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PubMed2026

Lysine iminylation derived from ω-3 polyunsaturated fatty acids.

Protein posttranslational modifications (PTMs) play a central role for regulating protein function and cellular processes, with many PTMs arising from reactions with electrophilic metabolites. Here we extend the known landscape of PTMs with the identification of "lysine C3-iminylation," the conjugation of protein lysine residues with propionaldehyde. To stabilize iminylation for mass spectrometric analyses and distinguish it from other isomeric PTMs, we developed a fixation and stable-isotope labeling approach based on parallel reduction of proteome with sodium borohydride and borodeuteride. Analyses of protein hydrolysates confirmed the presence of C3-iminylation in Caenorhabditis elegans and mouse. Additionally, proteomics results demonstrated specificity of this PTM in vitro and in vivo and revealed C3-iminylation in proteins related to critical metabolic pathways. Importantly, collective evidence from isotope tracing as well as genetic, dietary, and pharmacological manipulation experiments uncovered that C3-iminylation originates from cytochrome P450 (CYP)-mediated oxidation of omega-3 fatty acids. Correspondingly, C3-iminylation levels were elevated in C. elegans daf-2(e1370) mutants, an aging model, in which CYP activity is generally increased. These findings not only expand our understanding of the biochemical diversity of PTMs but also underscore the complex interplay between lipid metabolism and protein modifications, enabling further exploration of their biological and clinical implications.

Animals↗

PubMed2026

Functional analysis of down-regulated CYP6AE gene clusters involved in the insecticidal mechanism of lycorine against Spodoptera litura.

BACKGROUND: Plants have evolved abundant defensive secondary metabolites to resist insect herbivores. Lycorine is an alkaloid with insecticidal activity from Amaryllidaceae plants, which the destructive pest Spodoptera litura naturally avoids. Cytochrome P450 enzymes are central to xenobiotic detoxification in insects, but the mechanism by which lycorine acts against S. litura remains unknown. This study aimed to reveal the toxic mechanism of lycorine focusing on P450-mediated detoxification. RESULTS: Lycorine exhibited substantial toxicity to first-instar S. litura larvae (LD50 = 0.55 μg larva-1). Subsequently, when fifth-instar larvae were exposed to a sublethal dose (LD30) of lycorine, Lyc disrupted metabolic pathways, damaged Malpighian tubules, and induced oxidative stress. Furthermore, lycorine strongly repressed a CYP6AE gene cluster (CYP6AE47, CYP6AE50, CYP6AE70, CYP6AE138 and CYP6AE139) and decreased total P450 activity to 45% in the Malpighian tubules. RNAi co-silencing of these cluster genes increased larval mortality (+30%) under lycorine treatment. Finally, molecular docking and microscale thermophoresis analyses further confirmed direct binding between Lyc and this CYP6AE gene cluster, with the strongest affinity observed for CYP6AE47 (Kd = 518.5 nM). A key residue, ARG170, may be vital for the interaction between Lyc and CYP6AE47. CONCLUSIONS: These results demonstrate that the insecticidal mechanism of Lyc involves suppressing the expression and function of a CYP6AE gene cluster, thereby impairing detoxification capacity, which leads to Lyc accumulation and larval mortality. Elucidation of the detoxification system-targeted mechanism for this plant-derived compound provides a foundation for developing novel, sustainable pest management strategies against S. litura and potentially other noctuid pests. © 2026 Society of Chemical Industry.

Animals↗

PubMed2026

The transcriptional regulator CasR controls mycobacterial antioxidant defense and biofilm formation via multiple direct targets.

