Protein Methylation Research Articles

Post-translational modifications and bronchopulmonary dysplasia

Bronchopulmonary dysplasia is a prevalent respiratory disorder posing a significant threat to the quality of life in premature infants. Its pathogenesis is intricate, and therapeutic options are limited. Besides genetic coding, protein post-translational modification plays a pivotal role in regulating cellular function, contributing complexity and diversity to substrate proteins and influencing various cellular processes. Substantial evidence indicates that post-translational modifications of several substrate proteins are intricately related to the molecular mechanisms underlying bronchopulmonary dysplasia. These modifications facilitate the progression of bronchopulmonary dysplasia through a cascade of signal transduction events. This review outlines the relationships between substrate protein phosphorylation, acetylation, ubiquitination, SUMOylation, methylation, glycosylation, glycation, S-glutathionylation, S-nitrosylation and bronchopulmonary dysplasia. The aim is to provide novel insights into bronchopulmonary dysplasia's pathogenesis and potential therapeutic targets for clinical management.

Exploring oncogenic roles and clinical significance of EZH2: focus on non-canonical activities.

The enhancer of zeste homolog 2 (EZH2) is a catalytic component of Polycomb repressive complex 2 (PRC2) mediating the methylation of histone 3 lysine 27 (H3K27me3) and hence the epigenetic repression of target genes, known as canonical function. Growing evidence indicates that EZH2 has non-canonical roles that are exerted as PRC2-dependent and PRC2-independent methylation of non-histone proteins, and methyltransferase-independent interactions of EZH2 with various proteins contributing to gene expression regulation and alterations in the protein stability. EZH2 is frequently mutated and/or its expression is deregulated in various cancer types. The cancer sensitivity to inhibitors of EZH2 enzymatic activity and state-of-the-art approaches to deplete EZH2 with chemical degraders are discussed. This review also presents the clinical trials in various phases that evaluate the use of EZH2 inhibitors, both as monotherapy and in combination with other agents for the treatment of patients with diverse types of cancers.

The PRMT5-splicing axis is a critical oncogenic vulnerability that regulates detained intron splicing.

Protein arginine methyltransferase 5 (PRMT5) is a promising cancer target, yet it's unclear which PRMT5 roles underlie this vulnerability. Here, we establish that PRMT5 inhibition induces a special class of unspliced introns, called detained introns (DIs). To interrogate the impact of DIs, we depleted CLNS1A, a PRMT5 cofactor that specifically enables Sm protein methylation. We found that many, but not all, cell lines are CLNS1A-dependent and established that loss of viability is linked to loss of Sm protein methylation and DI upregulation. Finally, we discovered that PRMT5-regulated DIs, and the impacted genes, are highly conserved across human, and also mouse, cell lines but display little interspecies conservation. Despite this, human and mouse DIs have convergent impacts on proliferation by affecting essential components of proliferation-regulating complexes. Together, these data argue that the PRMT5-splicing axis, including appropriate DI splicing, underlies cancer's vulnerability to PRMT5 inhibitors.

Regulation of autophagy and cellular signaling through non-histone protein methylation.

Autophagy is a highly conserved catabolic pathway that is precisely regulated and plays a significant role in maintaining cellular metabolic balance and intracellular homeostasis. Abnormal autophagy is directly linked to the development of various diseases, particularly immune disorders, neurodegenerative conditions, and tumors. The precise regulation of proteins is crucial for proper cellular function, and post-translational modifications (PTMs) are key epigenetic mechanisms in the regulation of numerous biological processes. Multiple proteins undergo PTMs that influence autophagy regulation. Methylation modifications on non-histone lysine and arginine residues have been identified as common PTMs critical to various life processes. This paper focused on the regulatory effects of non-histone methylation modifications on autophagy, summarizing related research on signaling pathways involved in autophagy-related non-histone methylation, and discussing current challenges and clinical significance. Our review concludes that non-histone methylation plays a pivotal role in the regulation of autophagy and its associated signaling pathways. Targeting non-histone methylation offers a promising strategy for therapeutic interventions in diseases related to autophagy dysfunction, such as cancer and neurodegenerative disorders. These findings provide a theoretical basis for the development of non-histone-methylation-targeted drugs for clinical use.

Commentary on: γ-enolase (ENO2) is methylated at the Nτ position of His-190 among enolase isozymes.

Post-translational modifications play crucial roles in regulating protein function. Protein methylation, occurring at lysine, arginine, and histidine, has gained attention, particularly for histone methylation. However, the mechanism and significance of protein methylation at histidine remains poorly understood. Kasai et al. developed a novel method to identify histidine-methylated proteins and discovered that γ-enolase in the mouse brain undergoes Nτ-methylation at His190. This modification reduces dimerization and enzymatic activity, suggesting this reaction plays a physiological role. This work will accelerate research on histidine methylation and help elucidate unknown phenomena in the brain.

Androgen receptor drives polyamine synthesis creating a vulnerability for prostate cancer.

