Optical trapping describes the interaction between light and matter to manipulate micro-objects through momentum transfer.In the case of 3D trapping with a single beam,this is termed optical tweezers.Optical tweezers ...Optical trapping describes the interaction between light and matter to manipulate micro-objects through momentum transfer.In the case of 3D trapping with a single beam,this is termed optical tweezers.Optical tweezers are a powerful and noninvasive tool for manipulating small objects,and have become indispensable in many fields,including physics,biology,soft condensed matter,among others.In the early days,optical trapping was typically accomplished with a single Gaussian beam.In recent years,we have witnessed rapid progress in the use of structured light beams with customized phase,amplitude,and polarization in optical trapping.Unusual beam properties,such as phase singularities on-axis and propagation invariant nature,have opened up novel capabilities to the study of micromanipulation in liquid,air,and vacuum.We summarize the recent advances in the field of optical trapping using structured light beams.展开更多
RNA granules are cytoplasmic, microscopically visible, non-membrane ribo-nucleoprotein structures and are important posttranscriptional regulators in gene expression by controlling RNA translation and stability. TIA/G...RNA granules are cytoplasmic, microscopically visible, non-membrane ribo-nucleoprotein structures and are important posttranscriptional regulators in gene expression by controlling RNA translation and stability. TIA/G3BP/PABP-specific stress granules(SG) and GW182/DCP-specific RNA processing bodies(PB) are two major distinguishable RNA granules in somatic cells and contain various ribosomal subunits, translation factors, scaffold proteins, RNA-binding proteins, RNA decay enzymes and helicases to exclude m RNAs from the cellular active translational pool. Although SG formation is inducible due to cellular stress, PB exist physiologically in every cell. Both RNA granules are important components of the host antiviral defense. Virus infection imposes stress on host cells and thus induces SG formation. However, both RNA and DNA viruses must confront the hostile environment of host innate immunity and apply various strategies to block the formation of SG and PB for their effective infection and multiplication. This review summarizes the current research development in the field and the mechanisms of how individual viruses suppress the formation of host SG and PB for virus production.展开更多
Dear Editor,The outbreak of SARS-CoV-2 leads global epidemic with high morbidity and mortality.However,the pathophysiology of this deadly virus is complex and largely unknown.Autophagy is a highly conserved homeostati...Dear Editor,The outbreak of SARS-CoV-2 leads global epidemic with high morbidity and mortality.However,the pathophysiology of this deadly virus is complex and largely unknown.Autophagy is a highly conserved homeostatic process that allows cells to recycle their components.Several studies provided evidence that human coronavirus infections are closely related to various cellular aspects associated with autophagy.1 Autophagy may play a crucial role in the SARS-CoV-2 viral lifecycle.展开更多
Human parainfluenza virus type 3(HPIV3), a member of the Paramyxoviridae family, can cause lower respiratory disease in infants and young children. The phosphoprotein(P) of HPIV3 is an essential cofactor of the viral ...Human parainfluenza virus type 3(HPIV3), a member of the Paramyxoviridae family, can cause lower respiratory disease in infants and young children. The phosphoprotein(P) of HPIV3 is an essential cofactor of the viral RNA-dependent RNA polymerase large protein(L). P connects nucleocapsid protein(N) with L to initiate genome transcription and replication.Sumoylation influences many important pathways of the target proteins, and many viral proteins are also themselves sumoylated. In this study, we found that the P of HPIV3 could be sumoylated, and mutation of K492 and K532 to arginine(PK492 R/K532 R) failed to be sumoylated within P, which enhances HPIV3 minigenome activity. Biochemical studies showed that PK492 R/K532 Rhad no effect on its interactions with N, formation of homo-tetramers and formation of inclusion bodies.Finally, we found that incorporation of K492 R/K532 R into a recombinant HPIV3(rHPIV3-PK492 R/K532 R) increased viral production in culture cells, suggesting that sumoylation attenuates functions of P and down-regulates viral replication.展开更多