AIMS: The antioxidant defense system of Mycobacterium tuberculosis is critical for pathogenicity and persistence within macrophages, yet the regulatory networks remain poorly understood. This study aims to elucidate the molecular mechanism by which the transcription factor CasR regulates antioxidant defense in mycobacteria through delineation of the regulatory axis linking CasR activity, target gene expression, and the antioxidant phenotype. METHODS AND RESULTS: Using Mycobacterium smegmatis as a model organism, we demonstrate that overexpression of CasR renders the bacteria significantly susceptible to hydrogen peroxide. Electrophoretic mobility shift assay (EMSA) and β-galactosidase reporter analyses reveal that CasR directly binds and represses the promoter of cyp144, an uncharacterized cytochrome P450-encoding gene. Deletion of casRMsmreduces biofilm formation, consistent with the expected derepression of cyp144Msm, a gene that negatively regulates both biofilm and oxidative stress tolerance. EMSA and β-galactosidase activity assays also demonstrate that CasR negatively regulates antioxidant gene katGI, suggesting that CasR exerts a broader, global regulatory role within the mycobacterial antioxidant defense network. Furthermore, we identify isoleucine 18 as a critical residue for the DNA-binding and regulatory function of CasR. CONCLUSION: This study establishes CasR as a pleiotropic transcriptional regulator that directly controls multiple antioxidant genes, including cyp144 and katGI, in mycobacteria. We report a previously unrecognized role for a cytochrome P450 family member in suppressing bacterial antioxidant capacity, as cyp144 overexpression reduces biofilm formation. These findings provide a valuable reference for further investigation into mycobacterial antioxidant mechanisms and identify CasR and Cyp144 as potential targets for the development of anti-tuberculosis drugs.

Biofilms↗

PubMed2026

Genetic and epigenetic determinants of cytochrome P450 activity in psychopharmacology: from pharmacogenetics to functional pharmacogenomics.

Classical pharmacogenetics has explained interindividual variability in psychotropic drug response primarily through inherited polymorphisms in cytochrome P450 enzymes. This framework successfully identified extreme metabolizer phenotypes and informed genotype-guided dosing recommendations. However, genotype-based predictions frequently correlate more strongly with pharmacokinetic parameters than with clinical outcomes. Patients sharing similar CYP genotypes often exhibit divergent therapeutic trajectories, while metabolic phenotypes may change during treatment without corresponding alterations in DNA sequence. These observations suggest the existence of a genotype-phenotype gap mediated by regulatory processes not captured by genotyping alone. Evidence from epigenetic regulation, environmental modulation of pharmacogene expression, and phenoconversion indicates that metabolic capacity is better understood as a dynamic functional state rather than a fixed inherited trait. This review examines the role of these mechanisms in psychiatric pharmacotherapy and explores the implications of shifting the predictive focus of precision medicine from static genotype to functional state.

Humans↗

PubMed2026

Novel compound heterozygous POR variants in a neonate with Antley-Bixler syndrome and 46,XY DSD: a case report and literature review.

BACKGROUND: Cytochrome P450 oxidoreductase deficiency (PORD) is an ultra-rare autosomal recessive disorder within the congenital adrenal hyperplasia (CAH) spectrum, characterized by a broad clinical spectrum involving steroidogenesis defects, genital anomalies, and skeletal abnormalities. CASE PRESENTATION: We report a phenotypically female neonate with a 46,XY karyotype whose postnatal diagnostic evaluation was initiated after newborn screening revealed elevated 17-hydroxyprogesterone (17-OHP) concentration. The patient presented with mild hypertelorism, mild nasal hypoplasia, and low-set bilateral ears, along with female external genitalia consistent with disorder of sex development (DSD) and anal atresia. Radiological evaluation revealed femoral bowing and subsequent fracture. The craniofacial and skeletal abnormalities were consistent with the features of Antley-Bixler syndrome (ABS). Endocrine evaluation revealed elevated progesterone, markedly reduced testosterone, and secondary hyperaldosteronism. Genetic analysis identified three novel variants in the POR gene (NM_001395413.1): the patient harbored a paternal c.1187_1195dup (p.Pro396_Glu398dup) variant and two maternally inherited variants in cis, c.1447G>A (p.Gly483Ser) and c.1806 + 4_1806 + 28del. Protein structural modeling predicted that the p.Pro396_Glu398dup and p.Gly483Ser may disrupt the flavin adenine dinucleotide (FAD)-binding domain. RNA sequencing (RNA-seq) confirmed that the intronic variant c.1806 + 4_1806 + 28del caused aberrant splicing, resulting in partial intron retention and predicted impairment of the nicotinamide adenine dinucleotide phosphate (NADPH)-binding domain. According to American College of Medical Genetics and Genomics (ACMG) guidelines and incorporating functional evidence, c.1187_1195dup and c.1806 + 4_1806 + 28del were reclassified as likely pathogenic (LP), whereas c.1447G>A remained a variant of uncertain significance (VUS). CONCLUSIONS: This study describes a neonate with PORD caused by three novel POR variants and expands the known clinical spectrum of PORD by identifying rare manifestations including anal atresia and hearing loss. RNA-seq provided valuable functional evidence for variant interpretation and facilitated accurate molecular diagnosis. These findings highlight the importance of integrating genetic phasing, transcript-level functional analysis, and comprehensive clinical evaluation for precise diagnosis and counseling in rare endocrine disorders.

