Biology subjects

Zhu, Y.

Publications and source records attributed to Zhu, Y..

At least 433 records · Page 24Linked to original sources

bioRxiv2023

TIAM-1 regulates polarized protrusions during dorsal intercalation in the C. elegans embryo through both its GEF and N-terminal domains

Mediolateral cell intercalation is a morphogenetic strategy used throughout animal development to reshape tissues. Dorsal intercalation in the C. elegans embryo involves the mediolateral intercalation of two rows of dorsal epidermal cells to create a single row that straddles the dorsal midline, and so is a simple model to study cell intercalation. Polarized protrusive activity during dorsal intercalation requires the C. elegans Rac and RhoG orthologs CED-10 and MIG-2, but how these GTPases are regulated during intercalation has not been thoroughly investigated. In this study, we characterize the role of the Rac-specific guanine nucleotide exchange factor (GEF), TIAM-1, in regulating actin-based protrusive dynamics during dorsal intercalation. We find that TIAM-1 can promote protrusion formation through its canonical GEF function, while its N-terminal domains function to negatively regulate this activity, preventing the generation of ectopic protrusions in intercalating cells. We also show that the guidance receptor UNC-5 inhibits ectopic protrusive activity in dorsal epidermal cells, and that this effect is in part mediated via TIAM-1. These results expand the network of proteins that regulate basolateral protrusive activity during directed cell rearrangement. Summary statementTIAM-1 activates the Rac pathway to promote protrusion formation via its GEF domain, while its N-terminal domains suppress ectopic protrusions during dorsal intercalation in the C. elegans embryo.

developmental biology↗

bioRxiv2023

A Phase Separation-Fortified Bi-Specific Adaptor for Conditional Tumor Killing

A common approach in the development of therapeutic proteins is the use of synthetic ligands with multivalency, allowing for sophisticated control of signal transduction. Leveraging the emerging concept of liquid-liquid phase separation (LLPS) and its ability to organize cell surface receptors into functional compartments, we herein have designed modular ligands with phase-separation modalities to engineer programmable interreceptor communications and precise control of signal pathways, thus inducing the rapid, potent, and specific apoptosis of tumor cells. Despite their simplicity, these "triggers", named phase-separated Tumor Killers (hereafter referred to as psTK), are sufficient to yield interreceptor clustering of death receptors (represented by DR5) and tumor-associated receptors, with the following features: LLPS-mediated robust high-order organization, well-choreographed conditional activation, and broad-spectrum capacity for potently inducing apoptosis of tumor cells. The development of novel therapeutic proteins with phase-separation modalities showcases the power of spatially reorganizing signal transduction. This approach enables the branching of cell fate and holds promising potential for targeted therapies against challenging tumors. One-Sentence SummaryEngineered modular ligands with phase-separation modalities can drive lethal dialog with tumor cells.

bioengineering↗

bioRxiv2023

DeepETPicker: Fast and accurate 3D particle picking for cryo-electron tomography using weakly supervised deep learning

Picking particles of biological macromolecules from their cryo-electron tomograms is critical to solving their 3D structures in situ. To reach sub-nanometre resolution, large numbers of particles often need to be picked, a laborious and time-consuming task if performed manually. To date, however, the adoption of automated particle-picking methods remains limited because of the limitations in their accuracy, processing speed and, for those based on learning models, manual annotation cost. To overcome the limitations, we develop DeepETPicker, a deep learning model for fast and accurate picking of 3D particles from cryo-electron tomograms. The training of DeepETPicker requires only weak supervision with low numbers of simplified Gaussian-type labels, reducing the burden of manual annotation of tomograms under very low signal-to-noise ratios. The simplified labels combined with the customized and lightweight model architecture of DeepETPicker as well as GPU-accelerated pooling enable substantially improved accuracy and accelerated processing speed. When tested on simulated as well as real tomograms, DeepETPicker outperforms the competing state-of-the-art methods by achieving the highest overall accuracy and speed, which translate into better quality of picked particles and higher resolutions of final reconstruction maps. DeepETPicker is provided in open source with a user-friendly interface to support automated particle picking for high-resolution cryo-electron tomography in situ.