Ebola virus(EBOV)is an enveloped negative-sense RNA virus and a member of the filovirus family.Nucleoprotein(NP)expression alone leads to the formation of inclusion bodies(IBs),which are critical for viral RNA synthes...Ebola virus(EBOV)is an enveloped negative-sense RNA virus and a member of the filovirus family.Nucleoprotein(NP)expression alone leads to the formation of inclusion bodies(IBs),which are critical for viral RNA synthesis.The matrix protein,VP40,not only plays a critical role in virus assembly/budding,but also can regulate transcription and replication of the viral genome.However,the molecular mechanism by which VP40 regulates viral RNA synthesis and virion assembly/budding is unknown.Here,we show that within IBs the N-terminus of NP recruits VP40 and is required for VLP-containing NP release.Furthermore,we find four point mutations(L692A,P697A,P698A and W699A)within the C-terminal hydrophobic core of NP result in a stronger VP40–NP interaction within IBs,sequestering VP40 within IBs,reducing VP40–VLP egress,abolishing the incorporation of NC-like structures into VP40–VLP,and inhibiting viral RNA synthesis,suggesting that the interaction of N-terminus of NP with VP40 induces a conformational change in the C-terminus of NP.Consequently,the C-terminal hydrophobic core of NP is exposed and binds VP40,thereby inhibiting RNA synthesis and initiating virion assembly/budding.展开更多
RNA-remodeling proteins,including RNA helicases and chaperones,play vital roles in the remodeling of structured RNAs.During viral replication,viruses require RNA-remodeling proteins to facilitate proper folding and/or...RNA-remodeling proteins,including RNA helicases and chaperones,play vital roles in the remodeling of structured RNAs.During viral replication,viruses require RNA-remodeling proteins to facilitate proper folding and/or re-folding the viral RNA elements.Coxsackieviruses B3(CVB3)and Coxsackieviruses B5(CVB5),belonging to the genus Enterovirus in the family Picornaviridae,have been reported to cause various infectious diseases such as hand-foot-and-mouth disease,aseptic meningitis,and viral myocarditis.However,little is known about whether CVB3 and CVB5 encode any RNA remodeling proteins.In this study,we showed that 2C proteins of CVB3 and CVB5 contained the conserved SF3 helicase A,B,and C motifs,and functioned not only as RNA helicase that unwound RNA helix bidirectionally in an NTP-dependent manner,but also as RNA chaperone that remodeled structured RNAs and facilitated RNA strand annealing independently of NTP.In addition,we determined that the NTPase activity and RNA helicase activity of 2C proteins of CVB3 and CVB5 were dependent on the presence of divalent metallic ions.Our findings demonstrate that 2C proteins of CVBs possess RNA-remodeling activity and underline the functional importance of 2C protein in the life cycle of CVBs.展开更多
Inclusion bodies(IBs)of respiratory syncytial virus(RSV)are formed by liquid-liquid phase separation(LLPS)and contain internal structures termed“IB-associated granules”(IBAGs),where anti-termination factor M2-1 and ...Inclusion bodies(IBs)of respiratory syncytial virus(RSV)are formed by liquid-liquid phase separation(LLPS)and contain internal structures termed“IB-associated granules”(IBAGs),where anti-termination factor M2-1 and viral mRNAs are concentrated.However,the mechanism of IBAG formation and the physiological function of IBAGs are unclear.Here,we found that the internal structures of RSV IBs are actual M2-1-free viral messenger ribonucleoprotein(mRNP)condensates formed by secondary LLPS.Mechanistically,the RSV nucleoprotein(N)and M2-1 interact with and recruit PABP to IBs,promoting PABP to bind viral mRNAs transcribed in IBs by RNArecognition motif and drive secondary phase separation.Furthermore,PABP-eIF4G1 interaction regulates viral mRNP condensate composition,thereby recruiting specific translation initiation factors(eIF4G1,eIF4E,eIF4A,eIF4B and eIF4H)into the secondary condensed phase to activate viral mRNAs for ribosomal recruitment.Our study proposes a novel LLPS-regulated translation mechanism during viral infection and a novel antiviral strategy via targeting on secondary condensed phase.展开更多
基金We thank Professor Kishan Dholakia for his instructive advice and help on the preparation of the manuscript.Y.Y thanks Dr.Leiming Zhou for the helpful discussion.This work was supported by the National Natural Science Foundation of China(11874102 and 61975047)the Sichuan Province Science and Technology Support Program(2020JDRC0006)the Fundamental Research Funds for the Central Universities(ZYGX2019J102).M.C.and Y.A.thank the UK Engineering and Physical Sciences Research Council for funding.
