Search bioRxiv⌕ Search

Biology subjects

Cao, Y.

Publications and source records attributed to Cao, Y..

At least 361 records · Page 20Linked to original sources

Plasticity of cell migration resulting from mechanochemical coupling

Eukaryotic cells can migrate using different modes, ranging from amoeboid-like, during which actin filled protrusions come and go, to keratocyte-like, characterized by a stable morphology and persistent motion. How cells can switch between these modes is still not well understood but waves of signaling events on the cell cortex are thought to play an important role in these transitions. Here we present a simple two component biochemical reaction-diffusion model based on relaxation oscillators and couple this to a model for the mechanics of cell deformations. Different migration modes, including amoeboid-like and keratocyte-like, naturally emerge through phase transitions determined by interactions between biochemical traveling waves, cell mechanics and morphology. The model predictions are explicitly verified by systematically reducing the protrusive force of the actin network in experiments using wild-type Dictyostelium discoideum cells. Our results indicate the importance of coupling signaling events to cell mechanics and morphology and may be applicable in a wide variety of cell motility systems.

biophysics↗

Genotype 1 Japanese encephalitis virus predominates in nature in China

IntroductionJapanese encephalitis virus (JEV), in the genus Flavivirus, family Flaviviridae, is the leading cause of viral encephalitis in the Asian-Pacific region. JEV has a wide range of vector hosts, including mosquitoes, swine, and wading birds. Culex species, especially Culex tritaeniorhynchus, are the main vectors for JEV transmission. JEV has been classified into five genotypes (G1-G5). JEV G1, G3, and G5 isolates have been found in China.\n\nMethodsMore than 200,000 mosquitoes collected in 14 provinces in China from 2004 to 2016 were examined for JEV using a TaqMan real-time RT-PCR assay. The JEV envelope (E) gene was sequenced from positive pools. The nucleic acid sequences were analyzed and aligned using ClustalX ver. 2.0. Representative JEV envelope (E) gene sequences were downloaded from GenBank and compared with the newly obtained JEV sequences. MEGA 5.05 was used to generate a phylogenetic tree based on the JEV sequences.\n\nResultsMore than 200,000 mosquitoes were divided into 3107 pools to test for JEV. Of the pools, 9.04% (281/3107) were positive. The JEV obtained from mosquitoes included three genotypes (G1, G3, and G5). JEV G1 was detected from different provinces during 2004-2016. G1 was the dominant genotype circulating in nature, comprising 98.93% (278/281). JEV G3 was detected in Yunnan and Chongqing Provinces before 2010; JEV G5 was detected only in Tibet. No pools were positive for JEV G2 and G4. C. tritaeniorhynchus was the major mosquito species and the principal vector for transmitting JEV in China. The results of the TaqMan real-time RT-PCR assay and phylogenetic analysis consistently indicated that all 50 newly identified JEV sequences belonged to JEV G1.\n\nConclusionG1 is the main genotype of JEV circulating in nature in China. Some G3 and G5 were found, but no G2 or G4.\n\nAuthor summaryJapanese encephalitis virus (JEV) is a member of the genus Flavivirus, family Flaviviridae and is the major pathogen agent of Japanese encephalitis (JE) in the Asian-Pacific region. The fatality rate of JE is 20-30%. JEV consists of five genotypes (G1-G5). The predominant genotype was G3 before the 20thcentury. G1 and G3 co-circulated in China at the end of the 20thand early 21stcentury. JEV G1 is the youngest genotype and has gradually been found in many areas worldwide. Using a sensitive TaqMan real-time RT-PCR assay, this study examined 3107 pools of mosquito. The main genotype of Japanese encephalitis virus in China was G1, with some G3 and G5, but no G2 or G4. C. tritaeniorhynchus was the major mosquito species and the principal vector for transmitting JEV in China. TaqMan real-time RT-PCR assay and phylogenetic analysis consistently indicated that all 50 newly identified JEV sequences belonged to JEV G1.

