RESUMO
Holistic understanding of physio-pathological processes requires noninvasive 3D imaging in deep tissue across multiple spatial and temporal scales to link diverse transient subcellular behaviors with long-term physiogenesis. Despite broad applications of two-photon microscopy (TPM), there remains an inevitable tradeoff among spatiotemporal resolution, imaging volumes, and durations due to the point-scanning scheme, accumulated phototoxicity, and optical aberrations. Here, we harnessed the concept of synthetic aperture radar in TPM to achieve aberration-corrected 3D imaging of subcellular dynamics at a millisecond scale for over 100,000 large volumes in deep tissue, with three orders of magnitude reduction in photobleaching. With its advantages, we identified direct intercellular communications through migrasome generation following traumatic brain injury, visualized the formation process of germinal center in the mouse lymph node, and characterized heterogeneous cellular states in the mouse visual cortex, opening up a horizon for intravital imaging to understand the organizations and functions of biological systems at a holistic level.
Assuntos
Imageamento Tridimensional , Animais , Camundongos , Imageamento Tridimensional/métodos , Microscopia Confocal/métodosRESUMO
Here, we report inducible mosaic animal for perturbation (iMAP), a transgenic platform enabling in situ CRISPR targeting of at least 100 genes in parallel throughout the mouse body. iMAP combines Cre-loxP and CRISPR-Cas9 technologies and utilizes a germline-transmitted transgene carrying a large array of individually floxed, tandemly linked gRNA-coding units. Cre-mediated recombination triggers expression of all the gRNAs in the array but only one of them per cell, converting the mice to mosaic organisms suitable for phenotypic characterization and also for high-throughput derivation of conventional single-gene perturbation lines via breeding. Using gRNA representation as a readout, we mapped a miniature Perturb-Atlas cataloging the perturbations of 90 genes across 39 tissues, which yields rich insights into context-dependent gene functions and provides a glimpse of the potential of iMAP in genome decoding.
Assuntos
Sistemas CRISPR-Cas , RNA Guia de Cinetoplastídeos , Animais , Sistemas CRISPR-Cas/genética , Edição de Genes , Genoma , Camundongos , RNA Guia de Cinetoplastídeos/genética , RNA Guia de Cinetoplastídeos/metabolismo , TransgenesRESUMO
Human gut commensals are increasingly suggested to impact non-communicable diseases, such as inflammatory bowel diseases (IBD), yet their targeted suppression remains a daunting unmet challenge. In four geographically distinct IBD cohorts (n = 537), we identify a clade of Klebsiella pneumoniae (Kp) strains, featuring a unique antibiotics resistance and mobilome signature, to be strongly associated with disease exacerbation and severity. Transfer of clinical IBD-associated Kp strains into colitis-prone, germ-free, and colonized mice enhances intestinal inflammation. Stepwise generation of a lytic five-phage combination, targeting sensitive and resistant IBD-associated Kp clade members through distinct mechanisms, enables effective Kp suppression in colitis-prone mice, driving an attenuated inflammation and disease severity. Proof-of-concept assessment of Kp-targeting phages in an artificial human gut and in healthy volunteers demonstrates gastric acid-dependent phage resilience, safety, and viability in the lower gut. Collectively, we demonstrate the feasibility of orally administered combination phage therapy in avoiding resistance, while effectively inhibiting non-communicable disease-contributing pathobionts.
Assuntos
Bacteriófagos , Colite , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Animais , Colite/terapia , Humanos , Inflamação/terapia , Doenças Inflamatórias Intestinais/terapia , Klebsiella pneumoniae , CamundongosRESUMO
Two and a half years into the COVID-19 pandemic, we have gained many insights into the human antibody response to the causative SARS-CoV-2 virus. In this Review, we summarize key observations of humoral immune responses in people with COVID-19, discuss key features of infection- and vaccine-induced neutralizing antibodies, and consider vaccine designs for inducing antibodies that are broadly protective against different variants of the SARS-CoV-2 virus.