Humans↗

PubMed2026

Enzymatic innovations in Angelica pubescens reveal dual coumarin biosynthetic pathways driving metabolic diversification.

Coumarins are structurally diverse phenylpropanoid derivatives with ecological and pharmacological significance, yet the biosynthetic logic underlying their diversification remains incompletely understood in non-model medicinal plants. Angelica pubescens (Apiaceae), widely used in traditional Chinese medicine, accumulates a rich repertoire of furanocoumarins and dihydrofuranocoumarins, making it an ideal system to investigate this metabolic complexity. Here, we combined chromosome-level genome assembly, transcriptome and metabolite profiling, phylogenetics, and heterologous expression assays to dissect coumarin biosynthesis in A. pubescens. We identified two functionally specialized O-methyltransferases, ApOMT1 and ApOMT2, which catalyze regioselective methylation of xanthotoxol and bergaptol to yield the furanocoumarins xanthotoxin and bergapten. We also characterized ApCYP736A121, a cytochrome P450 enzyme that converts osthenol to the dihydrofuranocoumarin columbianetin via a previously unknown mechanism. Gene expression and metabolite accumulation patterns across tissues and developmental stages revealed functional partitioning among pathway branches. Phylogenetic and syntenic analyses indicated that ApOMT1 and ApOMT2 arose through subfunctionalization following gene duplication, whereas ApCYP736A121 evolved via neofunctionalization from a distantly related CYP736 ancestor. Together, our findings uncover dual biosynthetic routes to structurally distinct coumarins in A. pubescens and provide insights into the evolutionary mechanisms contributing to metabolic innovation in Apiaceae. This work lays a foundation for future efforts to engineer coumarin pathways and understand their ecological functions in medicinal plants.

Coumarins↗

PubMed2025

A multifunctional sesquiterpene synthase integrates with cytochrome P450s to reinforce the terpenoid defense network in maize.

Terpenoids, the largest and most structurally diverse class of plant natural products, play essential roles in maize defense and ecological interactions. In this study, we identified and functionally characterized a sesquiterpenoid-based defense pathway in maize centered on α-santalenoic acid, a pathogen-inducible sesquiterpenoid antibiotic. Using a combination of metabolite-based genome-wide association studies (mGWAS), linkage mapping, and heterologous expression assays, we identified ZmTPS9 as a multiproduct terpene synthase that primarily produces α-santalene and β-bisabolene. Sequence analysis and site-directed mutagenesis revealed that threonine at position 413 is critical for enzyme activity, with its deletion resulting in a complete loss of enzyme activity. The sesquiterpene hydrocarbons produced by ZmTPS9 are further oxidized by three cytochrome P450 monooxygenases, ZmCYP71Z16, ZmCYP71Z18, and ZmCYP71Z19, to yield antimicrobial metabolites including α-santalenoic acid, zealexin D1 (ZD1), and zealexin D2 (ZD2). Together, these findings demonstrate a convergent biosynthetic strategy in maize, where multiproduct terpene synthases and promiscuous P450s collaboratively generate a flexible and robust terpenoid defense network.

