bims-toxgon Biomed News
on Toxoplasma gondii metabolism
Issue of 2026–08–16
24 papers selected by
Lakesh Kumar, BITS Pilani



  1. Cell. 2026 Aug 11. pii: S0092-8674(26)00827-5. [Epub ahead of print]
      Diverse organisms adjust metabolic gene expression during crowding as they encounter nutrient scarcity, oxidative stress, and waste accumulation. Apicomplexan parasites experience these stresses during intracellular growth within host cells yet lack known regulators of metabolic adaptation. We screened the apicomplexan parasite Toxoplasma gondii to identify genes that support parasite fitness during crowding. Nicotinamide adenine dinucleotide (NAD)(P)+ biosynthesis was required at high parasite density, along with several parasite-specific factors, including an RNA-binding protein we named "T. gondii parasite response to oxidation" (TgPRO). TgPRO loss elevated reactive oxygen species under ambient conditions, which was rescued by growth at low oxygen levels. TgPRO regulates the expression of transcripts involved in carbon metabolism and iron-sulfur cluster assembly. Regulation of the iron-sulfur cluster assembly protein ISCU relies on TgPRO binding to the transcript's 3' UTR. Through convergent evolution, TgPRO performs a role analogous to that of known metabolic regulators from other species, representing the first dedicated regulator of metabolic gene expression in apicomplexans.
    Keywords:  RNA-binding protein; Toxoplasma gondii; apicomplexan; convergent evolution; iron; iron-sulfur cluster; metabolic regulation; oxidative stress; parasitology
    DOI:  https://doi.org/10.1016/j.cell.2026.07.029
  2. Cells. 2026 Jul 24. pii: 1324. [Epub ahead of print]15(15):
      Bumped kinase inhibitors are safe with promising efficacy against apicomplexan parasites. The 5-aminopyrazole-4-carboxamide BKI-1708 effectively inhibited vertical transmission of Toxoplasma gondii and significantly reduced the cerebral parasite loads in experimentally infected pregnant mice. In vitro experiments revealed that exposure of T. gondii tachyzoites to BKI-1708 induces the formation of intracellular multinucleated complexes called "baryzoites", exhibiting increased expression of bradyzoite-stage proteins while still displaying classical tachyzoite markers. Differential affinity chromatography of T. gondii extracts identified numerous BKI-1708-binding proteins involved in invasion/egress, redox homeostasis, and RNA processing. To understand the transcriptional implications of BKI-1708 treatment on T. gondii tachyzoites and human foreskin fibroblast host cells, T. gondii-infected host cells, either treated with BKI-1708 or untreated, were subjected to dual RNA-seq analysis. BKI-1708 induced a significant transcriptional remodeling in the parasite, with an enrichment in pathways related to translation, RNA metabolism, and stress responses. In contrast, host-cell transcriptional changes were more limited, with transcripts related to metabolic and detoxification programs upregulated in uninfected fibroblasts, and increased transcription of immune, lysosomal, and glycan degradation pathways in infected fibroblasts. These findings suggest that BKI-1708 modulates the transcriptome in a predominantly parasite-specific manner, disrupting essential biological processes in T. gondii while largely preserving host cell function.
    Keywords:  Toxoplasma; anti-parasitic activity; bumped kinase inhibitor; differential gene expression; human fibroblast; mode of action; transcriptome
    DOI:  https://doi.org/10.3390/cells15151324
  3. J Biol Chem. 2026 Aug 12. pii: S0021-9258(26)02308-2. [Epub ahead of print] 113436
      Toxoplasma gondii, a highly successful apicomplexan parasite, primarily relies on post-transcriptional mechanisms to regulate mRNA stability and translation during rapid life-cycle stage transitions and to adapt to diverse host environments. While RNA-binding proteins (RBPs) are crucial for these regulatory processes, their specific roles in mRNA translation, storage, and degradation during life-stage transitions and under physiological stress in Toxoplasma remain poorly understood. Here, we identified the PUF family of RBPs and characterized two conserved members, TgPuf1 and TgPuf2. We examined their expression, localization, RNA-binding activity, essentiality during asexual stages in cell culture and mouse host, responses to stress conditions, and roles in transcript regulation. Gene-knockout studies in cell-culture showed that TgPuf1 modestly supports parasite fitness under both normal and stress conditions, while TgPuf2 appears largely dispensable. Mice infected with Puf1-deleted tachyzoites showed delayed mortality compared with wild-type, whereas neither Puf1 nor Puf2 deletion affected bradyzoite development. Both TgPuf proteins bind to a conserved RNA sequence known as PUF Recognition Elements (PREs), associate with ribonucleoprotein complexes, and interact with the deadenylase enzyme TgPop2. Using synthetic RNA reporter systems, we demonstrated that, upon interaction with TgPop2, TgPuf proteins stimulate the removal of the poly(A) tail from RNA targets, thereby promoting RNA degradation. The inability to generate the double knockout is adequately addressed using TgPuf1-mAID in the delta TgPuf2 background, indicating that individual Puf proteins are dispensable; however, the lack of both results in severe growth defects. Overall, these findings suggest that PUF proteins regulate transcript levels in Toxoplasma through a deadenylation-dependent mechanism.
