Biology subjects

Yu, M.

Publications and source records attributed to Yu, M..

At least 91 records · Page 5Linked to original sources

bioRxiv2023

Targeting the Hippo pathway in cancers via ubiquitination dependent TEAD degradation

The Hippo pathway is among the most frequently altered key signaling pathways in cancer. TEAD1-4 are essential transcription factors and key downstream effectors in the Hippo pathway in human cells. Here, we identified RNF146 as a ubiquitin ligase (E3) of TEADs, which negatively regulates their stability in cells through proteasome-mediated degradation. We show that RNF146-mediated TEAD ubiquitination is dependent on the TEAD PARylation state. We further validated the genetic interaction between RNF146 and the Hippo pathway in cancer cell lines and the model organism Drosophila melanogaster. Despite the RNF146 and proteasome-mediated degradation mechanisms, TEADs are stable proteins with a long half-life in cells. We demonstrate that degradation of TEADs can be greatly enhanced pharmacologically with heterobifunctional chemical inducers of protein degradation (CIDEs). These TEAD-CIDEs can effectively suppress activation of YAP/TAZ target genes in a dose-dependent manner and exhibit significant anti-proliferative effects in YAP/TAZ-dependent tumor cells, thus phenocopying the effect of genetic ablation of TEAD protein. Collectively, this study demonstrates that the ubiquitin-proteasome system plays an important role in regulating TEAD functions and provides a proof-of-concept demonstration that pharmacologically induced TEAD ubiquitination could be leveraged to target YAP/TAZ-driven cancers.

cancer biology↗

bioRxiv2023

Single-molecule analysis unveils the phosphorylation of FLS2 regulates its spatiotemporal dynamics and immunity

The Arabidopsis thaliana FLAGELLIN-SENSITIVE2 (FLS2), a typical receptor kinase, recognizes the conserved 22 amino acid sequence in the N-terminal region of flagellin (flg22) to initiate plant defense pathways, which was intensively studied in the past decades. However, the dynamic regulation of FLS2 phosphorylation at the plasma membrane after flg22 recognition needs further elucidation. Through single-particle tracking, we demonstrated that upon flg22 treatment, the phosphorylation of Ser-938 in FLS2 impacts its spatiotemporal dynamics and lifetime. Following forster resonance energy transfer-fluorescence lifetime (FRET-FLIM) imaging microscopy and protein proximity indexes (PPI) assays revealed that flg22 treatment increased the co-localization of GFP-tagged FLS2/FLS2S938D but not FLS2S938A with AtRem1.3-mCherry, a sterol-rich lipid marker, indicating that the phosphorylation of FLS2S938 affects FLS2 sorting efficiency to AtRem1.3-associated nanodomains. Importantly, we found that the phosphorylation of Ser-938 enhanced flg22-induced FLS2 internalization and immune responses, demonstrating that the phosphorylation may activate flg22-triggered immunity through partitioning FLS2 into functional AtRem1.3-associated nanodomains, which fills the gap between the FLS2S938 phosphorylation and FLS2-mediated immunity.

cell biology↗

bioRxiv2023

LrhA promotes CRISPR-Cas immunity by promoting reciprocal interplay between interference and primed adaptation in Escherichia coli

The CRISPR-based defense system protects prokaryotes against foreign genetic elements. Previous studies indicated that the activity of the CRISPR-Cas system is the outcome of the combined effect of adaptation and interference. However, it remains unclear how coordination of the two processes is regulated to optimize the efficacy of adaptive immunity. Here, we identify the LysR-type transcriptional regulator LrhA as a new CRISPR-Cas activator which plays an important role in coordinating adaptation and interference. Through directly binding to the promoter of the cas operon, LrhA enhances the CRISPR-Cas adaptive immunity against bacteriophage infection by stimulating the transcription of cas genes. Moderate activation of cas genes by LrhA efficiently promoted the clearance of horizontally transferred CRISPR-targeted plasmid via increasing the acquisition of new spacers by interference-driven adaptation in Escherichia coli. Our results indicate that intermediate level of transcription of cas genes achieved optimal outcomes of the adaptive immunity through triggering positive feedback between adaptation and interference, highlighting the importance of fine-tuning expression of CRISPR-Cas system.

microbiology↗

bioRxiv2023

Single-cell transcriptomic analysis of pea shoot development and cell-type-specific responses to boron deficiency

