Zebrafish（Danio rerio） is a well-established vertebrate animal model.A comprehensive collection of reverse genetics tools has been developed for studying gene function in this useful organism.Morpholino is the most ...Zebrafish（Danio rerio） is a well-established vertebrate animal model.A comprehensive collection of reverse genetics tools has been developed for studying gene function in this useful organism.Morpholino is the most widely used reagent to knock down target gene expression post-transcriptionally.For a long time,targeted genome modification has been heavily relied on large-scale traditional forward genetic screens,such as ENU（N-ethyl-N-nitrosourea） mutagenesis derived TILLING（Targeting Induced Local Lesions IN Genomes） strategy and pseudo-typed retrovirus mediated insertional mutagenesis.Recently,engineered endonucleases,including ZFNs（zinc finger nucleases） and TALENs（transcription activator-like effector nucleases）,provide new and efficient strategies to directly generate site-specific indel mutations by inducing double strand breaks in target genes.Here we summarize the major reverse genetic approaches for loss-of-function studies used and emerging in zebrafish,including strategies based on genome-wide mutagenesis and methods for site-specific gene targeting.Future directions and expectations will also be discussed.展开更多
In the present medicine world antibiotic resistance is one of the key threats to universal health coverage.Researchers continue to work hard to combat this global health concern.Phage therapy,an age-old practice durin...In the present medicine world antibiotic resistance is one of the key threats to universal health coverage.Researchers continue to work hard to combat this global health concern.Phage therapy,an age-old practice during the early twentieth century,was outshined by the discovery of antibiotics.With the advent of widespread antibiotic resistance,phage therapy has again redeemed itself as a potential alternative owing to its adeptness to target bacteria precisely.Limited side effects,the ability to migrate to different body organs,a distinct mode of action,and proliferation at the infection site,make phages a profitable candidate to replace conventional antibiotics.The progressive outcome of numerous in vitro studies and case reports has validated the clinical efficacy of phage therapy.The bright perspective of using phages to treat bacterial infections has fueled enormous medical research to exploit their potential as therapeutics.The gaps in the information about phages and the lack of consent for clinical trials is major hurdle for consideration of phage therapy.Crafting phage therapy as a reality in medicine requires a coordinated effort from different fraternities.With this review,we aim to emphasize the importance of phage therapy in modern medicine.This review explains their historical journey,basic phage biology,cross-talk with the host immunity,obstacles with phage therapy,and their possible remedies.Comprehensive data on the various significant clinical trials of phage therapy has been presented.We evaluated the efficacy of antibiotics and phage therapy in part and in combination,along with recent progress and future perspectives of phage therapy.展开更多
Endomembrane trafficking is a fundamental cellular process in all eukaryotic cells and its regulatory mechanisms have been extensively studied.In plants,the endomembrane trafficking system needs to be constantly adjus...Endomembrane trafficking is a fundamental cellular process in all eukaryotic cells and its regulatory mechanisms have been extensively studied.In plants,the endomembrane trafficking system needs to be constantly adjusted to adapt to the ever-changing environment.Evidence has accumulated supporting the idea that endomembrane trafficking is tightly linked to stress signaling pathways to meet the demands of rapid changes in cellular processes and to ensure the correct delivery of stress-related cargo molecules.However,the underlying mechanisms remain unknown.In this review,we summarize the recent findings on the functional roles of both secretory trafficking and endocytic trafficking in different types of abiotic stresses.We also highlight and discuss the unique properties of specific regulatory molecules beyond their conventional functions in endosomal trafficking during plant growth under stress conditions.展开更多
Plant and non-plant species possess cryptochrome(CRY)photoreceptors to mediate blue light regulation of development or the circadian clock.The blue light-dependent homooligomerization of Arabidopsis CRY2 is a known ea...Plant and non-plant species possess cryptochrome(CRY)photoreceptors to mediate blue light regulation of development or the circadian clock.The blue light-dependent homooligomerization of Arabidopsis CRY2 is a known early photoreaction necessary for its functions,but the photobiochemistry and function of light-dependent homooligomerization and heterooligomerization of cryptochromes,collectively referred to as CRY photooligomerization,have not been well established.Here,we show that photooligomerization is an evolutionarily conserved photoreaction characteristic of CRY photoreceptors in plants and some non-plant species.Our analyses of the kinetics of the forward and reverse reactions of photooligomerization of Arabidopsis CRY1 and CRY2 provide a previously unrecognized mechanism underlying the different photosensitivity and photoreactivity of these two closely related photoreceptors.We found that photooligomerization is necessary but not sufficient for the functions of CRY2,implying that CRY photooligomerization is presumably accompanied by additional function-empowering conformational changes.We further demonstrated that the CRY2-CRY1 heterooligomerization plays roles in regulating functions of Arabidopsis CRYs in vivo.Taken together,these results suggest that photooligomerization is an evolutionarily conserved mechanism determining the photosensitivity and photoreactivity of plant CRYs.展开更多
