RNA interference(RNAi)is an intrinsic antiviral immune mechanism conserved in diverse eukaryotic organisms.However,the mechanism by which antiviral RNAi in mammals is regulated is poorly understood.In this study,we un...RNA interference(RNAi)is an intrinsic antiviral immune mechanism conserved in diverse eukaryotic organisms.However,the mechanism by which antiviral RNAi in mammals is regulated is poorly understood.In this study,we uncovered that the E3 ubiquitin ligase STIP1 homology and U-box-containing protein 1(STUB1)was a new regulator of the RNAi machinery in mammals.We found that STUB1 interacted with and ubiquitinated AGO2,and targeted it for degradation in a chaperon-dependent manner.STUB1 promoted the formation of Lys48(K48)-linked polyubiquitin chains on AGO2,and facilitated AGO2 degradation through ubiquitin-proteasome system.In addition to AGO2,STUB1 also induced the protein degradation of AGO1,AGO3 and AGO4.Further investigation revealed that STUB1 also regulated Dicer's ubiquitination via K48-linked polyubiquitin and induced the degradation of Dicer as well as its specialized form,termed antiviral Dicer(avi Dicer)that expresses in mammalian stem cells.Moreover,we found that STUB1 deficiency up-regulated Dicer and AGO2,thereby enhancing the RNAi response and efficiently inhibiting viral replication in mammalian cells.Using the newborn mouse model of Enterovirus A71(EV-A71),we confirmed that STUB1 deficiency enhanced the virus-derived si RNAs production and antiviral RNAi,which elicited a potent antiviral effect against EV-A71 infection in vivo.In summary,our findings uncovered that the E3 ubiquitin ligase STUB1 was a general regulator of the RNAi machinery by targeting Dicer,avi Dicer and AGO1–4.Moreover,STUB1 regulated the RNAi response through mediating the abundance of Dicer and AGO2 during viral infection,thereby providing novel insights into the regulation of antiviral RNAi in mammals.展开更多
A new class of RNA regulatory genes known as microRNAs(miRNAs)has been found to introduce a whole new layer of gene regulation in eukaryotes.The intensive studies of the past several years have demonstrated that miRNA...A new class of RNA regulatory genes known as microRNAs(miRNAs)has been found to introduce a whole new layer of gene regulation in eukaryotes.The intensive studies of the past several years have demonstrated that miRNAs are not only found intracellularly,but are also detectable outside cells,including in various body fluids(e.g.serum,plasma,saliva,urine and milk).This phenomenon raises questions about the biological function of such extracellular miRNAs.Substantial amounts of extracellular miRNAs are enclosed in small membranous vesicles(e.g.exosomes,shedding vesicles and apoptotic bodies)or packaged with RNA-binding proteins(e.g.high-density lipoprotein,Argonaute 2 and nucleophosmin 1).These miRNAs may function as secreted signaling molecules to influence the recipient cell phenotypes.Furthermore,secreted extracellular miRNAs may reflect molecular changes in the cells from which they are derived and can therefore potentially serve as diagnostic indicators of disease.Several studies also point to the potential application of siRNA/miRNA delivery as a new therapeutic strategy for treating diseases.In this review,we summarize what is known about the mechanism of miRNA secretion.In addition,we describe the pathophysiological roles of secreted miRNAs and their clinical potential as diagnostic biomarkers and therapeutic drugs.We believe that miRNA transfer between cells will have a significant impact on biological research in the coming years.展开更多
Hepatitis C virus (HCV), a positive single-stranded RNA virus, is a major cause of liver disease in humans. Herein we report a novel strategy to inhibit the reproduction and translation of HCV using a short RNA, named...Hepatitis C virus (HCV), a positive single-stranded RNA virus, is a major cause of liver disease in humans. Herein we report a novel strategy to inhibit the reproduction and translation of HCV using a short RNA, named an Additional RNA, to activate the endonuclease activity of Argonaute 2 (Ago2). In the presence of the Additional RNA, the HCV genome RNA has the requisite 12 nucleotides of base-pairing with microRNA-122. This activates the endonuclease activity of Ago2, resulting in cleavage and release of the HCV genome RNA from Ago2 and microRNA-122. The free HCV genome RNA would be susceptible to intracellular degradation, effectively inhibiting its reproduction and translation. This study presents a new method to inhibit HCV that may hold great potential for HCV treatment in the future.展开更多
