Biology subjects

Ma, W.

Publications and source records attributed to Ma, W..

At least 109 records · Page 6Linked to original sources

bioRxiv2024

Human transcription factor combinations mapped by genome-wide footprinting with deaminase

An individuals somatic cells have the same genome but exhibit cell-type-specific transcriptome regulated by a combination of transcription factors (TFs) for each gene. Mapping of TF sites on the human genome is critically important for understanding functional genomics. Here we report a novel technique to measure human TFs binding sites genome-wide with single-base resolution by footprinting with deaminase (FOODIE). Single-molecule sequencing reads from thousands of cells after in situ deamination yielded site-specific TF binding fractions and the cooperativity among adjacent TFs. In a human lymphoblastoid cell line, we found that genes in a correlated gene module (CGM) share TF(s) in their cis-regulatory elements to participate a particular biological function. Finally, single-cell resolved experiments (scFOODIE) allow cell-type-specific TF footprinting in heterogeneous brain tissues.

genomics↗

bioRxiv2024

Potent and broadly neutralizing antibodies against sarbecoviruses elicited by single ancestral SARS-CoV-2 infection

Monoclonal antibody (mAb) therapeutics hold promise for both preventing and treating infectious diseases, especially among vulnerable populations. However, the emergence of various variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presents challenges for current mAb treatments, emphasizing the need for more potent and broadly neutralizing antibodies. In this study, we employed an unbiased screening approach to discover broadly neutralizing antibodies and successfully isolated two mAbs from individuals with only exposure to ancestral SARS-CoV-2. One of these antibodies, CYFN1006-1, exhibited robust cross-neutralization against a spectrum of SARS-CoV-2 variants, including the latest JN.1 and KP.2 variants, with consistent IC50 values ranging from [~]1 to 5 ng/mL. Notably, it also displayed broad neutralization activity against SARS-CoV and related sarbecoviruses, such as WIV1, SHC014, RaTG13, and GD-Pangolin. Structural analysis revealed that these mAbs target shared hotspot but mutation-resistant epitopes, with their Fabs locking the RBD in the "down" conformation through interactions with adjacent Fabs and RBDs, and cross-linking Spike trimers into di-trimers to block viral infection. In vivo studies conducted in a JN.1-infected hamster model validated the protective efficacy of CYFN1006-1, emphasizing its therapeutic potential. These findings suggest that, through meticulous approaches, rare antibodies with cross-neutralization activities against SARS-CoV-2 and related sarbecoviruses can be identified from individuals with exclusively ancestral virus exposure.

microbiology↗

bioRxiv2024

Improving Cell-type-specific 3D Genome Architectures Prediction Leveraging Graph Neural Networks

The mammalian genome organizes into complex three-dimensional structures, where interactions among chromatin regulatory elements play a pivotal role in mediating biological functions, highlighting the significance of genomic region interactions in biological research. Traditional biological sequencing techniques like HiC and MicroC, commonly employed to estimate these interactions, are resource-intensive and time-consuming, especially given the vast array of cell lines and tissues involved. With the advent of advanced machine learning (ML) methodologies, there has been a push towards developing ML models to predict genomic interactions. However, while these models excel in predicting interactions for cell lines similar to their training data, they often fail to generalize across distantly related cell lines or accurately predict interactions specific to certain cell lines. Identifying the potential oversight of excluding example genomic region interaction information from model inputs as a fundamental limitation, this paper introduces GRACHIP, a model rooted in graph neural network technology aiming to address this issue by incorporating detailed interaction information as a hint. Through extensive testing across various cell lines, GRACHIP not only demonstrates exceptional accuracy in predicting chromatin interaction intensity but showcases remarkable generalizability to cell lines not encountered during training. Consequently, GRACHIP emerges as a potent research tool, offering a viable alternative to conventional sequencing methods for analyzing the interactions and three-dimensional organization of mammalian genomes, thus alleviating the dependency on expensive and time-consuming biological sequencing techniques. It also offers an alternative way for researchers to investigate 3D chromatin interactions and simulate their changes in model systems to test their hypotheses.