    Keywords:  Apicomplexan; Deadenylase; PUF; RNA degradation; RNA-binding protein; Toxoplasma gondii
    DOI:  https://doi.org/10.1016/j.jbc.2026.113436
  4. Biochim Biophys Acta Biomembr. 2026 Aug 14. pii: S0005-2736(26)00070-2. [Epub ahead of print] 184567
      Apicomplexan parasites, including Toxoplasma gondii and Plasmodium falciparum, reside within a specialized compartment known as the parasitophorous vacuole (PV) during their intracellular life cycle. The PV membrane (PVM), which derives from the host plasma membrane upon invasion, serves as a selective barrier that permits nutrient acquisition while shielding the parasite from host defense mechanisms. Although the protein composition of the PVM has been studied extensively, its lipid organization remains poorly understood. Using the quick-freeze, freeze-fracture replica labeling (QF-FRL) method, we quantitatively analyzed the transbilayer distribution of phosphatidylserine (PtdSer), phosphatidylethanolamine (PtdEtn), and GM3 ganglioside in the PVM of T. gondii and P. falciparum. Unlike host cell plasma membranes, where these lipids exhibit strict asymmetry-PtdSer and PtdEtn confined to the cytoplasmic leaflet and GM3 to the exoplasmic leaflet-we found that all three lipids were symmetrically distributed across both leaflets of the PVM. This striking loss of lipid asymmetry suggests that the PVM undergoes profound remodeling during infection. The presence of PtdSer and PtdEtn in the luminal leaflet may facilitate the binding of perforin-like proteins (PLP1s) during egress. These findings reveal a unique feature of the PVM that redefines our understanding of host-parasite membrane biology.
    Keywords:  Electron microscopy; Freeze-fracture; Nanoscale; Phospholipids; Rapid freeze
    DOI:  https://doi.org/10.1016/j.bbamem.2026.184567
  5. Parasitol Int. 2026 Aug 10. pii: S1383-5769(26)00128-5. [Epub ahead of print]116 103357
      Bromodomains (BRDs) are protein interaction modules that exclusively recognize acetylation motifs, and are evolutionarily conserved and present in diverse nuclear proteins. Toxoplasma gondii is the causative agent of toxoplasmosis, with the tachyzoite stage driving pathogenesis through rapid invasion and replication within nucleated cells. Bromodomain-containing protein 4 (BDP4) is a conserved BRD protein across apicomplexans. To address the roles of T. gondii bromodomain-containing protein 4 (TgBDP4) in the lytic circle of T. gondii, the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 and an auxin-inducible degron-based conditional knockdown strategy were used to construct a conditional knockdown parasite line. Phenotypic analysis revealed a growth defect in parasite replication when TgBDP4 was depleted conditionally. TgBDP4 localized in the parasite's nucleus. Depletion of the TgBDP4 led to changes in the expression level of 874 genes. The loss of TgBDP4 resulted in widespread dysregulation of gene expression, highlighting its involvement in both transcriptional activation and repression. Notably, perturbation in the expression of seven APiAP2 transcription factors was accompanied by the down-regulation of specific secretory proteins, such as ROP37, ROP15, ROP30, MIC3, and MIC12. These findings suggest that TgBDP4 may be implicated in the regulatory network controlling secretory protein expression.
    Keywords:  APiAP2; Bromodomain-containing protein 4; Conditional ablation; Toxoplasma gondii; Virulence factors
    DOI:  https://doi.org/10.1016/j.parint.2026.103357
  6. Acta Trop. 2026 Aug 12. pii: S0001-706X(26)00312-8. [Epub ahead of print] 108279
      Toxoplasmosis is a widespread zoonotic disease causing severe outcomes in immunocompromised individuals and during pregnancy. Current therapeutic options target actively replicating stages of the parasite and show limited efficacy against chronic infection. While research has focused on parasite-directed therapies, host-directed strategies to enhance tolerance and preserve tissue integrity remain underexplored. In this study, we analyzed untargeted serum metabolomics data to identify host metabolic alterations during acute and chronic Toxoplasma gondii (T. gondii) infection in a murine model. Analysis of metabolomic data revealed widespread infection-associated metabolic remodeling, with consistent perturbations in lipid metabolism and amino acid pathways. Among the metabolites most robustly depleted during infection was the essential amino acid L-lysine. We evaluated the impact of L-lysine supplementation on disease outcomes in vivo. L-lysine supplementation was associated with a trend toward improved survival and reduced tissue pathology during both acute and chronic infection. Supplemented mice also exhibited reduced inflammatory cytokine dysregulation and lower tissue parasite burdens, effects that are consistent with enhanced host resilience rather than direct antiparasitic activity. These findings identify L-lysine depletion as a metabolic feature of T. gondii infection and demonstrate that its supplementation confers measurable host-protective benefits. Our study highlights the value of metabolomics-guided approaches for uncovering host metabolic vulnerabilities and supports the concept of L-lysine supplementation as a host-directed adjunctive intervention to mitigate pathology during toxoplasmosis.
