Publications by authors named "Yi-ming Shi"

Article Synopsis
  • Pyrrolizidine alkaloids (PAs) are a diverse group of compounds found in plants and bacteria, characterized by a specific chemical structure and produced through two main pathways (one in plants and another in bacteria).
  • The study identified a gene cluster in the bacterium Xenorhabdus hominickii responsible for the production of a specific PA called pyrrolizwilline, shedding light on its biosynthesis.
  • Researchers also characterized an important enzyme in the pathway, XhpG, utilizing advanced techniques like X-ray crystallography to understand its role in converting a precursor compound into pyrrolizwilline.
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Covering: up to March 2024.Microbial natural products have historically been a cornerstone for the discovery of therapeutic agents. Advanced (meta)genome sequencing technologies have revealed that microbes harbor far greater biosynthetic capabilities than previously anticipated.

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The bacterial cell membrane primarily houses lipids, carbohydrates, and proteins forming a barrier and interface that maintains cellular integrity, supports homeostasis, and senses environmental changes. Compared to lipid components and excreted secondary metabolites, compounds embedded in the producer cell membrane are often overlooked due to their low abundance and niche-specific functions. The accumulation of findings has led to an increased appreciation of their crucial roles in bacterial cell biochemistry, physiology, and ecology, as well as their impact on mutualistic and pathogenic bacteria-eukaryote interactions.

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The aim of this study was to comprehensively assess the causal relationship between the overall genetic effect of circulating ApoE levels and panvascular lesions using newer genome-wide association data and two-sample bidirectional Mendelian randomization (MR) analysis. Two-way MR using single-nucleotide polymorphisms of circulating ApoE as instrumental variables was performed using the highest-priority Genome-wide association study (GWAS) data, with factor-adjusted and data-corrected statistics, to estimate causal associations between circulating ApoE levels and 10 pan-vascular diseases in > 500,000 UK Biobank participants, > 400,000 participants of Finnish ancestry, and numerous participants in a consortium of predominantly European ancestry. Meta-analysis was conducted to assess positive results.

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The discovery of novel bioactive compounds produced by microorganisms holds significant potential for the development of therapeutics and agrochemicals. In this study, we conducted genome mining to explore the biosynthetic potential of entomopathogenic bacteria belonging to the genera Xenorhabdus and Photorhabdus. By utilizing next-generation sequencing and bioinformatics tools, we identified novel biosynthetic gene clusters (BGCs) in the genomes of the bacteria, specifically plu00736 and plu00747.

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Three unusual sesterterpenoids featuring unprecedented rearranged colquhounane (C) and tetranorcolquhounane (C) frameworks, colquhounoids E () and F () and norcolquhounoid F (), were isolated from a Lamiaceae medicinal plant var. . Their structures were elucidated by spectroscopic analysis and quantum chemical calculations.

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Rheumatoid arthritis(RA) is an autoimmune disease that seriously affects the physical and mental health of patients, but its pathogenesis is still unclear. At present, clinical treatment drugs include conventional synthetic disease modifing anti-rheumatic drugs(csDMARDs), nonsteroid anti-inflammtory drugs(NSAIDs), hormones, small molecule targeted drugs, biological agents, etc. These drugs can relieve the clinical symptoms of most patients with RA to a certain extent, but there are still many limitations, such as drug adverse reactions and individual differences in drug efficacy.

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Public health studies indicate that artificial light is a high-risk factor for metabolic disorders. However, the neural mechanism underlying metabolic modulation by light remains elusive. Here, we found that light can acutely decrease glucose tolerance (GT) in mice by activation of intrinsically photosensitive retinal ganglion cells (ipRGCs) innervating the hypothalamic supraoptic nucleus (SON).

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Benzoxazolinate is a rare bis-heterocyclic moiety that interacts with proteins and DNA and confers extraordinary bioactivities on natural products, such as C-1027. However, the biosynthetic gene responsible for the key cyclization step of benzoxazolinate remains unclear. Herein, we show a putative acyl AMP-ligase responsible for the last cyclization step.

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Piscibactins and photoxenobactins are metallophores and virulence factors, whose biosynthetic gene cluster, termed , is the most prevalent polyketide synthase/non-ribosomal peptide synthetase hybrid cluster across entomopathogenic bacteria. They are structurally similar to yersiniabactin, which contributes to the virulence of the human pathogen . However, the -derived products feature various chain lengths and unusual carboxamide, thiocarboxylic acid, and dithioperoxoate termini, which are rarely found in thiotemplated biosyntheses.

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Microorganisms contribute to the biology and physiology of eukaryotic hosts and affect other organisms through natural products. Xenorhabdus and Photorhabdus (XP) living in mutualistic symbiosis with entomopathogenic nematodes generate natural products to mediate bacteria-nematode-insect interactions. However, a lack of systematic analysis of the XP biosynthetic gene clusters (BGCs) has limited the understanding of how natural products affect interactions between the organisms.

