Ebola virus infection causes severe hemorrhagic fever in human and non-human primates with high mortality. Viral entry/infection is initiated by binding of glycoprotein GP protein on Ebola virion to host cells, follow...Ebola virus infection causes severe hemorrhagic fever in human and non-human primates with high mortality. Viral entry/infection is initiated by binding of glycoprotein GP protein on Ebola virion to host cells, followed by fusion of virus-cell membrane also mediated by GP. Using an human immunodeficiency virus (HIV)-based pseudotyping system, the roles of 41 Ebola GP1 residues in the receptor-binding domain in viral entry were studied by alanine scanning substitutions. We identified that four residues appear to be involved in protein folding/structure and four residues are important for viral entry. An improved entry interference assay was developed and used to study the role of these residues that are important for viral entry. It was found that R64 and K95 are involved in receptor binding. In contrast, some residues such as I170 are important for viral entry, but do not play a major role in receptor binding as indicated by entry interference assay and/or protein binding data, suggesting that these residues are involved in post-binding steps of viral entry. Furthermore, our results also suggested that Ebola and Marburg viruses share a common cellular molecule for entry.展开更多
Antiviral defense is one of the important roles of RNA silencing in plants. Virus-derived small interfering RNAs (vsiRNAs) are found in the infected host cells, indicating that the host RNA silencing machinery can tar...Antiviral defense is one of the important roles of RNA silencing in plants. Virus-derived small interfering RNAs (vsiRNAs) are found in the infected host cells, indicating that the host RNA silencing machinery can target viral RNAs for destruction. With the development of high-throughput sequencing of vsiRNAs, recent genetic studies have shed light on the origin and composition of vsiRNAs and their potential functions in the regulation of gene expression. Here, we briefly describe the origin and biogenesis of vsiRNAs, and review the recent discoveries regarding vsiRNA-mediated RNA silencing of viral genomes and host transcripts. This will better our understanding of virus pathogenicity and RNA silencing-related host-pathogen inter- actions in plants.展开更多
基金National Institutes of Health Grant (AI059570 and AI077767)
文摘Ebola virus infection causes severe hemorrhagic fever in human and non-human primates with high mortality. Viral entry/infection is initiated by binding of glycoprotein GP protein on Ebola virion to host cells, followed by fusion of virus-cell membrane also mediated by GP. Using an human immunodeficiency virus (HIV)-based pseudotyping system, the roles of 41 Ebola GP1 residues in the receptor-binding domain in viral entry were studied by alanine scanning substitutions. We identified that four residues appear to be involved in protein folding/structure and four residues are important for viral entry. An improved entry interference assay was developed and used to study the role of these residues that are important for viral entry. It was found that R64 and K95 are involved in receptor binding. In contrast, some residues such as I170 are important for viral entry, but do not play a major role in receptor binding as indicated by entry interference assay and/or protein binding data, suggesting that these residues are involved in post-binding steps of viral entry. Furthermore, our results also suggested that Ebola and Marburg viruses share a common cellular molecule for entry.
文摘Antiviral defense is one of the important roles of RNA silencing in plants. Virus-derived small interfering RNAs (vsiRNAs) are found in the infected host cells, indicating that the host RNA silencing machinery can target viral RNAs for destruction. With the development of high-throughput sequencing of vsiRNAs, recent genetic studies have shed light on the origin and composition of vsiRNAs and their potential functions in the regulation of gene expression. Here, we briefly describe the origin and biogenesis of vsiRNAs, and review the recent discoveries regarding vsiRNA-mediated RNA silencing of viral genomes and host transcripts. This will better our understanding of virus pathogenicity and RNA silencing-related host-pathogen inter- actions in plants.
