Structural insights into the interaction of papain-like protease 2 from the alphacoronavirus porcine epidemic diarrhea virus and ubiquitin

Author(s):  
Ian A. Durie ◽  
John V. Dzimianski ◽  
Courtney M. Daczkowski ◽  
Jack McGuire ◽  
Kay Faaberg ◽  
...  

Porcine epidemic diarrhea is a devastating porcine disease that is caused by the alphacoronavirus porcine epidemic diarrhea virus (PEDV). Like other members of the Coronaviridae family, PEDV encodes a multifunctional papain-like protease 2 (PLP2) that has the ability to process the coronavirus viral polyprotein to aid in RNA replication and antagonize the host innate immune response through cleavage of the regulatory proteins ubiquitin (Ub) and/or interferon-stimulated gene product 15 (ISG15) (deubiquitination and deISGylation, respectively). Because Betacoronavirus PLPs have been well characterized, it was sought to determine how PLP2 from the alphacoronavirus PEDV differentiates itself from its related counterparts. PEDV PLP2 was first biochemically characterized, and a 3.1 Å resolution crystal structure of PEDV PLP2 bound to Ub was then solved, providing insight into how Alphacoronavirus PLPs bind to their preferred substrate, Ub. It was found that PEDV PLP2 is a deubiquitinase and readily processes a variety of di-Ub linkages, in comparison with its Betacoronavirus counterparts, which have a narrower range of di-Ub activity but process both Ub and ISG15.

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 367 ◽  
Author(s):  
Shasha Li ◽  
Jinping Yang ◽  
Zixiang Zhu ◽  
Haixue Zheng

Porcine epidemic diarrhea virus (PEDV), a swine enteropathogenic coronavirus (CoV), is the causative agent of porcine epidemic diarrhea (PED). PED causes lethal watery diarrhea in piglets, which has led to substantial economic losses in many countries and is a great threat to the global swine industry. Interferons (IFNs) are major cytokines involved in host innate immune defense, which induce the expression of a broad range of antiviral effectors that help host to control and antagonize viral infections. PEDV infection does not elicit a robust IFN response, and some of the mechanisms used by the virus to counteract the host innate immune response have been unraveled. PEDV evades the host innate immune response by two main strategies including: 1) encoding IFN antagonists to disrupt innate immune pathway, and 2) hiding its viral RNA to avoid the exposure of viral RNA to immune sensors. This review highlights the immune evasion mechanisms employed by PEDV, which provides insights for the better understanding of PEDV-host interactions and developing effective vaccines and antivirals against CoVs.


Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 240 ◽  
Author(s):  
Gang Ye ◽  
Xiaowei Wang ◽  
Xiaohan Tong ◽  
Yuejun Shi ◽  
Zhen F. Fu ◽  
...  

Porcine epidemic diarrhea virus (PEDV), being highly virulent and contagious in piglets, has caused significant damage to the pork industries of many countries worldwide. There are no commercial drugs targeting coronaviruses (CoVs), and few studies on anti-PEDV inhibitors. The coronavirus 3C-like protease (3CLpro) has a conserved structure and catalytic mechanism and plays a key role during viral polyprotein processing, thus serving as an appealing antiviral drug target. Here, we report the anti-PEDV effect of the broad-spectrum inhibitor GC376 (targeting 3Cpro or 3CLpro of viruses in the picornavirus-like supercluster). GC376 was highly effective against the PEDV 3CLpro and exerted similar inhibitory effects on two PEDV strains. Furthermore, the structure of the PEDV 3CLpro in complex with GC376 was determined at 1.65 Å. We elucidated structural details and analyzed the differences between GC376 binding with the PEDV 3CLpro and GC376 binding with the transmissible gastroenteritis virus (TGEV) 3CLpro. Finally, we explored the substrate specificity of PEDV 3CLpro at the P2 site and analyzed the effects of Leu group modification in GC376 on inhibiting PEDV infection. This study helps us to understand better the PEDV 3CLpro substrate specificity, providing information on the optimization of GC376 for development as an antiviral therapeutic against coronaviruses.


2013 ◽  
Vol 94 (7) ◽  
pp. 1554-1567 ◽  
Author(s):  
Yaling Xing ◽  
Jianfei Chen ◽  
Jian Tu ◽  
Bailing Zhang ◽  
Xiaojuan Chen ◽  
...  