Background:Notch is one of the most important signaling pathways involved in cell fate determination.Activation of the Notch pathway requires the binding of a membrane-bound ligand to the Notch receptor in the adjacen...Background:Notch is one of the most important signaling pathways involved in cell fate determination.Activation of the Notch pathway requires the binding of a membrane-bound ligand to the Notch receptor in the adjacent cell which induces proteolytic cleavages and the activation of the receptor.A unique feature of the Notch signaling is that processes such as modification,endocytosis or recycling of the ligand have been reported to play critical roles during Notch signaling,however,the underlying molecular mechanism appears context-dependent and often controversial.Results:Here we identified SNX17 as a novel regulator of the Notch pathway.SNX17 is a sorting nexin family protein implicated in vesicular trafficking and we find it is specifically required in the ligand-expressing cells for Notch signaling.Mechanistically,SNX17 regulates the protein level of Jag1a on plasma membrane by binding to Jag1a and facilitating the retromer-dependent recycling of the ligand.In zebrafish,inhibition of this SNX17-mediated Notch signaling pathway results in defects in neurogenesis as well as pancreas development.Conclusions:Our results reveal that SNX17,by acting as a cargo-specific adaptor,promotes the retromer dependent recycling of Jag1a and Notch signaling and this pathway is involved in cell fate determination during zebrafish neurogenesis and pancreas development.展开更多
A major unanswered question is how a TCR discriminates between foreign and self-peptides presented on the APC surface.Here,we used in situ fluorescence resonance energy transfer(FRET)to measure the distances of single...A major unanswered question is how a TCR discriminates between foreign and self-peptides presented on the APC surface.Here,we used in situ fluorescence resonance energy transfer(FRET)to measure the distances of single TCR–pMHC bonds and the conformations of individual TCR–CD3ζreceptors at the membranes of live primary T cells.We found that a TCR discriminates between closely related peptides by forming single TCR–pMHC bonds with different conformations,and the most potent pMHC forms the shortest bond.The bond conformation is an intrinsic property that is independent of the binding affinity and kinetics,TCR microcluster formation,and CD4 binding.The bond conformation dictates the degree of CD3ζdissociation from the inner leaflet of the plasma membrane via a positive calcium signaling feedback loop to precisely control the accessibility of CD3ζITAMs for phosphorylation.Our data revealed the mechanism by which a TCR deciphers the structural differences among peptides via the TCR–pMHC bond conformation.展开更多
基金partially supported by the grants from National Program on Key Basic Research Project(973 program)(Nos.2012CB945101 and 201 ICBAO 1000)National Natural Science Foundation of China(NSFC)(Nos. 31110103904 and 30730056)
文摘Zebrafish（Danio rerio） is a well-established vertebrate animal model.A comprehensive collection of reverse genetics tools has been developed for studying gene function in this useful organism.Morpholino is the most widely used reagent to knock down target gene expression post-transcriptionally.For a long time,targeted genome modification has been heavily relied on large-scale traditional forward genetic screens,such as ENU（N-ethyl-N-nitrosourea） mutagenesis derived TILLING（Targeting Induced Local Lesions IN Genomes） strategy and pseudo-typed retrovirus mediated insertional mutagenesis.Recently,engineered endonucleases,including ZFNs（zinc finger nucleases） and TALENs（transcription activator-like effector nucleases）,provide new and efficient strategies to directly generate site-specific indel mutations by inducing double strand breaks in target genes.Here we summarize the major reverse genetic approaches for loss-of-function studies used and emerging in zebrafish,including strategies based on genome-wide mutagenesis and methods for site-specific gene targeting.Future directions and expectations will also be discussed.
文摘In the present medicine world antibiotic resistance is one of the key threats to universal health coverage.Researchers continue to work hard to combat this global health concern.Phage therapy,an age-old practice during the early twentieth century,was outshined by the discovery of antibiotics.With the advent of widespread antibiotic resistance,phage therapy has again redeemed itself as a potential alternative owing to its adeptness to target bacteria precisely.Limited side effects,the ability to migrate to different body organs,a distinct mode of action,and proliferation at the infection site,make phages a profitable candidate to replace conventional antibiotics.The progressive outcome of numerous in vitro studies and case reports has validated the clinical efficacy of phage therapy.The bright perspective of using phages to treat bacterial infections has fueled enormous medical research to exploit their potential as therapeutics.The gaps in the information about phages and the lack of consent for clinical trials is major hurdle for consideration of phage therapy.Crafting phage therapy as a reality in medicine requires a coordinated effort from different fraternities.With this review,we aim to emphasize the importance of phage therapy in modern medicine.This review explains their historical journey,basic phage biology,cross-talk with the host immunity,obstacles with phage therapy,and their possible remedies.Comprehensive data on the various significant clinical trials of phage therapy has been presented.We evaluated the efficacy of antibiotics and phage therapy in part and in combination,along with recent progress and future perspectives of phage therapy.