genomics↗

bioRxiv2024

Control of Inflammatory Response by Tissue Microenvironment

Inflammation is an essential defense response but operates at the cost of normal tissue functions. Whether and how the negative impact of inflammation is monitored remains largely unknown. Acidification of the tissue microenvironment is associated with inflammation. Here we investigated whether macrophages sense tissue acidification to adjust inflammatory responses. We found that acidic pH restructured the inflammatory response of macrophages in a gene-specific manner. We identified mammalian BRD4 as a novel intracellular pH sensor. Acidic pH disrupts the transcription condensates containing BRD4 and MED1, via histidine-enriched intrinsically disordered regions. Crucially, a decrease in macrophage intracellular pH is necessary and sufficient to regulate transcriptional condensates in vitro and in vivo, acting as negative feedback to regulate the inflammatory response. Collectively, these findings uncovered a pH-dependent switch in transcriptional condensates that enables environment-dependent control of inflammation, with a broader implication for calibrating the magnitude and quality of inflammation by the inflammatory cost. HighlightsO_LIAcidic pH regulates a switch-like gene-specific inflammatory response in macrophages C_LIO_LIAcidic pH impacts chromatin remodeling and transcription circuits to control inflammatory programs C_LIO_LIBRD4 transcriptional condensates are regulated by intracellular pH via the histidine-enriched intrinsically disordered region C_LIO_LITissue inflammation decreases intracellular pH and disrupts BRD4 condensates as a negative feedback C_LI

immunology↗

bioRxiv2024

Differential effects of prolonged post-fixation on immunohistochemical and histochemical staining for postmortem human brains

Immunohistochemical (IHC) and histochemical (HC) staining is widely used for human brains post-fixed in formalin and stored in brain banks worldwide for months, years and decades. Understanding the effect of prolonged post-fixation, postmortem interval (PMI) and age on these staining procedures is important for interpreting their outcomes, thus improving diagnosis and research of brain disorders afflicting millions of world populations. In this study, we performed both IHC and HC staining for prefrontal cortex (PFC) of postmortem human brains post-fixed for 1, 5, 10, 15 and 20 years. A negative correlation was detected between the intensity of neuron marker neuron nuclear specific marker (NeuN), microglia marker ionized calcium-binding adaptor molecule 1 (Iba1), cresyl violet (CV) and Luxol fast blue (LFB) staining versus post-fixation durations. By contrast, a positive correlation was seen between the intensity of astrocyte marker glial fibrillary acidic protein (GFAP) and hemaetoxylin and eosin Y (H&E) staining versus post-fixation durations. No correlation was found between the staining intensity of NeuN, GFAP, Iba1, H&E, CV and LFB versus PMI. Moreover, no correlation was seen between NeuN, Iba1, H&E, CV and LFB, except GFAP, versus age. These data suggest that prolonged post-fixation exerts both positive and negative effects, but age and PMI have limited effects, on these IHC and HC parameters. Hence these differential changes need to be considered in interpretation of the results when using tissues with prolonged post-fixation. Furthermore, if feasible, it is recommended to perform IHC and HC staining for human brains with the same post-fixation time windows and to use the most optimal antibodies to offset its impact on downstream analyses.

neuroscience↗

bioRxiv2024

Glutamate (E299) is a key residue in the evolutionarily divergence of the SAM-dependent methyltransferases DnrK and RdmB in anthracycline biosynthesis

A novel sub-class of S-adenosyl-L-methionine (SAM)-dependent methyltransferases catalyze atypical chemical transformations in the biosynthesis of anthracyclines, which include antineoplastic compounds. Intriguingly, the closely related methyltransferases DnrK and RdmB have markedly divergent functions. We investigated their catalytic activities and discovered a previously unknown 10-hydroxylation activity for DnrK and 4-O-methylation activity for RdmB. Isotope-labeling demonstrated that the 10-hydroxy group introduced by DnrK is derived from water molecules while RdmB utilizes O2. A single residue, E299, was the key modulator in the differing catalytic functions of DnrK and RdmB, especially the decarboxylative oxidation activity. Furthermore, the multifunctionality of DnrK was demonstrated to be SAM-tunable and concerted, whereas RdmB activity was cofactor-dependent and stepwise. Our findings expand the versatility and importance of methyltransferases and should aid studies to enrich the structural diversity and bioactivities of anthracyclines.

biochemistry↗

bioRxiv2024

MtrAB two-component system is crucial for the intrinsic resistance and virulence of Mycobacterium abscessus