    Keywords:  L-lysine supplementation; Toxoplasma gondii; inflammatory cytokines; metabolomics
    DOI:  https://doi.org/10.1016/j.actatropica.2026.108279
  7. Biochem J. 2026 Aug 12. pii: BCJ20260439. [Epub ahead of print]
      The spliceosome is emerging as a key regulatory hub in Toxoplasma gondii, yet the molecular basis of spliceosomal protein interactions remains largely unexplored. TgCyp23, a predicted nuclear cyclophilin from T. gondii, shares sequence similarity and catalytic properties with the human spliceosomal cyclophilin H (hCypH) that interacts with the splicing factors PRP4 and PRP18. Here, we investigated whether TgCyp23 engages in analogous interactions with the T. gondii orthologs TgPRP4 and TgPRP18 using peptides corresponding to their predicted cyclophilin-binding regions. High-resolution crystal structures of TgCyp23 in complex with a TgPRP4-derived peptide, including a ternary complex with the cyclophilin inhibitor cyclosporin A, reveal that spliceosomal partner recognition occurs outside the catalytic site, which remains accessible and inhibitor-sensitive. NMR analyses extend this binding mode to TgPRP18, demonstrating that recognition motifs from both spliceosomal factors engage the same surface in solution. Isothermal titration calorimetry shows that TgCyp23 binds both peptides with low- to mid-micromolar affinity, while circular dichroism and molecular dynamics support a folding-upon-binding mechanism. Notably, binding of either peptide does not affect the peptidyl-prolyl isomerase activity of TgCyp23, indicating that partner recognition and catalytic function are mechanistically separable. Together, these findings identify a non-catalytic interaction surface in TgCyp23 that mediates recognition of spliceosomal factors. The similar interaction mode observed for TgCyp23 and hCypH suggests that spliceosomal partner recognition may be conserved and supports a role for TgCyp23 as a spliceosome-associated cyclophilin in T. gondii, providing a structural framework for understanding cyclophilin interactions within the parasite spliceosome.
    Keywords:  Cyclophilins; Toxoplasma gondii; crystal structure; cyclosporin A; protein-peptide interactions; spliceosome
    DOI:  https://doi.org/10.1042/BCJ20260439
  8. Front Cell Infect Microbiol. 2026 ;16 1897580
       Background: Triggering receptor expressed on myeloid cells 2 (Trem2) deficiency aggravated adverse pregnancy outcomes caused by Toxoplasma gondii (T. gondii) infection during pregnancy; however, the precise molecular mechanisms involved remain to be fully elucidated.
    Methods: Molecular docking, co-immunoprecipitation, and alanine scanning mutagenesis were employed to identify the interaction between Trem2 and mammalian target of rapamycin (MTOR). In vivo experiments utilized a T. gondii-infected pregnant mouse model with wild-type and Trem2-knockout mice, while in vitro studies were performed using Raw264.7 macrophages and bone marrow-derived macrophages (BMDMs) with T. gondii antigen stimulation, Trem2 overexpression, and siRNA-mediated MTOR knockdown.
    Results: A direct high-affinity interaction between Trem2 and MTOR was identified, with GLN-198, ARG-195, and LYS-199 as critical binding residues. T. gondii infection significantly downregulated Trem2 expression while upregulating MTOR and its downstream effector protein kinase C alpha (PKCα). Trem2 deficiency exacerbated MTOR-PKCα hyperactivation upon infection and aggravated placental hemorrhage, necrosis, and fetal growth restriction. Conversely, Trem2 overexpression suppressed MTOR and PKCα expression, and MTOR knockdown confirmed that PKCα acts downstream of MTOR.
    Conclusion: Trem2 negatively regulates the MTOR-PKCα axis through direct interaction, and T. gondii infection downregulates Trem2 to relieve this inhibition, leading to MTOR-PKCα hyperactivation and adverse pregnancy complications.
    Keywords:  PKCα; Toxoplasma gondii; Trem2; adverse pregnancy outcomes; mTOR
    DOI:  https://doi.org/10.3389/fcimb.2026.1897580
  9. Cell Chem Biol. 2026 Aug 12. pii: S2451-9456(26)00282-5. [Epub ahead of print]
      Lysine acylation has emerged as a rapidly expanding family of post-translational modifications that directly links cellular metabolism to protein regulation. Beyond lysine acetylation, advances in mass spectrometry and chemical biology have uncovered a diverse repertoire of acyl modifications spanning short-chain, branched, unsaturated, aromatic, and dicarboxylic groups. Together these modifications establish lysine acylation as a molecular interface through which metabolic state can shape protein function, chromatin regulation, and cell signaling. Yet fundamental questions remain regarding their biological significance, enzymatic regulation, site specificity, and whether many acylations function as bona fide regulatory signals or reflect metabolite-driven mechanisms. Here, we synthesize the current understanding of the metabolic origins, structural and biochemical properties, and their writer, reader, and eraser systems that govern lysine acylations. We further highlight emerging chemical biology approaches for detecting, manipulating, and functionally interrogating acyl marks and discuss the conceptual and technological advances needed to distinguish closely related modifications and establish their causal biological roles.
