Biology subjects

Tang, L.

Publications and source records attributed to Tang, L..

At least 73 records · Page 4Linked to original sources

bioRxiv2023

Temporal colonization of the gut microbiome in neonatal Bos taurus at single nucleotide resolution

BackgroundThe rumen of neonatal calves is underdeveloped and exhibits limited functionality during early life. Thus, the acquisition and colonization of microbes in the gut are key to establishing a healthy host-microbiome symbiosis for neonatal calves. Microbiome-linked health outcomes appear to be the consequences of individual strains of specific microbes. However, the temporal colonization of pioneering microbial strains and their linkages to the health and growth of neonatal calves are poorly understood. ResultsTo address this, we longitudinally profiled the gut microbiome of 36 neonatal calves from birth up to 2 months postpartum and carried out microbial transplantation (MT) to reshape their gut microbiome. Genomic reconstruction of deeply sequenced fecal samples resulted in a total of 3,931 metagenomic assembled genomes (MAGs), of which 397 were identified as new species when compared with existing databases of Bos taurus. Single nucleotide level metagenomic profiling shows a rapid influx of microbes after birth, followed by strong selection during the first few weeks of life. MT was found to reshape the genetic makeup of 33 MAGs (FDR<0.05), mainly from Prevotella and Bacteroides species. We further linked over 20 million microbial single nucleotide variations (SNVs) to 736 plasma metabolites, which enabled us to characterize 24 study-wide significant associations (P < 4.4x10-9) that identify the potential microbial genetic regulation of host immune and neuro-related metabolites, including glutathione and L-dopa. Our integration analyses further revealed that microbial genetic variations may influence the health status and growth performance of neonatal calves by modulating metabolites via structural regulation of their encoded proteins. For instance, we found that the albumin levels and total antioxidant capacity in neonatal calves were correlated with L-dopa, which was determined by SNVs via structural regulations of metabolic enzymes. ConclusionsThe current results indicate that the temporal colonization of microbial strains and MT-induced strain replacement are integral in the development of the gut microbiome of neonatal calves and may help to develop strategies that can improve the health status and growth performance of neonatal calves.

microbiology↗

bioRxiv2023

Integrated Drivers of Basal and Acute Immunity in Diverse Human Populations

Prior studies have identified genetic, infectious, and biological associations with immune competence and disease severity; however, there have been few integrative analyses of these factors and study populations are often limited in demographic diversity. Utilizing samples from 1,705 individuals in 5 countries, we examined putative determinants of immunity, including: single nucleotide polymorphisms, ancestry informative markers, herpesvirus status, age, and sex. In healthy subjects, we found significant differences in cytokine levels, leukocyte phenotypes, and gene expression. Transcriptional responses also varied by cohort, and the most significant determinant was ancestry. In influenza infected subjects, we found two disease severity immunophenotypes, largely driven by age. Additionally, cytokine regression models show each determinant differentially contributes to acute immune variation, with unique and interactive, location-specific herpesvirus effects. These results provide novel insight into the scope of immune heterogeneity across diverse populations, the integrative effects of factors which drive it, and the consequences for illness outcomes.

immunology↗

bioRxiv2023

Plastome-based Phylogenomic analyses provide insights into the germplasm resource diversity of Cibotium in China

Germplasm resource is the source of herbal medicine production. Cultivation of superior germplasm resources helps to resolve the serious conflict between long-term population persistence and growing market demand by producing materials with high quality consistently. Cibotium barometz is the original plant of cibotii rhizoma ("Gouji"), a traditional Chinese medicine used in the therapy of pain, weakness, and numbness of lower extremity. Long-history use of Cibotium has rendered wild populations of this species declined seriously in China. Without sufficient understanding of species and lineage diversity of Cibotium, it is difficult to propose a targeted conservation scheme at present, let alone selecting high-quality germplasm resources. In order to fill such a knowledge gap, this study sampled C. barometz and relative species throughout their distribution in China, performed genome skimming to obtain plastome data, and conducted phylogenomic analyses. We constructed a well-supported plastome phylogeny of Chinese Cibotium, which showed that three species with significant genetic difference distributed in China, namely C. barometz, C. cumingii, and C. sino-burmaense, a cryptic species endemic to NW Yunnan and adjacent region of NE Myanmar. Moreover, our results revealed two differentiated lineages of C. barometz distributed in the east and west side of a classic phylogeographic boundary that probably shaped by monsoons and landforms in China. We also evaluated the resolution of nine traditional barcode loci, and designed five new DNA barcodes based on the plastome data which can discriminate all these species and lineages of Chinese Cibotium accurately. These novel findings integrated genetic basis will guide conservation planners and medicinal plant breeders to build systematic conservation plans and exploit germplasm resources of Cibotium in China.

