important virus replication pathogenesis. Within Mac1, there are several regions highly across CoVs, including the glycine-isoleucine-phenylalanine motif. While we previously demonstrated importance of glycine residue CoV pathogenesis, impact isoleucine phenylalanine residues remains unknown. To determine how biochemical activities these replication, were mutated to alanine (I-A/F-A) both recombinant proteins murine hepatitis virus, Middle East respiratory syndrome coronavirus (MERS-CoV), severe acute 2 (SARS-CoV-2). The F-A mutant had ADP-ribose binding and/or hydrolysis defects correlated with attenuated pathogenesis MERS-CoV SARS-CoV-2 viruses cell culture mice. In contrast, I-A normal enzyme activity enhanced binding. Despite only demonstrating increased binding, mice, indicating this acts as gate controls efficient replication. These results highlight function provide unique insight into macrodomains control promote viral IMPORTANCE (CoV) counters host ADP-ribosyltransferases critical As such, potential therapeutic CoV-induced disease. However, lack basic knowledge its pocket contribute virological functions. We engineered mutations two (MERS-CoV) Interestingly, isoleucine-to-alanine which proved be detrimental beneficial will development novel inhibitors targeting could used treat

Language: Английский

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PARPs and ADP-Ribosylation in Chronic Inflammation: A Focus on Macrophages

Pathogens, Journal Year: 2023, Volume and Issue: 12(7), P. 964 - 964

Published: July 23, 2023

Aberrant adenosine diphosphate-ribose (ADP)-ribosylation of proteins and nucleic acids is associated with multiple disease processes such as infections chronic inflammatory diseases. The poly(ADP-ribose) polymerase (PARP)/ADP-ribosyltransferase (ART) family members promote mono- or poly-ADP-ribosylation. Although evidence has linked PARPs/ARTs macrophages in the context inflammation, underlying mechanisms remain incompletely understood. This review provides an overview literature focusing on roles PARP1/ARTD1, PARP7/ARTD14, PARP9/ARTD9, PARP14/ARTD8 macrophages. regulate changes during not only via catalytic modifications but also non-catalytic mechanisms. Untangling complex mechanisms, by which modulate macrophage phenotype, providing molecular bases for development new therapeutics require implementation innovative technologies.

Language: Английский

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An Update on the Current State of SARS-CoV-2 Mac1 Inhibitors

Pathogens, Journal Year: 2023, Volume and Issue: 12(10), P. 1221 - 1221

Published: Oct. 7, 2023

Non-structural protein 3 (nsp3) from all coronaviruses (CoVs) contains a conserved macrodomain, known as Mac1, that has been proposed potential therapeutic target for CoVs due to its critical role in viral pathogenesis. Mac1 is an ADP-ribose binding and ADP-ribosylhydrolase promotes replication blocks IFN responses, though the precise mechanisms it uses carry out these functions remain unknown. Over past years following onset of COVID-19, several groups have used high-throughput screening with multiple assays chemical modifications create unique inhibitors SARS-CoV-2 protein. Here, we summarize current efforts identify selective potent Mac1.

Language: Английский

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Discovery of potent SARS-CoV-2 nsp3 macrodomain inhibitors uncovers lack of translation to cellular antiviral response

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 21, 2024

Abstract A strategy for pandemic preparedness is the development of antivirals against a wide set viral targets with complementary mechanisms action. SARS-CoV-2 nsp3-mac1 macrodomain ADP-ribosylhydrolase activity, which counteracts host immune response. Targeting virus’ immunomodulatory functionality offers differentiated to inhibit compared approved therapeutics, target replication directly. Here we report fragment-based lead generation campaign guided by computational approaches. We discover tool compounds activity at low nanomolar concentrations, and responsive structure-activity relationships, high selectivity, drug-like properties. Using our inhibitors, show that inhibition increases ADP-ribosylation, but surprisingly does not translate demonstrable antiviral in cell culture iPSC-derived pneumocyte models. Further, no synergistic observed combination interferon gamma, main protease inhibitor, nor papain-like inhibitor. Our results question extent targeting modulation innate immunity-driven ADP-ribosylation can influence replication. Moreover, these findings suggest might be suitable therapeutics development.

Language: Английский

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