Mycobacterium abscessus (Mab) poses serious therapeutic challenges, principally due to its intrinsic resistance to a wide array of antibiotics. The pressing issue of drug resistance has spurred an urgent need to explore novel targets and develop new therapeutic agents against Mab. The MtrAB two-component system, conserved among Actinobacteria, is pivotal for regulating various metabolic processes. Nevertheless, the role of MtrAB in Mab remains elusive. In this study, we uncovered that Mab strains with disrupted mtrA, mtrB or both exhibited heightened susceptibility to a variety of antibiotics with diverse mechanisms of action, in contrast to the wild-type strain. In a murine model, rifabutin, bedaquiline, and amikacin, which were inactive against the wild-type Mab strain, demonstrated efficacy against all the mtrA, mtrB and mtrAB knockout strains, significantly reducing pulmonary bacterial burdens compared to vehicle controls after ten days of treatment. Notably, the virulence of all the mtrA, mtrB, and mtrAB knockout strains was highly diminished in the murine model, as evidenced by a substantial decrease in bacterial load in the lungs of mice after 16 days. We observed that all three knockout strains exhibited a significantly reduced growth rate compared to the wild-type strain. We discovered that cells lacking mtrA, mtrB or both exhibited an elongated cell length and had multiple septa, suggesting that both MtrA and MtrB regulate cell division of Mab. Subsequently, an ethidium bromide accumulation assay disclosed that the absence of either mtrA or mtrB or both significantly increased cell envelope permeability. In summary, this study suggests that mtrA and mtrB play an important role in the intrinsic resistance and virulence of Mab by affecting cell division and altering cell permeability. Consequently, MtrA and MtrB represent promising targets for the discovery of anti-Mab drugs. HIGHLIGHTSO_LIKnockout of mtrA, mtrB or mtrAB leads to increased sensitivity of M. abscessus in vitro and in vivo. C_LIO_LIThe mtrA, mtrB or mtrAB knockout M. abscessus strains exhibit highly reduced virulence. C_LIO_LIMtrA and MtrB are potential targets for anti-M. abscessus drug discovery. C_LIO_LIKnockout of mtrA, mtrB or mtrAB results in defective cell division in M. abscessus. C_LI

microbiology↗

bioRxiv2024

Deep learning based genomic breeding of pest-resistant grapevine

Crop pests have profoundly deleterious effects on crop yield and food security. However, conventional pest control depends heavily on the utilization of insecticides, which develops strong pesticide resistance and concerns of food safety. Crop and their wild relatives display diverse levels of pest resistance, indicating the feasibility for breeding of pest-resistant crop varieties. In this study, we integrate deep learning (DL)/machine learning (ML) algorithms, plant phenomics and whole genome sequencing (WGS) data to conduct genomic selection (GS) of pest-resistance in grapevine. We employ deep convolutional neural networks (DCNN) to accurately calculate the severity of damage by pests on grape leaves, which achieves a classification accuracy of 95.3% (Visual Geometry Group 16, VGG16, for binary trait) and a correlation coefficient of 0.94 in regression analysis (DCNN with Pest Damage Score, DCNN-PDS, for continuous trait). We apply DL models to predict and integrate phenotype (both binary and continuous) along with WGS data from 231 grape accessions, conducting Genome-Wide Association Studies (GWAS). This analysis detects a total of 69 QTLs, encompassing 139 candidate genes involved in pathways associated with pest resistance, including jasmonic acid (JA), salicylic acid (SA), ethylene, and other related pathways. Furthermore, through the combination with transcriptome data, we identify specific pest-resistant genes, such as ACA12 and CRK3, which play distinct roles in resisting herbivore attacks. Machine learning-based GS demonstrates a high accuracy (95.7%) and a strong correlation (0.90) in predicting the leaf area damaged by pests as binary and continuous traits in grapevine, respectively. In general, our study highlights the power of DL/ML in plant phenomics and GS, facilitating genomic breeding of pest-resistant grapevine.

plant biology↗

bioRxiv2024

Multivalent 28S rRNA Is the Organizer of the Nucleolus's Multi-layered Architecture

