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Results for “Protein Processing, Post-Translational”

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PubMed2026

Redox-activated chemistry for probing and perturbing the proteome: Lessons from protein redox switches.

Covalent drug discovery and chemical proteomics have historically relied on a nucleophilic logic, where electrophilic "warheads" react with nucleophilic amino acid side chains. While powerful, this paradigm probes only a single dimension of the protein's chemical surface. In contrast, biology leverages a second axis: redox potential. This is exemplified by the regulated redox proteome, where specific residues undergo reversible oxidation and reduction as functional post-translational modifications. Inspired by this natural machinery, researchers are developing redox-activated probes to label proteins at oxidizable residues and deploying similar chemistry to selectively perturb protein function. This review highlights recent advances in redox-activated covalent chemistry and explores its burgeoning potential for the development of next-generation targeted therapeutics.

Oxidation-Reduction↗

PubMed2026

Protein persulfidation emerges as a conserved component of the redox response to DNA damage.

Genotoxic stress is frequently accompanied by alterations in cellular redox homeostasis; however, the mechanisms linking redox regulation to the DNA damage response (DDR) remain incompletely understood. Here, we investigated the early redox response to DNA damage induced by methyl methanesulfonate (MMS) in Saccharomyces cerevisiae, focusing on cysteine oxidative post-translational modifications (PTM). We show that activation of the DNA damage response is accompanied by rapid redox changes that occur in the absence of a generalized oxidative stress response. MMS exposure promotes selective remodeling of cysteine oxidative modifications, characterized by decreased free thiols, robust induction of protein persulfidation, and comparatively modest changes in sulfenylation. These alterations are accompanied by increased intracellular hydrogen sulfide levels, supporting the involvement of reactive sulfur species in the cellular response to DNA damage. Proteome-wide analyses revealed that cysteine oxidative modifications preferentially target proteins involved in central metabolism, nucleotide biosynthesis, and genome maintenance. Consistent with these observations, MMS-induced genotoxic stress promotes metabolic adaptation characterized by increased mitochondrial respiration, elevated ATP production, and mitochondrial morphological remodeling, linking bioenergetic adaptation to redox regulation. Importantly, perturbation of intracellular redox balance using N-acetylcysteine compromises survival under DNA-damaging conditions, supporting a functional role for redox signaling during the DDR. Finally, MMS treatment also induces protein persulfidation in mammalian cells. Moreover, exposure to etoposide, a mechanistically distinct genotoxic agent that induces DNA double-strand breaks through topoisomerase II inhibition, showed a similar trend, suggesting that protein persulfidation may not be restricted to alkylation-induced DNA damage. Together our findings identify protein persulfidation as a prominent component of the redox response to DNA damage and provide new insight into the functional interplay between mitochondrial metabolism, cysteine-based redox regulation, and genome maintenance.

Oxidation-Reduction↗

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

Dynamic lysine acetylation and succinylation of platelet proteins regulates platelet storage lesion: mechanistic insights from multi-omics.

OBJECTIVES: Platelet storage lesion (PSL) severely impairs platelet function during storage, presenting a major hurdle in transfusion medicine; however, the dynamic interplay between global proteomic changes and post-translational modifications (PTMs) underlying these functional deteriorations remains insufficiently characterized. Here, we report the first comprehensive multi-omics analysis integrating global proteomics, acetylomics, and succinylomics to dissect the molecular dynamics during platelet storage. METHODS: We performed quantification of global proteomics, acetylome and succinylome based on TMT-labeled LC-MS/MS analysis, combined with antibody-affinity enrichment and purification. Dynamic molecular changes and functional transformation of platelet were also characterized under proper conditions stored for 1, 3, 5, 7 days, respectively. RESULTS: We systematically characterized 3,609 proteins, 1,308 acetylation sites, and 1,947 succinylation sites across multiple storage time points (D1, D3, D5, D7). We distinct temporal patterns of post-translational modifications, with succinylation showing more extensive coverage than acetylation in platelets. Pathway enrichment analysis revealed extensive metabolic reprogramming involving complement activation, energy metabolism, and cellular detoxification processes. The identification of specific motif patterns provided mechanistic insights into the functional specificity of these modifications. Random forest machine learning identified 20 core regulatory proteins representing critical nodes in PSL development. Furthermore, we employed real - time quantitative polymerase chain reaction (RT - QPCR) to measure the expression levels of key genes related to platelet function and PTM - associated pathways. CONCLUSION: By mapping the interplay between proteomic abundance shifts and PTM dynamics, this study provides a multidimensional understanding of PSL, establishing a foundational framework for optimizing storage protocols and enhancing transfusion safety.