evolutionary biology↗

bioRxiv2023

A promising QTL QSns.sau-MC-3D.1 likely superior to WAPO1 for wheat spikelet number per spike shows no adverse effects on yield-related traits

Spikelet number per spike (SNS) is one of the crucial factors determining wheat yield. Thus, improving our understanding of the genes that regulate SNS could help develop higher-yielding wheat varieties. A genetic linkage map constructed using the GenoBaits Wheat 16K Panel and the 660K SNP array contained 5991 polymorphic SNP markers spanning 2813.26 cM. A total of twelve QTL for SNS were detected in the recombinant inbred line (RIL) population msf x Chuannong 16 (MC), and two of them, i.e., QSns.sau-MC-3D.1 and QSns.sau-MC-7A, were stably expressed. QSns.sau-MC-3D.1 had high LOD values ranging from 4.99 to 11.06 and explained 9.71-16.75% of the phenotypic variation. Comparison of QSns.sau-MC-3D.1 with previously reported SNS QTL suggested that it is likely a novel one. A kompetitive allele-specific PCR (KASP) marker, KASP-10, tightly linked to QSns.sau-MC-3D.1 was developed to successfully validate its effect in three segregated populations and a natural population. Genetic analysis indicated that WHEAT ORTHOLOG OFAPO1 (WAPO1) was a candidate gene for QSns.sau-MC-7A. The combined additive effect of QSns.sau-MC-3D.1 and WAP01 had a great additive effect increasing SNS by 7.10%. In addition, our results suggested that SNS is not affected by 1BL/1RS translocations in the MC RIL population. Correlation analysis between two major QTL and other agronomic traits showed that QSns.sau-MC-3D.1 was likely independent of these agronomic traits. However, the H2 haplotype of WAPO1 may affect effective tiller number and plant height. This indicated that the breeding potential of QSns.sau-MC-3D.1 is better than that of WAPO1. The geographical distribution of QSns.nsau-MC-3D.1 showed that QSns.sau-MC-3D.1 positive allele frequency was dominant in most wheat-producing regions of China and it has been positively selected among modern cultivars released in China since the 1940s. Two genes, TraesCS3D03G0222600 and TraesCS3D03G0216800, associated with SNS development were predicted in the physical interval of QSns.sau-MC-3D.1. qRT-PCR results of the two genes showed that only the expression level of TraesCS3D03G0216800 was significantly different between msf and CN16. These results enrich our understanding of the genetic basis of wheat SNS and will be useful for fine mapping and cloning of genes underlying QSns.sau-MC-3D.1, and provide a basis for marker-assisted selection breeding. Author summaryIn this study, we identified two major QTL (QSns.sau-MC-3D.1 and QSns.sau-MC-7A) in a RIL population. WAPO1 was demonstrated to be the candidate gene for QSns.sau-MC-7A. QSns.sau-MC-3D.1 was a novel and stably expressed QTL, and further confirmed in different genetic backgrounds. Our results further demonstrate that QSns.sau-MC-3D.1 has better breeding potential because of its no adverse effect on other agronomic traits than WAPO1, and it has been positively selected during Chinese breeding programs since the 1940s. Taken together, the identification of QSns.sau-MC-3D.1 offers a promising resource to further increase wheat yields.

genetics↗

bioRxiv2023

Mucociliary Clearance Augmenting Drugs Block SARS-Cov-2 Replication in Human Airway Epithelial Cells