Zea mays↗

PubMed2026

Sexually dimorphic expression and hormonal responsiveness of steroidogenic Cyp genes during gonadal differentiation in mandarin fish.

Steroid hormones play a pivotal role in fish sex differentiation, yet the dynamic expression patterns of key steroidogenic enzymes during this process remain incompletely characterized. Here, we combined genome-wide identification, time series transcriptomes spanning gonadal development (5-360 days post-hatch), and multiple hormone treatment experiments (17α-methyltestosterone, estrone, and etonogestrel) to investigate the Cyp11, Cyp17, Cyp19, and Cyp21 subfamilies in mandarin fish (Siniperca chuatsi). Seven steroidogenic Cyp genes were identified, showing teleost-specific expansion, with one duplicated pair (cyp17a2 and cyp2u1) exhibiting strong purifying selection. Expression profiling revealed pronounced sexually dimorphic and stage-specific patterns: During female differentiation (20-30 days), cyp19a1a and associated genes were highly expressed, coinciding with ovarian differentiation; during male differentiation (30-60 days), cyp17a2 and related genes were upregulated, aligning with testicular development. Exogenous hormone treatments further demonstrated that these genes are dynamically responsive: cyp19a1a and cyp17a2 were highly responsive to androgenic and progestogenic treatments, and their expression changes correlated closely with gonadal sex reversal phenotypes observed histologically. Collectively, this study provides a comprehensive expression atlas of steroidogenic Cyp genes during gonadal differentiation and identifies key hormonally responsive candidates for sex control in aquaculture.

Animals↗

PubMed1975

The effects of the continuous administration of N,N-dimethyl-4-phenylazoaniline (DAB) on the activities and the inducibilities of some drug-metabolizing enzymes in rat liver.

(1) The effect of feeding a relatively low-protein diet containing 0.06% DAB for 29 weeks on the activity of DAB-azoreductase, nitroreductase (p-nitrobenzoic acid), N-oxidase (N,N-dimethylaniline), N-demethylase (DAB), cytochrome P-450, NADPH-cytochrome c reductase, beta-glucuronidase and arylsulphatase A were studied. Rapid decreases occurred in the activities of the first six enzymes, reaching minimal values at between 4 and 8 weeks. Activities then increased in all cases to control or nearly control levels. This rate of increase was least for cytochrome P-450. At 4 weeks azoreductase activity with the chemotherapeutic agent CB10-252 (I) as substrate was significantly higher than in control rats. Early increases occurred in the activities of beta-glucuronidase and arylsulphatase A and the activity of the latter never dropped below the control level. (2) An investigation was made of the differential effects of dye feeding on some of the enzyme activities in the two major liver lobes and differences were found. (3) The effect of phenobarbital (PB) pretreatment on the DAB-fed rats was studied at 4-week intervals. The activities of DAB-azoreductase and of nitroreductase increased throughout the whole period, while the activities of the lysosomal enzymes were decreased. (4) After feeding DAB for 4 weeks the effect of PB and 3-methylcholanthrene (MC) on the activities of DAB-azoreductase, CB10-252-azoreductase and components of the azoreductases-cytochrome P-450, NADPH-cytochrome c reductase, the CO-CB10-252-azoreductase was not induced by PB or MC, and CO did not inhibit its reduction. Its reduction depended only slightly on NADH. CO caused a greater relative decrease in the activity of DAB-azoreductase in dye-fed animals and also in animals following PB and MC pretreatment, implying a greater role of cytochrome P-450 in dye-fed animals.

Animals↗

PubMed2026

Complete biosynthesis of the anticancer cephalotaxinone and homoerythratine.