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is a phytopathogenic fungus responsible for corn smut disease. Although it is a very well-established model organism for the study of plant-microbe interactions, its potential to produce specialized metabolites, which might contribute to this interaction, has not been studied in detail. By analyzing the genome, we identified a biosynthetic gene cluster whose activation led to the production of a black melanin pigment.

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Fruiting body-forming members of the Basidiomycota maintain their ecological fitness against various antagonists like ascomycetous mycoparasites. To achieve that, they produce myriads of bioactive compounds, some of which are now being used as agrochemicals or pharmaceutical lead structures. Here, we screened ethyl acetate crude extracts from cultures of thirty-five mushroom species for antifungal bioactivity, for their effect on the ascomycete and the basidiomycete .

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Article Synopsis
  • - The study examined the relationship between risk communication, anxiety, and preventive behaviors during the early phase of COVID-19, involving 846 adults in high- and low-risk areas from January 26 to February 17, 2020.
  • - Findings showed that higher perceived quality of risk communication helped reduce anxiety and emotional contagion, leading to increased adoption of preventive measures.
  • - It was noted that individuals in high-risk areas, especially frontline responders, were more affected by risk communication, highlighting the need for effective messaging during health crises.
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Article Synopsis
  • Light plays a significant role in regulating mood and while daytime light therapy can help alleviate depression, excessive light exposure at night is linked to depressive symptoms.
  • Research using a light-at-night (LAN) model in mice revealed that LAN can trigger depressive-like behaviors without affecting the circadian rhythm.
  • The study identified a neural pathway involving retinal cells, the dorsal perihabenular nucleus (dpHb), and the nucleus accumbens (NAc) that is more active at night, suggesting that this pathway is responsible for the negative effects of nighttime light exposure on mental health.
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The western corn rootworm (WCR) decimates maize crops worldwide. One potential way to control this pest is treatment with entomopathogenic nematodes (EPNs) that harbor bacterial symbionts that are pathogenic to insects. However, WCR larvae sequester benzoxazinoid secondary metabolites that are produced by maize and use them to increase their resistance to the nematodes and their symbionts.

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Natural products (NPs) from microorganisms have been important sources for discovering new therapeutic and chemical entities. While their corresponding biosynthetic gene clusters (BGCs) can be easily identified by gene-sequence-similarity-based bioinformatics strategies, the actual access to these NPs for structure elucidation and bioactivity testing remains difficult. Deletion of the gene encoding the RNA chaperone, Hfq, results in strains losing the production of most NPs.

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It is generally believed that exchange of secondary metabolite biosynthetic gene clusters (BGCs) among closely related bacteria is an important driver of BGC evolution and diversification. Applying this idea may help researchers efficiently connect many BGCs to their products and characterize the products' roles in various environments. However, existing genetic tools support only a small fraction of these efforts.

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Two new dimeric compounds of the alternariol class, (±)-alternarlactones A () and B (), were isolated along with 11 known compounds from the fungus P1210. Their structures were elucidated with the assistance of long-range HSQMBC to address inadequate cross-peaks in HMBC that result from the highly dense quaternary carbons, as well as theoretical calculations. All isolated altenuisol derivatives were screened for their antiparasitic activities, which provide a preliminary structure-activity relationship of this class of compounds against neglected tropical diseases.

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Bacteria of the genera Photorhabdus and Xenorhabdus produce a plethora of natural products to support their similar symbiotic life cycles. For many of these compounds, the specific bioactivities are unknown. One common challenge in natural product research when trying to prioritize research efforts is the rediscovery of identical (or highly similar) compounds from different strains.

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Many synthetic biology approaches aim at expanding the product diversity of enzymes or whole biosynthetic pathways. However, the chemical structure space of natural product forming routes is often restricted by the limited cellular availability of different starting intermediates. Although the terpene biosynthesis pathways are highly modular, their starting intermediates are almost exclusively the C units IPP and DMAPP.

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Aryl polyene (APE) pigments are a widely distributed class of bacterial polyketides. So far, little is known about the biosynthesis of these compounds, which are produced by a novel type II polyketide synthase (PKS). We have identified all enzymes involved in APE biosynthesis and determined their peculiar functions.

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Biosynthetic gene clusters (BGCs) bridging genotype and phenotype continuously evolve through gene mutations and recombinations to generate chemical diversity. Phenazine BGCs are widespread in bacteria, and the biosynthetic mechanisms of the formation of the phenazine structural core have been illuminated in the last decade. However, little is known about the complex phenazine core-modification machinery.

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Members of the genera Xenorhabdus and Photorhabdus are capable of producing a huge repertoire of different natural products to support a complex life cycle involving insect pathogenesis and nematode symbiosis. Many of the natural products have direct functions, specifically targeting different facets of nematode development or the insect immune system. These adaptations have allowed the bacteria to thrive in a unique environment and become highly efficient, versatile insect pathogens.

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