Understanding how nutrient stress impacts plant growth is fundamentally important to the development of approaches to improve crop production under nutrient limitation. Here we applied single-cell RNA sequencing to shoot apices of Pisum sativum grown under boron (B) deficiency. We identified up to fifteen cell clusters based on the clustering of gene expression profiles and verified cell identity with cell-type-specific marker gene expression. Different cell types responded differently to B deficiency. Specifically, the expression of photosynthetic genes in mesophyll cells (MCs) was down-regulated by B deficiency, consistent with impaired photosynthetic rate. Furthermore, the down-regulation of stomatal development genes in guard cells (GCs), including homologs of MUTE and TOO MANY MOUTHS, correlated with a decrease in stomatal density under B deficiency. We also constructed the developmental trajectory of the shoot apical meristem (SAM) cells and a transcription factor (TF) interaction network. The developmental progression of SAM to MC was characterized by up-regulation of genes encoding histones and chromatin assembly and remodeling proteins including homologs of FASCIATA1 (FAS1) and SWITCH DEFECTIVE/SUCROSE NON-FERMENTABLE (SWI/SNF) complex. However, B deficiency suppressed their expression, which helps to explain impaired SAM development under B deficiency. These results represent a major advance over bulk-tissue RNA-seq analysis in which cell-type-specific responses are lost and hence important physiological responses to B deficiency are missed. The reported approach and resources have potential applications well beyond P. sativum species and could be applied to various legumes to improve their adaptability to multiple nutrient or abiotic stresses.

plant biology↗

bioRxiv2023

Design of multi-epitope vaccine candidate against Brucella type IV secretion system (T4SS)

Objective the dominant epitopes of T and B cells of VirB8 and VirB10 of Brucella type IV. Secretory systems were predicted and analyzed by bioinformatics, and then multi-epitope vaccines were constructed by reverse vaccination. Methods The amino acid sequences of VirB8 and VirB10 were obtained from the UniProt database, T and B cell dominant epitopes were selected and supplemented with adjuvants to construct a multi-epitope vaccine, SOPMA and RoseTTAFold were applied to predict secondary and tertiary structures respectively for immune simulations. Finally, molecular dynamics simulations of iMEV-TLR4 were then performed. Results one cytotoxic T lymphocyte (CTL) epitope, five helper T lymphocyte (HTL) epitopes, two linear B cell epitopes and three conformational B cell epitopes were obtained in VirB8. 1 cytotoxic T lymphocyte (CTL) epitope, 4 helper T lymphocyte (HTL) epitopes, 4 linear B cell epitopes, and 3 conformational B cell epitopes were obtained in VirB10. The resulting multiepitope vaccine is a protein with good antigenicity, hydrophilicity, and stability. Conclusion a novel brucella multiepitope vaccine was designed by reverse vaccination, and this study provides a theoretical basis for further research.

bioinformatics↗

bioRxiv2023

Collection of Biospecimens from the Inspiration4 Mission Establishes the Standards for the Space Omics and Medical Atlas (SOMA)

The SpaceX Inspiration4 mission provided a unique opportunity to study the impact of spaceflight on the human body. Biospecimen samples were collected from the crew at different stages of the mission, including before (L-92, L-44, L-3 days), during (FD1, FD2, FD3), and after (R+1, R+45, R+82, R+194 days) spaceflight, creating a longitudinal sample set. The collection process included samples such as venous blood, capillary dried blood spot cards, saliva, urine, stool, body swabs, capsule swabs, SpaceX Dragon capsule HEPA filter, and skin biopsies, which were processed to obtain aliquots of serum, plasma, extracellular vesicles, and peripheral blood mononuclear cells. All samples were then processed in clinical and research laboratories for optimal isolation and testing of DNA, RNA, proteins, metabolites, and other biomolecules. This paper describes the complete set of collected biospecimens, their processing steps, and long-term biobanking methods, which enable future molecular assays and testing. As such, this study details a robust framework for obtaining and preserving high-quality human, microbial, and environmental samples for aerospace medicine in the Space Omics and Medical Atlas (SOMA) initiative, which can also aid future experiments in human spaceflight and space biology.

molecular biology↗

bioRxiv2023

Redundant and distinct roles of two 14-3-3 proteins in Fusarium sacchari, pathogen of sugarcane Pokkah boeng disease