Porcine epidemic diarrhea virus (PEDV) is the cause of an economically important swine disease. Previous studies suggested that PEDV does not elicit a robust IFN response, but the mechanism(s) used to evade or block this innate immune response was not known. In this study, we found that PEDV infection blocked synthetic dsRNA-induced IFN-β production by interfering with the activation of interferon regulatory factor 3 (IRF3). We identified PEDV replicase encoded papain-like protease 2 (PLP2) as an IFN antagonist that depends on catalytic activity for its function. We show that levels of ubiquitinated proteins are reduced during PEDV infection and that PEDV PLP2 has deubiquitinase (DUB) activity that recognizes and processes both K-48 and K-63 linked polyubiquitin chains. Furthermore, we found that PEDV PLP2 strongly inhibits RIG-I- and STING-activated IFN expression and that PEDV PLP2 can be co-immunoprecipitated with and deubiquitinates RIG-I and STING, the key components of the signalling pathway for IFN expression. These results show that PEDV infection suppresses production of IFN-β and provides evidence indicating that the PEDV papain-like protease 2 acts as a viral DUB to interfere with the RIG-I- and STING-mediated signalling pathway.


2021 ◽  
Author(s):  
Jidong Xu ◽  
Junyong Mao ◽  
Xiao Han ◽  
Fushan Shi ◽  
Qin Gao ◽  
...  

Porcine epidemic diarrhea virus (PEDV) is an enteric coronavirus causing acute intestinal infection in pigs, with high mortality often seen in neonatal pigs. The newborns rely on innate immune responses against invading pathogens because of lacking adaptive immunity. However, how PEDV disables the innate immunity of newborns towards severe infection remains unknown. We found that PEDV infection led to reduced expression of histone deacetylases (HDACs), especially HDAC1 in porcine IPEC-J2 cells. HDACs are considered as important regulators of innate immunity. We hypothesized that PEDV might interact with certain host factors to regulate HDAC1 expression in favor of its replication. We show that HDAC1 acted as a negative regulator of PEDV replication in IPEC-J2 cells, as shown by chemical inhibition, gene knockout and overexpression. A GC-box ( GCCCCACCCCC ) within the HDAC1 promoter region was identified for Sp1 binding in IPEC-J2 cells. Treatment of the cells with Sp1 inhibitor, mithramycin A, inhibited HDAC1 expression, indicating direct regulation of HDAC1 expression by Sp1. Of the viral proteins that were overexpressed in IPEC-J2 cells, the N protein was found to be present in the nuclei and more inhibitory to HDAC1 transcription. The putative NLS 261 PKKNKSR 267 contributed to its nuclear localization. The N protein interacted with Sp1 and interfered with its binding to the promoter region, thereby inhibiting its transcriptional activity for HDAC1 expression. Our findings reveal a novel mechanism of PEDV evasion of the host responses, offering implications for studying the infection processes of other coronaviruses. Importance The enteric coronavirus porcine epidemic diarrhea virus (PEDV) causes fatal acute intestinal infection in neonatal pigs that rely on innate immune responses. Histone deacetylases (HDACs) play important roles in innate immune regulation. Our study found PEDV suppresses HDAC1 expression via the interaction of its N protein and porcine Sp1, which identified a novel mechanism of PEDV evasion of the host responses to benefit its replication. This study suggests that other coronaviruses, including SARS-CoV and SARS-CoV-2, may also make use of their N proteins to intercept the host immune responses in favor of their infection.


2019 ◽  
Author(s):  
Dandan Liu ◽  
Lei Ge ◽  
Qing Wang ◽  
Jiarui Su ◽  
Xingxiang Chen ◽  
...  