molecular biology↗

A chemical counterpunch: Chromobacterium violaceum ATCC31532 produces violacein in response to translation-inhibiting antibiotics

Bacterially produced antibiotics play important roles in microbial interactions and competition. Antibiosis can induce resistance mechanisms in target organisms and may induce other countermeasures as well. Here, we show that hygromycin A from Streptomyces sp. 2AW induces Chromobacterium violaceum ATCC31532 to produce the purple antibiotic violacein. Sublethal doses of other antibiotics that similarly target the polypeptide elongation step of translation likewise induced violacein production, unlike antibiotics with different targets. C. violaceum biofilm formation and virulence against Drosophila melanogaster were also induced by translation-inhibiting antibiotics, and we identified an antibiotic-induced response (air) two-component regulatory system that is required for these responses. Genetic analyses indicated a connection between the Air system, quorum-dependent signaling, and the negative regulator VioS, leading us to propose a model for induction of violacein production. This work suggests a novel mechanism of interspecies interaction in which a bacterium produces an antibiotic in response to inhibition by another bacterium.

microbiology↗

Characterization of pathology-inducing α-synuclein species from human diseased brain tissue

Synucleinopathies are a group of neurodegenerative diseases characterized by the presence of pathological accumulations of misfolded, phosphorylated -synuclein (Syn) protein. Multiple lines of evidence indicate that synucleinopathy disease progression is driven by a prion-like process of transmission of a pathologic form of Syn. One potential therapeutic approach to prevent cell-to-cell propagation is to target this transmissible species with selective antibodies. In this study, a rodent primary neuronal culture reporter system was developed to monitor induction of detergent-insoluble, phosphorylated (pS129) aggregates of Syn. Induction of pS129 Syn pathology was observed with both synthetic Syn fibrils (PFFs) and brain lysates from multiple system atrophy (MSA) patients but not Syn monomers or human brain lysate controls. The induction-competent species in MSA lysates could be enriched by high-speed centrifugation suggesting that it is present as a high molecular weight aggregate. Furthermore, samples derived from brain lysates from Parkinsons disease (PD) and Dementia with Lewy Bodies (DLB) patients also induced pS129 Syn pathology, but required longer incubation times. Lastly, the potential of Syn selective antibodies to immunodeplete induction-competent forms of Syn from both PFF and synucleinopathy brain samples is described. The results demonstrate that antibodies targeting the C-terminal of Syn are most effective for immunodepletion of pathology-inducing forms of Syn from samples derived from human synucleinopathy brains. Furthermore, the data support the hypothesis that antibodies that recognize a C-terminal epitope and exhibit selectivity for oligomeric forms over monomeric forms of Syn represent a desirable target for immunotherapy for synucleinopathy patients.

neuroscience↗

Chemokine signaling links cell cycle progression and cilia formation for left-right symmetry breaking