The nucleolus widely exists in all eukaryotic species. Throughout evolution, two types of nucleoli have emerged: bipartite, which has two-layered subcompartments, and tripartite, which features three nested sub-compartments: granular component (GC), dense fibrillar component (DFC), and fibrillar center (FC). FC and DFC form a core-shell architecture and are immersed by a large GC. However, factors that mediated the formation of the three-layered architecture remain largely unknown. Here, we discovered that rRNAs have specific localizations within the nucleolus, with 28S rRNA forming assemblies surrounding the DFC. Multivalent interactions of 28S rRNA drove the formation of the hollow shell structure of DFC, which mediated the development of a three-layered structure resembling nucleolar GC-DFC-FC. Moreover, in organisms with a tripartite nucleolus, 28S rRNA has evolved to acquire a higher degree of multivalency. Our data implies that the emergence of multivalency of 28S rRNA facilitates the transition of bipartite to tripartite nucleolus.

cell biology↗

bioRxiv2024

Reduction in activity and abundance of mitochondrial electron transport chain supercomplexes in pulmonary hypertension-induced right ventricular dysfunction

Pulmonary hypertension (PH) results in RV hypertrophy, fibrosis and dysfunction resulting in RV failure which is associated with impaired RV metabolism and mitochondrial respiration. Mitochondrial supercomplexes (mSC) are assemblies of multiple electron transport chain (ETC) complexes that consist of physically associated complex I, III and IV that may enhance respiration and lower ROS generation. The goal of this study was to determine if mSCs are reduced in RV dysfunction associated with PH. We induced PH in Sprague-Dawley rats by Sugen/Hypoxia (3 weeks) followed by normoxia (4 weeks). Control and PH rats were subjected to echocardiography, blue and clear native-PAGE to assess mSC abundance and activity, and cardiomyocyte isolation to assess mitochondrial reactive oxygen species (ROS). mSC formation was also assessed in explanted human hearts with and without RV dysfunction. RV activity of CI and CIV and abundance of CI, CIII and CIV in mitochondrial mSCs was severely reduced in PH rats compared to control. There were no differences in total CI or CIV activity or abundance in smaller ETC assemblies. There were no changes in both RV and LV of expression of representative ETC complex subunits. PAT, TAPSE and RV Wall thickness significantly correlated with CIV and CI activity in mSC, but not total CI and CIV activity in the RV. Consistent with reduced mSC activity, isolated PH RV myocytes had increased mitochondrial ROS generation compared to control. Reduced mSC activity was also demonstrated in explanted human RV tissue from patients undergoing cardiac transplant with RV dysfunction. The right atrial pressure/pulmonary capillary wedge pressure ratio (RAP/PCWP, an indicator of RV dysfunction) negatively correlated with RV mSC activity level. In conclusion, reduced assembly and activity of mitochondrial mSC is correlated with RV dysfunction in PH rats and humans with RV dysfunction.

pathology↗

bioRxiv2024

High-throughput Screening of Compounds against Autoluminescent Nonreplicating Mycobacterium tuberculosis under Diverse Conditions

The screening of new anti-mycobacterial chemicals is primarily focused on inhibiting the active growing bacteria. However, a major challenge in tuberculosis control is the ability of Mycobacterium tuberculosis to enter a nonreplicating state for extended periods, rendering it resistant to many clinical drugs and complicating eradication efforts. Existing low-oxygen-recovery assays designed for screening compounds targeting nonreplicating M. tuberculosis have limitations, including the colony-forming unit counting for non-luminous M. tuberculosis and the instability of the free plasmid carrying luxAB genes in luminescent M. tuberculosis, along with exogenous substrate requirements for light producing. Moreover, these assays fail to accurately replicate the growth conditions of nonreplicating M. tuberculosis in vitro, thus resulting in less convincing results. To address these challenges, we have developed an autoluminescence-based, cholesterol-enriched culture evaluation model to assess 17 anti-tuberculosis drugs of different classes against nonreplicating M. tuberculosis. Our findings indicate that the relative light unit, measured in real-time, serves as a reliable surrogate marker for colony-forming unit, which typically becomes available one month later. This suggests the utility of our model for the rapid determination of drug susceptibility dynamically. The autoluminescent M. tuberculosis, harbouring luxCDABE gene cluster within its genome, can emit blue-green light stably and autonomously without requiring an external substrate supplement. The minimal inhibitory concentrations of all the drugs tested under anaerobic conditions are significantly different from that detected in aerobic environment. Our model allows for rapid, precise, and efficient assessment of drug activity under anaerobic conditions, thereby enabling a more comprehensive evaluation of anti-mycobacterial efficacy. Overall, our model represents a significant advancement in anti-tuberculosis drug discovery and pharmaceutical development.