Assuntos
COVID-19 , Vacinas Virais , Anticorpos Neutralizantes , Anticorpos Antivirais , Humanos , Imunidade Humoral , Pandemias , SARS-CoV-2RESUMO
Mutations in the RNA splicing factor gene SF3B1 are common across hematologic and solid cancers and result in widespread alterations in splicing, yet there is currently no therapeutic means to correct this mis-splicing. Here, we utilize synthetic introns uniquely responsive to mutant SF3B1 to identify trans factors required for aberrant mutant SF3B1 splicing activity. This revealed the G-patch domain-containing protein GPATCH8 as required for mutant SF3B1-induced splicing alterations and impaired hematopoiesis. GPATCH8 is involved in quality control of branchpoint selection, interacts with the RNA helicase DHX15, and functionally opposes SURP and G-patch domain containing 1 (SUGP1), a G-patch protein recently implicated in SF3B1-mutant diseases. Silencing of GPATCH8 corrected one-third of mutant SF3B1-dependent splicing defects and was sufficient to improve dysfunctional hematopoiesis in SF3B1-mutant mice and primary human progenitors. These data identify GPATCH8 as a novel splicing factor required for mis-splicing by mutant SF3B1 and highlight the therapeutic impact of correcting aberrant splicing in SF3B1-mutant cancers.
Assuntos
Neoplasias Hematológicas , Mutação , Fosfoproteínas , Fatores de Processamento de RNA , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo , Humanos , Animais , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/patologia , Neoplasias Hematológicas/metabolismo , Camundongos , Splicing de RNA , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Hematopoese/genética , Células HEK293 , Íntrons , RNA Helicases/genética , RNA Helicases/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
SARS-CoV-2 Omicron variant has presented significant challenges to current antibodies and vaccines. Herein, we systematically compared the efficacy of 50 human monoclonal antibodies (mAbs), covering the seven identified epitope classes of the SARS-CoV-2 RBD, against Omicron sub-variants BA.1, BA.1.1, BA.2, and BA.3. Binding and pseudovirus-based neutralizing assays revealed that 37 of the 50 mAbs lost neutralizing activities, whereas the others displayed variably decreased activities against the four Omicron sub-variants. BA.2 was found to be more sensitive to RBD-5 antibodies than the other sub-variants. Furthermore, a quaternary complex structure of BA.1 RBD with three mAbs showing different neutralizing potencies against Omicron provided a basis for understanding the immune evasion of Omicron sub-variants and revealed the lack of G446S mutation accounting for the sensitivity of BA.2 to RBD-5 mAbs. Our results may guide the application of the available mAbs and facilitate the development of universal therapeutic antibodies and vaccines against COVID-19.
Assuntos
Anticorpos Neutralizantes , COVID-19 , Anticorpos Monoclonais , Anticorpos Antivirais , Vacinas contra COVID-19 , Humanos , Glicoproteínas de Membrana , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Proteínas do Envelope ViralRESUMO
The Hippo signaling pathway functions through Yorkie to control tissue growth and homeostasis. How this pathway regulates non-developmental processes remains largely unexplored. Here, we report an essential role for Hippo signaling in innate immunity whereby Yorkie directly regulates the transcription of the Drosophila IκB homolog, Cactus, in Toll receptor-mediated antimicrobial response. Loss of Hippo pathway tumor suppressors or activation of Yorkie in fat bodies, the Drosophila immune organ, leads to elevated cactus mRNA levels, decreased expression of antimicrobial peptides, and vulnerability to infection by Gram-positive bacteria. Furthermore, Gram-positive bacteria acutely activate Hippo-Yorkie signaling in fat bodies via the Toll-Myd88-Pelle cascade through Pelle-mediated phosphorylation and degradation of the Cka subunit of the Hippo-inhibitory STRIPAK PP2A complex. Our studies elucidate a Toll-mediated Hippo signaling pathway in antimicrobial response, highlight the importance of regulating IκB/Cactus transcription in innate immunity, and identify Gram-positive bacteria as extracellular stimuli of Hippo signaling under physiological settings.
Assuntos
Drosophila melanogaster/imunologia , Imunidade Inata , Transdução de Sinais , Animais , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Drosophila melanogaster/microbiologia , Escherichia coli/fisiologia , Corpo Adiposo/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Larva/metabolismo , Masculino , Pectobacterium carotovorum/fisiologia , Fosfoproteínas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Staphylococcus aureus/fisiologia , Receptores Toll-Like/metabolismoRESUMO
Cyclic GMP-AMP synthase (cGAS) binds pathogenic and other cytoplasmic double-stranded DNA (dsDNA) to catalyze the synthesis of cyclic GMP-AMP (cGAMP), which serves as the secondary messenger to activate the STING pathway and innate immune responses. Emerging evidence suggests that activation of the cGAS pathway is crucial for anti-tumor immunity; however, no effective intervention method targeting cGAS is currently available. Here we report that cGAS is palmitoylated by ZDHHC9 at cysteines 404/405, which promotes the dimerization and activation of cGAS. We further identified that lysophospholipase-like 1 (LYPLAL1) depalmitoylates cGAS to compromise its normal function. As such, inhibition of LYPLAL1 significantly enhances cGAS-mediated innate immune response, elevates PD-L1 expression, and enhances anti-tumor response to PD-1 blockade. Our results therefore reveal that targeting LYPLAL1-mediated cGAS depalmitoylation contributes to cGAS activation, providing a potential strategy to augment the efficacy of anti-tumor immunotherapy.