Zebrafish dorsal forerunner cells (DFCs) undergo vigorous proliferation during epiboly and then exit cell cycle to generate Kupffers vesicle (KV), a ciliated organ necessary for establishing left-right (L-R) asymmetry. DFC proliferation defects are often accompanied by impaired cilia elongation in KV, but the functional and molecular interaction between cell-cycle progression and cilia formation remains unknown. Here we show that chemokine receptor Cxcr4a is required for L-R laterality by controlling DFC proliferation and KV ciliogenesis. Functional analysis revealed that Cxcr4a accelerates G1/S transition in DFCs and stabilizes Foxj1a, a master regulator of motile cilia, by stimulating Cyclin D1 expression through ERK1/2 signaling. Mechanistically, Cyclin D1-CDK4/6 drives G1/S transition during DFC proliferation and phosphorylates Foxj1a, thereby disrupting its association with Psmd4b, a 19S regulatory subunit. This prevents the ubiquitin-independent proteasomal degradation of Foxj1a. Our study uncovers a role for Cxcr4 signaling in L-R patterning and provides fundamental insights into the molecular linkage between cell-cycle progression and ciliogenesis.\n\nAuthor summaryDuring the organogenesis of zebrafish L-R organizer named KV, DFCs proliferate rapidly during epiboly and then exit the cell cycle to differentiate into ciliated epithelial KV cells. Cell cycle defects in DFCs are often accompanied by an alteration in KV cilia elongation. However, whether the cell cycle and cilia formation are mechanistically linked remains as an open question. In this study, we report that Cxcr4 signaling is required for DFC proliferation and KV ciliogenesis. We reveal that Cxcl12b/Cxcr4a signaling activates ERK1/2, which then promotes Cyclin D1 expression. Cyclin D1-CDK4/6 accelerates the G1/S transition in DFCs, while also facilitates cilia formation via stabilization of Foxj1a. Notably, Foxj1 undergoes proteasomal degradation via Ub-independent pathway during KV organogenesis. Our study further demonstrates that CDK4 phosphorylates and stabilizes Foxj1a by disrupting its association with Psmd4b, a 19S regulatory subunit. In summary, Cxcl12b/Cxcr4a chemokine signaling links cell cycle progression and cilia formation for L-R symmetry breaking via regulating Cyclin D1 expression.

developmental biology↗

Massive computational acceleration by using neural networks to emulate mechanism-based biological models

Mechanism-based mathematical models are the foundation for diverse applications. It is often critical to explore the massive parametric space for each model. However, for many applications, such as agent-based models, partial differential equations, and stochastic differential equations, this practice can impose a prohibitive computational demand. To overcome this limitation, we present a fundamentally new framework to improve computational efficiency by orders of magnitude. The key concept is to train an artificial neural network using a limited number of simulations generated by a mechanistic model. This number is small enough such that the simulations can be completed in a short time frame but large enough to enable reliable training of the neural network. The trained neural network can then be used to explore the system dynamics of a much larger parametric space. We demonstrate this notion by training neural networks to predict self-organized pattern formation and stochastic gene expression. With this framework, we can predict not only the 1-D distribution in space (for partial differential equation models) and probability density function (for stochastic differential equation models) of variables of interest with high accuracy, but also novel system dynamics not present in the training sets. We further demonstrate that using an ensemble of neural networks enables the self-contained evaluation of the quality of each prediction. Our work can potentially be a platform for faster parametric space screening of biological models with user defined objectives.

systems biology↗

Flower-like patterns in multi-species biofilms

Diverse interactions among species within bacterial biofilms often lead to intricate spatiotemporal dynamics. The spatial structure of biofilms can determine growth and survival of different species, but the mechanisms driving formation of this structure are not fully understood. Here, we describe the emergence of complex structures in a biofilm grown from mixtures of motile and non-motile bacterial species on a soft agar surface. Time-lapse imaging shows that non-motile bacteria "hitchhike" on the motile bacteria as the latter migrate outward. The non-motile bacteria accumulate at the boundary of the colony and trigger an instability that leaves behind striking flower-like patterns. The mechanism of the front instability governing this pattern formation is elucidated by a mathematical model for the frictional motion of the colony interface, with friction depending on the local concentration of the nonmotile species along the interface. A more elaborate two-dimensional phase-field model that explicitly accounts for the interplay between growth, mechanical stress from the motile species, and friction provided by the non-motile species, fully reproduces the observed flower-like patterns.

