SARS coronavirus （SARS-CoV） is the etiologic agent of severe acute respiratory syndrome. The aim of this study was to construct Sars-CoV membrane （M）, nucleocapsid （N） and spike 2 （$2） gene eukaryotic expressi...SARS coronavirus （SARS-CoV） is the etiologic agent of severe acute respiratory syndrome. The aim of this study was to construct Sars-CoV membrane （M）, nucleocapsid （N） and spike 2 （$2） gene eukaryotic expression plasmids, and identify their expression in vitro. Gene fragments encoding N protein, M protein and $2 protein of SARS-CoV were amplified by PCR using cDNA obtained from lung samples of SARS patients as template, and subcloned into pcDNA3.1 vector to form eukaryotic expression plasmids. SARS-CoV protein eukaryotic expression plasmids were transfected respectively into CHO cells. Immunohistochemistry was employed to detect the expression of the structural proteins of SARS-CoV in transfected cells. SARS-CoV protein eukaryotic expression plasmids were successfully constructed by identification with digestion of restriction enzymes and sequencing. M, N and S2 proteins of SARS-CoV were detected in the cytoplasm of transfected CHO cells. It was concluded that these recombinant eukaryotic expression plasmids were constructed successfully, and SARS-CoV encoding proteins could activate transcription and expression of hfgl2 gene.展开更多
Different from reversible agonist-stimulated receptor activation,singlet oxygen oxidation activates permanently G protein-coupled receptor(GPCR)cholecystokinin 1(CCK1R)in type II photodynamic action,with soluble photo...Different from reversible agonist-stimulated receptor activation,singlet oxygen oxidation activates permanently G protein-coupled receptor(GPCR)cholecystokinin 1(CCK1R)in type II photodynamic action,with soluble photosensitizer dyes(sulphonated aluminum phthalocyanine,λmax 675 nm)or genetically encoded protein photosensitizers(KillerRedλmax 585 nm;mini singlet oxygen generatorλmax 450 nm),together with a pulse of light(37 mW/cm2,1-2 minutes).Three lines of evidence shed light on the mechanism of GPCR activated by singlet oxygen(GPCR-ABSO):(1)CCK1R is quantitatively converted from dimer to monomer;(2)Transmembrane domain 3,a pharmacophore for permanent photodynamic CCK1R activation,can be transplanted to non-susceptible M3 acetylcholine receptor;and(3)Larger size of disordered region in intracellular loop 3 correlates with higher sensitivity to photodynamic CCK1R activation.GPCR-ABSO will add to the arsenal of engineered designer GPCR such as receptors activated solely by synthetic ligands and designer receptors exclusively activated by designer drugs,but show some clear advantages:Enhanced selectivity(double selectivity of localized photosensitizer and light illumination),long-lasting activation with no need for repeated drug administration,antagonist-binding site remains intact when needed,ease to apply to multiple GPCR.This type of permanent photodynamic activation may be applied to functional proteins other than GPCR.展开更多
Many eukaryotic genes are members of multi-gene families due to gene duplications, which generate new copies that allow functional divergence. However, the relationship between
Plants have developed a complicated defense mechanism during evolution to resist the harmful pathogens they encountered.The mechanism involves the interaction of the plant resistance(R)
Fluorescent probes have revolutionized optical imaging and biosensing by enabling real-time visualization, quantification, and tracking of biological processes at molecular and cellular levels. These probes, ranging f...Fluorescent probes have revolutionized optical imaging and biosensing by enabling real-time visualization, quantification, and tracking of biological processes at molecular and cellular levels. These probes, ranging from organic dyes to genetically encoded proteins and nanomaterials, provide unparalleled specificity, sensitivity, and multiplexing capabilities. However, challenges such as brightness, photobleaching, biocompatibility, and emission range continue to drive innovation in probe design and application. This special issue, comprising four review papers and seven original research studies, highlights cutting-edge advancements in fluorescent probe technologies and their transformative roles in super-resolution imaging, in vivo diagnostics, and cancer therapeutics.展开更多
Synthesis of macromolecular systems with precise structural and functional control constitutes a fundamental challenge for materials science and engineering. Development of the ability to construct complex bio-macromo...Synthesis of macromolecular systems with precise structural and functional control constitutes a fundamental challenge for materials science and engineering. Development of the ability to construct complex bio-macromolecular architectures provides a solution to this challenge. The past few years have witnessed the emergence of a new category of peptide-protein chemistry which can covalently stitch together protein]peptide molecules with high specificity under mild physiological conditions. It has thus inspired the concept of genetically encoded click chemistry （GECC）. As a prototype of GECC, SpyTag/ SpyCatcher chemistry has enabled the precise synthesis ofmacromolecules both in vitro and in vivo, exerting precise control over the fundamental properties of these macromolecules including length, sequence, stereochemistry and topology and leading to the creation of diverse biomaterials for a variety of applications. We thus anticipate a potential toolbox of GECC comprising multiple mutually orthogonal, covalent-bond forming peptide-protein reactive pairs with diverse features, which shall bridge synthetic biology and materials science and open up enormous opportunities for biomaterialsin the future.展开更多