Blood Platelets↗

PubMed2026

Deciphering S-nitrosylation-regulated metabolic networks in postmortem beef based on label-free modificomics: Identification of ferroptosis as a novel quality-related pathway.

This study elucidated the molecular mechanisms of S-nitrosylation on postmortem beef metabolism and quality based on the label-free modificomics. Varying degrees of S-nitrosylation were exogenously induced in beef semimembranosus (SM) muscle. Results indicated that a high S-nitrosylation level significantly increased beef pH and Warner-Bratzler shear force (WBSF) while reducing centrifugal loss (P < 0.05). A total of 828 S-nitrosylated proteins and 1458 modification sites were identified, of which 114 sites on 81 proteins (DSNPs) exhibited differential modification abundance, representing an increase of 125% compared with previous proteomics studies. DSNPs were mainly involved in glycolysis, the tricarboxylic acid cycle, oxidative phosphorylation, calcium signaling, cell structure, and ferroptosis. Notably, this study provides the first evidence in postmortem muscle that S-nitrosylation regulates key ferroptosis-related proteins, including ACSL, CP, and TF, offering new insights into the link between S-nitrosylation and the ferroptosis pathway in meat. Correlation analysis demonstrated that TF was significantly negatively correlated with pH and WBSF, but positively correlated with centrifugal loss (P < 0.05). Collectively, protein S-nitrosylation critically modulates postmortem beef quality through the coordinated regulation of multiple metabolic processes. More importantly, the identification of ferroptosis as a S-nitrosylation-sensitive pathway provides a new perspective for regulating meat quality through protein post-translational modifications.

Animals↗

PubMed2025

Systematic Identification of Microtubule Posttranslational Modification "Readers" by Quantitative Proteomics.

Microtubules, dynamic polymers assembled from α, β-tubulin dimers, contribute to myriad cellular processes. This is largely attributed to microtubule-associated proteins (MAPs). How MAPs selectively bind microtubules to carry out various functions is not known. The "Tubulin Code" theory proposes that posttranslational modifications (PTMs) of microtubules serve as signs that can be read by specific MAPs, thereby conferring specific functional properties to the microtubules. In support of this hypothesis, "reader" MAPs have been identified for various tubulin PTMs, but, until recently, no systematic screening had been performed to identify readers in an unbiased manner. We addressed this by developing a reader identification pipeline that uses quantitative mass spectrometry to interrogate the microtubule proteome of cells programmed to express specific PTMs. This pipeline can be used to identify readers for any tubulin PTM from various cell types as long as the writer enzymes are known. We also provide an alternative, complementary approach to obtain modified microtubules using a generic writer enzyme in vitro.

Protein Processing, Post-Translational↗

PubMed2026

Viral replication through phase separation: Cytosolic and nuclear condensates.

Replication of many RNA and DNA viruses occurs within specialized intracellular hubs organized as membraneless biomolecular condensates (BCs) driven by liquid-liquid phase separation. As obligate intracellular parasites, viruses depend on the host cell machinery to complete their replication cycles and therefore actively remodel the intracellular environment to favor viral genome replication, transcription, and assembly. Cytosolic and nuclear phase-separated replication compartments (RC) provide concentrated and dynamic platforms that promote efficient interactions between viral genomes and viral or host proteins essential for infection. The formation of viral replication BCs is typically facilitated by viral proteins enriched in intrinsically disordered regions and low-complexity domains, which enable multivalent interactions with viral nucleic acids and cellular factors. These interactions are mediated by diverse biophysical forces, including hydrophobic and π interactions, hydrogen bonding, molecular crowding, and osmotic effects. Throughout infection, viral BCs remain highly dynamic, allowing continuous exchange of components and functional maturation of replication hubs. Their properties and activities are further regulated by post-translational modifications of viral and host proteins, such as phosphorylation, acetylation, and methylation. In this review, we summarize current evidence supporting liquid-liquid phase separation as a central organizing principle of viral RCs. We focus on representative RNA and DNA viruses that replicate in the cytosol or nucleus, highlighting virus-specific strategies, conserved mechanisms, and the consequences of BC formation for viral replication efficiency, host antiviral responses, and therapeutic intervention.