bioinformatics↗

bioRxiv2023

Augmented Super-Resolution Radial Fluctuations (aSRRF) Pushing the Limits of Structured Illumination Microscopy

Structured illumination microscopy (SIM) is a versatile super-resolution technique known for its compatibility with a wide range of probes and fast implementation. While 3D SIM is capable of achieving a spatial resolution of [~]120 nm laterally and [~]300 nm axially, attempting to further enhance the resolution through methods such as nonlinear SIM or 4-beam SIM introduces complexities in optical configurations, increased phototoxicity, and reduced temporal resolution. Here, we have developed a novel method that combines SIM with augmented super-resolution radial fluctuations (aSRRF) utilizing a single image through image augmentation. By applying aSRRF reconstruction to SIM images, we can enhance the SIM resolution to [~]50 nm isotopically, without requiring any modifications to the optical system or sample acquisition process. Additionaly, we have incorporated the aSRRF approach into an ImageJ plugin and demonstrated its versatility across various fluorescence microscopy images, showcasing a remarkable two-fold resolution increase.

cell biology↗

bioRxiv2023

T4SEpp: a pipeline integrated with protein language models effectively predicting bacterial type IV secreted effectors

Many pathogenic bacteria use type IV secretion systems(T4SSs) to deliver effectors (T4SEs) into the cytoplasm of eukaryotic cells, causeing diseases. The identification of effectors is a crucial step in understanding the mechanisms of bacterial pathogenicity, but this remains a major challenge. In this study, we used the full-length embedding features generated by six pre-trained protein language models to train classifiers predicting T4SEs, and compared their performance. An integrated model T4SEpp was assembled by a module searching full-length, signal sequence and effector domain homologs of known T4SEs, a machine learning module based on the hand-crafted features extracted from the signal sequences, and the third module containing three best-performing protein language pre-trained models. T4SEpp outperformed the other state-of-the-art (SOTA) software tools, achieving [~]0.95 sensitivity at a high specificity of [~]0.99, based on the assessment of an independent testing dataset. Additionally, we performed a comprehensive search among 8,761 bacterial species, leading to the discovery of 227 species belonging to 3 phyla and 117 genera that possess T4SSs. Furthermore, leveraging the power of T4SEpp, we successfully identified a grand total of 12,622 plausible T4SEs. Overall, T4SEpp provides a better solution to assist in the identification of bacterial T4SEs, and facilitates studies of bacterial pathogenicity. T4SEpp is freely accessible at https://bis.zju.edu.cn/T4SEpp.

bioinformatics↗

bioRxiv2023

Unravelling Biosynthesis and Biodegradation Potentials of Microbial Dark Matters in Hypersaline Lakes

Biosynthesis and biodegradation of microorganisms critically underpin the development of biotechnology, new drugs and therapies, and environmental remediation. However, the vast majority of uncultured microbial species along with their metabolic capacities in extreme environments remain obscured. To unravel the metabolic potentials of these microbial dark matters (MDMs), we investigated four deep-inland hypersaline lakes with largely diversified environmental parameters in Xinjiang Uygur Zizhiqu, China. Metagenomic binning obtained 3,030 metagenome-assembled genomes (MAGs) spanning 82 phyla, of which 2,363 MAGs could not be assigned to a known genus. These unknown MAGs were abundantly observed with distinct taxa among lakes, possibly linked to the diversification of physiochemical conditions. Analysis of biosynthetic potentials identified 9,635 biosynthesis gene clusters (BGCs), of which 9,403 BGCs were considered novel. We found that some MAGs from putatively novel phyla consistently comprised enriched BGCs, which may have substantial potentials in biotechnological applications. In addition, biodegradation potentials such as dehalogenation, anaerobic ammonium oxidation (Anammox), polycyclic aromatic hydrocarbon (PAH), and plastic degradation were found in new microbial clades from hypersaline lakes. These findings substantially expanded the genetic repository of biosynthesis and biodegradation potentials, which can further assist the development of new and innovative applications in biotechnology.