The coronavirus disease (COVID-19) pandemic, caused by SARS-CoV-2 coronavirus, is devastatingly impacting human health. A prominent component of COVID-19 is the infection and destruction of the ciliated respiratory cells, which perpetuates dissemination and disrupts protective mucociliary transport (MCT) function, an innate defense of the respiratory tract. Thus, drugs that augment MCT could improve barrier function of the airway epithelium, reduce viral replication and, ultimately, COVID-19 outcomes. We tested five agents known to increase MCT through distinct mechanisms for activity against SARS-CoV-2 infection using a model of human respiratory epithelial cells terminally differentiated in an air/liquid interphase. Three of the five mucoactive compounds tested showed significant inhibitory activity against SARS-CoV-2 replication. An archetype mucoactive agent, ARINA-1, blocked viral replication and therefore epithelial cell injury, thus, it was further studied using biochemical, genetic and biophysical methods to ascertain mechanism of action via improvement of MCT. ARINA-1 antiviral activity was dependent on enhancing the MCT cellular response, since terminal differentiation, intact ciliary expression and motion was required for ARINA-1-mediated anti-SARS-CoV2 protection. Ultimately, we showed that improvement of cilia movement was caused by ARINA-1-mediated regulation of the redox state of the intracellular environment, which benefited MCT. Our study indicates that Intact MCT reduces SARS-CoV-2 infection, and its pharmacologic activation may be effective as an anti-COVID-19 treatment.

microbiology↗

bioRxiv2022

Alternative Complement Pathway Regulates Thermogenic Fat Function via Adipsin and Adipocyte-derived C3aR1 in a Sex-dependent Fashion

Thermogenesis in beige/brown adipose tissues can be leveraged to combat metabolic disorders such as type 2 diabetes and obesity. The complement system plays pleiotropic roles in metabolic homeostasis and organismal energy balance with canonical effects on immune cells and non-canonical effects on non-immune cells. The adipsin/C3a/C3aR1 pathway stimulates insulin secretion and sustains pancreatic beta cell mass. However, its role in adipose thermogenesis has not been defined. Here, we show that Adipsin knockout mice exhibit increased energy expenditure and white adipose tissue (WAT) browning. C3a, a downstream product of adipsin, is generated from complement component 3 and decreases Ucp1 expression in subcutaneous adipocytes. In addition, adipocyte-specific C3aR1 knockout male mice show enhanced WAT thermogenesis and increased respiration. In stark contrast, adipocyte-specific C3aR1 knockout female mice display decreased brown fat thermogenesis and are cold intolerant. Female mice express lower levels of Adipsin in thermogenic adipocytes and adipose tissues than males. C3aR1 is also lower in female subcutaneous adipose tissue than males. Collectively, these results reveal sexual dimorphism in the adipsin/C3a/C3aR1 axis in regulating adipose thermogenesis. Our findings establish a newly discovered role of the alternative complement pathway in adipose thermogenesis and highlight sex-specific considerations in potential therapeutic targets for metabolic diseases.

cell biology↗

bioRxiv2022

Rational design of chemically controlled antibodies and protein therapeutics

Protein-based therapeutics such as monoclonal antibodies and cytokines are important therapies in various pathophysiological conditions such as oncology, auto-immune disorders, and viral infections. However, the wide application of such protein therapeutics is often hindered by dose-limiting toxicities and adverse effects, namely cytokine storm syndrome, organ failure and others. Therefore, spatiotemporal control of the activities of these proteins is crucial to further expand their application. Here, we report the design and application of small molecule-controlled switchable protein therapeutics by taking advantage of a previously engineered OFF-switch system. We used Rosetta modeling suite to computationally optimize the affinity between B-cell lymphoma 2 (Bcl-2) protein and a previously developed computationally designed protein partner (LD3) to obtain a fast and efficient heterodimer disruption upon addition of a competing drug (Venetoclax). The incorporation of the engineered OFF-switch system into CTLA4, anti-HER2 antibodies or an Fc-fused IL-15 cytokine demonstrated an efficient disruption in vitro, as well as fast clearance in vivo upon addition of the competing drug Venetoclax. These results provide a proof-of-concept for the rational design of controllable biologics by introducing a drug-induced OFF-switch into existing protein-based therapeutics.

bioengineering↗

bioRxiv2022

Molecular dynamics analysis of Superoxide Dismutase 1 mutations suggests decoupling between mechanisms underlying ALS onset and progression