文摘Optical trapping describes the interaction between light and matter to manipulate micro-objects through momentum transfer.In the case of 3D trapping with a single beam,this is termed optical tweezers.Optical tweezers are a powerful and noninvasive tool for manipulating small objects,and have become indispensable in many fields,including physics,biology,soft condensed matter,among others.In the early days,optical trapping was typically accomplished with a single Gaussian beam.In recent years,we have witnessed rapid progress in the use of structured light beams with customized phase,amplitude,and polarization in optical trapping.Unusual beam properties,such as phase singularities on-axis and propagation invariant nature,have opened up novel capabilities to the study of micromanipulation in liquid,air,and vacuum.We summarize the recent advances in the field of optical trapping using structured light beams.
基金supported by grants from the China Natural Science Foundation (81825015 and 31630086)the Natural Science Foundation of Hubei Province Innovation Group (2017CFA022)Intramural Research Program of NCI/NIH (1ZIASC010357 to ZMZ)
文摘RNA granules are cytoplasmic, microscopically visible, non-membrane ribo-nucleoprotein structures and are important posttranscriptional regulators in gene expression by controlling RNA translation and stability. TIA/G3BP/PABP-specific stress granules(SG) and GW182/DCP-specific RNA processing bodies(PB) are two major distinguishable RNA granules in somatic cells and contain various ribosomal subunits, translation factors, scaffold proteins, RNA-binding proteins, RNA decay enzymes and helicases to exclude m RNAs from the cellular active translational pool. Although SG formation is inducible due to cellular stress, PB exist physiologically in every cell. Both RNA granules are important components of the host antiviral defense. Virus infection imposes stress on host cells and thus induces SG formation. However, both RNA and DNA viruses must confront the hostile environment of host innate immunity and apply various strategies to block the formation of SG and PB for their effective infection and multiplication. This review summarizes the current research development in the field and the mechanisms of how individual viruses suppress the formation of host SG and PB for virus production.
基金Emergency Science and Technology Project of China's Ministry of Science and Technology(2020YFC0845600)Emergency Science and Technology Project of Hubei Province(2020FCA046)+4 种基金the Fundamental Research Funds for the Central University(2042021 kf0049)the Special Fund for COVID-19 Research of Wuhan University,National Key R&D Program of China(2017YFA0505801)the National Natural Science Foundation of China(81825015,81871650,and 31630086)National Science and Technology Major Project(2018ZX10101004)the Natural Science Foundation of Hubei Province Innovation Group(2017CFA022).
文摘Dear Editor,The outbreak of SARS-CoV-2 leads global epidemic with high morbidity and mortality.However,the pathophysiology of this deadly virus is complex and largely unknown.Autophagy is a highly conserved homeostatic process that allows cells to recycle their components.Several studies provided evidence that human coronavirus infections are closely related to various cellular aspects associated with autophagy.1 Autophagy may play a crucial role in the SARS-CoV-2 viral lifecycle.
基金supported by grants from National Key R&D Program of China (2017YFA0505801)the National Natural Science Foundation of China (81825015, 81871650 and 31630086)+2 种基金National Science and Technology Major Project (2018ZX10101004)the Natural Science Foundation of Hubei Province Innovation Group (2017CFA022)Advanced Customer Cultivation Project of Wuhan National Biosafety Laboratory (2019ACCP-MS06)。
文摘Human parainfluenza virus type 3(HPIV3), a member of the Paramyxoviridae family, can cause lower respiratory disease in infants and young children. The phosphoprotein(P) of HPIV3 is an essential cofactor of the viral RNA-dependent RNA polymerase large protein(L). P connects nucleocapsid protein(N) with L to initiate genome transcription and replication.Sumoylation influences many important pathways of the target proteins, and many viral proteins are also themselves sumoylated. In this study, we found that the P of HPIV3 could be sumoylated, and mutation of K492 and K532 to arginine(PK492 R/K532 R) failed to be sumoylated within P, which enhances HPIV3 minigenome activity. Biochemical studies showed that PK492 R/K532 Rhad no effect on its interactions with N, formation of homo-tetramers and formation of inclusion bodies.Finally, we found that incorporation of K492 R/K532 R into a recombinant HPIV3(rHPIV3-PK492 R/K532 R) increased viral production in culture cells, suggesting that sumoylation attenuates functions of P and down-regulates viral replication.