microbiology↗

Predicting Pathogenicity of Missense Variants with Weakly Supervised Regression

Quickly growing genetic variation data of unknown clinical significance demand computational methods that can reliably predict clinical phenotypes and deeply unravel molecular mechanisms. On the platform enabled by CAGI (Critical Assessment of Genome Interpretation), we develop a novel "weakly supervised" regression (WSR) model that not only predicts precise clinical significance (probability of pathogenicity) from inexact training annotations (class of pathogenicity) but also infers underlying molecular mechanisms in a variant-specific fashion. Compared to multi-class logistic regression, a representative multi-class classifier, our kernelized WSR improves the performance for the ENIGMA Challenge set from 0.72 to 0.97 in binary AUC (Area Under the receiver operating characteristic Curve) and from 0.64 to 0.80 in ordinal multi-class AUC. WSR model interpretation and protein structural interpretation reach consensus in corroborating the most probable molecular mechanisms by which some pathogenic BRCA1 variants confer clinical significance, namely metal-binding disruption for C44F and C47Y, protein-binding disruption for M18T, and structure destabilization for S1715N.

bioinformatics↗

Bayesian Active Learning for Optimization and Uncertainty Quantification in Protein Docking

MotivationAb initio protein docking represents a major challenge for optimizing a noisy and costly "black box"-like function in a high-dimensional space. Despite progress in this field, there is no docking method available for rigorous uncertainty quantification (UQ) of its solution quality (e.g. interface RMSD or iRMSD). ResultsWe introduce a novel algorithm, Bayesian Active Learning (BAL), for optimization and UQof such black-box functions and flexible protein docking. BAL directly models the posterior distribution of the global optimum (or native structures for protein docking) with active sampling and posterior estimation iteratively feeding each other. Furthermore, we use complex normal modes to represent a homogeneous Euclidean conformation space suitable for high-dimension optimization and construct funnel-like energy models for encounter complexes. Over a protein docking benchmark set and a CAPRI set including homology docking, we establish that BAL significantly improve against both starting points by rigid docking and refinements by particle swarm optimization, providing for one third targets a top-3 near-native prediction. BAL also generates tight confidence intervals with half range around 25% of iRMSD and confidence level at 85%. Its estimated probability of a prediction being native or not achieves binary classification AUROC at 0.93 and AUPRC over 0.60 (compared to 0.14 by chance); and also found to help ranking predictions. To the best of knowledge, this study represents the first uncertainty quantification solution for protein docking, with theoretical rigor and comprehensive assessment. AvailabilitySource codes are available at https://github.com/Shen-Lab/BAL. Contactyshen@tamu.edu Supplementary informationhttps://github.com/Shen-Lab/BAL/tree/master/Paper_SI/

bioinformatics↗

Cyclin A2/Cdk1 is Essential for the in vivo S Phase Entry by Phosphorylating Top2a.

Cyclin-dependent kinase 1 (CDK1) plays essential roles in cell cycle regulation. However, due to the early embryonic lethality of mouse Cdk1 mutants, the in vivo role of CDK1 in regulating cell cycle and embryonic development remains unclear. Here, by generating zebrafish cdk1 mutants using CRISPR/Cas9 system, we show that cdk1-/- embryos exhibit severe microphthalmia accompanied with multiple defects in polarized cell division, S phase entry and M phase progression, cell apoptosis and cell differentiation, but not in interkinetic nuclear migration (IKNM). By informatics analysis, we identified Top2a as a potential downstream target, and Cyclin A2 and Cyclin B1 as partners of Cdk1 in cell cycle. Depletion of either Cyclin A2 or Top2a leads to decreased S phase entry and increased DNA damage response in zebrafish retinal cells, and depletion of Cyclin B1 leads to M phase arrest. Immunoprecipitation shows that Cdk1 and Cyclin A2 physically interact in vivo. Moreover, phosphorylation of Top2a on Serine 1213 (S1213) site is almost absent in either cdk1 or ccna2 mutants, but in not ccnb1 mutants. Furthermore, overexpression of TOP2AS1213, the phosphomimetic form of human TOP2A, rescues S phase entry and microphthalmia defects in cdk1-/- and ccna2-/- embryos. Taken together, our data suggests that Cdk1 interacts with Cyclin A2 to regulate S phase entry through phosphorylating Top2a, and with Cyclin B1 to regulate M phase progression in vivo.