Mutations in the superoxide dismutase 1 (SOD1) gene are the second most common known cause of ALS. SOD1 variants express high phenotypic variability and over 200 have been reported in people with ALS. Investigating how different SOD1 variants affect the protein dynamics might help in understanding their pathogenic mechanism and explaining their heterogeneous clinical presentation. It was previously proposed that variants can be broadly classified in two groups, wild-type like (WTL) and metal binding region (MBR) variants, based on their structural location and biophysical properties. MBR variants are associated with a loss of SOD1 enzymatic activity. In this study we used molecular dynamics and large clinical datasets to characterise the differences in the structural and dynamic behaviour of WTL and MBR variants with respect to the wild-type SOD1, and how such differences influence the ALS clinical phenotype. Our study identified marked structural differences, some of which are observed in both variant groups, while others are group specific. Moreover, applying graph theory to a network representation of the proteins, we identified differences in the intramolecular contacts of the two classes of variants. Finally, collecting clinical data of approximately 500 SOD1 ALS patients carrying variants from both classes, we showed that the survival time of patients carrying an MBR variant is generally longer (~6 years median difference, p < 0.001) with respect to patients with a WTL variant. In conclusion, our study highlights key differences in the dynamic behaviour of the WTL and MBR SOD1 variants, and wild-type SOD1 at an atomic and molecular level. We identified interesting structural features that could be further investigated to explain the associated phenotypic variability. Our results support the hypothesis of a decoupling between mechanisms of onset and progression of SOD1 ALS, and an involvement of loss-of-function of SOD1 with the disease progression.

neuroscience↗

bioRxiv2022

A 3D genome atlas of genetic variants and their pathological effects

The spatial architecture of the genome can be categorized into distinct layers. Each layer plays a critical role in transcriptional regulation and/or genomic integrity. Alterations at any level of the 3D genome can lead to an unwanted cascade of molecular events, which may ultimately drive the manifestation of disease. However, a comprehensive atlas of the mutations and structural genetic defects that affect genome organization has yet to be compiled. Moreover, we lack a centralized resource for interpretating the pathological effects of such genetic mutations. Therefore, we curated from the literature all the pathological alterations from the chromosome level on down to single nucleotide polymorphisms (SNPs) in order to investigate these diverse genetic mutations. Using a two-phase scoring algorithm, 3DFunc, we scored the transcriptomic causality of all variants in the context of 3D genome architecture from 20 cancer and 15 normal tissues. Further, 3DFunc can identify pathological variant-gene pairs in non-oncological diseases. Finally, we constructed a web-based database, 3DGeOD (https://www.csuligroup.com/3DGeOD/home), to provide all the curated variants, genomic disruptions, as well as the scoring results derived from 3DFunc. In summary, our study constructed a 3D genome atlas of genetic variants and will serve as a valuable resource for mining the putative pathological effects of any genetic mutation.

bioinformatics↗

bioRxiv2022

ADOLESCENT EXPOSURE TO LOW-DOSE THC DISRUPTS ENERGY BALANCE AND ADIPOSE ORGAN HOMEOSTASIS IN ADULTHOOD

One of cannabis most iconic effects is the stimulation of hedonic high-calorie eating - the munchies - yet habitual cannabis users are on average leaner than non-users. We asked whether this unexpected phenotype might result from lasting changes in energy balance established during adolescence, when habitual use of the drug often begins. We found that daily low-dose administration of cannabis intoxicating constituent, {Delta}9-tetrahydrocannabinol (THC), to adolescent mice causes an adult metabolic phenotype characterized by reduced fat mass, increased lean mass and utilization of fat as fuel, partial resistance to diet-induced obesity and dyslipidemia, and enhanced thermogenesis. Multi-omics analyses revealed that this phenotype is associated with multiple molecular anomalies in the adipose organ, which include ectopic overexpression of muscle-associated proteins and heightened anabolic processing. Thus, adolescent exposure to THC may promote an enduring pseudo-lean state that superficially resembles healthy leanness but might in fact be rooted in adipose organ dysfunction.

pharmacology and toxicology↗

bioRxiv2022

BysR, a LysR-type Pleiotropic Regulator, Controls Production of Occidiofungin by Activating the LuxR-type transcriptional regulator AmbR1 in Burkholderia sp. JP2-270