microbiology↗

bioRxiv2024

Exo70 promotes herpesvirus secretory vesicle tethering and virion release in an exocyst complex-dependent manner

The exocyst complex, a multisubunit protein complex, mediates secretory vesicles fusion with the plasma membrane (PM) to deliver materials to the cell surface or to release cargoes to the extracellular space, but whether it is related to viral secretory vesicles tethering and virion release is unknown. Here, we identified that the exocyst complex subunit Exo70 promotes the trafficking of herpesvirus secretory vesicles and the release of mature virions in an exocyst complex-dependent manner. Mechanistically, mutation of Exo70 Lys632 and Lys635 diminishes viral secretory vesicles anchoring to PM. Moreover, the small GTPase Rab11a is necessary for the transport of viral secretory vesicles, and the Snapin-Exo70-SNAP23 axis is involved in fusion of viral secretory vesicles to the PM and release of virions. Most significantly, we discovered that Endosidin2 (ES2), an inhibitor of exocytosis via the exocyst complex, provides protection against herpesvirus infection in cells and mice. Overall, these findings unveil a previously uncharacterized role and mechanism of the exocyst complex in viral replication, highlighting its potential as an effective strategy against herpesvirus infection. Author summaryHerpesviruses, such as herpes simplex virus 1 (HSV-1) and bovine herpes virus type 1 (BoHV-1), are highly prevalent pathogens that establish lifelong infections and cause various diseases in humans and animals. While the mechanisms underlying the transport of herpesvirus secretory vesicles from the Golgi to the PM and the subsequent viral release are still poorly understood. In our study, we have discovered that Exo70 promotes the trafficking of HSV-1 and BoHV-1 secretory vesicles and facilitates the release of mature virions in an exocyst complex-dependent manner. Mechanistically, both knockdown of Exo70 and a phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2)-binding-deficient mutant of Exo70 caused virions to be trapped in the cytoplasm and unable to tether to PM, indicating that the binding of Exo70 to PI(4,5)P2 is critical for the docking virus secretory vesicles with PM. Additionally, the Snapin-Exo70-SNAP23 axis plays a pivotal role in the fusion between viral secretory vesicles and the PM, ultimately facilitating the release of virions. We found that Rab11a is necessary for viral secretory vesicle trafficking mediated by Exo70. Most importantly, we discovered that ES2, a transport inhibitor that combines with Exo70 to terminate the final stage of exocytosis via the exocyst complex, can protect cells and mice from -herpesvirus infection.

microbiology↗

bioRxiv2024

Near telomere-to-telomere genome assemblies of two Chlorella species unveil the composition and evolution of centromeres in green algae

BackgroundCentromeres play a crucial and conserved role in cell division, although their composition and evolutionary history in green algae, the evolutionary ancestors of land plants, remains largely unknown. ResultsWe constructed near telomere-to-telomere (T2T) assemblies for two Trebouxiophyceae species, Chlorella sorokiniana NS4-2 and Chlorella pyrenoidosa DBH, with chromosome numbers of 12 and 13, and genome sizes of 58.11 Mb and 53.41 Mb, respectively. We identified and validated their centromere sequences using CENH3 ChIP-seq and found that, similar to humans and higher plants, the centromeric CENH3 signals of green algae display a pattern of hypomethylation. Interestingly, the centromeres of both species largely comprised transposable elements, although they differed significantly in their composition. Species within the Chlorella genus display a more diverse centromere composition, with major constituents including members of the LTR/Copia, LINE/L1, and LINE/RTEX families. This is in contrast to green algae including Chlamydomonas reinhardtii, Coccomyxa subellipsoidea, and Chromochloris zofingiensis, in which centromere composition instead has a pronounced single-element composition. Moreover, we observed significant differences in the composition and structure of centromeres among chromosomes with strong collinearity within the Chlorella genus, suggesting that centromeric sequence evolves more rapidly than sequence in non-centromeric regions. ConclusionsThis study not only provides high-quality genome data for comparative genomics of green algae but gives insight into the composition and evolutionary history of centromeres in early plants, laying an important foundation for further research on their evolution.