developmental biology↗

Combined Transcriptomics and Proteomics Forecast Analysis for Potential Genes Regulating the Columbian Plumage Color in Chickens

BackgroundColoration is one of the most recognizable characteristics in chickens, and clarifying the coloration mechanisms will help us understand feather color formation. \"Yufen I\" is an commercial egg-laying chicken breed in China, that was developed by a three-line cross using lines H, N and D. Columbian plumage is a typical feather character of the \"Yufen I\" H line. To elucidate the molecular mechanism underlying pigmentation of Columbian plumage, this study utilizes the technology of high-throughput sequencing to compare the transcriptome and proteome differences in different feather follicular tissue, including the dorsal neck with black and white striped feather follicles (Group A) and the ventral neck with white feather follicles (Group B) in the \"Yufen I\" H line.\n\nResultsIn this study, we identified a total of 21,306 genes and 5203 proteins in chicken feather follicles. Among these, 209 genes and 382 proteins were differentially expressed in two different locations, Group A and Group B, respectively. A total of 8 differentially expressed genes (DEGs) and 9 differentially expressed proteins (DEPs) were found to be involved in the melanogenesis pathway. Besides, a specifically expressed MED23 gene and a differential expressed GNAQ protein were involved in melanin synthesis. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis mapped 190 DEGs and 322 DEPs, to 175 and 242 pathways, respectively, and there were 166 pathways correlated with both DEGs and DEPs. 49 DEPs/DEGs overlapped and were enriched for 12 pathways. Transcriptomic and proteomic analyses revealed that the following pathways were activated: melanogenesis, cardiomycete adrenergic, calcium and the cGMP-PKG. The expression of DEGs was validated by real-time quantitative polymerase chain reaction (qRT-PCR) that was similar to that of RNA-seq. In addition, we found that MED23, FZD10, WNT7B and WNT11 genes expression peaked at approximately 8 weeks in the \"Yufen I\" H line, which is consistent with the molting cycle. As both the groups showed significant differences in terms of expression of the genes studied, this study opens up avenues for study in the future to assess their exact function in color of plumage.\n\nConclusionThese common DEGs and DEPs were enriched in the melanogenesis pathway. The MED23 and GNAQ were also reported to have a crucial part synthesis of melanin. In addition, this study is the first to reveal variations in gene and protein in the \"Yufen I\" H line during Columbian feather color development, and discover principal genes and proteins that would aid in the functional genomics studies in future. The results of the present study provide a significant conceptual basis for the \"Yufen I\" H line future breeding schemes and provide a basis for research on the mechanisms of feather pigmentation.

molecular biology↗

Causal inference in the multisensory brain

When combining information across different senses humans need to flexibly select cues of a common origin whilst avoiding distraction from irrelevant inputs. The brain could solve this challenge using a hierarchical principle, by deriving rapidly a fused sensory estimate for computational expediency and, later and if required, filtering out irrelevant signals based on the inferred sensory cause(s). Analysing time- and source-resolved human magnetoencephalographic data we unveil a systematic spatio-temporal cascade of the relevant computations, starting with early segregated unisensory representations, continuing with sensory fusion in parietal-temporal regions and culminating as causal inference in the frontal lobe. Our results reconcile previous computational accounts of multisensory perception by showing that prefrontal cortex guides flexible integrative behaviour based on candidate representations established in sensory and association cortices, thereby framing multisensory integration in the generalised context of adaptive behaviour.

neuroscience↗

Consensus interpretation of the Met34Thr and Val37Ile variants in GJB2 by the ClinGen Hearing Loss Expert Panel