Occidiofungin is a highly effective antifungal glycopeptide produced by certain Burkholderia strains. The ocf gene cluster directing occidiofungin biosynthesis is regulated by cluster-specific regulators encoded by ambR homolog(s) within the same gene cluster, while it remains unknown to what extent occidiofungin biosynthesis is connected with the core regulation network. Here, we report that a LysR-type regulator BysR acts as a pleotropical regulator, and is essential for occidiofungin biosynthesis by directly activating ambR1 transcription in Burkholderia sp. JP2-270. Deletion of bysR and ocfE both abolished the antifungal activity in JP2-270. This defect of the bysR mutant can be recovered by constitutively expressing bysR or ambR1 but not by ambR2. The EMSA assay collectively showed that BysR regulates ambR1 through direct binding to its promoter region. Taken together, occidiofungin produced by JP2-270 is the main substance inhibiting M. oryzae, and BysR controls occidiofungin production by directly activating the expression of ambR1. Besides, transcriptomic analysis revealed altered expression of 350 genes in response to bysR deletion, and the genes engaged in flagellar assembly and bacterial chemotaxis are the most enriched pathways. Also, 400 putative loci targeted by BysR were identified by DAP-seq in JP2-270. These loci not only include genes engaged in key metabolic pathways but also genes involved in secondary metabolic pathways. Collectively, we proposes that BysR may be a novel pleiotropic regulator, and ambR1 is an important target gene of BysR, which is an intra-cluster transcriptional regulatory gene that further activates the transcription of ocf gene cluster. IMPORTANCEThis study shows that BysR, a LysR-type transcriptional regulator (LTTR) from Burkholderia sp. JP2-270, activates the expression of ambR1 gene responsible for regulating the synthesis of occidiofungin. BysR also acts as a pleiotropic regulator that controls primary and secondary metabolism, antibiotic resistance, motility, transport and other cellular processes in Burkholderia sp. JP2-270. This study provides insight into the regulatory mechanism of occidiofungin synthesis and enhances our understanding of the regulatory patterns of the LysR-type regulator.

microbiology↗

bioRxiv2022

Benzidine Induces Proliferation of UMUC3 Bladder Cancer Cells Through Activation of ERK5 Pathway

Mounting evidences have revealed that benzidine, a known human carcinogen, is a pivotal risk factor for bladder cancer (BC). Dysregulated cell proliferation serves as a pivotal pathophysiological step in BC development. The potential mechanisms of MAPK pathways, particularly extracellular regulated protein kinases 5 (ERK5), regarding the modulation of benzidine-elicited cell proliferation are still elusive. Herein, human BC cells UMUC-3 were exposed to indicated levels of benzidine for 5 days. Cell growth, cell cycle progression, cell cycle-related, MAPK genetic expression, and related protein contents were investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, flow cytometry, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and western blotting (WB), respectively. XMD8-92 (a specific suppressor of ERK5) and small interfering RNA (siRNA) were utilized to identify the roles of ERK5. Our results illustrated that benzidine elevated the proliferative ability of UMUC3 cells and accelerated the cell cycle transition from G1 to S phase, and it increased the expressions of cyclin D1 and proliferating cell nuclear antigen (PCNA) and reduced the expression of p21. Meanwhile, benzidine treatment resulted in the activation of ERK5 pathway and activator protein 1 (AP-1) proteins. In addition, benzidine-elicited cell proliferation and ERK5 stimulation were fully inhibited by XMD8-92 and siRNAs specific to ERK5. Taken together, these results demonstrated that ERK5-mediated cell proliferation was tightly related to benzidine-assoicated BC development, which established the foundation for targeting the ERK5 pathway in BC treatment.

biochemistry↗

bioRxiv2022

Comparative genomics of five Valsa species gives insights on their pathogenicity evolution