    Keywords:  PTMs; acylation; epigenetics; lysine post-translational modifications; mass spectrometry; metabolism
    DOI:  https://doi.org/10.1016/j.chembiol.2026.07.009
  10. Front Immunol. 2026 ;17 1784874
      Atherosclerosis (AS) is the leading cause of cardiovascular disease-related mortality worldwide and serves as the core pathological basis for cardiovascular events. Protein acetylation, a widespread and highly dynamic post-translational modification, has emerged as a critical link connecting epigenetic regulation, metabolic homeostasis, and inflammatory signaling, thereby playing an important role in both the initiation and progression of AS. This review systematically summarizes the major forms of protein acetylation, including N-terminal acetylation and lysine acetylation, as well as the key regulatory enzymes involved, such as acetyltransferases (e.g., HATs and NATs) and deacetylases (e.g., HDACs and sirtuins). Particular emphasis is placed on the cell type-specific regulatory roles of acetylation in macrophages, vascular endothelial cells, and vascular smooth muscle cells. Accumulating evidence indicates that protein acetylation modulates gene transcription and protein function through multiple mechanisms, thereby influencing a broad spectrum of AS-related processes, including inflammation, glycolipid metabolism, oxidative stress, energy metabolism, apoptosis, proliferation, and migration. Based on these mechanisms, therapeutic strategies targeting enzymes that regulate acetylation, particularly selective HDAC inhibitors and sirtuin activators, have emerged as promising approaches for the treatment of AS. By integrating recent advances in cellular heterogeneity, plaque stage-specific regulation, and human translational evidence, this review further discusses the therapeutic potential of targeting acetylation-regulating enzymes and critically evaluates the current limitations of this strategy, including contradictory findings, off-target effects, and barriers to clinical translation. Overall, protein acetylation represents a key regulatory hub linking epigenetics, metabolism, and inflammation. A deeper understanding of its regulatory network may provide new insights into the development of precision therapies for AS.
    Keywords:  atherosclerosis; inflammatory response; protein acetylation; protein acetyltransferases; protein deacetylases
    DOI:  https://doi.org/10.3389/fimmu.2026.1784874
  11. Int J Mol Sci. 2026 Jul 30. pii: 6840. [Epub ahead of print]27(15):
      Sirtuins (SIRTs) are NAD+-dependent enzymes implicated in cancer and other diseases, but the high conservation of their catalytic sites complicates the development of isoform-selective inhibitors. BZD9L1 is a benzimidazole-based sirtuin inhibitor with previously reported activity against SIRT1 and SIRT2. However, its potential interactions with other human sirtuin isoforms remain incompletely characterized. Here, we applied a comparative structure-based modelling framework integrating homology modelling, molecular docking, and targeted experimental assessment to investigate plausible binding modes of BZD9L1 across human SIRT1-7. Docking predicted that BZD9L1 could occupy the ADP-ribose cofactor-binding region of all seven isoforms, with broadly conserved orientations but differences in the predicted interaction networks. Hydrogen-bonding and π-mediated contacts predominated in the selected SIRT1-3 poses, whereas hydrophobic contacts were more apparent in several selected SIRT4-7 poses. The modest differences in docking scores were interpreted qualitatively and do not establish differential binding affinities or isoform selectivity. In colorectal cancer cells, BZD9L1 treatment altered acetyl-SOD2 levels, consistent with altered SIRT3-associated deacetylation in a cellular context. In a separate cell-free enzymatic assay, no measurable SIRT5 inhibition was detected under the conditions tested. These complementary assays provided distinct, independently interpreted readouts of SIRT3-associated cellular activity and SIRT5 enzymatic activity. Collectively, this study provides testable structural hypotheses regarding BZD9L1 recognition by human sirtuins and identifies interaction features that may guide subsequent biochemical and structure-based investigations.