PURPOSEPathogenic variants in GJB2 are the most common cause of autosomal recessive sensorineural hearing loss. The classification of c.101T>C/p.Met34Thr and c.109G>A/p.Val37Ile in GJB2 are controversial. Therefore, an expert consensus is required for the interpretation of these two variants.\n\nMETHODSThe ClinGen Hearing Loss Expert Panel (HL-EP) collected published data and shared unpublished information from participating laboratories regarding the two variants. Functional, computational, allelic, and segregation data were also obtained.\n\nRESULTSThe panel reviewed the synthesized information, and classified the Met34Thr and Val37Ile variants according to professional variant interpretation guidelines. We found that Met34Thr and Val37Ile are significantly overrepresented in hearing loss patients, compared to the general population. Met34Thr or Val37Ile homozygotes or compound heterozygotes typically manifest mild to moderate hearing loss. Several other types of evidence also support pathogenic roles for those two variants.\n\nCONCLUSIONResolving controversies in variant classification requires coordinated effort among a panel of international multi-institutional experts to share data, standardize classification rules, review evidence, and reach a consensus. The ClinGen HL-EP concluded that Met34Thr and Val37Ile variants in GJB2 are pathogenic for autosomal recessive nonsyndromic hearing loss with variable expressivity and age-dependent penetrance.

genetics↗

Intake of dietary fiber, fruits, and vegetables, and risk of diverticulitis

Background & AimsAlthough low fiber intake has been considered a risk factor for diverticulitis, prospective evidence is limited and conflicting, with little known about variation in the protective effects according to food sources. We assessed the associations of intakes of fiber and major food sources of fiber including fruits and vegetables with risk of diverticulitis.\n\nMethodsWe followed 50,019 women in the Nurses Health Study (1990-2014) and 48,292 men in the Health Professionals Follow-up Study (1986-2014) who were free of diverticulitis, cancer, and inflammatory bowel disease at baseline. Incident diverticulitis was identified through self-report with validity confirmed by review of medical records.\n\nResultsDuring a mean follow-up time of 22 years, we documented 4,343 incident cases of diverticulitis in women and 1,142 cases in men. Compared to participants in the lowest quintile, the multivariable HRs (95% CIs) of diverticulitis in the highest quintile of total fiber intake were 0.86 (0.78-0.95; P-trend=0.002) among women and 0.63 (0.51-0.79; P-trend<0.001) among men. Fiber from different food sources, except for vegetable fiber in women, was associated with a decreased risk of diverticulitis. Furthermore, total whole fruit intake was associated with reduced risk of diverticulitis in both cohorts with a multivariable HR for diverticulitis of 0.95 (0.92-0.98; P-trend<0.001) in women and 0.91 (0.86-0.96; P-trend<0.001) in men for every serving increase of total whole fruit intake per day.\n\nConclusionsHigher intake of dietary fiber and fiber from different food sources are associated with a lower risk of diverticulitis. A greater intake of whole fruit is also associated with reduced risk.

epidemiology↗

Accurate loop calling for 3D genomic data with cLoops

Sequencing-based 3D genome mapping technologies can identify loops formed by interactions between regulatory elements hundreds of kilobases apart. Existing loop-calling tools are mostly restricted to a single data type, with accuracy dependent on a pre-defined resolution contact matrix or called peaks, and can have prohibitive hardware costs. Here we introduce cLoops ( see loops) to address these limitations. cLoops is based on the clustering algorithm cDBSCAN that directly analyzes the paired-end tags (PETs) to find candidate loops and uses a permuted local background to estimate statistical significance. These two data-type-independent processes enable loops to be reliably identified for both sharp and broad peak data, including but not limited to ChIA-PET, Hi-C, HiChIP and Trac-looping data. Loops identified by cLoops showed much less distance-dependent bias and higher enrichment relative to local regions than existing tools. Altogether, cLoops improves accuracy of detecting of 3D-genomic loops from sequencing data, is versatile, flexible, efficient, and has modest hardware requirements, and is freely available at: https://github.com/YaqiangCao/cLoops.

bioinformatics↗

The research progress of p53 tumour suppressor activity controlled by Numb in triple-negative breast cancer