Valsa is a genus of ascomycetes fungi within the family Valsaceae that includes many wood destructive pathogens. The species such as Valsa mali and Valsa pyri that colonize fruit trees are threatening the global fruit production. Rapid host adaptation and fungicide resistance emergence are the main characteristics that make them devastating and hard to control. Efficient disease management can be achieved from early infection diagnosis and fungicide application, but lack of understandings of their genetic diversity and genomic features that underpin their pathogenicity evolution and drug resistance is essentially impeding the progress of effective and sustainable disease control. Here, we report genome assemblies of Valsa malicola, Valsa persoonii and Valsa sordida which represents close relatives of the two well known Valsa mali and Valsa pyri that cause canker disease with different host preferences. Comparative genomics analysis revealed that segmental rearrangements, inversions and translocations frequently occurred among Valsa spp. genomes. Genes identified in highly active regions exhibited high sequence differentiation and are enriched in membrane transporter proteins involved in anti-drug and nutrient transportation activities. Consistently, we also found membrane transporter gene families have been undergoing significant expansions in Valsa clade. Furthermore, unique genes that possessed or retained by each of the five Valsa species are more likely part of the secondary metabolic (SM) gene clusters which suggests SM one of the critical components that diverge along with the evolution of Valsa species. Repeat sequence content contributes significantly to genome size variation across the five species. The wide spread AT-rich regions resulted from repeat induced point C to T mutation (RIP) exhibited a specific proximity to secondary metabolic gene clusters and this positional proximity is correlated with the diversification of SM clusters suggesting a potential companion evolution between repeat sequence and secondary metabolism cluster. Lastly, we show that LaeA, the global regulator of secondary metabolic gene cluster, exhibiting diverged manner of regulation on the expression of clusters in vegetative and invasive mycelia of the devastating V. mali indicating the complexity of secondary metabolism in fungal species.

bioinformatics↗

bioRxiv2022

Reprogrammed Schwann cells organize into dynamic tracks that promote pancreatic cancer invasion

Nerves are a component of the tumor microenvironment contributing to cancer progression, but the role of cells from nerves in facilitating cancer invasion remains poorly understood. Here we show that Schwann cells (SCs) activated by cancer cells collectively function as Tumor Activated Schwann cell Tracks (TASTs) that promote cancer cell migration and invasion. Non-myelinating SCs form TASTs and have cell gene expression signatures that correlate with diminished survival in patients with pancreatic ductal adenocarcinoma. In TASTs, dynamic SCs form tracks that serve as cancer pathways and apply forces on cancer cells to enhance cancer motility. These SCs are activated by c-Jun, analogous to their reprogramming during nerve repair. This study reveals a mechanism of cancer cell invasion that co-opts a wound repair process and exploits the ability of SCs to collectively organize into tracks. These findings establish a novel paradigm of how cancer cells spread and reveal therapeutic opportunities. SIGNIFICANCEHow the tumor microenvironment participates in pancreatic cancer progression is not fully understood. Here, we show that Schwann cells are activated by cancer cells and collectively organize into tracks that dynamically enable cancer invasion in a c-Jun dependent manner.

cancer biology↗

bioRxiv2022

Improved pathogen and stress tolerance in tomato mutants of SET domain histone 3 lysine methyltransferases

Histone lysine methylations (HLMs) are implicated in control of gene expression in different eukaryotes. However, the role of HLMs in regulating desirable crop traits and the enzymes involved in these modifications are poorly understood. We studied the functions of tomato histone H3 lysine methyltransferases Set Domain Group 33 (SDG33) and SDG34 in biotic and abiotic stress responses. SDG33 and SDG34 mutants were altered in H3K36 and H3K4 methylations, and expression of genes involved in diverse processes and responses to biotic and abiotic stimuli. The double but not the single mutants show resistance to the fungal pathogen Botrytis cinerea. Interestingly, single mutants were tolerant to drought and the double mutant showed superior tolerance consistent with independent and additive functions. Mutants maintained higher water status during drought and improved recovery and survival after lapse of drought. Notably, diminution of H3K4 and H3K36 trimethylation and expression of negative regulators in challenged plants contributes to stress tolerance of the mutants. Mutations in SDG33 and SDG34 remove predisposition to biotic and abiotic stress by disrupting permissive transcriptional context promoting expression of negative regulatory factors. These allows improvement of stress and pathogen tolerance through modification of histone epigenetic marks.

plant biology↗

bioRxiv2022

Dynamic evolution of small signaling peptide compensation in plant stem cell control