RNA editing is a posttranscriptional process that is important in mitochondria and plastids of higher plants. All RNA editing-specific trans-factors reported so far belong to PLS-class of pentatricopeptide repeat(PPR)...RNA editing is a posttranscriptional process that is important in mitochondria and plastids of higher plants. All RNA editing-specific trans-factors reported so far belong to PLS-class of pentatricopeptide repeat(PPR)proteins. Here, we report the map-based cloning and molecular characterization of a defective kernel mutant dek39 in maize. Loss of Dek39 function leads to delayed embryogenesis and endosperm development, reduced kernel size, and seedling lethality. Dek39 encodes an E subclass PPR protein that targets to both mitochondria and chloroplasts, and is involved in RNA editing in mitochondrial NADH dehydrogenase3(nad3) at nad3-247 and nad3-275. C-to-U editing of nad3-275 is not conserved and even lost in Arabidopsis, consistent with the idea that no close DEK39 homologs are present in Arabidopsis. However, the amino acids generated by editing nad3-247 and nad3-275 are highly conserved in many other plant species, and the reductions of editing at these two sites decrease the activity of mitochondria NADH dehydrogenase complex I,indicating that the alteration of amino acid sequence is necessary for Nad3 function. Our results indicate that Dek39 encodes an E sub-class PPR protein that is involved in RNA editing of multiple sites and is necessary for seed development of maize.展开更多
基金supported by a grant from National Key Project of Science and Technology Ministry of China for 973-SARS (No. 2003CB514112)SARS funding first granted from Ministry of education of China ([2003]64)The National 10th Five-Year Plan Key Project of China (2004BA720A01)
文摘SARS coronavirus （SARS-CoV） is the etiologic agent of severe acute respiratory syndrome. The aim of this study was to construct Sars-CoV membrane （M）, nucleocapsid （N） and spike 2 （$2） gene eukaryotic expression plasmids, and identify their expression in vitro. Gene fragments encoding N protein, M protein and $2 protein of SARS-CoV were amplified by PCR using cDNA obtained from lung samples of SARS patients as template, and subcloned into pcDNA3.1 vector to form eukaryotic expression plasmids. SARS-CoV protein eukaryotic expression plasmids were transfected respectively into CHO cells. Immunohistochemistry was employed to detect the expression of the structural proteins of SARS-CoV in transfected cells. SARS-CoV protein eukaryotic expression plasmids were successfully constructed by identification with digestion of restriction enzymes and sequencing. M, N and S2 proteins of SARS-CoV were detected in the cytoplasm of transfected CHO cells. It was concluded that these recombinant eukaryotic expression plasmids were constructed successfully, and SARS-CoV encoding proteins could activate transcription and expression of hfgl2 gene.
基金Supported by the National Natural Science Foundation of China,No.32271278 and No.31971170.
文摘Different from reversible agonist-stimulated receptor activation,singlet oxygen oxidation activates permanently G protein-coupled receptor(GPCR)cholecystokinin 1(CCK1R)in type II photodynamic action,with soluble photosensitizer dyes(sulphonated aluminum phthalocyanine,λmax 675 nm)or genetically encoded protein photosensitizers(KillerRedλmax 585 nm;mini singlet oxygen generatorλmax 450 nm),together with a pulse of light(37 mW/cm2,1-2 minutes).Three lines of evidence shed light on the mechanism of GPCR activated by singlet oxygen(GPCR-ABSO):(1)CCK1R is quantitatively converted from dimer to monomer;(2)Transmembrane domain 3,a pharmacophore for permanent photodynamic CCK1R activation,can be transplanted to non-susceptible M3 acetylcholine receptor;and(3)Larger size of disordered region in intracellular loop 3 correlates with higher sensitivity to photodynamic CCK1R activation.GPCR-ABSO will add to the arsenal of engineered designer GPCR such as receptors activated solely by synthetic ligands and designer receptors exclusively activated by designer drugs,but show some clear advantages:Enhanced selectivity(double selectivity of localized photosensitizer and light illumination),long-lasting activation with no need for repeated drug administration,antagonist-binding site remains intact when needed,ease to apply to multiple GPCR.This type of permanent photodynamic activation may be applied to functional proteins other than GPCR.
