Understanding the interaction between biological structures and nanoscale technologies,dubbed the nano-bio interface,is required for successful development of safe and efficient nanomedicine products.The lack of a uni...Understanding the interaction between biological structures and nanoscale technologies,dubbed the nano-bio interface,is required for successful development of safe and efficient nanomedicine products.The lack of a universal reporting system and decentralized methodologies for nanomaterial characterization have resulted in a low degree of reliability and reproducibility in the nanomedicine literature.As such,there is a strong need to establish a characterization system to support the reproducibility of nanoscience data particularly for studies seeking clinical translation.Here,we discuss the existing key standards for addressing robust characterization of nanomaterials based on their intended use in medical devices or as pharmaceuticals.We also discuss the challenges surrounding implementation of such standard protocols and their implication for translation of nanotechnology into clinical practice.We,however,emphasize that practical implementation of standard protocols in experimental laboratories requires long-term planning through integration of stakeholders including institutions and funding agencies.展开更多
Genetic engineering of plants is at the core of sustainability efforts,natural product synthesis,and agricultural crop improvement.The past several decades have brought remarkable progress in biotechnology with the im...Genetic engineering of plants is at the core of sustainability efforts,natural product synthesis,and agricultural crop improvement.The past several decades have brought remarkable progress in biotechnology with the improvement of genome editing and sequencing tools,which stand to advance plant synthetic biology and bioengineering.In agriculture,genetic engineering can be employed to create crops that have in creased yields and nu tritio nal value,are resista nt to herbicides,in sects,diseases,and abiotic stresses,in cludi ng drought and heat .In pharmaceuticals and therapeutics,genetically engineered plants can be used to synthesize valuable small-molecule drugs and recombinant proteins.展开更多
The nucleotide-binding and leucine-rich repeat(NLR)proteins comprise a major class of intracellular immune receptors that are capable of detecting pathogen-derived molecules and activating immunity and cell death in p...The nucleotide-binding and leucine-rich repeat(NLR)proteins comprise a major class of intracellular immune receptors that are capable of detecting pathogen-derived molecules and activating immunity and cell death in plants.The activity of some NLRs,particularly the Toll-like/interleukin-1 receptor(TIR)type,is highly correlated with their nucleocytoplasmic distribution.However,whether and how the nucleocytoplasmic homeostasis of NLRs is coordinated through a bidirectional nuclear shuttling mechanism remains unclear.Here,we identified a nuclear transport receptor,KA120,which is capable of affecting the nucleocytoplasmic distribution of an NLR protein and is essential in preventing its autoactivation.We showed that the ka120 mutant displays an autoimmune phenotype and NLR-induced transcriptome features.Through a targeted genetic screen using an artificial NLR microRNA library,we identified the TIR-NLR gene SNC1 as a genetic interactor of KA120.Loss-of-function snc1 mutations as well as compromising SNC1 protein activities all substantially suppressed ka120-induced autoimmune activation,and the enhanced SNC1 activity upon loss of KA120 functionappeared to occur at the protein level.Overexpression of KA120 efficiently repressed SNC1 activity and led to a nearly complete suppression of the autoimmune phenotype caused by the gain-of-function snc1-1 mutation or SNC1 overexpression in transgenic plants.Further florescence imaging analysis indicated that SNC1 undergoes altered nucleocytoplasmic distribution with significantly reduced nuclear signal when KA120 is constitutively expressed,supporting a role of KA120 in coordinating SNC1 nuclear abundance and activity.Consistently,compromising the SNC1 nuclear level by disrupting the nuclear pore complex could also partially rescue ka120-induced autoimmunity.Collectively,our study demonstrates that KA120 is essential to avoid autoimmune activation in the absence of pathogens and is required to constrain the nuclear activity of SNC1,possibly through coordinating SNC1 nucleocytoplasmic homeostasis as a potential mechanism.展开更多
Plant leucine-rich repeat(LRR)receptor-like kinases(RLKs)and LRR receptor-like proteins(RLPs)comprise a large family of cell surface receptors that play critical roles in signal perception and transduction.Both LRR-RL...Plant leucine-rich repeat(LRR)receptor-like kinases(RLKs)and LRR receptor-like proteins(RLPs)comprise a large family of cell surface receptors that play critical roles in signal perception and transduction.Both LRR-RLKs and LRR-RLPs rely on regulatory LRR-RLKs to initiate downstream signaling pathways.BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE 1/SOMATIC EMBRYOGENESIS RECEPTOR KINASE 3(BAK1/SERK3)and SUPPRESSOR OF BIR1-1(SOBIR1)are important and extensively studied regulatory LRR-RLKs with distinct functions.Although the regulatory mechanism of BAK1 activation has been studied in detail,the activation mechanism of SOBIR1 remains poorly understood.Here,the crystal structures of the catalytically inactive kinase domain of SOBIR1(SOBIR1-KD)from Arabidopsis thaliana were determined in complexes with AMP-PNP and Mg^(2+).The results show that SOBIR1-KD contains a uniquely long β3-αC loop and adopts an Src-like inactive conformation with an unusual architecture at the activation segment,which comprises three helices.Biochemical studies revealed that SOBIR1 is transphosphorylated by BAK1 following its autophosphorylation via an intermolecular mechanism,and the phosphorylation of Thr529 in the activation segment and the β3-αC loop are critical for SOBIR1 phosphorylation.Further functional analysis confirmed the importance of Thr529 and the β3-αC loop for the SOBIR1-induced cell death response in Nicotiana benthamiana.Taken together,these findings provide a structural basis for the regulatory mechanism of SOBIR1 and reveal the important elements and phosphorylation events in the special stepwise activation of SOBIR1-KD,the first such processes found in regulatory LRR-RLKs.展开更多
