scholarly journals Inhibition of EV71 replication by L3HYPDH, a newly identified interferon-stimulated gene product

2018 ◽  
Author(s):  
Jian Liu ◽  
Luogen Liu ◽  
Shinuan Zeng ◽  
Xiaobin Meng ◽  
Nanfeng Lei ◽  
...  
Keyword(s):  
Enterovirus 71 ◽  
Protein Translation ◽  
Amino Acid Position ◽  
Terminal Region ◽  
Entry Site ◽  
Interferon Stimulated Genes ◽  
Antiviral Effects ◽  
Hand Foot Mouth Disease ◽  
Underlying Mechanisms ◽  
Hcv Ires

ABSTRACTUp-regulation of interferon-stimulated genes (ISGs) is key to antiviral states mediated by interferon (IFN) but little is known about activity and underlying mechanisms of most ISGs against Enterovirus 71 (EV71). EV71 causes hand-foot-mouth disease in infants and occasionally severe neurological symptoms. Here we report that the product ofL3HYPDH, a newly identified ISG, inhibits the replication of EV71. This anti-EV71 activity was mapped to the C-terminal 60 amino acids region as well as the N-terminal region spanning from amino acid position 61 to 120 of L3HYPDH protein. L3HYPDH was shown to interfere with EV71 propagation at the RNA replication and protein translation levels. Specifically, L3HYPDH impairs translation mediated by the EV71 international ribosome entry site (IRES) but not by the HCV IRES, and this activity is conferred by the C-terminal region of L3HYPDH. Thus, L3HYPDH has antiviral activity against EV71, suggesting a potential mechanism for broad-spectrum antiviral effects of IFN.

scholarly journals Enterovirus 71 Represses Interleukin Enhancer-Binding Factor 2 Production and Nucleus Translocation to Antagonize ILF2 Antiviral Effects

Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 22
Author(s):  
Jing Jin ◽  
Wenbiao Wang ◽  
Sha Ai ◽  
Weiyong Liu ◽  
Yu Song ◽  
...  
Keyword(s):  
Nonstructural Protein ◽  
Enterovirus 71 ◽  
Ev71 Infection ◽  
Health It ◽  
Antiviral Effects ◽  
Distinct Mechanism ◽  
Binding Factor ◽  
2B Protein ◽  
Rd Cells ◽  
Hand Foot Mouth Disease

Enterovirus 71 (EV71) infection causes hand-foot-mouth disease (HFMD), meningoencephalitis, neonatal sepsis, and even fatal encephalitis in children, thereby presenting a serious risk to public health. It is important to determine the mechanisms underlying the regulation of EV71 infection. In this study, we initially show that the interleukin enhancer-binding factor 2 (ILF2) reduces EV71 50% tissue culture infective dose (TCID50) and attenuates EV71 plaque-formation unit (PFU), thereby repressing EV71 infection. Microarray data analyses show that ILF2 mRNA is reduced upon EV71 infection. Cellular studies indicate that EV71 infection represses ILF2 mRNA expression and protein production in human leukemic monocytes (THP-1) -differentiated macrophages and human rhabdomyosarcoma (RD) cells. In addition, EV71 nonstructural protein 2B interacts with ILF2 in human embryonic kidney (HEK293T) cells. Interestingly, in the presence of EV71 2B, ILF2 is translocated from the nucleus to the cytoplasm, and it colocalizes with 2B in the cytoplasm. Therefore, we present a distinct mechanism by which EV71 antagonizes ILF2-mediated antiviral effects by inhibiting ILF2 expression and promoting ILF2 translocation from the nucleus to the cytoplasm through its 2B protein.

scholarly journals Nuclear Protein Sam68 Interacts with the Enterovirus 71 Internal Ribosome Entry Site and Positively Regulates Viral Protein Translation