microbiology↗

bioRxiv2023

Cell Type- and Tissue-specific Enhancers in Craniofacial Development

The genetic basis of craniofacial birth defects and general variation in human facial shape remains poorly understood. Distant-acting transcriptional enhancers are a major category of non-coding genome function and have been shown to control the fine-tuned spatiotemporal expression of genes during critical stages of craniofacial development1-3. However, a lack of accurate maps of the genomic location and cell type-specific in vivo activities of all craniofacial enhancers prevents their systematic exploration in human genetics studies. Here, we combined histone modification and chromatin accessibility profiling from different stages of human craniofacial development with single-cell analyses of the developing mouse face to create a comprehensive catalogue of the regulatory landscape of facial development at tissue- and single cell-resolution. In total, we identified approximately 14,000 enhancers across seven developmental stages from weeks 4 through 8 of human embryonic face development. We used transgenic mouse reporter assays to determine the in vivo activity patterns of human face enhancers predicted from these data. Across 16 in vivo validated human enhancers, we observed a rich diversity of craniofacial subregions in which these enhancers are active in vivo. To annotate the cell type specificities of human-mouse conserved enhancers, we performed single-cell RNA-seq and single-nucleus ATAC-seq of mouse craniofacial tissues from embryonic days e11.5 to e15.5. By integrating these data across species, we find that the majority (56%) of human craniofacial enhancers are functionally conserved in mice, providing cell type- and embryonic stage-resolved predictions of their in vivo activity profiles. Using retrospective analysis of known craniofacial enhancers in combination with single cell-resolved transgenic reporter assays, we demonstrate the utility of these data for predicting the in vivo cell type specificity of enhancers. Taken together, our data provide an expansive resource for genetic and developmental studies of human craniofacial development. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=138 HEIGHT=200 SRC="FIGDIR/small/546603v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@7595a9org.highwire.dtl.DTLVardef@1b48b81org.highwire.dtl.DTLVardef@32fe86org.highwire.dtl.DTLVardef@1e41fed_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2023

Intrinsically disordered CsoS2 acts as a general molecular thread for α-carboxysome shell assembly

Carboxysomes are a paradigm of self-assembling proteinaceous organelles found in nature, offering compartmentalisation of enzymes and pathways to enhance carbon fixation. In -carboxysomes, the disordered linker protein CsoS2 plays an essential role in carboxysome assembly and Rubisco encapsulation. Its mechanism of action, however, is not fully understood. Here we synthetically engineered -carboxysome shells using minimal shell components and determined cryoEM structures of these to decipher the principle of shell assembly and encapsulation. The structures reveal that the intrinsically disordered CsoS2 C-terminus is well-structured and acts as a universal "molecular thread" stitching through multiple shell protein interfaces. We further uncovered in CsoS2 a remarkable highly conserved repetitive key interaction motif, [IV]TG, which is critical to the shell assembly and architecture. Our study provides a general mechanism for the CsoS2-govern carboxysome shell assembly and cargo encapsulation and further advances synthetic engineering of carboxysomes for diverse biotechnological applications.

microbiology↗

bioRxiv2023

Inhibition of Retinoic Acid Signaling in Proximal Tubular Epithelial cells Protects against Acute Kidney Injury by Enhancing Kim-1-dependent Efferocytosis

Retinoic acid receptor (RAR) signaling is essential for mammalian kidney development, but in the adult kidney is restricted to occasional collecting duct epithelial cells. We now show there is widespread reactivation of RAR signaling in proximal tubular epithelial cells (PTECs) in human sepsis-associated acute kidney injury (AKI), and in mouse models of AKI. Genetic inhibition of RAR signaling in PTECs protects against experimental AKI but is associated with increased expression of the PTEC injury marker, Kim-1. However, Kim-1 is also expressed by de-differentiated, proliferating PTECs, and protects against injury by increasing apoptotic cell clearance, or efferocytosis. We show that the protective effect of inhibiting PTEC RAR signaling is mediated by increased Kim-1 dependent efferocytosis, and that this is associated with de-differentiation, proliferation, and metabolic reprogramming of PTECs. These data demonstrate a novel functional role that reactivation of RAR signaling plays in regulating PTEC differentiation and function in human and experimental AKI. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/545113v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@140ba6borg.highwire.dtl.DTLVardef@8f02f0org.highwire.dtl.DTLVardef@10a123eorg.highwire.dtl.DTLVardef@33b564_HPS_FORMAT_FIGEXP M_FIG C_FIG