    Keywords:  BZD9L1; molecular docking; predicted binding modes; protein–ligand interactions; sirtuins; structure-based modelling
    DOI:  https://doi.org/10.3390/ijms27156840
  12. Curr Opin Struct Biol. 2026 Aug 13. pii: S0959-440X(26)00139-9. [Epub ahead of print]101 103357
      Cryo-electron tomography (cryo-ET) has emerged as a transformative technique for visualizing the native ultrastructure of eukaryotic parasites, from proteins to cellular architecture. Recent technical advances in sample preparation, data collection, and computational analysis have enabled unprecedented insights into structural cell biology of medically important pathogens including Toxoplasma gondii, Plasmodium falciparum, Trypanosoma brucei and Trypanosoma cruzi, Cryptosporidium parvum, and Microsporidia. This review highlights the range of resolutions and cellular structures accessible by cryo-ET, and the kinds of biological insights that may be obtained, using eukaryotic parasites as case studies. Lower-resolution data (20-30 Å) provide structural information on organelles, whole-cells, and cell-cell interactions, while at the higher-resolution end, near-atomic structures can be resolved in situ using subtomogram averaging, typically for large, abundant particles such as ribosomes. Combined with orthogonal techniques, cryo-ET is a powerful tool for studying the structural cell biology of parasites.
    DOI:  https://doi.org/10.1016/j.sbi.2026.103357
  13. Front Immunol. 2026 ;17 1830954
       Introduction: Toxoplasma gondii can cause toxoplasmosis. It is an important type of pathogen within the broad category of emerging and re-emerging zoonoses. As an infectious disease featuring a complex multi-host transmission cycle, it poses an increasingly severe threat to global public health. No licensed vaccines are currently available for pets and humans, and thus a novel high-efficiency vaccine is urgently required.
    Methods: Six antigens (GRA1, MIC17A, OWP2, LEA880, LEA870, and a hypothetical protein LEA530) representing different stages of the parasite lifecycle were selected from ToxoDB. T-cell and B-cell epitopes were predicted using immunoinformatics tools and screened based on antigenicity, allergenicity, and toxicity. The multi-epitope peptide (MEP1) was evaluated using molecular docking with Toll-like receptor 4 (TLR4) and immune simulation. The optimized sequence was expressed in HEK293T cells as a recombinant plasmid (MEP1-pcDNA3.1) and further evaluated in BALB/c mice.
    Results: MEP1 contained 13 cytotoxic T lymphocyte epitopes, 16 helper T lymphocyte epitopes, and 12 B-cell epitopes, with a length of 732 amino acids and a predicted molecular weight of 75.73 kDa. The antigenicity score was 0.7343, and structural modeling indicated stable secondary and tertiary conformations. Molecular docking suggested strong binding affinity to TLR4. Immune simulation predicted increased B-cell and T-cell responses following vaccination. In vivo, MEP1-pcDNA3.1 immunization significantly increased serum IFN-γ levels (526.81 pg/mL) compared with PBS and pcDNA3.1 controls. Splenocyte proliferation was significantly enhanced in the MEP1-pcDNA3.1 group (SI = 1.58 ± 0.21) compared with PBS (1.10 ± 0.09) and pcDNA3.1 (1.12 ± 0.04) groups (P < 0.01). Following challenge with 5 × 10³ tachyzoites of the PLK strain, survival was markedly prolonged in vaccinated mice, whereas all control mice died within 2-4 days.
    Conclusion: This study demonstrates an immunoinformatics-guided multi-epitope vaccine strategy against T. gondii, supported by in vivo immunogenicity and partial protective efficacy in a mouse model.
    Keywords:  MEP1; Toxoplasma gondii; bioinformatics; multi-epitope vaccine; protective efficacy assessment
    DOI:  https://doi.org/10.3389/fimmu.2026.1830954
  14. Nano Lett. 2026 Aug 11.
      Apicomplexan parasites exhibit gliding motility, a fast locomotion mode, yet the precise localization of the migration motor myosin A (MyoA) remains unresolved because of limitations in light microscopy axial resolution, leading to two competing models: one placing MyoA in the cytoplasm and the linear model positioning it between the plasma membrane and the inner membrane complex (IMC), a doubled membrane underneath. To distinguish between these models, we applied graphene energy transfer (GET), a fluorescence-based axial ruler with nanometer precision, and determined the vertical position of MyoA relative to IMC1, a structural IMC marker. GET measured IMC dimensions with accuracy comparable to electron microscopy while preserving molecular specificity. The results were independently validated using live stimulated emission depletion (STED) imaging of vertically oriented parasites in agarose cylinders and expansion microscopy STED. Our data localize a major fraction of MyoA within the membrane-IMC space, supporting a linear motor model and establishing GET for nanoscale protein mapping.
    Keywords:   Toxoplasma ; Apicomplexa; GET; graphene; linear model; migration; myosin A; super-resolution
    DOI:  https://doi.org/10.1021/acs.nanolett.6c01982
  15. Front Cell Dev Biol. 2026 ;14 1881073
      Fatty acid oxidation is a major metabolic pathway responsible for fatty acid breakdown and energy production. Carnitine palmitoyltransferase 1A (CPT1A), the rate-limiting enzyme in this process, catalyzes the conversion of acyl-coenzyme A into acyl-carnitine, enabling mitochondrial transport for oxidative metabolism. Emerging evidence indicates that dysregulated CPT1A contributes to metabolic disorders and cancer progression by driving metabolic reprogramming, modulating oxidative stress, and regulating protein modifications, including histone acetylation and lysine succinylation. Colorectal cancer (CRC), one of the leading causes of cancer-related mortality worldwide, has recently been linked to aberrant CPT1A activity. Studies demonstrate that CPT1A promotes CRC progression by regulating oncogenic signaling pathways, enhancing cancer stemness, supporting tumor proliferation and metastasis, and shaping the tumor microenvironment. Increasing evidence suggests that targeting CPT1A may be a promising therapeutic strategy for CRC. In this review, we summarize the biological functions of CPT1A, discuss its mechanistic role in CRC progression, and highlight its emerging potential as a metabolic and therapeutic target in CRC.