Phase Separation↗

PubMed2026

Post-translational chemical modification of E3 ligase for efficient target protein degradation.

Targeted protein degradation (TPD) has emerged as a powerful therapeutic strategy, with proteolysis-targeting chimeras (PROTACs) leading efforts to address previously undruggable targets. However, PROTACs face challenges such as low bioavailability and poor pharmacokinetic properties which limit their biological applications. Here, we report a strategy termed post-translational chemical modification targeting chimera (PTcM-TAC), which integrates ligand-directed chemistry into the PROTAC framework to achieve sustained target protein degradation through covalent modification of E3 ligases. PTcM-TAC incorporates an electrophilic dibromophenyl benzoate warhead into the linker connecting the E3 ligase ligand and the protein-of-interest (POI) ligand, enabling selective transfer of the POI ligand onto the recruited E3 ligase while releasing the E3-binding moiety. Mechanistic studies, including LC-MS/MS peptide mapping, pull-down assays, and structural modeling, demonstrated site-selective modification of CRBN by the PTcM-TAC. The resulting ligand-labeled E3 ligase enables sustained pseudo-catalytic target recognition through a simplified binary interaction, thereby maintaining degradation activity even after compound washout. Furthermore, we successfully applied the PTcM-TAC strategy to another representative E3 ligase, von Hippel-Lindau (VHL), which exhibited substantially sustained degradation activity compared with conventional PROTACs. To our knowledge, PTcM-TAC represents the first ligand-directed chemical strategy that converts transient PROTAC-mediated ternary complex formation into binary target recognition via post-translational chemical modification of an E3 ligase. We believe that PTcM-TAC could provide a platform for next-generation targeted protein degraders to overcome the current limitation of PROTAC approach.

Ubiquitin-Protein Ligases↗

PubMed2026

Comprehensive multi-post-translational modifications profiling reveals age-associated remodeling in skeletal muscle.

Sarcopenia, characterized by the progressive loss of skeletal muscle mass and function, is a major hallmark of aging. Post-translational modifications (PTMs) play essential roles in regulating protein activity and cellular homeostasis; however, how multiple PTMs are remodeled during skeletal muscle aging remains incompletely characterized. Here, we performed comprehensive multi-layered proteomic profiling of skeletal muscle from young (3-month-old) and aged (24-month-old) mice, systematically quantifying the global proteome together with five major PTMs: acetylation, phosphorylation, N-glycosylation, O-glycosylation, and ubiquitination. In total, we identified 5 337 proteins and mapped thousands of PTM sites, generating an integrated atlas of age-associated proteomic and PTM remodeling in skeletal muscle. Pathway enrichment analyses revealed distinct modification-specific patterns: acetylation and phosphorylation were predominantly associated with metabolic and mitochondrial-related pathways; N-glycosylation was enriched in immune- and secretory pathway-related processes; O-glycosylation was associated with muscle contraction-related pathways; and ubiquitination was preferentially linked to cytoskeletal organization in muscle cells. Correlation analyses further uncovered diverse association patterns among different PTMs across protein- and modification-level datasets. Phosphorylation and ubiquitination exhibited consistent positive associations, whereas acetylation and ubiquitination showed both inverse and concordant co-variation patterns across subsets of proteins. Phosphorylation and O-glycosylation displayed heterogeneous association patterns across different proteins, and acetylation and phosphorylation demonstrated positive correlations with distinct age-associated directional changes across protein subsets. Together, these results provide a comprehensive, multi-dimensional view of age-associated remodeling of the skeletal muscle proteome and multiple PTM layers, offering a valuable resource for understanding molecular alterations accompanying muscle aging and sarcopenia.

Animals↗

PubMed2026

Comprehensive Landscape of Post-Translational Modification Alterations in Nephrolithiasis Revealing Activation of Multiple Cell Death Pathways.