Numb is known as a cell fate determinant as it determines the direction of cell differentiation by asymmetrically partitioning at mitosis. It has been shown to be a tumor suppressor, and there is frequent loss of Numb expression in breast cancer. Numb enters in a tricomplex with p53 and the E3 ubiquitin ligase HDM2 (also known as MDM2), thereby preventing ubiquitination and degradation of p53. The aim of this study was to investigate the expression and migration of Numb, HDM2 and p53 proteins in the membrane, cytoplasmic and nuclear fractions of MCF-10A cells and MDA-MB-231 cells. We extracted the cell fractions to detect changes of these three protein levels after re-expression of NUMB in the basal-like triple-negative cell line MDA-MB-231 and knocking down NUMB in the normal mammary epithelial cell line MCF-10A. Our results show that Numb protein can migrate from cytoplasm to nucleus of the MDA-MB-231 cells. Numb protein regulates p53 levels in nucleus of MCF-10A cells and MDA-MB-231 cells, and the Numb levels is positively correlated with p53 levels. We have a finding on HDM2 protein that after knocking down NUMB in MCF-10A cells, it was remarkably reduced in the membrane fraction of NUMB knockdown cells, but its mRNA levels was significantly increased. We also examined the Numb expression in 125 patients with triple-negative breast cancer, 61(48.8%) displayed deficient or reduced expression of Numb. The percent of Ki67>14% in retained Numb group was significantly lower than that in the reduced and deficient Numb group (86.00% vs. 98.40%, P=0.0171).

molecular biology↗

Genome structure and evolution of Antirrhnum majus L.

Snapdragon (Antirrhinum majus L.), a member of Plantaginaceae, is an important model for plant genetics and molecular studies on plant growth and development, transposon biology and self-incompatibility. Here we report a high-quality genome assembly of A. majus cultivated JI7 (A. majus cv.JI7) of a 510 Mb with 37,714 annotated protein-coding genes. The scaffolds covering 97.12% of the assembled genome were anchored on 8 chromosomes. Comparative and evolutionary analyses revealed that Plantaginaceae and Solanaceae diverged from their most recent ancestor around 62 million years ago (MYA). We also revealed the genetic architectures associated with complex traits such as flower asymmetry and self-incompatibility including a unique TCP duplication around 46-49 MYA and a near complete{psi} S-locus of ca.2 Mb. The genome sequence obtained in this study not only provides the first genome sequenced from Plantaginaceae but also bring the popular plant model system of Antirrhinum into a genomic age.

genomics↗

(-)-Epigallocatechin-3-gallate inhibition of Epstein-Barr virus lytic replication involves latent membrane protein 1-mediated MAPK signaling pathways

AbstractEBV lytic replication has been shown to be important for carcinogenesis. Latent membrane protein 1 (LMP1) plays an important role in the viral latent infection and is abundantly expressed after EBV entry into the lytic cycle. However, the biological significance of LMP1 continuous expression in EBV lytic cycle is still not completely understood. We found that LMP1 promotes EBV reactivation by activating the downstream MAPK signaling in both AGS-EBV and B95.8 cells. In AGS-EBV cells, LMP1 induces EBV the initiation of the EBV lytic cycle in a p53 dependent manner. Activation of c-Jun by LMP1 through JNKs appears to be involved in EBV reactivation in p53 mutant B95.8 cells. We also demonstrated that EGCG, an anti-EBV agent, inhibits LMP1 expression and the activation of the downstream MAPK signaling pathways, followed by downregulation of EBV lytic protein expression level. Together, this study provides the first evidence that LMP1 promotes EBV reactivation via activation of the MAPK signaling pathways. Our findings further demonstrate that the mechanisms underlying EGCG inhibition of the EBV lytic replication involve the suppression of LMP1-mediated MAPK signaling pathways.\n\nSummary statementThis study definitely confirms the role of LMP1 in EBV reactivation and further explores the mechanism by which EGCG inhibits EBV lytic replication.

molecular biology↗