    Keywords:  cancer metabolic reprogramming; carnitine palmitoyltransferase 1a; colorectal cancer; fatty acid oxidation; tumor microenvironment
    DOI:  https://doi.org/10.3389/fcell.2026.1881073
  16. Mol Biol Rep. 2026 Aug 10. pii: 1370. [Epub ahead of print]53(1):
      Epigenetic regulation plays a central role in metabolic gene expression in eukaryotes. Focusing on Saccharomyces cerevisiae as a model, this review systematically examines how histone modifications, including acetylation, methylation, phosphorylation, ubiquitination, and SUMOylation, and ATP‑dependent chromatin remodeling regulate metabolic genes. It also summarizes the crosstalk between metabolic signals and epigenetic states. On this basis, practical progress, advantages, and limitations of applying these mechanisms in metabolic engineering are then discussed, including industrial strain optimization and the development of epigenetic molecular tools, as well as their technical limitations and scale-up challenges. In addition, yeast models for human diseases are introduced, covering tumor-associated histone dysregulation and antifungal drug resistance. Future research should focus on elucidating the dynamic and combinatorial mechanisms of epigenetic regulation, the direct regulation of chromatin remodeling complexes by metabolic signals, and the development of more precise and stable regulatory strategies. These findings provide insights into metabolic regulation in higher eukaryotes and lay a foundation for industrial biotechnology, synthetic biology, and disease research.
    Keywords:  Chromatin remodeling; Disease model; Histone modification; Metabolic engineering; Metabolic regulation
    DOI:  https://doi.org/10.1007/s11033-026-12568-2
  17. RSC Adv. 2026 Aug 11.
      The development of dual inhibitors of histone deacetylases (HDACs) and enhancer of zeste homologue 2 (EZH2) is an efficient strategy that not only synergistically suppresses critical pathways in tumorigenesis but also circumvents the potential risks of drug cocktails. In this study, a series of pyridone derivatives were rationally designed via pharmacophore merging, and N 1-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-N 8-hydroxyoctanediamide (15c) was identified as the most potent compound against hematological tumor cells MV4-11 and SU-DHL-10, with IC50 values in the submicromolar range. 15c also effectively inhibited HDAC1 and EZH2 with IC50 values of 9.2 nM and 311.1 nM, respectively. Molecular simulations revealed key interactions between 15c and both targets. These findings indicated that compound 15c warrants further investigation as a novel dual HDAC/EZH2 agent.
    DOI:  https://doi.org/10.1039/d6ra04928a
  18. Int J Mol Sci. 2026 Jul 24. pii: 6604. [Epub ahead of print]27(15):
      The review covers research on dual-target antitumor agents over the past five years. One of the targets is histone deacetylases (HDACs), while the second potential target is a protein group located both on the membrane surface (phosphatidylinositol 3-kinase (PI3K), anaplastic lymphoma kinase (ALK), receptor tyrosine kinase (AXL), tyrosine protein kinase (HER2), FMS-like tyrosine kinase (FLT3), and vascular endothelial growth factor receptor (VEGFR2)) and in the nucleus (serine/threonine protein kinase Wee1, DNA methyltransferase (DNMT), dual-specificity phosphatase (CDC25A), an enzyme from the cyclin-dependent kinase family (CDK9), dual-specificity tyrosine-serine/threonine kinase (DYRK2), and BET family proteins (BRD4, BD1, and BD2)). This review presents the results of studies on the inhibitory activity of various HDAC isoforms and other enzymes, as well as in vitro cytotoxicity studies on both neoplastic and healthy cells. It also includes selectivity studies, in vivo experiments (changes in tumor volume in mice) and oral bioavailability assessments. The review also describes the chemical structures of several dual-target agents and identifies the molecular fragments responsible for inhibiting different targets. Based on the studies reviewed in this paper, it can be concluded that some dual inhibitors have superior in vitro cytotoxicity and exhibit selectivity towards some tumor cells compared to monofunctional reference compounds. These findings may be useful for molecular design in the field of polypharmacology, with the aim of developing new dual-target molecules that exhibit improved antitumor activity and selectivity towards neoplastic cells.