pathology↗

bioRxiv2023

Identifying gastric cancer molecular subtypes by integrating DNA-based hierarchical classification strategy and clinical stratification

BackgroundMolecular subtyping has been introduced to better understand the genetic landscape of gastric cancer (GC), but current subtyping methods only had limited success because of the mixed use of molecular features, a lack of strategy optimization, and the limited availability of GC samples. The community urgently calls for a precise, and easily adoptable subtyping method to enable DNA-based early screening and treatment. MethodsBased on TCGA subtypes, we developed a novel classifier, termed Hierarchical DNA-based Classifier for Gastric Cancer Molecular Subtyping (HCG), leveraging all DNA-level alterations as predictors, including gene mutations, copy number aberrations and methylations. By adding the closely related esophageal adenocarcinomas (EA) dataset, we expanded the TCGA GC dataset for training and testing HCG (n=453). We optimized HCG with three hierarchical strategies evaluated by their overall accuracy using Lasso-Logistic regression, and by their clinical stratification capacity using multivariate survival analysis. We used difference tests to identify subtype-specific DNA alteration biomarkers based on HCG defined subtypes. ResultsOur HCG classifier achieved an overall AUC score of 0.95 and significantly improved the clinical stratification of patients (overall p-value=0.032). 25 subtype-specific DNA alterations were identified by difference tests, including high level of mutations in SYNE1, ITGB4 and COL22A1 genes for the MSI subtype, high level of methylations of ALS2CL, KIAA0406 and RPRD1B genes for the EBV subtype. ConclusionsHCG is an accurate and robust classifier for DNA-based GC molecular subtyping with high-performing clinical stratification capacity. The training and test datasets and analysis programs of HCG are available at https://github.com/labxscut/HCG.

bioinformatics↗

bioRxiv2023

Structural insight into CD93 recognition by IGFBP7

The CD93/IGFBP7 axis are key factors expressed in endothelial cells (EC) that mediate EC angiogenesis and migration. Upregulation of them contributes to tumor vascular abnormality and blockade of this interaction promotes a favorable tumor microenvironment for therapeutic interventions. However, how these two proteins associated to each other remains unclear. In this study, we solved the human CD93-IGFBP7 complex structure to elucidate the interaction between the EGF1 domain of CD93 and the IB domain of IGFBP7. Mutagenesis studies confirmed the binding interactions and specificities. Cellular and mouse tumor studies demonstrated the physiological relevance of the CD93-IGFBP7 interaction in EC angiogenesis. Our study provides hints for development of therapeutic agents to precisely disrupt unwanted CD93-IGFBP7 signaling in the tumor microenvironment. Additionally, analysis of the CD93 full-length architecture provides insights into how CD93 protrudes on the cell surface and forms a flexible platform for binding to IGFBP7 and other ligands.

cancer biology↗

bioRxiv2023

CRISPR-Cas12a-Based Rapid and Sensitive Detection of rpoBL378R in Mycobacterium tuberculosis