Cephalotaxine-type and homoerythrina-type alkaloids are structurally unique and biologically important natural products isolated from endangered species that belong to the genus Cephalotaxus. Among them, homoharringtonine (HHT [1]) is a marketed drug used to treat leukemia. However, the scalable production of HHT is significantly hindered by limited natural resources. Despite intensive investigation over half a century, the complete biosynthetic pathways of these alkaloids remain unknown. Here, we applied a comprehensive multi-omics analysis and used a set of chemically synthesized standard compounds to identify the missing enzymes required for the biosynthesis of cephalotaxinone and homoerythratine. We also uncovered a rare case of divergent oxidation catalyzed by two highly homologous cytochrome P450 enzymes, CfCYP2 and CfCYP3, in the biosynthesis of two structurally distinct alkaloids. We further identified the key residues that significantly affect the divergent oxidation outcomes and ultimately reconstituted the complete biosynthetic pathways for producing these two alkaloids in N. benthamiana.

Cephalotaxus↗

PubMed2025

Triazole-resistant Aspergillus fumigatus in the Netherlands between 1994 and 2022: a genomic and phenotypic study.

BACKGROUND: Aspergillus fumigatus is the main cause of invasive aspergillosis and triazole antifungals are the primary treatment option. The effectiveness of triazole therapy is hampered by the emergence of resistance, mainly caused by mutations in the cyp51A gene and a tandem repeat (TR) of 34 bases (TR34/Leu98His) and 46 bases (TR46/Tyr121Phe/Thr289Ala) in the promoter region, which correspond with signature triazole resistance phenotypes. We aimed to investigate the occurrence of triazole phenotype and genotype variation over a 29-year period in the Netherlands. METHODS: In this genomic and phenotypic study, we screened all clinical A fumigatus isolates from Dutch hospitals collected between Jan 6, 1994, and Dec 31, 2022, for resistance to triazole using agar-based methods, and characterised them by sequencing the cyp51A gene and in vitro susceptibility testing using the European Committee on Antimicrobial Susceptibility Testing reference method. Whole-genome sequencing was performed on selected isolates, including those harboring TR34 variants, high-frequency single-nucleotide polymorphisms, and wild-type strains. Clinical information such as age, underlying disease, diagnosis, therapy, and outcomes was collected for patients who had isolates cultured at the Radboud University Medical Centre, Nijmegen, Netherlands, between Jan 1, 2017, and Dec 31, 2022. FINDINGS: 1979 (15·6%) of the screened 12 679 A fumigatus isolates harboured cyp51A triazole resistance mutations, predominately TR34/Leu98His sensu stricto in 1338 (67·6%) resistant isolates and TR46/Tyr121Phe/Thr289Ala sensu stricto in 332 (16·8%) resistant isolates. Phenotype and genotype variations were observed in 325 (17·2%) triazole resistant isolates harbouring a TR-resistance mechanism, including 12 cyp51A genotype variants. Whole-genome sequencing showed that isolates with combinations of TR34-based and TR46-based polymorphisms seemed to be derived from separate populations, but there was some overlap. 59 cases of proven or probable invasive aspergillosis were identified, including 13 triazole-resistant cases, of which three were caused by genotype variants. Mixed genotype infection was observed in 11 (84·6%) of 13 triazole-resistant patients and the number of antifungal treatment switches was higher compared with triazole-susceptible disease (p<0·0001). INTERPRETATION: Our study showed variation in triazole genotypes and phenotypes in clinical A fumigatus isolates with cyp51A-mediated resistance, some of which were cultured from triazole-resistant invasive aspergillosis cases. Triazole resistance variation and mixed A fumigatus genotypes represent a major challenge in clinical management of Aspergillus diseases because current molecular diagnostic tools will increasingly fail to predict the resistance phenotype, underscoring the need for improved detection methods. FUNDING: National Key Research and Development Program of China, National Natural Science Foundation of China, and Wellcome Trust.

Aspergillus fumigatus↗

PubMed2026

Sex-specific expression of detoxification proteins contributes to differential metabolic detoxification capacity and acaricide sensitivity in female and male Tetranychus cinnabarinus (Boisduval).