    Keywords:  DNA methyltransferase; anaplastic lymphoma kinase; cancer; dual-target agent; histone deacetylase; hydroxamic acid; inhibitor
    DOI:  https://doi.org/10.3390/ijms27156604
  19. Parasit Vectors. 2026 Aug 11. pii: 330. [Epub ahead of print]19(1):
       ABSRACT: A vast body of literature has investigated the direct and indirect effects of parasites on hosts. While the key role of among-individual variation of host traits has long been acknowledged, individual parasite variation has mostly been overlooked due to the difficulties in studying individual parasites. This has hampered advances in our understanding of fundamental parasite biology as well as progress in the development of novel control strategies. Here, we show how recent technological and methodological innovations, coupled with an improved theoretical understanding, allow for a paradigm shift towards individual-based approaches in parasite-related research and highlight potential breakthroughs across fields. We suggest that ectoparasites-due to their life history as well as medical and veterinary importance-are ideal model systems for the study of individual parasite variation.
    Keywords:  Ectoparasites; Host–parasite interactions; Individual variation; Individual-based studies; Individual-based techniques; Paradigm shift in parasite-related research; Parasites; Population-based studies
    DOI:  https://doi.org/10.1186/s13071-026-07567-y
  20. Mol Microbiol. 2026 Aug 13.
      Plasmodium falciparum parasites cause the most virulent form of malaria, a disease that remains a major global health burden. The appearance of resistance to first line artemisinin-based therapies emphasizes the need to identify new parasite vulnerabilities to develop new therapeutics. Phosphoinositides are central regulators of membrane identity, vesicular trafficking, and signaling, and their synthesis depends on tightly controlled phosphatidylinositol transfer by Sec14-like phosphatidylinositol transfer proteins in many eukaryotes, yet their roles in P. falciparum remain poorly defined. Here, we analyzed six P. falciparum Sec14 domain-containing proteins: PfSec14-1 (PF3D7_0626400), PfSec14-2 (PF3D7_0629900), PfSec14-3 (PF3D7_0717100), PfSec14-4 (PF3D7_0920700), PfSec14-5 (PF3D7_1007200), and PfSec14-6 (PF3D7_1127600). Domain organization segregates these proteins into a BNIP-2 and Cdc42GAP homology (BCH) subfamily (PfSec14-3, PfSec14-5) and a canonical Sec14 subfamily (PfSec14-1, PfSec14-2, PfSec14-4, and PfSec14-6). Yeast complementation assays showed that PfSec14-1, PfSec14-4, and PfSec14-6 partially rescue growth of a temperature-sensitive sec14 mutant, suggesting phosphatidylinositol and phosphatidylcholine transfer activity. Gene disruption revealed that PfSec14-1 is important for asexual blood-stage proliferation, whereas PfSec14-2 is dispensable under standard culture conditions. In contrast, mislocalization of PfSec14-2 and PfSec14-4 using a knock-sideways approach did not impair asexual growth. Subcellular localization indicates distinct distributions for PfSec14-1, PfSec14-2, and PfSec14-4. Together, these findings reveal potential functional and spatial diversification of Sec14-like phosphatidylinositol transfer proteins in P. falciparum.
    Keywords:   Plasmodium ; PITP; malaria; phosphoinositides; sec14
    DOI:  https://doi.org/10.1111/mmi.70107
  21. Protein Expr Purif. 2026 Aug 14. pii: S1046-5928(26)00114-2. [Epub ahead of print] 106991
      Babesia bovis is a species of apicomplexan hemoparasitic protozoa that can be transmitted by ticks, causing a global cattle disease. As it depends mainly on the glycolytic pathway for energy production and life cycle maintenance, glycolytic enzymes are possible targets for drug development against Babesia. Glyceraldehyde-3-Phosphate Dehydrogenase (GAPDH) has been one of such targets, against several parasitic organisms. It performs the reversible oxidative phosphorylation of glyceraldehyde-3-phosphate to 1,3-bisphospho-D-glycerate in the presence of nicotinamide adenine dinucleotide. The protocol for Babesia bovis Glyceraldehyde-3-Phosphate Dehydrogenase (BbGAPDH) expression and purification has been developed to yields of 28 mg of pure protein per liter of culture medium, with a specific activity of 55.5 ± 6.99 U mg-1 after his-tag removal, indicating preservation of enzymatic activity. For crystallization, the his-tag removal proved essential. Crystals diffracted to 3.12 Å resolution in the P3121 space group; NAD+ cofactor molecules are observed in their respective sites. Comparisons to the theoretical model indicate a number of side chain conformation differences. These results provide support for future enzyme inhibition assays, in addition to crystallization assays with potential inhibitors.