文摘Many eukaryotic genes are members of multi-gene families due to gene duplications, which generate new copies that allow functional divergence. However, the relationship between
文摘Plants have developed a complicated defense mechanism during evolution to resist the harmful pathogens they encountered.The mechanism involves the interaction of the plant resistance(R)
文摘Fluorescent probes have revolutionized optical imaging and biosensing by enabling real-time visualization, quantification, and tracking of biological processes at molecular and cellular levels. These probes, ranging from organic dyes to genetically encoded proteins and nanomaterials, provide unparalleled specificity, sensitivity, and multiplexing capabilities. However, challenges such as brightness, photobleaching, biocompatibility, and emission range continue to drive innovation in probe design and application. This special issue, comprising four review papers and seven original research studies, highlights cutting-edge advancements in fluorescent probe technologies and their transformative roles in super-resolution imaging, in vivo diagnostics, and cancer therapeutics.
基金financial supports from the Research Grants Council of Hong Kong SAR Government to F. Sun (RGC-ECS Nos. #26103915 and Ao E/M-09/12)the 863 Program (No. 2015AA020941)+2 种基金the National Natural Science Foundation of China (Nos. 21474003, 91427304)"1000 Plan (Youth)"the Department of Chemical and Biological Engineering, HKUST for the faculty start-up fund
文摘Synthesis of macromolecular systems with precise structural and functional control constitutes a fundamental challenge for materials science and engineering. Development of the ability to construct complex bio-macromolecular architectures provides a solution to this challenge. The past few years have witnessed the emergence of a new category of peptide-protein chemistry which can covalently stitch together protein]peptide molecules with high specificity under mild physiological conditions. It has thus inspired the concept of genetically encoded click chemistry （GECC）. As a prototype of GECC, SpyTag/ SpyCatcher chemistry has enabled the precise synthesis ofmacromolecules both in vitro and in vivo, exerting precise control over the fundamental properties of these macromolecules including length, sequence, stereochemistry and topology and leading to the creation of diverse biomaterials for a variety of applications. We thus anticipate a potential toolbox of GECC comprising multiple mutually orthogonal, covalent-bond forming peptide-protein reactive pairs with diverse features, which shall bridge synthetic biology and materials science and open up enormous opportunities for biomaterialsin the future.
基金supported by the National Natural Science Foundation of China (91435206 31421005)+1 种基金National Key Technologies Research & Development ProgramSeven Major Crops Breeding Project (2016YFD0101803, 2016YFD0100404)the 948 project (2016-X33)
文摘RNA editing is a posttranscriptional process that is important in mitochondria and plastids of higher plants. All RNA editing-specific trans-factors reported so far belong to PLS-class of pentatricopeptide repeat(PPR)proteins. Here, we report the map-based cloning and molecular characterization of a defective kernel mutant dek39 in maize. Loss of Dek39 function leads to delayed embryogenesis and endosperm development, reduced kernel size, and seedling lethality. Dek39 encodes an E subclass PPR protein that targets to both mitochondria and chloroplasts, and is involved in RNA editing in mitochondrial NADH dehydrogenase3(nad3) at nad3-247 and nad3-275. C-to-U editing of nad3-275 is not conserved and even lost in Arabidopsis, consistent with the idea that no close DEK39 homologs are present in Arabidopsis. However, the amino acids generated by editing nad3-247 and nad3-275 are highly conserved in many other plant species, and the reductions of editing at these two sites decrease the activity of mitochondria NADH dehydrogenase complex I,indicating that the alteration of amino acid sequence is necessary for Nad3 function. Our results indicate that Dek39 encodes an E sub-class PPR protein that is involved in RNA editing of multiple sites and is necessary for seed development of maize.