Pronounced sex-specific differences exist in the toxicological traits of spider mite species. Our previous work showed that female Tetranychus cinnabarinus exhibit significantly higher tolerance to acaricides than males, primarily driven by elevated detoxification enzyme activity. However, the molecular basis underlying this sex-specific difference remains unclear. Here, we used pyridaben and cyflumetofen as representative acaricides to dissect the molecular mechanisms underlying sex-specific differences in detoxification metabolism between female and male mites. After 48 h of cyflumetofen exposure, GST activity increased significantly in female mites. Following pyridaben exposure, the activities of both P450 (24 h and 48 h) and CCE (48 h) increased significantly in female mites. Under the same conditions, only P450 activity increased significantly in male mites after 48 h of pyridaben exposure. Proteomic profiling identified 33 differentially expressed detoxification enzymes, predominantly from the major detoxification families P450, GST, and CCE; among them, 26 were significantly upregulated in females relative to males. Six detoxification enzymes, including CYP392A3, CYP389C5, TcGSTd02, TcGSTd13, TcCCE39, and TcCCE52, were selected for functional characterization. We successfully obtained six active recombinant detoxification enzymes through heterologous expression. IC50 and in vitro metabolism assays showed that these recombinant proteins display both shared and distinct capacities for metabolizing or sequestering cyflumetofen and pyridaben. RNAi and bioassay results demonstrated that silencing CYP389C5, TcGSTd02, and TcCCE52 resulted in more pronounced changes in acaricide susceptibility in female than in male mites. Collectively, this study demonstrates that the sex-biased protein abundance identifies candidate biochemical contributors to differential susceptibility in female and male mites.

Animals↗

PubMed2025

Enzymatic Anti-Baldwin Ring-Closure Cascade for Fused Bicyclic Ether Formation.

Pyrenulic acids are cytotoxic polyketides isolated from the ascomycete Pyrenula sp. derived from Vietnamese lichen that are characterized by complex fused cyclic core structures. Genome sequencing, in silico sequence analysis, and RT-PCR studies identified the pyrenulic acid (pya) biosynthetic gene cluster. Based on a functional analysis of the enzymes by expression of each gene in a heterologous host using Aspergillus nidulans, we discovered two cytochrome P450s PyaJ and PyaG that effect epoxidation and hydroxylation of the alkyl chain terminal, respectively, and an α/β hydrolase PyaF that constructs a 6- and 7-membered fused bicyclic diether skeleton by catalyzing successive epoxide ring-opening 6-endo and 7-endo cyclization reactions. To elucidate the detailed mechanism of pyrenulic acid formation, we obtained PyaF as a recombinant enzyme and performed an in vitro experiment, which confirmed catalysis by PyaF of the cyclization reaction. In addition, we performed alignment analysis of PyaF with α/β hydrolases with known functions, as well as an in-depth computational study. In-depth computational analyses of the cyclization reaction pathways with density functional theory quantum mechanics and detailed characterization of PyaF by Chai-1-based protein structure modeling with molecular dynamics simulations and site-specific mutagenesis predicted the active amino acid residues of this serine α/β hydrolase to be an unusual catalytic serine tetrad involving Ser170, Asn342, Asp314, and His169, with Tyr255 and His284 acting as general bases to facilitate opening of the epoxides. Our study provides insight into how regioselectivity of enzymatic anti-Baldwin epoxide ring-opening cascades for the formation of a fused cyclic ether structure is controlled.

Cyclization↗

PubMed2026

Cytochrome P450- and Dehydrogenase-Mediated Regiospecific and Stereoselective Formation of β- and γ-Lactones in Drimane-Type Sesquiterpenoid Biosynthesis.