Fusarium sacchari is one of the most important sugarcane pathogens that causes Pokkah boeng disease (PBD) in China. 14-3-3 proteins have been shown to play vital roles in developmental processes in dimorphic transition, signal transduction and carbon metabolism in some phytopathogenic fungi, but were poorly understood in F. sacchari. In this study, two 14-3-3 protein-encoding genes, FsBmh1 and FsBmh2 in F. sacchari, were investigated. Although both FsBmh1 and FsBmh2 were expressed at vegetative growth stage, FsBmh1 was repressed at sporulation stage in vitro. In order to clarify the roles of FsBmh1 and FsBmh2, deletion mutants {Delta}FsBmh1 and {Delta}FsBmh2 were constructed. Phenotypic defects, including hyphal branching, hyphal septation, conidiation, spore germination and colony growth, were more severe in {Delta}FsBmh2 than in {Delta}FsBmh1, although virulence attenuation was observed in both mutants. To further explore the relationship between FsBmh1 and FsBmh2, the combination of deletion and silencing ({Delta}FsBmh/sFsBmh) and overexpression (O-FsBmh) mutants were constructed and characterized. Compared to the single allele deletion, combinations of {Delta}FsBmh1/sFsBmh2 or {Delta}FsBmh2/sFsBmh1 showed more severe manifestations in general, suggesting a redundancy in function of the two 14-3-3 genes. Comparative transcriptome analysis revealed that more functional genes were affected in {Delta}FsBmh2 than in {Delta}FsBmh1. Redundancy in function between FsBmh1 and FsBmh2 suggests that 14-3-3 is vitally important for the organism and distinction in roles between the two isoforms may be resulted from the divergence in evolution. To the best of our knowledge, this was the first report on the distinct roles of 14-3-3 protein isoforms in a pathogenic fungus. Knowledge gained from this study should be of help to further understand the regulation mechanism of pathogenicity-related traits in fungal pathogens and for the development of new strategy for control of PBD in particular.

microbiology↗

bioRxiv2023

NULISA: a novel proteomic liquid biopsy platform with attomolar sensitivity and high multiplexing

The blood proteome holds great promise for precision medicine but poses substantial challenges due to the low abundance of most plasma proteins and the vast dynamic range across the proteome. We report a novel proteomic technology - NUcleic acid Linked Immuno-Sandwich Assay (NULISA) - that incorporates a dual capture and release mechanism to suppress the assay background and improves the sensitivity of the proximity ligation assay by over 10,000-fold to the attomolar level. It utilizes pairs of antibodies conjugated to DNA oligonucleotides that enable immunocomplex purification and generate reporter DNA containing target- and sample-specific barcodes for a next-generation sequencing-based, highly multiplexed readout. A 200-plex NULISA targeting 124 cytokines and chemokines and 80 other immune response-related proteins demonstrated superior sensitivity for detecting low-abundance proteins and high concordance with other immunoassays. The ultrahigh sensitivity allowed the detection of previously difficult-to-detect, but biologically important, low-abundance biomarkers in patients with autoimmune diseases and COVID-19. Fully automated NULISA addresses longstanding challenges in proteomic analysis of liquid biopsies and makes broad and in-depth proteomic analysis accessible to the general research community and future diagnostic applications.

genomics↗

bioRxiv2023

Toleration of Frameshift Mutations in mRNA Sequences Encoding the N-terminal Peptides of Bacterial Type III Effectors

Gram-negative bacteria deliver effector proteins into eukaryotic host cells through type III and type IV secretion systems, causing infections and diseases. It remains unclear about the signals guiding the specific secretion of the effectors. Here, we adopted an in silico approach to analyze the mRNA sequences encoding the putative peptides essential for effective secretion and translocation of type III and IV effectors. A surprisingly high proportion of type III effectors showed tolerance on frameshift mutations in signal-encoding mRNA sequences, and in contrast, very low percentage of type IV effectors showed the similar frameshift tolerance. The type III effectors with frameshift tolerance of secretion signals were widely distributed in effector or signal families and bacterial species. Natural frameshifts could be identified in type III effector genes, which were often remedied in time by nearby paired insertions or deletions. Frameshift-derived peptide sequences also retained the common properties present in the signal peptides of raw type III effectors. Natural language processing models were adopted to represent the common features in the mRNA sequences encoding N-terminal peptides of type III effectors or C-terminal peptides of type IV effectors, with which transfer learning models could well predict the effectors, especially type IV effectors. The observations in the study would facilitate us understand the nature and evolution of secretion signals of type III and IV effectors. SignificanceIt has been a debate on the nature of signals for translocation of type III secreted effectors for a long time. Meanwhile, there has been no examination on the possibility of mRNA being as translocation signals for type IV or other types of secreted effectors. By computational simulation, the study demonstrated the protein nature of translocation signals for both type IV effectors and most type III effectors. Despite wide frameshift tolerance and atypical common features in mRNA sequences encoding the putative N-terminal signal sequences of type III effectors, more typical common physicochemical and amino acid composition properties between the mutation-derived and raw peptides, and the frequent self-correction phenomenon for naturally happening frameshifts supported the translocation signals at protein level of type III effectors. The common features in mRNA sequences encoding the translocation signal peptides of type III and IV effectors could also be combined in models for better prediction of the effectors respectively.