Rifampin is the most effective drug in the treatment of tuberculosis, whose major pathogen is Mycobacterium tuberculosis (MTB), whereas there are still certain MTB strains resistant to the therapy of rifampin. The rpoB mutations play a central role in MTB resistance to the rifampin therapy, so it is crucial to identify these mutations in order to discover novel therapeutic approaches to these drug-resistant MTB strains. Here we show that a CRISPR-Cas12a-based detection platform with recombinase polymerase amplification and fluorescence reporter can be utilized to detect and visualize an MTB drug-resistant point mutation (rpoBL378R) from its rpoB wild type. Notably, this detection system is highly specific because it did not cross-react with contrived reference samples containing the genomes of MTB H37Rv, Mycobacterium smegmatis (M. smegmatis), Mycobacterium aureus (M. aureus), and Escherichia coli (E. coli). Collectively, this strategy based on CRISPR-Cas12a that we show in this report is simple, sensitive as well as specific for detection of the rifampin-resistant MTB H37Rv with the rpoBL378R mutation, indicating that this CRISPR-Cas12a-based detection platform has high potential to be exploited for clinic application to identify MTB mutations.

microbiology↗

bioRxiv2023

High-throughput mRNA-seq atlas of human placenta shows vast transcriptome remodeling from first to third trimester

BackgroundThe placenta, composed of chorionic villi, changes dramatically across gestation. Understanding differences in ongoing pregnancies are essential to identify the role of chorionic villi at specific times in gestation and develop biomarkers and prognostic indicators of maternal- fetal health. MethodsThe normative mRNA profile is established using next-generation sequencing of 124 first trimester and 43 third trimester human placentas from ongoing healthy pregnancies. Stably expressed genes not different between trimesters and with low variability are identified. Differential expression analysis of first versus third trimester adjusted for fetal sex is performed, followed by a subanalysis with 23 matched pregnancies to control for subject variability using the same genetic and environmental background. ResultsPlacenta expresses 14,979 mRNAs above sequencing noise (TPM>0.66), with 1,545 stably expressed genes across gestation. Differentially expressed genes account for 86.7% of genes in the full cohort (FDR<0.05). Fold changes highly correlate between the full cohort and subanalysis (Pearson = 0.98). At stricter thresholds (FDR<0.001, fold change>1.5), there are 6,941 differentially expressed protein coding genes (3,206 upregulated in first and 3,735 upregulated in third trimester). ConclusionThis is the largest mRNA atlas of healthy human placenta across gestation, controlling for genetic and environmental factors, demonstrating substantial changes from first to third trimester in chorionic villi. Specific differences and stably expressed genes may be used to understand the specific role of the chorionic villi throughout gestation and develop first trimester biomarkers of placental health that transpire across gestation, which can be used for future development of biomarkers in maternal-fetal disease.

developmental biology↗

bioRxiv2023

Haplotype-resolve genome assembly and resequencing provide insights into the origin and domestication of modern rose

Modern rose (Rosa hybrida) is a recently formed interspecific hybrid and has become one of the most important and widely cultivated ornamentals. Here, we report the haplotype-resolved chromosome-scale genome assembly of the tetraploid R. hybrida Samantha and a genome variation map of 233 Rosa accessions involving various wild species, and old and modern cultivars. The two subgenomes of Samantha show no significant global bias in gene loss but substantial expression bias, and homoeologous exchanges are frequently observed between subgenomes. Population genomic and genomic composition analyses reveal the contributions of wild Rosa species to modern roses, and highlight that R. odorata and its derived cultivars contribute more to modern roses than R. chinensis Old Blush. Furthermore, selective sweeps during modern rose breeding associated with major agronomic traits, including continuous flowering, floral organ identity, flower senescence, and disease resistance, are identified. This study provides insights into the genetic basis of modern rose origin and breeding history, and offers unprecedented genomic resources for rose improvement.

genomics↗

bioRxiv2023

A furin-deficient HEK293 cell line suggests a role for furin trafficking in the intoxication pathway of recombinant immunotoxins based on Pseudomonas exotoxin A