基金supported by grants from the National Natural Science Foundation of China (31872644) to X.W.the National Natural Science Foundation of China (31701246) to W.S.+1 种基金the National Natural Science Foundation of China (31671467, 31870171) to C.G.supported by Research Grants Council of Hong Kong (Ao E/M-05/12 and C4002-17G)
文摘Endomembrane trafficking is a fundamental cellular process in all eukaryotic cells and its regulatory mechanisms have been extensively studied.In plants,the endomembrane trafficking system needs to be constantly adjusted to adapt to the ever-changing environment.Evidence has accumulated supporting the idea that endomembrane trafficking is tightly linked to stress signaling pathways to meet the demands of rapid changes in cellular processes and to ensure the correct delivery of stress-related cargo molecules.However,the underlying mechanisms remain unknown.In this review,we summarize the recent findings on the functional roles of both secretory trafficking and endocytic trafficking in different types of abiotic stresses.We also highlight and discuss the unique properties of specific regulatory molecules beyond their conventional functions in endosomal trafficking during plant growth under stress conditions.
基金supported in part by the National Institutes of Health(GM56265 to C.L.)FAFU-ICE fund(KXGH17011 to Q.W.)+2 种基金FAFU OYIA fund(XJQ201801 to Q.W.)the National Natural Science Foundation of China(31801018 to Q.L.,31600228 to S.C.)the Natural Science Foundation of Fujian Province(2019J06014 to Q.W.,2018J01605 to Q.L.).
文摘Plant and non-plant species possess cryptochrome(CRY)photoreceptors to mediate blue light regulation of development or the circadian clock.The blue light-dependent homooligomerization of Arabidopsis CRY2 is a known early photoreaction necessary for its functions,but the photobiochemistry and function of light-dependent homooligomerization and heterooligomerization of cryptochromes,collectively referred to as CRY photooligomerization,have not been well established.Here,we show that photooligomerization is an evolutionarily conserved photoreaction characteristic of CRY photoreceptors in plants and some non-plant species.Our analyses of the kinetics of the forward and reverse reactions of photooligomerization of Arabidopsis CRY1 and CRY2 provide a previously unrecognized mechanism underlying the different photosensitivity and photoreactivity of these two closely related photoreceptors.We found that photooligomerization is necessary but not sufficient for the functions of CRY2,implying that CRY photooligomerization is presumably accompanied by additional function-empowering conformational changes.We further demonstrated that the CRY2-CRY1 heterooligomerization plays roles in regulating functions of Arabidopsis CRYs in vivo.Taken together,these results suggest that photooligomerization is an evolutionarily conserved mechanism determining the photosensitivity and photoreactivity of plant CRYs.
基金We thank M.Itoh,M.M.Chiu,G.Weinmaster,J.Hald,Z.Li and D.Yao for reagents and other members of our lab for technical support.This work was supported by grants from the“Strategic Priority Research Program”of the Chinese Academy of Sciences(XDA01020401,XDA01020307)Ministry of Science and Technology 973 program(2009CB941102)CAS 100-talent project(X.S.).
文摘Background:Notch is one of the most important signaling pathways involved in cell fate determination.Activation of the Notch pathway requires the binding of a membrane-bound ligand to the Notch receptor in the adjacent cell which induces proteolytic cleavages and the activation of the receptor.A unique feature of the Notch signaling is that processes such as modification,endocytosis or recycling of the ligand have been reported to play critical roles during Notch signaling,however,the underlying molecular mechanism appears context-dependent and often controversial.Results:Here we identified SNX17 as a novel regulator of the Notch pathway.SNX17 is a sorting nexin family protein implicated in vesicular trafficking and we find it is specifically required in the ligand-expressing cells for Notch signaling.Mechanistically,SNX17 regulates the protein level of Jag1a on plasma membrane by binding to Jag1a and facilitating the retromer-dependent recycling of the ligand.In zebrafish,inhibition of this SNX17-mediated Notch signaling pathway results in defects in neurogenesis as well as pancreas development.Conclusions:Our results reveal that SNX17,by acting as a cargo-specific adaptor,promotes the retromer dependent recycling of Jag1a and Notch signaling and this pathway is involved in cell fate determination during zebrafish neurogenesis and pancreas development.
基金This work was mainly supported by NIH grants R00AI106941 and R21AI120010NSF CAREER Award 1653782,a Chicago Biomedical Consortium Catalyst Award(to J.H.)+1 种基金postdoctoral grant PDR-092(to D.K.S.),with additional support from the Searle Funds at The Chicago Community TrustThis work is also supported by NIH grant R01AI126756(to E.J.A.)and R01CA022677(to H.S.).
文摘A major unanswered question is how a TCR discriminates between foreign and self-peptides presented on the APC surface.Here,we used in situ fluorescence resonance energy transfer(FRET)to measure the distances of single TCR–pMHC bonds and the conformations of individual TCR–CD3ζreceptors at the membranes of live primary T cells.We found that a TCR discriminates between closely related peptides by forming single TCR–pMHC bonds with different conformations,and the most potent pMHC forms the shortest bond.The bond conformation is an intrinsic property that is independent of the binding affinity and kinetics,TCR microcluster formation,and CD4 binding.The bond conformation dictates the degree of CD3ζdissociation from the inner leaflet of the plasma membrane via a positive calcium signaling feedback loop to precisely control the accessibility of CD3ζITAMs for phosphorylation.Our data revealed the mechanism by which a TCR deciphers the structural differences among peptides via the TCR–pMHC bond conformation.