microbiology↗

bioRxiv2023

Genetic control of cell layer interactions in plants via tissue mechanics

Plant development depends on coordination of growth between different cell layers. Coordination may be mediated by molecular signalling or mechanical connectivity between cells, but evidence for genetic control via direct mechanics has been lacking. We show that a brassinosteroid-deficient dwarf mutant of the aquatic plant Utricularia gibba has twisted internal tissue, likely caused by a mechanical constraint from a slow-growing epidermis creating tissue stresses. This conclusion is supported by showing that inhibition of brassinosteroid action in an Arabidopsis mutant compromised for cell adhesion, enhances epidermal crack formation, an indicator of increased tissue tension. Thus, genes driving brassinosteroid synthesis can promote growth of internal tissue by reducing mechanical epidermal constraint, showing that tissue mechanics plays a key role in coordinating growth between cell layers. One-Sentence SummaryInternal twists in a mutant carnivorous plant reveal how genes control growth via tissue mechanics.

plant biology↗

bioRxiv2022

The SUMO-interacting Motif in NS2 promotes adaptation of avian influenza virus to mammals

Species differences in the host factor ANP32A/B result in the restriction of avian influenza virus polymerase (vPol) in mammalian cells. Efficient replication of avian influenza viruses in mammalian cells often requires adaptive mutations, such as PB2-E627K, to enable the virus to utilize mammalian ANP32A/B. However, the molecular basis for the productive replication of avian influenza viruses without prior adaptation in mammals remain poorly understood. We show that influenza A virus protein NS2 help to overcome mammalian ANP32A/B-mediated restriction to avian vPol activity by promoting avian vRNP assembly and enhancing mammalian ANP32A/B-vRNP interactions. A conserved SUMO interaction motif (SIM) in NS2 is required for its avian polymerase-enhancing properties. We also demonstrate that disrupting SIM integrity in NS2 impairs avian influenza virus replication and pathogenicity in mammalian hosts, but not in avian hosts. Our results identify NS2 as a cofactor in the adaptation process of avian influenza viruses to mammals.

microbiology↗

bioRxiv2022

Single-cell multi-omics decodes regulatory programs during development of mouse secondary palate

The abnormal perturbation in gene regulation during palatogenesis may lead to cleft palate, a major congenital birth defect in humans and mice. However, a comprehensive multi-omic map of the developing secondary palate at single-cell resolution is lacking. In this study, we performed single-cell multiome sequencing and profiled chromatin accessibility and gene expression simultaneously within the same cells (n = 36,154) isolated from mouse secondary palate across embryonic days (E) 12.5, E13.5, E14.0, and E14.5. Application of optimal transport reconstructed five trajectories, representing continuous differentiation of multipotent cells into different subpopulations in later stages. By linking open chromatin signals to gene expression changes, we discovered a list of lineage-determining transcription factors, such as Shox2 for the anterior and Dlx1/2 for the posterior palatal mesenchymal trajectories. In conclusion, this study charted epigenetic and transcriptional dynamics during palatogenesis, which provides a valuable resource for the community and facilitate future research in cleft palate. HighlightsO_LIThe first report on building a single-cell multi-omics atlas with joint chromatin accessibility and gene expression measurements from the same cells during the development of mouse secondary palate. C_LIO_LIApplication of optimal transport calculated fate probabilities to different terminal states and recovered continuous landscapes during mouse secondary palate development. C_LIO_LIBy linking cis-regulatory DNA elements to target genes, we characterized a series of transcription factors governing the differentiation of cranial neural crest-derived multipotent cells to the anterior and posterior palatal mesenchymal trajectories, respectively. C_LIO_LITranscription factors Shox2 and Dlx1/2 exhibited top regulatory roles for the anterior and posterior palatal mesenchymal trajectories, respectively, showing significant enrichment in both motif accessibility and gene expression. C_LI

developmental biology↗

bioRxiv2022

Multiplatform Modeling of Atrial Fibrillation Identifies Phospholamban as Central Regulator of Cardiac Rhythm