基金We acknowledge Dr.Bo Zhang(Wuhan Institute of Virology)and Dr.Heinz Feldmann(National Institutes of Health,Hamilton,Montana,USA)for providing the Ebola cDNA and minigenome assay system,respectivelyThis research is supported by grants from the National Natural Science Foundation of China(81825015)+4 种基金National Key R&D Program of China(2017YFA0505801)National Science and Technology Major Project(2018ZX10101004)National Natural Science Foundation of China(81871650 and 31630086)The Natural Science Foundation of Hubei Province Innovation Group(2017CFA022)Advanced Customer Cultivation Project of Wuhan National Biosafety Laboratory(2019ACCP-MS06).
文摘Ebola virus(EBOV)is an enveloped negative-sense RNA virus and a member of the filovirus family.Nucleoprotein(NP)expression alone leads to the formation of inclusion bodies(IBs),which are critical for viral RNA synthesis.The matrix protein,VP40,not only plays a critical role in virus assembly/budding,but also can regulate transcription and replication of the viral genome.However,the molecular mechanism by which VP40 regulates viral RNA synthesis and virion assembly/budding is unknown.Here,we show that within IBs the N-terminus of NP recruits VP40 and is required for VLP-containing NP release.Furthermore,we find four point mutations(L692A,P697A,P698A and W699A)within the C-terminal hydrophobic core of NP result in a stronger VP40–NP interaction within IBs,sequestering VP40 within IBs,reducing VP40–VLP egress,abolishing the incorporation of NC-like structures into VP40–VLP,and inhibiting viral RNA synthesis,suggesting that the interaction of N-terminus of NP with VP40 induces a conformational change in the C-terminus of NP.Consequently,the C-terminal hydrophobic core of NP is exposed and binds VP40,thereby inhibiting RNA synthesis and initiating virion assembly/budding.
基金supported by the National Natural Science Foundation of China (82002155 to T.S., and U21A20423 and 31670161 to X.Z.)
文摘RNA-remodeling proteins,including RNA helicases and chaperones,play vital roles in the remodeling of structured RNAs.During viral replication,viruses require RNA-remodeling proteins to facilitate proper folding and/or re-folding the viral RNA elements.Coxsackieviruses B3(CVB3)and Coxsackieviruses B5(CVB5),belonging to the genus Enterovirus in the family Picornaviridae,have been reported to cause various infectious diseases such as hand-foot-and-mouth disease,aseptic meningitis,and viral myocarditis.However,little is known about whether CVB3 and CVB5 encode any RNA remodeling proteins.In this study,we showed that 2C proteins of CVB3 and CVB5 contained the conserved SF3 helicase A,B,and C motifs,and functioned not only as RNA helicase that unwound RNA helix bidirectionally in an NTP-dependent manner,but also as RNA chaperone that remodeled structured RNAs and facilitated RNA strand annealing independently of NTP.In addition,we determined that the NTPase activity and RNA helicase activity of 2C proteins of CVB3 and CVB5 were dependent on the presence of divalent metallic ions.Our findings demonstrate that 2C proteins of CVBs possess RNA-remodeling activity and underline the functional importance of 2C protein in the life cycle of CVBs.
基金supported by the grants from National Key R&D Program of China(2021YFC2300702 and 2021YFC2300200)the Hubei Provincial Natural Science Foundation of China(2021CFB364)+1 种基金the National Natural Science Foundation of China(82130064,81825015,U22A20337 and 32000119)the Key Biosafety Science and Technology Program of Hubei Jiangxia Laboratory(JXBS001).
文摘Inclusion bodies(IBs)of respiratory syncytial virus(RSV)are formed by liquid-liquid phase separation(LLPS)and contain internal structures termed“IB-associated granules”(IBAGs),where anti-termination factor M2-1 and viral mRNAs are concentrated.However,the mechanism of IBAG formation and the physiological function of IBAGs are unclear.Here,we found that the internal structures of RSV IBs are actual M2-1-free viral messenger ribonucleoprotein(mRNP)condensates formed by secondary LLPS.Mechanistically,the RSV nucleoprotein(N)and M2-1 interact with and recruit PABP to IBs,promoting PABP to bind viral mRNAs transcribed in IBs by RNArecognition motif and drive secondary phase separation.Furthermore,PABP-eIF4G1 interaction regulates viral mRNP condensate composition,thereby recruiting specific translation initiation factors(eIF4G1,eIF4E,eIF4A,eIF4B and eIF4H)into the secondary condensed phase to activate viral mRNAs for ribosomal recruitment.Our study proposes a novel LLPS-regulated translation mechanism during viral infection and a novel antiviral strategy via targeting on secondary condensed phase.