Nephrolithiasis is a common urinary disorder characterized by high prevalence and recurrence, but the molecular mechanisms underlying calcium oxalate (CaOx)-crystal-induced renal injury remain incompletely understood. We applied integrated proteomic, phosphoproteomic, acetylomic, and lactylomic analyses to kidney tissues from a mouse model of CaOx nephrolithiasis followed by bioinformatic analysis and experimental validation. We identified 658 differentially expressed proteins, 735 differential phosphorylation sites, 335 differential acetylation sites, and 113 differential lactylation sites. Functional enrichment indicated immune activation, fibrotic remodeling, and alterations in PI3K-Akt, NOD-like receptor, p53, and Toll-like receptor signaling together with changes in fatty acid degradation, the tricarboxylic acid cycle, and glycolysis. Kinase activity prediction suggested the relative activation of multiple cyclin-dependent kinases. Proteins associated with ferroptosis, autophagy, necroptosis, and pyroptosis, including ACSL4, BNIP3, RIPK3, and GSDMD, showed coordinated abundance and modification changes. Several candidate sites, including MTOR_S1849, GCLM_K94, GCLM_S59, and GSS_K172, were also dysregulated. These data provide a multiomics resource for CaOx nephrolithiasis and identify candidate PTM events and regulatory pathways for future mechanistic validation.

Animals↗

PubMed2026

A translocation within the Ogataea species complex alters local subtelomeric chromatin while maintaining overall genome organization.

Eukaryotic genomic DNA is packaged in the nucleus as chromatin-a DNA-protein aggregate regulating genome function, including transcription. Chromatin is classified as either active euchromatin or silent heterochromatin, with each marked by distinct histone post-translational modifications (PTMs). Chromatin composition also mediates genome organization, including how heterochromatin aggregates at the nuclear periphery while euchromatin localizes to the nucleus center. In fungi, heterochromatic loci cluster, including independent centromere and telomere clusters that form the Rabl chromosome conformation. However, it is unknown if chromatin composition and genome organization are conserved in closely related fungi, and how these features are impacted by large-scale chromosomal rearrangements. Here, we examined differences in histone PTM deposition, gene expression, and genome organization in 2 yeast species from the order Pichiales, which diverged from the common ancestor shared with Saccharomyces cerevisiae more than 200 million years ago. We focused on Ogataea polymorpha, which is used for industrial protein production, and Ogataea haglerorum, an isolate of which harbors a translocation between chromosomes 1 and 6. We show that the enrichment of 3 activating PTMs-the trimethylation of lysine 4 of histone H3 (H3K4me3) and the acetylation of lysine 9 of histone H3 (H3K9ac) or lysine 16 of histone H4 (H4K16ac)-are similar genome-wide, yet gene orthologs have distinct chromatin and expression patterns. While both Ogataea genomes organize into a Rabl conformation, the O. haglerorum translocation alters subtelomeric chromatin composition and expression of genes affected by the translocation. Our work highlights the genome function differences that occur on a microevolutionary scale.

Genome, Fungal↗

PubMed2026

Integrated histone and proteome analyses reveal convergent and distinct hepatotoxic mechanisms of tenuazonic acid and deoxynivalenol.

Mycotoxins are widespread dietary contaminants whose health impacts are expected to intensify under climate change. Although their mechanisms of toxicity remain incompletely understood, epigenetic dysregulation has been increasingly implicated. Here, mass spectrometry-based multi-omics was used to profile histone post-translational modifications and proteome dynamics in HepG2 cells exposed to seven mycotoxin conditions. Time-resolved analyses identified tenuazonic acid as the dominant cellular disruptor, inducing alterations in H3K27 and H1 variants, and revealing a previously unrecognized oxidative modification of the H1.0 N-terminal methionine (H1.0N-term0AcM0Ox) that retains the protein's N-terminal acetylation. An Alternaria toxin mixture induced similar H1 responses, largely driven by tenuazonic acid, while deoxynivalenol produced convergent chromatin and proteomic alterations. Proteomic remodeling was characterized by increased protein translation, reduced mitochondrial complex IV expression, and impaired cholesterol biosynthesis, whereas sterigmatocystin activated DNA replication and repair pathways. Together, these findings demonstrate that mycotoxins disrupt chromatin organization, protein synthesis, and lipid metabolism, providing toxicological insight into hepatocellular dysfunction. These findings warrant further validation and mechanistic investigation in future hypothesis-driven studies of mycotoxin exposure.