    Keywords:  Babesia bovis, Bovine Babesiosis; Glyceraldehyde-3-Phosphate Dehydrogenase; Inhibitor Search; Structure Based Drug Design
    DOI:  https://doi.org/10.1016/j.pep.2026.106991
  22. Carbohydr Polym. 2026 Oct 01. pii: S0144-8617(26)00743-5. [Epub ahead of print]389 125626
      Chitin is a ubiquitous structural biopolymer with significant potential for various high-value applications. Chitin deacetylases (CDAs) can potentially deacetylate chitinous molecules, producing chitosans and partially acetylated chitooligosaccharides (COS). Here, we describe the expression and characterization of a CDA from the filamentous fungus Absidia coerulea, AcCDA1, active toward colloidal chitin, partially deacetylated chitin, chitosan with different degrees of acetylation, and COS. When incubated with COS with degrees of polymerization 3-6, the enzyme rapidly produced fully deacetylated COS, which is a relatively rare property among known CDAs. The mode of action of AcCDA1 toward penta-N-acetyl chitopentaose ((GlcNAc)5) was studied by mass spectrometry, using a novel approach for labeling the reducing N-acetyl-D-glucosamine unit of the COS with chitooligosaccharide oxidase (FgChitO) from Fusarium graminearum. Kinetic studies with COS revealed high enzyme efficiency with kcat/Km values reaching 18.8 mM-1 s-1 for (GlcNAc)5. The enzyme removed 12% of the acetyl groups in colloidal chitin whereas it drastically reduced the degree of acetylation of various chitosans. A comparative study with three other CDAs showed that AcCDA1 is highly efficient enzyme and revealed both similarities and differences. These findings show that various CDAs can achieve different deacetylation targets during the enzymatic processing of chitinous materials.
    Keywords:  Absidia; CE4; Chitin; Chitin deacetylase; Chitooligosaccharides; Chitosan; Crystallinity
    DOI:  https://doi.org/10.1016/j.carbpol.2026.125626
  23. Chem Biol Interact. 2026 Aug 11. pii: S0009-2797(26)00409-6. [Epub ahead of print]438 112301
      To elucidate the role of Sirtuin 3 (SIRT3)/isocitrate dehydrogenase 2 (IDH2) axis in T-2 toxin-induced energy metabolism disorders and necroptosis in chondrocytes. Enrichment analysis was performed on differentially expressed genes in the articular cartilage and serum of Kashin-Beck disease patients. Sprague-Dawley rats were randomly divided into control (equal volume of normal saline), low T-2 toxin (100 ng/g·bw/day), and high T-2 toxin (200 ng/g·bw/day) groups. Human SW1353 cells were used to construct T-2 toxin exposed and SIRT3 intervened models in vitro. Enrichment analysis results indicated involvement of the tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS) in T-2 toxin-induced cartilage damage. The articular cartilage pathological changes including attenuated matrix staining, thinning of the cartilage layer, and blurred or disrupted marginal lines were observed in rats exposed to T-2 toxin. Western blot revealed that T-2 toxin downregulated SIRT3 expression and reduced the SIRT3-IDH2 interaction in chondrocyte. Immunoprecipitation confirmed decreased IDH2 deacetylation of chondrocyte induced by T-2 toxin. Additionally, the dose-dependently increased isocitrate content, while decreasing α-ketoglutarate and NADH levels of chondrocyte exposure to T-2 toxin. T-2 toxin also reduced activities of mitochondrial complexes II, III, and IV, inhibited oxygen consumption rate, and decreased adenosine triphosphate production of chondrocyte. Additionally, T-2 toxin upregulated necroptosis markers RIPK1, RIPK3, and MLKL, an effect reversed by a SIRT3 activator. In conclusion, T-2 toxin inhibited SIRT3 expression in chondrocytes, reduced IDH2 deacetylation, blocked the TCA cycle and OXPHOS, and ultimately led to energy metabolism disorder and necrosis of chondrocyte.
    Keywords:  Energy metabolism disorders; Necroptosis; SIRT3/IDH2; T-2 toxin; Tricarboxylic acid cycle
    DOI:  https://doi.org/10.1016/j.cbi.2026.112301
  24. Chembiochem. 2026 Aug 14. 27(15): e70501
      Phosphatidylethanolamine (PE) is the second most abundant phospholipid in mammalian cells. The cone-shaped structure of PE positions this lipid to act as a cornerstone of signaling events, such as those involving protein-protein and lipid-protein interactions, as it has been shown to promote conformational changes in both protein and lipid-based membrane structures. Despite this importance, chemical tools to interrogate the biological activity and trafficking of PE lipids are limited. Herein, we report the development of ethanolamine probes functionalized with clickable tags that are capable of infiltrating native cellular pathways and subsequently producing labeled PE lipids. Derivatization of click-tagged PE products enabled fluorescence microscopy imaging of these lipids in cells. Interrogation of the efficacy of these probes for biological incorporation was conducted using mass spectrometry and thin-layer chromatography analysis to identify various species of tagged PE molecules. This approach provides an invaluable step toward metabolic labeling strategies that will aid in the tracking of PE biosynthesis and trafficking pathways in cells.
    Keywords:  click chemistry; lipids; metabolic labeling; phosphatidylethanolamine
    DOI:  https://doi.org/10.1002/cbic.70501