Furin is a mammalian serine protease with important roles in cellular homeostasis and disease. It cleaves and activates numerous endogenous and exogenous substrates, including the SARS-CoV-2 viral spike protein and protein toxins such as diphtheria toxin and Pseudomonas exotoxin A (PE). Recombinant immunotoxins (RITs) are toxin conjugates used as cancer therapeutics that connect tumor-directed antibodies with toxins for targeted cell killing. RITs based on PE have shown success in treating a variety of cancers, but often suffer from safety and efficacy concerns when used clinically. We have explored furin as a potential limiting factor in the intoxication pathway of PE-based RITs. Although the furin has widely recognized importance in RIT intoxication, its role is incompletely understood. Circumstantial evidence suggests that furin may act as a transporter for RITs in addition to its role of activation by cleavage. Here, we describe the creation of a CRISPR-engineered furin-deficient HEK293 cell line, {Delta}Fur293. Using {Delta}Fur293 and derivatives that express mutant forms of furin, we confirm the importance of furin in the PE RIT intoxication pathway and show that furin trafficking has a significant impact on RIT efficacy. Our data support the hypothesis that furin acts as a transporter during RIT intoxication, and suggest furin as a target to improve the effectiveness of RITs.

molecular biology↗

bioRxiv2023

In-cell structural insight into the stability of sperm microtubule doublet

The propulsion for mammalian sperm swimming is generated by flagella beating. Microtubule doublets (DMTs) along with microtubule inner proteins (MIPs) are essential structural blocks of flagella. However, the intricate molecular architecture of sperm DMT remains elusive. Here, by in situ cryo-electron tomography, we solved the in-cell structure of mouse sperm DMT up to 3.6 [A] resolution and built its model with 36 kinds of MIPs in 48 nm periodicity. We identified multiple copies of Tektin5 that reinforce Tektin bundle, and multiple MIPs with different periodicities that anchor the Tektin bundle to tubulin wall. This architecture contributes to a superior stability of A-tubule than B-tubule of DMT, which was revealed by structural comparison of DMTs from the intact and deformed axonemes. Our work provides an overall molecular picture of sperm DMT that is essential to understand the molecular mechanism of sperm motility as well as the related ciliopathies.

cell biology↗

bioRxiv2023

ULDNA: Integrating Unsupervised Multi-Source Language Models with LSTM-Attention Network for Protein-DNA Binding Site Prediction

Accurate identification of protein-DNA interactions is critical to understand the molecular mechanisms of proteins and design new drugs. We proposed a novel deeplearning method, ULDNA, to predict DNA-binding sites from protein sequences through a LSTM-attention architecture embedded with three unsupervised language models pretrained in multiple large-scale sequence databases. The method was systematically tested on 1287 proteins with DNA-binding site annotation from Protein Data Bank. Experimental results showed that ULDNA achieved a significant increase of the DNA-binding site prediction accuracy compared to the state-of-the-art approaches. Detailed data analyses showed that the major advantage of ULDNA lies in the utilization of three pre-trained transformer language models which can extract the complementary DNA-binding patterns buried in evolution diversity-based feature embeddings in residue-level. Meanwhile, the designed LSTM-attention network could further enhance the correlation between evolution diversity and protein-DNA interaction. These results demonstrated a new avenue for high-accuracy deep-learning DNA-binding site prediction that is applicable to large-scale protein-DNA binding annotation from sequence alone.

molecular biology↗

bioRxiv2023

ChAdOx1 COVID vaccines express RBD open prefusion SARS-CoV-2 spikes on the cell surface

Vaccines against SARS-CoV-2 have been proven to be an effective means of decreasing COVID-19 mortality, hospitalization rates, and transmission. One of the vaccines deployed worldwide is ChAdOx1 nCoV-19, which uses an adenovirus vector to drive the expression of the original SARS-CoV-2 spike on the surface of transduced cells. Using cryo-electron tomography and subtomogram averaging, we determined the native structures of the vaccine product expressed on cell surfaces in situ. We show that ChAdOx1-vectored vaccines expressing the Beta SARS-CoV-2 variant produce abundant native prefusion spikes predominantly in one-RBD-up conformation. Furthermore, the ChAdOx1 vectored HexaPro stabilized spike yields higher cell surface expression, enhanced RBD exposure, and reduced shedding of S1 compared to the wild-type. We demonstrate in situ structure determination as a powerful means for studying antigen design options in future vaccine development against emerging novel SARS-CoV-2 variants and broadly against other infectious viruses.

microbiology↗