Trichothecenes↗

PubMed2026

MARK1 suppresses infectious bursal disease virus replication via phosphorylating VP3.

Infectious bursal disease virus (IBDV) of the Birnaviridae family is a non-envelope, double-stranded RNA virus that encodes a VP3 protein with multiple functions, which controls viral genome replication, IFN-β production, and virus traffic in infected cells. Posttranslational modifications (PTMs), such as ubiquitination, of VP3 have been demonstrated for affecting its function and stability. To clarify the mechanism by which VP3 is regulated in IBDV infected cells, we focused on the phosphorylation of VP3. Mass spectrometry analysis identified that microtubule-affinity regulating kinases 1 (MARK1) was a kinase interacting protein of VP3. Inhibitory function of MARK1 in affecting viral replication was validated. We describe the phosphorylation event at the serine 130 (S130) and serine 163 (S163) residues of VP3 mediated by MARK1 via mass spectrometry analysis. Alanine replacement of the phosphorylation sites in VP3 significantly enhanced its RNA-binding activity. Additionally, the mutation of two serine residues led to remarkably improved in its polymerase-enhancing function. We then incorporated the two mutations to rescue recombinant IBDV. Viral growth curve analysis revealed that replication of mutant IBDV was significantly enhanced relative to wild type (WT) virus. In conclusion, we found that VP3 functions are specifically regulated by MARK1 mediated phosphorylation at S130 and S163 and that this regulation suppresses IBDV replication ultimately.

Infectious bursal disease virus↗

PubMed2026

Hyperlactate-Associated Lysine Lactylome Remodeling in Laryngeal Squamous Cell Carcinoma.

Laryngeal squamous cell carcinoma (LSCC) lacks reliable biomarkers, and the roles of lactate metabolism and lysine lactylation (Kla) remain largely unknown. We profiled the lysine lactylome of LSCC, paired it with adjacent normal tissues, and integrated the data with quantitative proteomic and transcriptomic analyses. LSCC exhibited a hyperlactate-associated phenotype characterized by dysregulated lactate-related genes (LRGs), altered protein abundance, increased tissue lactate, and globally increased Kla levels. Data-independent acquisition mass spectrometry (DIA-MS) identified 1616 Kla sites on 1468 peptides from 688 proteins, with most differential sites being upregulated in tumors. Differentially lactylated proteins were enriched in cell-matrix adhesion, cell migration, chromatin remodeling, and gene-regulatory processes and were clustered into cytoskeletal and nuclear regulatory modules. Multiple Kla sites were also detected on the core histones. Immunoblotting and tissue microarray analyses confirmed increased pan-Kla expression in the LSCC. Pan-Kla levels were independent of sex and age but positively correlated with the tumor stage and lymph-node metastasis. These findings provide a systematic resource for hyperlactate-associated lactylome remodeling in LSCCs and identify candidate Kla-related molecular features associated with clinicopathological progression for future functional and clinical evaluation.

Humans↗

PubMed2026

Emerging Trends in Mass Spectrometry-Based Quantitative Proteome and Phosphoproteome Profiling in Maize.

Maize (Zea mays) is both an agronomically important crop and a reference model organism that has enabled the dissection of the molecular basis of plant development and environmental responses. Mass spectrometry-based proteomics provides a powerful approach to identify and quantify proteins and their post-translational modifications, facilitating the discovery of molecular mechanisms underlying complex biological processes. Unlike the study of gene expression using transcriptomics, analysis of the proteome and phosphoproteome provides direct measurement of proteins, which are responsible for driving or regulating nearly all cellular processes, thus offering a more complete picture of the cell's functional state. Over the past two decades, advancements in mass spectrometry have enabled large-scale profiling of protein abundance and phosphorylation sites in maize, improving our understanding of various biological phenomena. Here, we briefly summarize some of the major biological insights gained from maize proteome and phosphoproteome studies, and provide an overview of mass spectrometry sample preparation and acquisition/analysis workflows for the quantitative and reproducible analysis of protein abundance and phosphorylation dynamics in maize.