Lactone-containing natural products are important candidates for drug discovery. Drimane-type sesquiterpenes (DTSs), characterized by a bicyclic trans-decalin scaffold, can bear both β- and γ-lactone moieties. While γ-lactone-containing DTSs have frequently been reported, β-lactone-containing derivatives are rare, and their biosynthesis remains unexplored. Here, we identified a biosynthetic gene cluster (dri) in Aspergillus ustus and confirmed ustidrimane A (1), a β- and γ-lactone-containing DTS, as its product. Heterologous gene expression, precursor feeding, and enzymatic investigation provided evidence for the formation of both lactone rings. In both cases, the reaction cascade is initiated by regiospecific (and stereoselective) methyl hydroxylation, followed by regiospecific and stereoselective oxidation of one hydroxymethyl group to an aldehyde. The resulting hemiacetal was proven to be subsequently oxidized to a lactone. The β-lactone formation is catalyzed by two cytochrome P450 enzymes (DriE and DriF), followed by two oxidation steps catalyzed by two dehydrogenases (DriG and DriH). These findings differ entirely from the known β-lactone formation in fatty acid-, PKS-, and NRPS-derived metabolites. The subsequent γ-lactone formation is catalyzed by a P450 (DriJ) and a dehydrogenase (DriD). DriJ has been shown to be involved in both methyl hydroxylation and hemiacetal formation, while DriD is responsible for the hemiacetal oxidation and also contributes moderately to its formation. Collectively, these findings establish a sequential P450/dehydrogenase-mediated oxidative cascade for the construction of two distinct lactone motifs within a single DTS scaffold. Moreover, they provide the first insight into the β-lactone formation in terpenes, thus unveiling a new strategy for the construction of this structural motif.

Lactones↗

PubMed2026

Biosynthesis and heterologous production of the α-agarofuran scaffold of Celangulin V from Celastrus angulatus.

Celangulin V is a widely used biopesticide derived from Celastrus angulatus, and features antifeedant and insecticidal properties as a dihydro-β-agarofuran (DHβAF) sesquiterpenoid. Its biosynthesis remains largely unexplored. Here, we assemble a chromosome-level and haplotype-resolved reference genome of C. angulatus, with each haplotype assembled into 23 pseudochromosomes and achieving scaffold N50 of 14.31 and 14.01 Mb, respectively. This high-quality genome reveals that a recent β whole-genome triplication (β-WGT) event occurred ~34.3 million years ago, and that the expansion of sesquiterpene synthases and cytochrome P450s from the CYP71BE family results from whole-genome duplication (WGD) event and tandem duplication, respectively. We identify CaTPS16 as a γ-eudesmol synthase, and show that CYP71BE416 further catalyzes the γ-eudesmol to tetrahydrofuran ring α-agarofuran for Celangulin V biosynthesis. We further achieve the de novo synthesis of α-agarofuran in Saccharomyces cerevisiae through combined coexpression of these genes. This study has significantly increases the available genomic resources of the Celastraceae family, improves our understanding of the biosynthetic origins and evolution of the tetrahydrofuran ring in DHβAF sesquiterpenoids, and enables its heterologous bioproduction in microbial chassis.

Celastrus↗

PubMed2026

Prediction of bacterial protein-compound interactions with only positive samples.

MOTIVATION: Prediction of Compound-Protein Interactions (CPI) in bacteria is crucial to advance various pharmaceutical and chemical engineering fields, including biocatalysis, drug discovery, and industrial processing. However, current CPI models cannot be applied for bacterial CPI prediction due to the lack of curated negative interaction samples. RESULTS: We propose a novel Positive-Unlabeled (PU) learning framework, named BIN-PU, to address this limitation. BIN-PU generates pseudo positive and negative labels from known positive interaction data, enabling effective training of deep learning models for CPI prediction. We also propose a weighted positive loss function that weights to truly positive samples. We have validated BIN-PU coupled with multiple CPI backbone models, comparing the performance with the existing PU models using bacterial cytochrome P450 (CYP) data. Extensive experiments demonstrate the superiority of BIN-PU over the benchmark models in predicting CPIs with only truly positive samples. Furthermore, we have validated BIN-PU on additional bacterial proteins obtained from literature review, human CYP datasets, and uncurated data for its reproducibility. We have also validated the CPI prediction for the uncurated CYP data with biological and biophysical experiments. BIN-PU represents a significant advancement in CPI prediction for bacterial proteins, opening new possibilities for improving predictive models in related biological interaction tasks. AVAILABILITY AND IMPLEMENTATION: The source code and data are available at https://github.com/datax-lab/CYP.