Microscopic imaging of the brain continues to reveal details of its structure, connectivity, and function. To further improve our understanding of the emergent properties and functions of neural circuits, we need to d...Microscopic imaging of the brain continues to reveal details of its structure, connectivity, and function. To further improve our understanding of the emergent properties and functions of neural circuits, we need to directly visualize the relationship between brain structure, neuron activity, and neurochemistry. Advances in the chemical and optical properties of nanomaterials, and developments in deep-tissue microscopy, may help to overcome the current challenges of in-vivo brain imaging, particularly when imaging the brain through optically-dense brain tissue, skull, and scalp. Developments in nanomaterials may enable the implementation of tunable chemical functionality for neurochemical targeting and sensing, and fluorescence stability for long-term imaging. In this review, we summarize the current methods used for brain microscopy and describe the diverse classes of nanomaterials recently offered as contrast agents and functional probes for microscopic optical imaging of the brain.展开更多
CRISPR/Cas-mediated genome editing technology has been widely applied to create knockout alleles of genes by generating short insertions or deletions in various plant species.However,targeted insertion(knockin)or repl...CRISPR/Cas-mediated genome editing technology has been widely applied to create knockout alleles of genes by generating short insertions or deletions in various plant species.However,targeted insertion(knockin)or replacement of long DNA sequences by CRISPR/Cas remains challenging in plants(Chen et al.,2019).For such edits,donor DNA that acts as the repair template for the endogenous homology-directed repair(HDR)mechanism is often supplied with the CRISPR/Cas machinery that creates double-strand DNA breaks at designated genomic targets.However,precise gene replacement and insertion in plants via HDR with the supplied donor is inefficient,as HDR usually occurs at a much lower frequency compared with non-homologous end joining(NHEJ)-mediated repair in plants.展开更多
基金support from the U.S. National Institute of Diabetes and Digestive and Kidney Diseases (Grant DK131417) (MM)support of a Burroughs Wellcome Fund Career Award at the Scientific Interface (CASI) (MPL)+11 种基金a Dreyfus foundation award (MPL)the Philomathia foundation (MPL)an NIH MIRA award R35GM128922 (MPL)an NIH R21 NIDA award 1R03DA052810 (MPL)an NSF CAREER award 2046159 (MPL)an NSF CBET award 1733575 (to MPL)a CZI imaging award (MPL)a Sloan Foundation Award (MPL)a USDA BBT EAGER award (MPL)a Moore Foundation Award (MPL)a DOE office of Science grant DE-SC0020366 (MPL)support from a Fulbright fellowship (NNM)。
文摘Understanding the interaction between biological structures and nanoscale technologies,dubbed the nano-bio interface,is required for successful development of safe and efficient nanomedicine products.The lack of a universal reporting system and decentralized methodologies for nanomaterial characterization have resulted in a low degree of reliability and reproducibility in the nanomedicine literature.As such,there is a strong need to establish a characterization system to support the reproducibility of nanoscience data particularly for studies seeking clinical translation.Here,we discuss the existing key standards for addressing robust characterization of nanomaterials based on their intended use in medical devices or as pharmaceuticals.We also discuss the challenges surrounding implementation of such standard protocols and their implication for translation of nanotechnology into clinical practice.We,however,emphasize that practical implementation of standard protocols in experimental laboratories requires long-term planning through integration of stakeholders including institutions and funding agencies.
文摘Genetic engineering of plants is at the core of sustainability efforts,natural product synthesis,and agricultural crop improvement.The past several decades have brought remarkable progress in biotechnology with the improvement of genome editing and sequencing tools,which stand to advance plant synthetic biology and bioengineering.In agriculture,genetic engineering can be employed to create crops that have in creased yields and nu tritio nal value,are resista nt to herbicides,in sects,diseases,and abiotic stresses,in cludi ng drought and heat .In pharmaceuticals and therapeutics,genetically engineered plants can be used to synthesize valuable small-molecule drugs and recombinant proteins.
基金X.Shen and X.Shi were supported by Tsinghua-Peking Joint Center tor Life SciencesThis project was supported by the USDA National Institute of Food and Agriculture(HATCH project CA-B-PLB-0243-H)+1 种基金the National Science Foundation(grant MCB-2049931)startup funds from Inno-vative Genomics Institute and University of California Berkeley.