genomics↗

bioRxiv2024

Establishment of an Inhalation Administration Noninvasive Murine Model for Rapidly Testing Drug Activity against Mycobacterium tuberculosis

The efficacy of many compounds against Mycobacterium tuberculosis is often limited when administered via conventional oral or injection routes due to suboptimal pharmacokinetic characteristics. Inhalation delivery methods have been investigated to achieve high local therapeutic doses in the lungs. However, previous models, typically employing wild-type M. tuberculosis strains, were intricate, time-consuming, labor-intensive, and with poor repeatability. In this study, we developed an autoluminescence-based inhalation administration model to evaluate drug activity by quantifying relative light units (RLUs) emitted from live mice infected with autoluminescent M. tuberculosis. This novel approach has several improvements: it eliminates the need for anesthesia in mice during administration and simplifies the instrument manipulation; it is cost-effective by utilizing mice instead of larger animals; it shortens time from several months to 16 or 17 days for obtaining result; it is non-invasive by measuring the live RLUs of mice; up to six mice can be administrated daily and simultaneously, even 2-3 times/day; results are relatively objective and repeatable minimizing human factors. Proof-of-concept experiments demonstrated that inhalable rifampicin, isoniazid, and ethambutol showed anti-M. tuberculosis activity at concentrations as low as 0.5, 0.5, and 0.625 mg/mL, respectively, as evidenced by comparing the live RLUs of mice. Furthermore, consistency between RLUs and colony-forming units of the lungs reaffirms the reliability of RLUs as an indicator of drug efficacy, highlighting the potential of this approach for accurately assessing anti-M. tuberculosis activity in vivo. This autoluminescence-based and non-invasive inhalation model offers a substantial reduction in the time, effort, and cost required for evaluating the efficacy of screening new drugs and repurposing old drugs in vivo via inhalation administration.

microbiology↗

bioRxiv2024

Robust Neutralization of SARS-CoV-2 Variants Including JN.1 and BA.2.87.1 by Trivalent XBB Vaccine-Induced Antibodies

Newly emerged SARS-CoV-2 variants like JN.1, and more recently, the hypermutated BA.2.87.1, have raised global concern. We recruited two groups of participants who had BA.5/BF.7 breakthrough infection post three doses of inactivated vaccines: one group experienced subsequent XBB reinfection, while the other received the XBB-containing trivalent WSK-V102C vaccine. Our comparative analysis of their serum neutralization activities revealed that the WSK-V102C vaccine induced stronger antibody responses against a wide range of variants, notably including JN.1 and the highly escaped BA.2.87.1. Furthermore, our investigation into specific mutations revealed that fragment deletions in NTD significantly contribute to the immune evasion of the BA.2.87.1 variant. Our findings emphasize the necessity for ongoing vaccine development and adaptation to address the dynamic nature of SARS-CoV-2 variants.

microbiology↗

bioRxiv2024

The blast effector Pwl2 is a virulence factor that modifies the cellular localisation of host protein HIPP43 to suppress immunity.

The rice blast fungus Magnaporthe oryzae secretes a battery of effector proteins to facilitate host infection. Among these effectors, Pwl2 was first identified as a host specificity determinant for infection of weeping lovegrass (Eragrostis curvula) and is also recognised by the barley Mla3 resistance gene. However, its biological activity is not known. Here we show that PWL2 expression is regulated by the Pmk1 MAP kinase during cell-to-cell movement by M. oryzae at plasmodesmata (PD)-containing pit field sites. Consistent with its regulation, we provide evidence that Pwl2 binds to a barley heavy metal-binding isoprenylated protein HIPP43, which results in its displacement from plasmodesmata. Transgenic barley lines overexpressing either PWL2 or HIPP43 exhibit attenuated immune responses and increased disease susceptibility. By contrast, a Pwl2SNDEYWY mutant that does not interact with HIPP43, fails to alter the PD localisation of HIPP43. Targeted deletion of three copies of PWL2 in M. oryzae results in a{Delta} pwl2 mutant showing gain-of-virulence to weeping lovegrass and barley Mla3 lines, but also a reduction in severity of blast disease on susceptible host plants. Taken together, our results provide evidence that Pwl2 is a virulence factor that acts by suppressing host immunity through perturbing the plasmodesmatal deployment of HIPP43.