基金the National Natural Science Foundation of China(31970169 to X.Z.and 82172269 and 81873964 to Y.Q.)the International Partnership Program of Chinese Academy of Sciences(153B42KYSB20200004 to X.Z.)+3 种基金the Young Top-notch Talent Cultivation Program of Hubei Province(Y.Q.)the Grant from the CAS Youth Innovation Promotion Association(2020332 to Y.Q.)the Hubei Province Natural Science Funds for Distinguished Young Scholar(2021CFA047 to Y.Q.)the Young Top-notch Talent Cultivation Program of Hubei Province(Y.Q.)。
文摘RNA interference(RNAi)is an intrinsic antiviral immune mechanism conserved in diverse eukaryotic organisms.However,the mechanism by which antiviral RNAi in mammals is regulated is poorly understood.In this study,we uncovered that the E3 ubiquitin ligase STIP1 homology and U-box-containing protein 1(STUB1)was a new regulator of the RNAi machinery in mammals.We found that STUB1 interacted with and ubiquitinated AGO2,and targeted it for degradation in a chaperon-dependent manner.STUB1 promoted the formation of Lys48(K48)-linked polyubiquitin chains on AGO2,and facilitated AGO2 degradation through ubiquitin-proteasome system.In addition to AGO2,STUB1 also induced the protein degradation of AGO1,AGO3 and AGO4.Further investigation revealed that STUB1 also regulated Dicer's ubiquitination via K48-linked polyubiquitin and induced the degradation of Dicer as well as its specialized form,termed antiviral Dicer(avi Dicer)that expresses in mammalian stem cells.Moreover,we found that STUB1 deficiency up-regulated Dicer and AGO2,thereby enhancing the RNAi response and efficiently inhibiting viral replication in mammalian cells.Using the newborn mouse model of Enterovirus A71(EV-A71),we confirmed that STUB1 deficiency enhanced the virus-derived si RNAs production and antiviral RNAi,which elicited a potent antiviral effect against EV-A71 infection in vivo.In summary,our findings uncovered that the E3 ubiquitin ligase STUB1 was a general regulator of the RNAi machinery by targeting Dicer,avi Dicer and AGO1–4.Moreover,STUB1 regulated the RNAi response through mediating the abundance of Dicer and AGO2 during viral infection,thereby providing novel insights into the regulation of antiviral RNAi in mammals.
基金by grants from the National Natural Science Foundation of China(Nos.90813035,81101330,81171661,30890044,30772484,30725008,30890032,31071232,31000323,90608010,and J1103512)the Natural Science Foundation of Jiangsu Province(No.BK2011013)the Fundamental Research Funds for the Central Universities(No.1107020839).
文摘A new class of RNA regulatory genes known as microRNAs(miRNAs)has been found to introduce a whole new layer of gene regulation in eukaryotes.The intensive studies of the past several years have demonstrated that miRNAs are not only found intracellularly,but are also detectable outside cells,including in various body fluids(e.g.serum,plasma,saliva,urine and milk).This phenomenon raises questions about the biological function of such extracellular miRNAs.Substantial amounts of extracellular miRNAs are enclosed in small membranous vesicles(e.g.exosomes,shedding vesicles and apoptotic bodies)or packaged with RNA-binding proteins(e.g.high-density lipoprotein,Argonaute 2 and nucleophosmin 1).These miRNAs may function as secreted signaling molecules to influence the recipient cell phenotypes.Furthermore,secreted extracellular miRNAs may reflect molecular changes in the cells from which they are derived and can therefore potentially serve as diagnostic indicators of disease.Several studies also point to the potential application of siRNA/miRNA delivery as a new therapeutic strategy for treating diseases.In this review,we summarize what is known about the mechanism of miRNA secretion.In addition,we describe the pathophysiological roles of secreted miRNAs and their clinical potential as diagnostic biomarkers and therapeutic drugs.We believe that miRNA transfer between cells will have a significant impact on biological research in the coming years.
基金supported by the National Science Fund for Distinguished Young Scholars (20925520)the National Natural Science Foundation of China (21235003)the Leading Academic Discipline Project of Shanghai Municipal Education Commission (J50108)
文摘Hepatitis C virus (HCV), a positive single-stranded RNA virus, is a major cause of liver disease in humans. Herein we report a novel strategy to inhibit the reproduction and translation of HCV using a short RNA, named an Additional RNA, to activate the endonuclease activity of Argonaute 2 (Ago2). In the presence of the Additional RNA, the HCV genome RNA has the requisite 12 nucleotides of base-pairing with microRNA-122. This activates the endonuclease activity of Ago2, resulting in cleavage and release of the HCV genome RNA from Ago2 and microRNA-122. The free HCV genome RNA would be susceptible to intracellular degradation, effectively inhibiting its reproduction and translation. This study presents a new method to inhibit HCV that may hold great potential for HCV treatment in the future.