Atrial fibrillation (AF) is the most common form of sustained cardiac arrhythmia in humans, present in > 33 million people worldwide. Although AF is often developed secondary to cardiovascular diseases, endocrine disorders, or lifestyle factors, recent GWAS studies have identified >200 genetic variants that substantially contribute to AF risk. However, it is currently not known how these genetic predispositions contribute to the initiation and/or maintenance of AF-associated phenotypes. In this context, one major barrier to progress is the lack of experimental systems enabling to rapidly explore the function of large cohort of genes on rhythm parameters in models with human atrial relevance. To address these modeling challenges, we have developed a new multi-model platform enabling 1) high-throughput characterization of the role of AF-associated genes on action potential duration and rhythm parameters at the cellular level, using human iPSC-derived atrial-like cardiomyocytes (ACMs), and at the whole organ level, using the Drosophila heart model, and 2) validation of the physiological relevance of our experimental results using computational models of heterogenous human adult atrial myocytes (HAMs) and tissue. As proof of concept, we screened a cohort of 20 AF-associated genes and identified Phospholamban (PLN) loss of function as a top conserved hit that significantly shortens action potential duration in ACMs, HAMs and fly cardiomyocytes. Remarkably, while PLN knock-down (KD) was not sufficient to induce arrhythmia phenotypes, addition of environmental stressors (i.e fibroblasts, {beta}-adrenergic stimulation) to the model systems, led to the robust generation of irregular beat to beat intervals, delayed after depolarizations, and triggered action potentials, as compared to controls. Finally, to delineate the mechanism underlying PLN KD-dependent arrhythmia, we used a logistic regression approach in HAM populations, and predicted that PLN functionally interacts with both NCX (loss of function) and L-type calcium channels (gain of function) to mediate these arrhythmic phenotypes. Consistent with our predictions, co-KD of PLN and NCX in ACMs and flies, led to increased arrhythmic events, while treatment of ACMs with L-type calcium channel inhibitor, verapamil, reverted these phenotypes. In summary, these results collectively demonstrate that our integrated multi-model system approach was successful in identifying and characterizing conserved roles (i.e regulation of Ca2+ homeostasis) for AF-associated genes and phenotypes, and thus paves the way for the discovery and molecular delineation of new gene regulatory networks controlling atrial rhythm with application to AF.

pathology↗

bioRxiv2022

Genomic and transcriptional profiling stratifies VQ myeloma lines into two clusters with distinct risk signatures and drug responses

Multiple myeloma (MM) is a cancer of malignant plasma cells in the bone marrow and extramedullary sites. We previously characterized a VQ model for human high-risk MM. Different VQ lines display distinct disease phenotypes and survivals, suggesting significant intra-model variation. Here, we use whole exome sequencing and copy number variation (CNV) analysis coupled with RNA-Seq to stratify VQ lines into corresponding clusters: Cluster I VQ cells carried recurrent amplification of chromosome (chr) 3 and displayed upregulation of growth pathways and high-risk myeloma gene signatures, whereas Cluster II cells had monosomy chr5 and overexpressed genes and pathways associated with positive response to bortezomib (Btz) treatment in human MM patients. Consistently, in sharp contrast to Cluster II VQ cells that showed short-term response to Btz, Cluster I VQ cells were de novo resistant to Btz in vivo. Our study highlights Cluster I VQ lines as highly representative of human high-risk MM subset.

cancer biology↗

bioRxiv2022

SnapHiC-D: a computational pipeline to identify differential chromatin contacts from single cell Hi-C data

Single cell Hi-C (scHi-C) has been used to map genome organization in complex tissues. However, computational tools to detect dynamic chromatin contacts from scHi-C datasets in development and through disease pathogenesis are still lacking. Here, we present SnapHiC-D, a computational pipeline to identify differential chromatin contacts (DCCs) between two scHi-C datasets. Compared to methods designed for bulk Hi-C data, SnapHiC-D detects DCCs with high sensitivity and accuracy. We used SnapHiC-D to identify celltype-specific chromatin contacts at 10 kilobase resolution in mouse hippocampal and human prefrontal cortical tissues, and demonstrated that DCCs detected in the cortical and hippocampal cell types are generally correlated with cell-type-specific gene expression patterns and epigenomic features.