AbstractPorcine epidemic diarrhea virus (PEDV) is a highly contagious pathogenic virus that causes severe diarrhea and dehydration in pigs of all ages. Deoxynivalenol (DON), the most abundant trichothecene in food and feed, causes vomit and diarrhea in animals and human. However, whether DON exposure could affect PEDV infection remains unknown. Herein, we investigated the impacts of DON on entry and replication of PEDV, morbidity situation of piglets and the mechanisms involved. In vivo, twenty-seven piglets infected naturally with PEDV were randomly divided into three groups, receiving the basal diet containing 0, 750 and 1500 μg/kg DON, respectively. We observed significant increases in the diarrhea rates, the villous injury of jejunums and the PEDV proliferation of duodenum, jejunum, ileum and mesenterium of piglets in experimental groups compared with control. Additionally, the autophagosome-like vesicles and the autophagy-related protein expressions were also increased in experimental groups. In vitro, we observed that, approximately 2 hrs post-infection, 0.1, 0.5 and 1.0 μM DON promoted PEDV entry (P < 0.05) in IPEC-J2s and resulted in tight junction protein occludin internalization. Knockdown of occludin and CRISPR-Cas9-mediated knockout of LC3B indicated a vital role of autophagy-induced occludin internalization in DON-promoted PEDV entry. We also observed that, 24 hrs post-infection, a significant increase in PEDV replication after 0.1, 0.5 and 1.0 μM DON treatment, along with the induction of a complete autophagy. Specifically, deletion of LC3B indicated a crucial role of autophagy in DON-promoted PEDV replication. Pretreatment with SB202190, a p38 signaling inhibitor, abolished the induction of autophagy. Furthermore, downregulation of type I interferon revealed that DON contributed PEDV to escape innate immune. Mechanistically, DON-caused innate immune escape was related to the upregulation of LC3B, which further inhibited STING phosphorylation. Taken together, DON could promote PEDV infection by inducing occludin internalization and innate immune escape via triggering p38-mediated autophagy.Author summaryPorcine epidemic diarrhea (PED), a devastating enteric disease, leads to catastrophic economic loss to the global pig industry. Its primary pathogen is the coronavirus PED virus (PEDV). Growing evidence indicates that pathogen infection is not the only factor of PED outbreaks, other non-infectious factors is also related to this disease. We guessed some ubiquitous substances, such as deoxynivalenol (DON), that lead to pig intestinal epithelial cell stress might encourage the progress and spread of PED. In the present study, the weaning piglets infected naturally with PEDV and the IPEC-J2 cell line were selected as models to explore the effects of DON on PEDV infection, morbidity and gut barrier. Our results showed that DON exposure can promote PEDV infection in vitro and in vivo, and the underlying mechanism might be related to LC3B-mediated autophagy. Our findings reveal new pathways for developing potential novel antiviral strategies against PEDV infection.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Gustavo Machado ◽  
Carles Vilalta ◽  
Mariana Recamonde-Mendoza ◽  
Cesar Corzo ◽  
Montserrat Torremorell ◽  
...  

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 216-217
Author(s):  
O L Harrison ◽  
G E Nichols ◽  
J T Gebhardt ◽  
Cassandra K Jones ◽  
Jason C Woodworth ◽  
...  

Abstract Recent research has demonstrated that swine viruses can be transmitted via feed. Chemical feed additives have been suggested for the mitigation of these viruses in complete feed. Therefore, the objective of this study was to evaluate the efficacy of a commercially available formaldehyde-based feed additive, medium chain fatty acid blend (MCFA), and commercially available fatty acid-based products for mitigation of porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) in a feed matrix. Treatments consisted of: 1) non-treated positive control, 2) 0.33% commercial formaldehyde-based product (Sal Curb; Kemin Industries, Inc.; Des Moines, IA), 3) 0.5% MCFA blend (1:1:1 ratio of C6:0, C8:0, and C10:0, Sigma Aldrich, St. Louis, MO), 4) 0.25%, 5) 0.5%, or 6) 1% of commercial dry mono and diglyceride-based product (Furst Strike; Furst-McNess Company, Freeport, IL), 7) 0.25%, 8) 0.5%, or 9) 1% of commercial dry mono and diglyceride-based product (Furst Protect; Furst-McNess Company, Freeport, IL), 10) 0.25%, 11) 0.5%, or 12) 1% dry mono and diglyceride-based experimental product (Furst-McNess Company, Freeport, IL) with 3 replications/treatment. Treatments were applied to complete swine feed before inoculation with 106 TCID50/g of feed with PEDV or PRRSV. Post inoculation feed was held at ambient temperature for 24 h before being analyzed via qRT-PCR. The analyzed values represent the cycle threshold. Formaldehyde and MCFA decreased (P &lt; 0.05) the detectable RNA of PEDV and PRRSV compared to all other treatments. Furst Strike, Furst Protect, and the experimental product did not significantly impact detectability of PEDV or PRRSV RNA. In conclusion, MCFA and formaldehyde treatments are effective at reducing detection of RNA from PEDV and PRRSV in feed.


Sign in / Sign up

Export Citation Format

Share Document