2015 ◽  
Vol 89 (19) ◽  
pp. 10031-10043 ◽  
Author(s):  
Hua Zhang ◽  
Lei Song ◽  
Haolong Cong ◽  
Po Tien
Keyword(s):  
Life Cycle ◽  
Internal Ribosome Entry Site ◽  
Viral Protein ◽  
Nuclear Protein ◽  
Binding Protein ◽  
Enterovirus 71 ◽  
Protein Translation ◽  
Entry Site ◽  
Internal Ribosome Entry ◽  
Cellular Factors

ABSTRACTEnterovirus 71 (EV71) recruits various cellular factors to assist in the replication and translation of its genome. Identification of the host factors involved in the EV71 life cycle not only will enable a better understanding of the infection mechanism but also has the potential to be of use in the development of antiviral therapeutics. In this study, we demonstrated that the cellular factor 68-kDa Src-associated protein in mitosis (Sam68) acts as an internal ribosome entry site (IRES)trans-acting factor (ITAF) that binds specifically to the EV71 5′ untranslated region (5′UTR). Interaction sites in both the viral IRES (stem-loops IV and V) and the heterogeneous nuclear ribonucleoprotein K homology (KH) domain of Sam68 protein were further mapped using an electrophoretic mobility shift assay (EMSA) and biotin RNA pulldown assay. More importantly, dual-luciferase (firefly) reporter analysis suggested that overexpression of Sam68 positively regulated IRES-dependent translation of virus proteins. In contrast, both IRES activity and viral protein translation significantly decreased in Sam68 knockdown cells compared with the negative-control cells treated with short hairpin RNA (shRNA). However, downregulation of Sam68 did not have a significant inhibitory effect on the accumulation of the EV71 genome. Moreover, Sam68 was redistributed from the nucleus to the cytoplasm and interacts with cellular factors, such as poly(rC)-binding protein 2 (PCBP2) and poly(A)-binding protein (PABP), during EV71 infection. The cytoplasmic relocalization of Sam68 in EV71-infected cells may be involved in the enhancement of EV71 IRES-mediated translation. Since Sam68 is known to be a RNA-binding protein, these results provide direct evidence that Sam68 is a novel ITAF that interacts with EV71 IRES and positively regulates viral protein translation.IMPORTANCEThe nuclear protein Sam68 is found as an additional new host factor that interacts with the EV71 IRES during infection and could potentially enhance the translation of virus protein. To our knowledge, this is the first report that describes Sam68 actively participating in the life cycle of EV71 at a molecular level. These studies will not only improve our understanding of the replication of EV71 but also have the potential for aiding in developing a therapeutic strategy against EV71 infection.

scholarly journals Enterovirus 71 Represses Interleukin Enhancer Binding Factor 2 Production and Nucleus Translocation to Antagonize ILF2 Antiviral Effects

2019 ◽  
Author(s):  
Jing Jin ◽  
Wenbiao Wang ◽  
Sha Ai ◽  
Qi Zhang ◽  
Kailang Wu ◽  
...  
Keyword(s):  
Health Hazard ◽  
Enterovirus 71 ◽  
Ev71 Infection ◽  
Structural Protein ◽  
Antiviral Effects ◽  
Distinct Mechanism ◽  
Binding Factor ◽  
2B Protein ◽  
Rd Cells ◽  
Hand Foot Mouth Disease

Enterovirus 71 (EV71) infection hand-foot-mouth disease (HFMD), meningoencephalitis, neonatal sepsis, and even fatal encephalitis in children, thereby representing a serious public health hazard. It is important to determine the mechanisms underlying the regulation of EV71 infection. In this study, we initially reveal that the interleukin enhancer binding factor 2 (ILF2) down-regulates EV71 50% tissue culture infective dose (TCID50), attenuates EV71 plaque formation unit (PFU), thereby repressing EV71 infection. Moreover, we reveal a distinct mechanism by which EV71 antagonizes ILF2-mediated antiviral effects. Chip data analyses show that ILF2 mRNA is reduced upon EV71 infection. Cellular studies indicate that EV71 infection represses ILF2 mRNA expression and protein production in human leukemic monocytes (THP-1) differentiated macrophages and in human rhabdomyosarcoma (RD) cells. Additionally, EV71 non-structural protein 2B interacts with ILF2 in human embryonic kidney (HEK293T) cells. Interestingly, in the presence of EV71 2B, ILF2 is translocated from the nucleus to the cytoplasm and co-localizes with 2B in the cytoplasm. Therefore, we reveal a distinct mechanism by which EV71 antagonizes ILF2-mediated antiviral effects by inhibiting ILF2 expression and promoting ILF2 translocation from the nucleus to cytoplasm through its 2B protein.