bioinformatics↗

bioRxiv2022

Prevalent regulation of GATA2/3 and MSX2 on endogenous retrovirus-derived regulatory elements in human trophoblast stem cells

The placenta is an organ with extraordinary phenotypic diversity in eutherian mammals. Recent evidence suggests that numerous human placental enhancers are evolved from lineage-specific insertions of endogenous retroviruses (ERVs), yet the transcription factors (TFs) underlying their regulation remain largely elusive. Here, by first focusing on MER41, a primate-specific ERV family previously linked to placenta and innate immunity, we uncover the binding motifs of multiple crucial trophoblast TFs (GATA2/3, MSX2, GRHL2) in addition to innate immunity TFs STAT1 and IRF1. Integration of ChIP-Seq data confirms the binding of GATA2/3, MSX2 and their related factors on the majority of MER41-derived enhancers in human trophoblast stem cells (TSCs). Notably, MER41-derived enhancers that are constitutively active in human TSCs are distinct from those activated upon interferon stimulation, which is determined by the binding of relevant TFs and their sub-family compositions. We further demonstrate that GATA2/3 and MSX2 have prevalent binding on numerous other ERV families - indicating their broad impact on ERV-derived enhancers. Functionally, the derepression of many syncytiotrophoblast genes after disruption of MSX2 is likely to be mediated by regulatory elements derived from ERVs - suggesting ERVs are also important for mediating transcriptional repression. Overall, this study characterized the prevalent regulation of GATA2/3, MSX2 and their co-factors on ERV-derived regulatory elements in human TSCs and provided mechanistic insights into the importance of ERVs in human trophoblast regulatory network.

evolutionary biology↗

bioRxiv2022

Functional screening of lysosomal storage disorder genes identifies modifiers of alpha-synuclein mediated neurodegeneration

Heterozygous variants in the glucocerebrosidase (GBA) gene are common and potent risk factors for Parkinsons disease (PD). GBA also causes the autosomal recessive lysosomal storage disorder (LSD), Gaucher disease, and emerging evidence from human genetics implicates many other LSD genes in PD susceptibility. We have systemically tested 88 conserved fly homologs of 38 human LSD genes for requirements in the aging adult Drosophila brain and for potential genetic interactions with neurodegeneration caused by -synuclein (Syn), which forms Lewy body pathology in PD. Our screen identifies 15 genetic enhancers of Syn-induced progressive locomotor dysfunction, following knockdown of fly homologs of GBA and other LSD genes with independent support as PD susceptibility factors from human genetics (SCARB2, SMPD1, CTSD, GNPTAB, SLC17A5). For several genes, results from multiple alleles support dose-sensitivity and context-dependent pleiotropy in the presence or absence of Syn. Homologs of 2 genes causing cholesterol storage disorders, Npc1a / NPC1 and Lip4 / LIPA, were independently confirmed as loss-of-function enhancers of Syn-induced brain structural degeneration. The enzymes encoded by several modifier genes are upregulated in Syn transgenic flies, based on unbiased proteomics, revealing a possible compensatory response. Overall, our results reinforce the important role of lysosomal genes in brain health and PD pathogenesis, and implicate several metabolic pathways, including cholesterol homeostasis, in Syn-mediated neurodegeneration.

genetics↗

bioRxiv2022

A glycine zipper motif governs translocation of type VI secretion toxic effectors across the cytoplasmic membrane of target cells

Type VI secretion systems (T6SSs) can deliver diverse toxic effectors into eukaryotic and bacterial cells. Although much is known about the regulation and assembly of T6SS, the translocation mechanism of effectors into the periplasm and/or cytoplasm of target cells remains elusive. Here we use the Agrobacterium tumefaciens DNase effector Tde1 to unravel the mechanism of translocation from attacker to prey. We demonstrate that Tde1 binds to its adaptor Tap1 through the N-terminus, which harbours continuous copies of GxxxG motifs resembling the glycine zipper structure found in proteins involved in the membrane channel formation. Amino acid substitutions on G39xxxG43 motif does not affect Tde1-Tap1 interaction and secretion but abolish its membrane permeability and translocation of its fluorescent fusion protein into prey cells. The data suggest that G39xxxG43 governs the delivery of Tde1 into target cells by permeabilizing the cytoplasmic membrane. Considering the widespread presence of GxxxG motifs in bacterial effectors and pore-forming toxins, we propose that glycine zipper mediated permeabilization is a conserved mechanism used by bacterial effectors for translocation across target cell membranes.

microbiology↗