Assuntos
Neoplasias , Nucleotidiltransferases , Humanos , Nucleotidiltransferases/metabolismo , Imunidade Inata/genética , Neoplasias/genética , Neoplasias/terapia , ImunoterapiaRESUMO
BCL6 is required for development of follicular T helper (Tfh) cells to support germinal center (GC) formation. However, it is not clear what unique functions programmed by BCL6 can explain its absolute essentiality in T cells for GC formation. We found that ablation of one Bcl6 allele did not appreciably alter early T cell activation and follicular localization but inhibited GC formation and Tfh cell maintenance. BCL6 impinged on Tfh calcium signaling and also controlled Tfh entanglement with and CD40L delivery to B cells. Amounts of BCL6 protein and nominal frequencies of Tfh cells markedly changed within hours after strengths of T-B cell interactions were altered in vivo, while CD40L overexpression rectified both defective GC formation and Tfh cell maintenance because of the BCL6 haploinsufficiency. Our results reveal BCL6 functions in Tfh cells that are essential for GC formation and suggest that BCL6 helps maintain Tfh cell phenotypes in a T cell non-autonomous manner.
Assuntos
Linfócitos B/imunologia , Centro Germinativo/imunologia , Ativação Linfocitária/imunologia , Proteínas Proto-Oncogênicas c-bcl-6/imunologia , Células T Auxiliares Foliculares/imunologia , Animais , CamundongosRESUMO
Electrodeposition of lithium (Li) metal is critical for high-energy batteries1. However, the simultaneous formation of a surface corrosion film termed the solid electrolyte interphase (SEI)2 complicates the deposition process, which underpins our poor understanding of Li metal electrodeposition. Here we decouple these two intertwined processes by outpacing SEI formation at ultrafast deposition current densities3 while also avoiding mass transport limitations. By using cryogenic electron microscopy4-7, we discover the intrinsic deposition morphology of metallic Li to be that of a rhombic dodecahedron, which is surprisingly independent of electrolyte chemistry or current collector substrate. In a coin cell architecture, these rhombic dodecahedra exhibit near point-contact connectivity with the current collector, which can accelerate inactive Li formation8. We propose a pulse-current protocol that overcomes this failure mode by leveraging Li rhombic dodecahedra as nucleation seeds, enabling the subsequent growth of dense Li that improves battery performance compared with a baseline. While Li deposition and SEI formation have always been tightly linked in past studies, our experimental approach enables new opportunities to fundamentally understand these processes decoupled from each other and bring about new insights to engineer better batteries.
RESUMO
Antibody affinity maturation depends on positive selection in germinal centres (GCs) of rare B cell clones that acquire higher-affinity B cell receptors via somatic hypermutation, present more antigen to follicular helper T (TFH) cells and, consequently, receive more contact-dependent T cell help1. As these GC B cells and TFH cells do not maintain long-lasting contacts in the chaotic GC environment2-4, it is unclear how sufficient T cell help is cumulatively focused onto those rare clones. Here we show that, upon stimulation of CD40, GC B cells upregulate the chemokine CCL22 and to a lesser extent CCL17. By engaging the chemokine receptor CCR4 on TFH cells, CCL22 and CCL17 can attract multiple helper cells from a distance, thus increasing the chance of productive help. During a GC response, B cells that acquire higher antigen-binding affinities express higher levels of CCL22, which in turn 'highlight' these high-affinity GC B cells. Acute increase or blockade of TFH cells helps to rapidly increase or decrease CCL22 expression by GC B cells, respectively. Therefore, a chemokine-based intercellular reaction circuit links the amount of T cell help that individual B cells have received recently to their subsequent ability to attract more help. When CCL22 and CCL17 are ablated in B cells, GCs form but B cells are not affinity-matured efficiently. When competing with wild-type B cells in the same reaction, B cells lacking CCL22 and CCL17 receive less T cell help to maintain GC participation or develop into bone-marrow plasma cells. By uncovering a chemokine-mediated mechanism that highlights affinity-improved B cells for preferential help from TFH cells, our study reveals a principle of spatiotemporal orchestration of GC positive selection.