scholarly journals Construction and Mutagenesis of an Artificial Bicistronic Tick-Borne Encephalitis Virus Genome Reveals an Essential Function of the Second Transmembrane Region of Protein E in Flavivirus Assembly

2006 ◽  
Vol 80 (24) ◽  
pp. 12197-12208 ◽  
Author(s):  
Klaus K. Orlinger ◽  
Verena M. Hoenninger ◽  
Regina M. Kofler ◽  
Christian W. Mandl
Keyword(s):  
Signal Sequence ◽  
Protein Translation ◽  
Encephalitis Virus ◽  
Surface Proteins ◽  
Coding Region ◽  
Transmembrane Region ◽  
Entry Site ◽  
Tick Borne Encephalitis ◽  
Rna Genome ◽  
Tick Borne Encephalitis Virus

ABSTRACT Flaviviruses have a monopartite positive-stranded RNA genome, which serves as the sole mRNA for protein translation. Cap-dependent translation produces a polyprotein precursor that is co- and posttranslationally processed by proteases to yield the final protein products. In this study, using tick-borne encephalitis virus (TBEV), we constructed an artificial bicistronic flavivirus genome (TBEV-bc) in which the capsid protein and the nonstructural proteins were still encoded in the cap cistron but the coding region for the surface proteins prM and E was moved to a separate translation unit under the control of an internal ribosome entry site element inserted into the 3′ noncoding region. Mutant TBEV-bc was shown to produce particles that packaged the bicistronic RNA genome and were infectious for BHK-21 cells and mice. Compared to wild-type controls, however, TBEV-bc was less efficient in both RNA replication and infectious particle formation. We took advantage of the separate expression of the E protein in this system to investigate the role in viral assembly of the second transmembrane region of protein E (E-TM2), a second copy of which was retained in the cap cistron to fulfill its other role as an internal signal sequence in the polyprotein. Deletion analysis and replacement of the entire TBEV E-TM2 region with its counterpart from another flavivirus revealed that this element, apart from its role as a signal sequence, is important for virion formation.

scholarly journals Differential Effects on the Hepatitis C Virus (HCV) Internal Ribosome Entry Site by Vitamin B12 and the HCV Core Protein

2004 ◽  
Vol 78 (21) ◽  
pp. 12075-12081 ◽  
Author(s):  
Dongsheng Li ◽  
William B. Lott ◽  
John Martyn ◽  
Gholamreza Haqshenas ◽  
Eric J. Gowans
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Internal Ribosome Entry Site ◽  
Core Protein ◽  
Vitamin B ◽  
Entry Site ◽  
Internal Ribosome Entry ◽  
Hcv Core Protein ◽  
Hcv Ires

ABSTRACT To investigate the role of the hepatitis C virus internal ribosome entry site (HCV IRES) domain IV in translation initiation and regulation, two chimeric IRES elements were constructed to contain the reciprocal domain IV in the otherwise HCV and classical swine fever virus IRES elements. This permitted an examination of the role of domain IV in the control of HCV translation. A specific inhibitor of the HCV IRES, vitamin B12, was shown to inhibit translation directed by all IRES elements which contained domain IV from the HCV and the GB virus B IRES elements, whereas the HCV core protein could only suppress translation from the wild-type HCV IRES. Thus, the mechanisms of translation inhibition by vitamin B12 and the core protein differ, and they target different regions of the IRES.

scholarly journals Enhanced virus translation enables miR-122-independent Hepatitis C Virus propagation