Bacterial Proteins↗

PubMed2025

Inference of Cytochrome P450 Evolutionary History Using Structural and Physicochemical Metrics.

Cytochrome P450s are a superfamily of heme-binding monooxygenases involved with the detoxification of intrinsic and extrinsic toxins. They are near ubiquitous within biological domains and are found in all domains. Members of families within the superfamily are defined based on amino acid identity thresholds, with thresholds as low as 40% in some families. Relationships among Cytochrome P450 families have proven elusive due to sub-Twilight Zone interfamily identities (<30%) that result in poor multiple sequence alignment quality and thus low levels of support for downstream phylogenetic reconstructions. Despite the low identities, Cytochrome P450 structures are remarkably well conserved both within and among families. In such cases, structural phylogenetics has the potential to unveil elusive relationships because the selectively favored physicochemical properties giving rise to the structure and function of the proteins persist despite sequence-level divergence. Recently, in two separate publications, we demonstrated that by utilizing physicochemical vectors, dynamic time warping, and hierarchical clustering (PCDTW), large swaths of protein domain families and betacoronavirus receptor-binding domain clades were congruent with validated functional/structural relationships. These were important findings because anomalous sequence alignment-based maximum likelihood phylogenetic findings, which were not congruent with the known functional relationships, were resolved. That also validated the use of physicochemical vectors in making inferences about structural/functional homology. Additionally, it illuminated that the same methods might be applied to other protein families with relationships that are difficult to resolve from sequence data alone. Herein, we used Molecular Weight and Hydrophobicity Physicochemical Dynamic Time Warping (MWHP PCDTW) along with structural and sequence alignment-based phylogenetic methodologies to analyze all of the Cytochrome P450s found both in the high-fidelity Structural Classificaction of Proteins (SCOP) database and the reviewed sequences with both experimentally resolved and de novo predicted structures in the Protein Data Bank and the AlphaFold (AF) Protein Structure Database, respectively. We compared the resulting phylogenetic topologies and found that in some cases, structure-based methods may be less able to resolve random/convergent similarity than physicochemical and sequence-based methodologies. This finding agrees with previous findings that demonstrate the usefulness of physicochemical properties in resolving both random structural similarity and potentially convergent relationships.

Cytochrome P-450 Enzyme System↗

PubMed2026

Ultraviolet-B-induced OsKOL4 promotes ABA accumulation by inhibiting OsABA8ox1 and OsABA8ox2 expression.

Ultraviolet-B (UV-B) light is a component of sunlight that influences plant survival and adaptation. UV-B induces plants to regulate their phenotypes and metabolism to increase resistance to UV-B and associated stresses. Abscisic acid (ABA) metabolism and signaling are important for plant responses to UV-B. However, the mechanisms underlying UV-B-induced ABA accumulation and signaling in rice remain poorly understood. Here, we report that ENT-KAURENE OXIDASE LIKE 4 (OsKOL4) regulates UV-B-induced responses and ABA biosynthesis. UV-B activates OsKOL4 expression via OsbZIP48, an ELONGATED HYPOCOTYL 5 (HY5) homolog that directly binds to the OsKOL4 promoter. Rice plants overexpressing OsKOL4 exhibit UV-B-induced phenotypes under normal conditions, along with ABA overaccumulation phenotypes resulting from increased ABA levels. Moreover, UV-B promotes ABA accumulation by inhibiting the expression of the ABA 8'-HYDROXYLASE1 and ABA 8'-HYDROXYLASE 2 (OsABA8ox1/2) genes through OsKOL4. OsKOL4 interacts with the transcription factor AP2/ERF ON CHROMOSOME 3 (OsAPE3), which in turn represses the transcription of OsABA8ox1/2. Furthermore, both UV-B and OsKOL4 enhance the binding of OsAPE3 to the OsABA8ox1/2 promoters. Collectively, our findings demonstrate that the OsKOL4-OsAPE3 module regulates ABA homeostasis in response to UV-B signaling by reducing ABA catabolism.

Abscisic Acid↗