Assuntos
Quimiocina CCL22/metabolismo , Centro Germinativo/citologia , Centro Germinativo/imunologia , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Células Cultivadas , Quimiocina CCL17/deficiência , Quimiocina CCL17/genética , Quimiocina CCL22/deficiência , Quimiocina CCL22/genética , Feminino , Humanos , Masculino , Camundongos , Tonsila Palatina/citologia , Receptores CCR4/deficiência , Receptores CCR4/genética , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/imunologia , Regulação para CimaRESUMO
The kinetochore scaffold 1 (KNL1) protein recruits spindle assembly checkpoint (SAC) proteins to ensure accurate chromosome segregation during mitosis. Despite such a conserved function among eukaryotic organisms, its molecular architectures have rapidly evolved so that the functional mode of plant KNL1 is largely unknown. To understand how SAC signaling is regulated at kinetochores, we characterized the function of the KNL1 gene in Arabidopsis thaliana. The KNL1 protein was detected at kinetochores throughout the mitotic cell cycle, and null knl1 mutants were viable and fertile but exhibited severe vegetative and reproductive defects. The mutant cells showed serious impairments of chromosome congression and segregation, that resulted in the formation of micronuclei. In the absence of KNL1, core SAC proteins were no longer detected at the kinetochores, and the SAC was not activated by unattached or misaligned chromosomes. Arabidopsis KNL1 interacted with SAC essential proteins BUB3.3 and BMF3 through specific regions that were not found in known KNL1 proteins of other species, and recruited them independently to kinetochores. Furthermore, we demonstrated that upon ectopic expression, the KNL1 homolog from the dicot tomato was able to functionally substitute KNL1 in A. thaliana, while others from the monocot rice or moss associated with kinetochores but were not functional, as reflected by sequence variations of the kinetochore proteins in different plant lineages. Our results brought insights into understanding the rapid evolution and lineage-specific connection between KNL1 and the SAC signaling molecules.
Assuntos
Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Pontos de Checagem da Fase M do Ciclo Celular/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Ligação Proteica , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Mitose , Cinetocoros/metabolismo , Fuso Acromático/genética , Fuso Acromático/metabolismo , Segregação de CromossomosRESUMO
The spindle assembly checkpoint (SAC) ensures faithful chromosome segregation during cell division by monitoring kinetochore-microtubule attachment. Plants produce both sequence-conserved and diverged SAC components, and it has been largely unknown how SAC activation leads to the assembly of these proteins at unattached kinetochores to prevent cells from entering anaphase. In Arabidopsis thaliana, the noncanonical BUB3.3 protein was detected at kinetochores throughout mitosis, unlike MAD1 and the plant-specific BUB1/MAD3 family protein BMF3 that associated with unattached chromosomes only. When BUB3.3 was lost by a genetic mutation, mitotic cells often entered anaphase with misaligned chromosomes and presented lagging chromosomes after they were challenged by low doses of the microtubule depolymerizing agent oryzalin, resulting in the formation of micronuclei. Surprisingly, BUB3.3 was not required for the kinetochore localization of other SAC proteins or vice versa. Instead, BUB3.3 specifically bound to BMF3 through two internal repeat motifs that were not required for BMF3 kinetochore localization. This interaction enabled BMF3 to recruit CDC20, a downstream SAC target, to unattached kinetochores. Taken together, our findings demonstrate that plant SAC utilizes unconventional protein interactions for arresting mitosis, with BUB3.3 directing BMF3's role in CDC20 recruitment, rather than the recruitment of BUB1/MAD3 proteins observed in fungi and animals. This distinct mechanism highlights how plants adapted divergent versions of conserved cell cycle machinery to achieve specialized SAC control.