2021 ◽  
Author(s):  
Mamata Panigrahi ◽  
Michael Palmer ◽  
Joyce A Wilson
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Replication ◽  
Rna Structure ◽  
Genome Stability ◽  
Internal Ribosomal Entry Site ◽  
Terminal Region ◽  
Translation Regulation ◽  
Virus Propagation ◽  
Entry Site

The 5’UTR of the Hepatitis C Virus genome forms RNA structures that regulate virus replication and translation. The region contains a viral internal ribosomal entry site and a 5’ terminal region. Binding of the liver specific miRNA, miR-122, to two conserved binding sites in the 5’ terminal region regulates viral replication, translation, and genome stability, and is essential for efficient virus replication, but its precise mechanism of its action is still under debate. A current hypothesis is that miR-122 binding stimulates viral translation by facilitating the viral 5’ UTR to form the translationally active HCV IRES RNA structure. While miR-122 is essential for detectable virus replication in cell culture, several viral variants with 5’ UTR mutations exhibit low level replication in the absence of miR-122. We show that HCV mutants capable of replicating independently of miR-122 also replicate independently of other microRNAs generated by the canonical miRNA synthesis pathway. Further, we also show that the mutant genomes display an enhanced translation phenotype that correlates with their ability to replicate independently of miR-122. Finally, we provide evidence that translation regulation is the major role for miR-122, and show that miR-122-independent HCV replication can be rescued to miR-122-dependent levels by the combined impacts of 5’ UTR mutations that stimulate translation, and by stabilizing the viral genome by knockdown of host exonucleases and phosphatases that degrade the genome. Thus, we provide a model suggesting that translation stimulation and genome stabilization are the primary roles for miR-122 in the virus life cycle.

Genetic Diversity and Detection of Atypical Porcine Pestivirus Infections

2021 ◽  
Author(s):  
Kylee M Sutton ◽  
Christian W Eaton ◽  
Tudor Borza ◽  
Thomas E Burkey ◽  
Benny E Mote ◽  
...  
Keyword(s):  
Rna Virus ◽  
Protein Translation ◽  
Template Switching ◽  
Substantial Variation ◽  
Functional Importance ◽  
Entry Site ◽  
Internal Ribosome Entry ◽  
Viral Cdna ◽  
Viral Polyprotein ◽  
Congenital Tremor

Abstract Atypical porcine pestivirus (APPV), an RNA virus member of the Flaviviridae family, has been associated with congenital tremor in newborn piglets. Previously reported qPCR-based assays were unable to detect APPV in novel cases of congenital tremor originated from multiple farms from U.S. Midwest (MW). These assays targeted the viral polyprotein coding genes, which were shown to display substantial variation, with sequence identity ranging from 58.2 to 70.7% among 15 global APPV strains. In contrast, the 5’ UTR was found to have a much higher degree of sequence conservation. In order to obtain the complete 5’ UTR of the APPV strains originated from MW, the 5’ end of the viral cDNA was obtained by using template switching approach followed by amplification and dideoxy sequencing. Eighty one percent of the 5’UTR was identical across 14 global and 5 MW strains with complete, or relatively complete 5’ UTR. Notably, some of the most highly conserved 5’UTR segments overlapped with potentially important regions of an internal ribosome entry site (IRES), suggesting their functional role in viral protein translation. A newly designed single qPCR assay, targeting 100% conserved 5’UTR regions across 19 strains, was able to detect APPV in samples of well documented cases of congenital tremor which originated from five MW farm sites (1-18 samples/site). As these fully conserved 5’ UTR sequences may have functional importance, we expect that assays targeting this region would broadly detect APPV strains that are diverse in space and time.

scholarly journals BDNF-induced local translation of GluA1 is regulated by HNRNP A2/B1