文摘The nucleotide-binding and leucine-rich repeat(NLR)proteins comprise a major class of intracellular immune receptors that are capable of detecting pathogen-derived molecules and activating immunity and cell death in plants.The activity of some NLRs,particularly the Toll-like/interleukin-1 receptor(TIR)type,is highly correlated with their nucleocytoplasmic distribution.However,whether and how the nucleocytoplasmic homeostasis of NLRs is coordinated through a bidirectional nuclear shuttling mechanism remains unclear.Here,we identified a nuclear transport receptor,KA120,which is capable of affecting the nucleocytoplasmic distribution of an NLR protein and is essential in preventing its autoactivation.We showed that the ka120 mutant displays an autoimmune phenotype and NLR-induced transcriptome features.Through a targeted genetic screen using an artificial NLR microRNA library,we identified the TIR-NLR gene SNC1 as a genetic interactor of KA120.Loss-of-function snc1 mutations as well as compromising SNC1 protein activities all substantially suppressed ka120-induced autoimmune activation,and the enhanced SNC1 activity upon loss of KA120 functionappeared to occur at the protein level.Overexpression of KA120 efficiently repressed SNC1 activity and led to a nearly complete suppression of the autoimmune phenotype caused by the gain-of-function snc1-1 mutation or SNC1 overexpression in transgenic plants.Further florescence imaging analysis indicated that SNC1 undergoes altered nucleocytoplasmic distribution with significantly reduced nuclear signal when KA120 is constitutively expressed,supporting a role of KA120 in coordinating SNC1 nuclear abundance and activity.Consistently,compromising the SNC1 nuclear level by disrupting the nuclear pore complex could also partially rescue ka120-induced autoimmunity.Collectively,our study demonstrates that KA120 is essential to avoid autoimmune activation in the absence of pathogens and is required to constrain the nuclear activity of SNC1,possibly through coordinating SNC1 nucleocytoplasmic homeostasis as a potential mechanism.
基金This work was supported by the National Natural Science Foundation of China(31571963).
文摘Plant leucine-rich repeat(LRR)receptor-like kinases(RLKs)and LRR receptor-like proteins(RLPs)comprise a large family of cell surface receptors that play critical roles in signal perception and transduction.Both LRR-RLKs and LRR-RLPs rely on regulatory LRR-RLKs to initiate downstream signaling pathways.BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE 1/SOMATIC EMBRYOGENESIS RECEPTOR KINASE 3(BAK1/SERK3)and SUPPRESSOR OF BIR1-1(SOBIR1)are important and extensively studied regulatory LRR-RLKs with distinct functions.Although the regulatory mechanism of BAK1 activation has been studied in detail,the activation mechanism of SOBIR1 remains poorly understood.Here,the crystal structures of the catalytically inactive kinase domain of SOBIR1(SOBIR1-KD)from Arabidopsis thaliana were determined in complexes with AMP-PNP and Mg^(2+).The results show that SOBIR1-KD contains a uniquely long β3-αC loop and adopts an Src-like inactive conformation with an unusual architecture at the activation segment,which comprises three helices.Biochemical studies revealed that SOBIR1 is transphosphorylated by BAK1 following its autophosphorylation via an intermolecular mechanism,and the phosphorylation of Thr529 in the activation segment and the β3-αC loop are critical for SOBIR1 phosphorylation.Further functional analysis confirmed the importance of Thr529 and the β3-αC loop for the SOBIR1-induced cell death response in Nicotiana benthamiana.Taken together,these findings provide a structural basis for the regulatory mechanism of SOBIR1 and reveal the important elements and phosphorylation events in the special stepwise activation of SOBIR1-KD,the first such processes found in regulatory LRR-RLKs.
文摘Microscopic imaging of the brain continues to reveal details of its structure, connectivity, and function. To further improve our understanding of the emergent properties and functions of neural circuits, we need to directly visualize the relationship between brain structure, neuron activity, and neurochemistry. Advances in the chemical and optical properties of nanomaterials, and developments in deep-tissue microscopy, may help to overcome the current challenges of in-vivo brain imaging, particularly when imaging the brain through optically-dense brain tissue, skull, and scalp. Developments in nanomaterials may enable the implementation of tunable chemical functionality for neurochemical targeting and sensing, and fluorescence stability for long-term imaging. In this review, we summarize the current methods used for brain microscopy and describe the diverse classes of nanomaterials recently offered as contrast agents and functional probes for microscopic optical imaging of the brain.
文摘CRISPR/Cas-mediated genome editing technology has been widely applied to create knockout alleles of genes by generating short insertions or deletions in various plant species.However,targeted insertion(knockin)or replacement of long DNA sequences by CRISPR/Cas remains challenging in plants(Chen et al.,2019).For such edits,donor DNA that acts as the repair template for the endogenous homology-directed repair(HDR)mechanism is often supplied with the CRISPR/Cas machinery that creates double-strand DNA breaks at designated genomic targets.However,precise gene replacement and insertion in plants via HDR with the supplied donor is inefficient,as HDR usually occurs at a much lower frequency compared with non-homologous end joining(NHEJ)-mediated repair in plants.