plant biology↗

bioRxiv2024

Tumor relapse-free survival prognosis related consistency between cancer tissue and adjacent normal tissue in drug repurposing for solid tumor via connectivity map

Traditional drug discovery encounters challenges, including high costs, time-intensive processes, and inherent risks. Drug repurposing emerges as a compelling alternative strategy to identify new indications for investigational or approved drugs, circumventing these obstacles. Among the various drug repurposing methods, the Disease-specific Signature-based Connectivity Map (Cmap) approach is widely utilized. However, the commonly employed method for constructing disease-specific signatures, known as Differentially Expressed Genes (DEG), faces issues related to inconsistencies between dysregulated genes and the prognosis of genes in tumor tissue, as well as discrepancies in prognosis genes between tumor and normal tissues. In this study, we propose a novel approach, Prognosis Consistency Scoring (PCS), aimed at addressing these inconsistencies. PCS measures the consistency of gene prognosis between tumor and normal tissues by combining the Recurrence-Free Survival (RFS) prognosis power of genes in both contexts. Disease-specific signatures are then constructed based on PCS, and drug repurposing is performed using the Cmap and Lincs Unified Environment (CLUE). Validation of predicted drugs is conducted using data from DrugBank and ClinicalTrials databases. Our findings reveal that the aforementioned inconsistencies are pervasive. Compared to signatures based on DEGs, PCS-based signatures exhibit superior performance, identifying more drugs with higher prediction accuracy, as confirmed by DrugBank annotations. Notably, a significant proportion of predicted drugs without corresponding indications were subsequently validated in the ClinicalTrials database. Additionally, PCS-based signatures demonstrate elevated disease specificity and association with Drug Related Gene (DRG).

bioinformatics↗

bioRxiv2023

Homology detection using a protein secondary structure-based large language model

Detection of homology among proteins is fundamental to understanding protein function. Unfortunately, traditional homology searches using amino acid sequence similarity are limited when numerous amino acid substitutions have accumulated either due to billions of years of evolution or through processes of accelerated change. Recent applications of deep-learning approaches demonstrate that "protein language" models of amino acid sequences can improve the accuracy of the traditional homology searches. Ultimately, the ability to work seamlessly with tertiary structures of proteins will solve the homology detection challenge and provide accompanying insights directly related to function, but to date the use of 3D structures suffers both from data availability and computational bottlenecks. Herein, we present the Protein Secondary Structure Language (ProSSL) model, an efficient encoding of protein secondary structure information in a Transformer-based deep-learning architecture. We conjecture that the secondary protein structure, which is better conserved than primary sequences and much more easily predictable and available than tertiary protein structure, could aid in the task of homology detection. ProSSL has the computational advantages of primary sequence-based homology detection, while also providing important structural information for similarity scoring. Using two case studies of large, diverse viral protein families, we show that the ProSSL model successfully captures patterns of secondary structure arrangements and is effective in detecting homologs either as a pre-trained or fine-tuned model. In both tasks, we accurately detect members of these protein families, including those missed in traditional amino acid similarity searches. We also illustrate how functional insights from the individual ProSSL models could be obtained from the use of the Shapley Additive exPlanations (SHAP) values. Author SummaryWhen DNA is obtained from an organism or an environment, scientists are tasked with determining the functions of the proteins encoded in the genetic material. Such "functional annotation" relies on assigning functions based on the similarity of the proteins to counterparts in databases comprising annotated sequence data. Especially challenging is an ability to recognize similarity in proteins that accumulated a lot of amino acid changes. It is well-known that spatial structure of proteins that share ancestry and perform similar functions evolves much slower than the sequences of the proteins amino acids. Thus, comparison of 3D structures could address this challenge, but the data is still limited to certain classes of proteins, and the requisite computations are expensive. Herein we present a deep-learning model derived from protein secondary structure representation, a symbolic encoding of the way neighboring amino acid residues of a protein interact with each other. Unlike 3D structure, the secondary structure is quickly and accurately predictable from amino acid sequences of proteins. Using two viral proteins as case studies, we demonstrate that our model works well for detection of protein similarity, including identification of very distantly related proteins.

bioinformatics↗