Gene duplications are a hallmark of plant genome evolution and a foundation for genetic interactions that shape phenotypic diversity1-5. Compensation is a major form of paralog interaction6-8, but how compensation relationships change as allelic variation accumulates is unknown. Here, we leveraged genomics and genome editing across the Solanaceae family to capture the evolution of compensating paralogs. Mutations in the stem cell regulator CLV3 cause floral organs to overproliferate in many plants9-11. In tomato, this phenotype is partially suppressed by transcriptional upregulation of a closely related paralog12. Tobacco lost this paralog, resulting in no compensation and extreme clv3 phenotypes. Strikingly, the paralogs of petunia and groundcherry nearly completely suppress clv3, indicating a potent ancestral state of compensation. Cross-species transgenic complementation analyses show this potent compensation partially degenerated in tomato due to a single amino acid change in the paralog and cis-regulatory variation that limits its transcriptional upregulation. Our findings show how genetic interactions are remodeled following duplications, and suggest that dynamic paralog evolution is widespread over short time scales and impacts phenotypic variation from natural and engineered mutations.

plant biology↗

bioRxiv2021

ATP and Substrate Binding Regulates Conformational Changes of Human Peroxisomal ABC Transporter ALDP

The malfunction of ABCD1 causes X-linked adrenoleukodystrophy (X-ALD), a rare neurodegenerative disease that affect all tissues in human. Residing in the peroxisome membrane, ABCD1 plays a role in the translocation of very long chain fatty acids (VLCFA) for their damage by {beta}-oxidation. Here, we present five Cryo-Electron microscopy structures of ABCD1 in four conformational states. Combined with functional analysis, we found that substrate and ATP trigger the closing of two nucleotide binding domains (NBDs) over a distance of 40 [A] and the rearrangement of the transmembrane domains. Each of the three inward-facing structure of ABCD1 has a vestibule opens to cytosol with variable size. Furthermore, the structure of ABCD1 in the outward-facing state supports that ATP molecules pull the two NBDs together and open the transmembrane domain to the peroxisomal lumen for substrate release. The five structures provide a snapshot of substrate transporting cycle and mechanistic implications for disease-causing mutations.

biochemistry↗

bioRxiv2021

Immunological profiling of COVID-19 patients with pulmonary sequelae

Cellular immunity may be involved in organ damage and rehabilitation in patients with coronavirus disease 2019 (COVID-19). We aimed to delineate immunological features of COVID-19 patients with pulmonary sequelae (PS) one year after discharge. 50 COVID-19 survivors were recruited and classified according to radiological characteristics: 24 patients with PS and 26 patients without PS. Phenotypic and functional characteristics of immune cells were evaluated by multiparametric flow cytometry. Patients with PS had an increased proportion of natural killer (NK) cells and lower percentage of B cells compared to patients without PS. Phenotypic and functional features of T cells in patients with PS were predominated by the accumulation of CD4+ T cells secreting IL-17A, short-lived effector-like CD8+ T cells (CD27-CD62L-) and senescent T cells with excessive secretion of granzyme-B/perforin/IFN-{gamma}. NK cells were characterized by the excessive secretion of granzyme-B and perforin and the downregulation of NKP30 and NKP46; highly activated NKT and {gamma}{delta} T cells exhibited NKP30 and TIM-3 upregulation and NKB1 downregulation in patients with PS. However, immunosuppressive cells were comparable between the two groups. The interrelation of immune cells in COVID-19 was intrinsically identified, whereby T cells secreting IL-2, IL-4 and IL-17A were enriched among CD28+ and CD57-cells and cells secreting perforin/granzyme-B/IFN-{gamma}/TNF- expressed markers of terminal differentiation. CD57+NK cells, CD4+perforin+ T cells and CD8+CD27+CD62L+ T cells were identified as the independent predictors for residual lesions. Overall, our findings unveil the profound imbalance of immune landscape that may correlate with organ damage and rehabilitation in COVID-19. IMPORTANCEA considerable proportion of COVID-19 survivors have residual lung lesions, such as ground glass opacity and fiber streak shadow. To determine the relationship between host immunity and residual lung lesions, we performed an extensive analysis of immune responses in convalescent patients with COVID-19 one year after discharge. We found significant differences in immunological characteristics between patients with pulmonary sequelae and patients without pulmonary sequelae one year after discharge. Our study highlights the profound imbalance of immune landscape in the COVID-19 patients with pulmonary sequelae, characterized by the robust activation of cytotoxic T cells, NK cells and {gamma}{delta} T cells as well as the deficiencies of immunosuppressive cells. Importantly, CD57+NK cells, CD4+perforin+ T cells and CD8+CD27+CD62L+ T cells were identified as the independent predictors for residual lesions.

immunology↗