2020 ◽  
Vol 6 (47) ◽  
pp. eabd2163
Author(s):  
Youngseob Jung ◽  
Ji-Young Seo ◽  
Hye Guk Ryu ◽  
Do-Yeon Kim ◽  
Kyung-Ha Lee ◽  
...  
Keyword(s):  
Ampa Receptor ◽  
Molecular Mechanisms ◽  
Receptor Expression ◽  
Spine Density ◽  
Entry Site ◽  
Independent Manner ◽  
Internal Ribosome Entry ◽  
Ampa Receptor Subunit ◽  
Internal Initiation ◽  
Underlying Mechanisms

The AMPA receptor subunit GluA1 is essential for induction of synaptic plasticity. While various regulatory mechanisms of AMPA receptor expression have been identified, the underlying mechanisms of GluA1 protein synthesis are not fully understood. In neurons, axonal and dendritic mRNAs have been reported to be translated in a cap-independent manner. However, molecular mechanisms of cap-independent translation of synaptic mRNAs remain largely unknown. Here, we show that GluA1 mRNA contains an internal ribosome entry site (IRES) in the 5′UTR. We also demonstrate that heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 interacts with GluA1 mRNA and mediates internal initiation of GluA1. Brain-derived neurotrophic factor (BDNF) stimulation increases IRES-mediated GluA1 translation via up-regulation of HNRNP A2/B1. Moreover, BDNF-induced GluA1 expression and dendritic spine density were significantly decreased in neurons lacking hnRNP A2/B1. Together, our data demonstrate that IRES-mediated translation of GluA1 mRNA is a previously unidentified feature of local expression of the AMPA receptor.

scholarly journals Enterovirus 71 Infection Cleaves a Negative Regulator for Viral Internal Ribosomal Entry Site-Driven Translation

2013 ◽  
Vol 87 (7) ◽  
pp. 3828-3838 ◽  
Author(s):  
L.-L. Chen ◽  
Y.-A. Kung ◽  
K.-F. Weng ◽  
J.-Y. Lin ◽  
J.-T. Horng ◽  
...  
Keyword(s):  
Internal Ribosomal Entry Site ◽  
Enterovirus 71 ◽  
Negative Regulator ◽  
Entry Site ◽  
Ribosomal Entry ◽  
Enterovirus 71 Infection

scholarly journals Plant-Produced Anti-Enterovirus 71 (EV71) Monoclonal Antibody Efficiently Protects Mice Against EV71 Infection

Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 560 ◽  
Author(s):  
Kaewta Rattanapisit ◽  
Zhang Chao ◽  
Konlavat Siriwattananon ◽  
Zhong Huang ◽  
Waranyoo Phoolcharoen
Keyword(s):  
Monoclonal Antibody ◽  
Therapeutic Option ◽  
Enterovirus 71 ◽  
Cost Effective ◽  
Ev71 Infection ◽  
Asia Pacific ◽  
Variable Regions ◽  
Hand Foot Mouth Disease ◽  
Protection Against Infection

Enterovirus 71 (EV71) is the main causative agent of severe hand-foot-mouth disease. EV71 affects countries mainly in the Asia-Pacific region, which makes it unattractive for pharmaceutical companies to develop drugs or vaccine to combat EV71 infection. However, development of these drugs and vaccines is vital to protect younger generations. This study aims to develop a specific monoclonal antibody (mAb) to EV71 using a plant platform, which is a cost-effective and scalable production technology. A previous report showed that D5, a murine anti-EV71 mAb, binds to VP1 protein of EV71, potently neutralizes EV71 in vitro, and effectively protects mice against EV71 infection. Herein, plant-produced chimeric D5 (cD5) mAb, variable regions of murine D5 antibody linked with constant regions of human IgG1, was transiently expressed in Nicotiana benthamiana using geminiviral vectors. The antibody was expressed at high levels within six days of infiltration. Plant-produced cD5 retained its in vitro high-affinity binding and neutralizing activity against EV71. Furthermore, a single dose (10 µg/g body weight) of plant-produced cD5 mAb offered 100% protection against infection in mice after a lethal EV71 challenge. Therefore, our results showed that plant-produced anti-EV71 mAb is an effective, safe, and affordable therapeutic option against EV71 infection.

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