Assuntos
Arabidopsis , Cinetocoros , Animais , Cinetocoros/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Pontos de Checagem da Fase M do Ciclo Celular/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Pontos de Checagem do Ciclo Celular , Fuso Acromático/metabolismoRESUMO
Angiogenesis is vital to developmental, regenerative and repair processes. It is normally regulated by a balanced production of pro- and anti-angiogenic factors. Alterations in this balance under pathological conditions are generally mediated through up-regulation of pro-angiogenic and/or downregulation of anti-angiogenic factors, leading to growth of new and abnormal blood vessels. The pathological manifestation of many diseases including cancer, ocular and vascular diseases are dependent on the growth of these new and abnormal blood vessels. Thrompospondin-1 (TSP1) was the first endogenous angiogenesis inhibitor identified and its anti-angiogenic and anti-inflammatory activities have been the subject of many studies. Studies examining the role TSP1 plays in pathogenesis of various ocular diseases and vascular dysfunctions are limited. Here we will discuss the recent studies focused on delineating the role TSP1 plays in ocular vascular development and homeostasis, and pathophysiology of various ocular and vascular diseases with a significant clinical relevance to human health.
Assuntos
Neoplasias , Doenças Vasculares , Humanos , Neoplasias/patologia , Neovascularização Patológica/patologiaRESUMO
Structural Variants (SVs) are a crucial type of genetic variant that can significantly impact phenotypes. Therefore, the identification of SVs is an essential part of modern genomic analysis. In this article, we present kled, an ultra-fast and sensitive SV caller for long-read sequencing data given the specially designed approach with a novel signature-merging algorithm, custom refinement strategies and a high-performance program structure. The evaluation results demonstrate that kled can achieve optimal SV calling compared to several state-of-the-art methods on simulated and real long-read data for different platforms and sequencing depths. Furthermore, kled excels at rapid SV calling and can efficiently utilize multiple Central Processing Unit (CPU) cores while maintaining low memory usage. The source code for kled can be obtained from https://github.com/CoREse/kled.
Assuntos
Algoritmos , Genômica , Fenótipo , SoftwareRESUMO
Efficient and precise targeted insertion holds great promise but remains challenging in plant genome editing. An efficient nonhomologous end-joining-mediated targeted insertion method was recently developed by combining clustered regularly interspaced short palindromic repeat (CRISPR)/Streptococcus pyogenes CRISPR-associated nuclease 9 (SpCas9) gene editing with phosphorothioate modified double-stranded oligodeoxynucleotides (dsODNs). Yet, this approach often leads to imprecise insertions with no control over the insertion direction. Here, we compared the influence of chemical protection of dsODNs on efficiency of targeted insertion. We observed that CRISPR/SpCas9 frequently induced staggered cleavages with 1-nucleotide 5' overhangs; we also evaluated the effect of donor end structures on the direction and precision of targeted insertions. We demonstrate that chemically protected dsODNs with 1-nucleotide 5' overhangs significantly improved the precision and direction control of target insertions in all tested CRISPR targeted sites. We applied this method to endogenous gene tagging in green foxtail (Setaria viridis) and engineering of cis-regulatory elements for disease resistance in rice (Oryza sativa). We directionally inserted 2 distinct transcription activator-like effector binding elements into the promoter region of a recessive rice bacterial blight resistance gene with up to 24.4% efficiency. The resulting rice lines harboring heritable insertions exhibited strong resistance to infection by the pathogen Xanthomonas oryzae pv. oryzae in an inducible and strain-specific manner.
Assuntos
Oligonucleotídeos , Oryza , Edição de Genes/métodos , Plantas/genética , Sequências Reguladoras de Ácido Nucleico , Genoma de Planta , Oryza/genética , Oryza/microbiologiaRESUMO
Rhinovirus (RV), a prominent causative agent of both upper and lower respiratory diseases, ranks among the most prevalent human respiratory viruses. RV infections are associated with various illnesses, including colds, asthma exacerbations, croup and pneumonia, imposing significant and extended societal burdens. Characterized by a high mutation rate and genomic diversity, RV displays a diverse serological landscape, encompassing a total of 174 serotypes identified to date. Understanding RV genetic diversity is crucial for epidemiological surveillance and investigation of respiratory diseases. This study introduces a comprehensive and high-quality RV data resource, designated RVdb (http://rvdb.mgc.ac.cn), covering 26 909 currently identified RV strains, along with RV-related sequences, 3D protein structures and publications. Furthermore, this resource features a suite of web-based utilities optimized for easy browsing and searching, as well as automatic sequence annotation, multiple sequence alignment (MSA), phylogenetic tree construction, RVdb BLAST and a serotyping pipeline. Equipped with a user-friendly interface and integrated online bioinformatics tools, RVdb provides a convenient and powerful platform on which to analyse the genetic characteristics of RVs. Additionally, RVdb also supports the efforts of virologists and epidemiologists to monitor and trace both existing and emerging RV-related infectious conditions in a public health context.