Zea mays↗

PubMed2026

Cholesterol dysregulation in APOE4 astrocytes promotes α-synuclein pathology in miBrains.

The pathological hallmarks of neurodegeneration are the aberrant post-translational modification and aggregation of proteins. Genetic factors, like APOE4, increase the prevalence and severity of tau, amyloid, and α-synuclein pathologies. However, the human brain is largely inaccessible during this process, limiting mechanistic understanding. Here, we developed an iPSC-based 3D model that integrates neurons, glia, myelin, and cerebrovascular cells into a human brain-like tissue ("miBrain"). Single-nucleus RNA sequencing of miBrains confirmed the presence of diverse cell populations and revealed transcriptional responses to α-synuclein pathology. Like the human brain, pathogenic α-synuclein is increased in APOE4/4 miBrains. Combinatorial experiments revealed that endolysosomal dysfunction caused by cholesterol accumulation in APOE4/4 astrocytes impairs the degradation of soluble α-synuclein leading to a pathogenic transformation that seeds α-synuclein inclusions in neurons. Collectively, this study establishes a robust model for investigating protein inclusions in human iPSC-derived brain tissue and highlights the role of astrocytes and cholesterol in APOE4-mediated pathologies.

alpha-Synuclein↗

PubMed2026

Plant U-box E3 ligases: Versatile regulators of environmental stress adaptation and ABA signaling.

Ubiquitination is a reversible post-translational modification that orchestrates a wide spectrum of fundamental processes throughout the plant life cycle. Executed by a hierarchical E1-E2-E3 cascades, this modification tags targets with ubiquitin to modulate their turnover, activity, or subcellular compartmentalization. Among the diverse E3 ligase families, plant U-box (PUB) proteins stand out as a prominent class that determines substrate selection and has emerged as a focal point of stress biology. In this review, we first delineate the structural features of PUB proteins, highlighting their conserved domains and associated regulatory motifs. We then systematically dissect their multifaceted functions in abiotic stress adaptation, encompassing drought, salinity, extreme temperatures, oxidative stress, heavy metal toxicity, with particular emphasis on their integration with ABA signaling networks. We further outline critical knowledge gaps and propose future strategies to decode the regulatory architecture of PUBs. Collectively, this review provides a theoretical foundation and new insights for facilitating the genetic improvement of crop resilience in the face of continuously intensifying environmental stresses through the manipulation of PUB-mediated ubiquitination networks.

ABA signaling↗

PubMed2026

ChIP-seq profiling identifies diapause-regulated H3K27me3 targets in the fat body of Culex pipiens.

Culex pipiens, a principal vector of significant arboviruses, survives winter through diapause, a hormonally controlled inactive phase that enhances endurance under severe cold circumstances. Recent data suggests that epigenetic processes, namely histone post-translational modifications (hPTMs), play a crucial role in regulating seasonal dormancy. Prior studies from our laboratory indicated a decrease in the methylation of Histone 3 (H3K27me3) in diapausing fat body tissue, associated with elevated expression of the histone demethylase UTX. Nonetheless, the precise genomic areas impacted by these chromatin alterations remained unidentified. We used chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) to delineate the genome-wide distribution of H3K27me3 across fat body chromatin in diapausing (D) and non-diapausing (ND) female Cx. pipiens. Notably, the higher signal at transcription start sites (TSSs) reflects localized redistribution rather than a global decrease, as diapausing fat bodies retain less H3K27me3 overall but concentrate it at promoters. To investigate the functional significance of these chromatin alterations, we confirmed a number of target loci via ChIP-qPCR and assessed gene expression with qRT-PCR. We identified many critical genes that were markedly increased in diapausing mosquitoes, exhibiting an inverse relation to H3K27me3 enrichment. Our data demonstrates different H3K27me3 chromatin landscapes between diapausing and non-diapausing Cx. pipiens, corroborating a hypothesis of selective, locus-specific repression in the non-diapause state and its targeted removal during diapause to permit activation of dormancy-associated genes. These results suggest that chromatin remodeling is a core driver of the diapause switch.

Animals↗