Assuntos
Asma , Infecções por Enterovirus , Infecções por Picornaviridae , Rhinovirus , Humanos , Genômica , Filogenia , Infecções por Picornaviridae/genética , Rhinovirus/genéticaRESUMO
Leymus chinensis, a dominant perennial grass in the Eurasian Steppe, is well known for its remarkable adaptability and forage quality. Hardly any breeding has been done on the grass, limiting its potential in ecological restoration and forage productivity. To enable genetic improvement of the untapped, important species, we obtained a 7.85-Gb high-quality genome of L. chinensis with a particularly long contig N50 (318.49 Mb). Its allotetraploid genome is estimated to originate 5.29 million years ago (MYA) from a cross between the Ns-subgenome relating to Psathyrostachys and the unknown Xm-subgenome. Multiple bursts of transposons during 0.433-1.842 MYA after genome allopolyploidization, which involved predominantly the Tekay and Angela of LTR retrotransposons, contributed to its genome expansion and complexity. With the genome resource available, we successfully developed a genetic transformation system as well as the gene-editing pipeline in L. chinensis. We knocked out the monocot-specific miR528 using CRISPR/Cas9, resulting in the improvement of yield-related traits with increases in the tiller number and growth rate. Our research provides valuable genomic resources for Triticeae evolutionary studies and presents a conceptual framework illustrating the utilization of genomic information and genome editing to accelerate the improvement of wild L. chinensis with features such as polyploidization and self-incompatibility.
Assuntos
Melhoramento Vegetal , Poaceae , Poaceae/genética , Genoma , Evolução MolecularRESUMO
Drought stress is one of the dominating challenges to the growth and productivity in crop plants. Elucidating the molecular mechanisms of plants responses to drought stress is fundamental to improve fruit quality. However, such molecular mechanisms are poorly understood in apple (Malus domestica Borkh.). In this study, we explored that the BTB-BACK-TAZ protein, MdBT2, negatively modulates the drought tolerance of apple plantlets. Moreover, we identified a novel Homeodomain-leucine zipper (HD-Zip) transcription factor, MdHDZ27, using a yeast two-hybrid (Y2H) screen with MdBT2 as the bait. Overexpression of MdHDZ27 in apple plantlets, calli, and tomato plantlets enhanced their drought tolerance by promoting the expression of drought tolerance-related genes [responsive to dehydration 29A (MdRD29A) and MdRD29B]. Biochemical analyses demonstrated that MdHDZ27 directly binds to and activates the promoters of MdRD29A and MdRD29B. Furthermore, in vitro and in vivo assays indicate that MdBT2 interacts with and ubiquitinates MdHDZ27, via the ubiquitin/26S proteasome pathway. This ubiquitination results in the degradation of MdHDZ27 and weakens the transcriptional activation of MdHDZ27 on MdRD29A and MdRD29B. Finally, a series of transgenic analyses in apple plantlets further clarified the role of the relationship between MdBT2 and MdHDZ27, as well as the effect of their interaction on drought resistance in apple plantlets. Collectively, our findings reveal a novel mechanism by which the MdBT2-MdHDZ27 regulatory module controls drought tolerance, which is of great significance for enhancing the drought resistance of apple and other plants.
Assuntos
Secas , Regulação da Expressão Gênica de Plantas , Malus , Proteínas de Plantas , Plantas Geneticamente Modificadas , Fatores de Transcrição , Ubiquitinação , Malus/genética , Malus/fisiologia , Malus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Estresse Fisiológico , Resistência à SecaRESUMO
Protein function annotation is one of the most important research topics for revealing the essence of life at molecular level in the post-genome era. Current research shows that integrating multisource data can effectively improve the performance of protein function prediction models. However, the heavy reliance on complex feature engineering and model integration methods limits the development of existing methods. Besides, models based on deep learning only use labeled data in a certain dataset to extract sequence features, thus ignoring a large amount of existing unlabeled sequence data. Here, we propose an end-to-end protein function annotation model named HNetGO, which innovatively uses heterogeneous network to integrate protein sequence similarity and protein-protein interaction network information and combines the pretraining model to extract the semantic features of the protein sequence. In addition, we design an attention-based graph neural network model, which can effectively extract node-level features from heterogeneous networks and predict protein function by measuring the similarity between protein nodes and gene ontology term nodes. Comparative experiments on the human dataset show that HNetGO achieves state-of-the-art performance on cellular component and molecular function branches.