Supraphysiological androgen (SPA) treatment can paradoxically restrict growth of castration-resistant prostate cancer with high androgen receptor (AR) activity, which is the basis for use of Bipolar Androgen Therapy (BAT) for patients with this disease. While androgens are widely appreciated to enhance anabolic metabolism, how SPA-mediated metabolic changes alter prostate cancer progression and therapy response is unknown. Here, we report that SPA markedly increased intracellular and secreted polyamines in prostate cancer models. This occurred through AR binding at enhancer sites upstream of the ODC1 promoter to increase abundance of ornithine decarboxylase (ODC), a rate-limiting enzyme of polyamine synthesis, and de novo synthesis of polyamines from arginine. SPA-stimulated polyamines enhance prostate cancer fitness, as dCas9-KRAB-mediated inhibition of AR regulation of ODC1 or direct ODC inhibition by difluoromethylornithine (DFMO) increased efficacy of SPA. Mechanistically, this occurred in part due to increased activity of S-adenosylmethionine decarboxylase 1 (AMD1), which was stimulated both by AR and by loss of negative feedback by polyamines, leading to depletion of its substrate S-adenosylmethionine and global protein methylation. These data provided the rationale for a clinical trial testing the safety and efficacy of BAT in combination with DFMO for patients with metastatic castration-resistant prostate cancer. Pharmacodynamic studies of this drug combination in the first five patients on trial indicated that the drug combination resulted in effective polyamine depletion in plasma. Thus, the AR potently stimulates polyamine synthesis, which constitutes a vulnerability in prostate cancer treated with SPA that can be targeted therapeutically.

A new target of multiple lysine methylation in bacteria.

Lysine methylation has been underexplored in prokaryotes, and information on it is limited to some pathogens. Our finding is the second case of multiple lysine methylation of bacterial outer membrane (OM) proteins, following that of OmpB of Rickettsia. The newly found target of methylation, AtaA, a trimeric autotransporter adhesin family protein of Acinetobacter sp. Tol 5 isolated from activated sludge, extends our understanding of OM protein methylation to non-pathogenic environmental strains. The newly identified enzyme KmtA shows higher specificity than rickettsial lysin methylases, protein lysine methyltransferases, and methylates more lysine residues of the target, which raises interest in the mechanism underlying its biological specificity. The widespread presence of KmtA-like PKMTs throughout Gram-negative bacteria suggests that lysine methylation functions more extensively in bacterial physiology than previously recognized.

Identification of potential methyltransferase NSD2 enzymatic inhibitors through a multi-step structure-based drug design.

Reversing aberrant protein methylation levels is widely recognized as a key focus in cancer therapy. As an essential lysine methylation regulator, NSD2 (Nuclear receptor-binding SET Domain 2, also known as WHSC1/MMSET) regulates chromatin structural sparsity and DNA repair processes. Abnormal enhancement of NSD2 methylation activity (caused by NSD2 overexpression and point mutations) has been closely related to the initiation and development of various cancers and diseases. However, the lack of selective inhibitors hinders further therapeutic intervention and limits the exploration of its biological mechanism. Therefore, this study developed an integrated approach that includes binding feature pharmacophore modeling, gradient database screening of 120 million compounds, flexible docking, and molecular dynamic simulation. This approach was used to identify hit compounds targeting the substrate/coenzyme binding site of NSD2. Subsequently, 20 lead compounds were retrieved by using molecular docking analysis and ADMET prediction. Finally, MD simulations were performed to validate the binding stability of selected drug candidates. The findings indicated that these newly obtained compounds might be potent NSD2 inhibitors. We hope the integrated virtual screening approach will provide a valuable idea for discovering novel H3K36 methyltransferase inhibitors.

KDM1A epigenetically enhances RAD51 expression to suppress the STING-associated anti-tumor immunity in esophageal squamous cell carcinoma

Histone lysine demethylase LSD1, also known as KDM1A, has been found to regulate multiple cancer hallmarks since it was first identified in 2004. Recently, it has emerged as a promising target for stimulating anti-tumor immunity, specifically boosting T cell activity. However, it remains unclear whether and how it remodels the tumor microenvironment to drive oncogenic processes in esophageal squamous cell carcinoma (ESCC). In this study, protein levels in ESCC tissues were evaluated by immunostaining of tissue microarrays. Cell growth was assessed by colony formation assays in vitro and subcutaneous xenograft models in vivo. High-throughput transcriptomics and spatial immune proteomics were performed using bulk RNA sequencing and digital spatial profiling techniques, respectively. Epigenetic regulation of RAD51 by methylated histone proteins was analyzed using chromatin immunoprecipitated quantitative PCR assays. Finally, our clinical data indicate that KDM1A precisely predicts the overall survival of patients with early-stage ESCC. Inhibition of KDM1A blocked the growth of ESCC cells in vitro and in vivo. Mechanistically, our transcriptomics and spatial immune proteomics data, together with rescue assays, demonstrated that KDM1A specifically removes methyl residues from the histone protein H3K9me2, a transcription repressive marker, thus reducing its enrichment at the promoter of RAD51 to epigenetically reactivate its transcription. Additionally, it significantly inhibits the expression of NF-κB signaling-dependent proinflammatory genes IL-6 and IL-1B through RAD51, thus blocking the STING-associated anti-tumor immunity in stromal tumor-infiltrating lymphocytes (sTIL). Overall, our findings not only indicate that KDM1A is a promising target for ESCC patients at early stages but also provide novel mechanistic insights into its spatial regulation of STING-associated anti-tumor immunity in sTILs to drive the oncogenic processes in ESCC. The translation of these findings will ultimately guide more appropriate combinations of spatial immunotherapies with KDM1A inhibitors to improve the overall survival of specific subgroups in ESCC.

SETD7 promotes LC3B methylation and degradation in ovarian cancer.

Microtubule-associated protein 1 light chain 3 (LC3) is a key autophagy-related protein involved in regulating autophagosome formation and autophagy activity. Post-translational modifications of LC3 are necessary to modulate its function. However, LC3 protein methylation and its physiological significance have not yet been elucidated. Here, we show that SET domain containing lysine methyltransferase 7 (SETD7) interacts with LC3B, a common isoform of LC3, and methylates LC3B at lysine 51 (K51). SETD7-mediated methylation of LC3B promotes ubiquitination and degradation of LC3B, resulting in reduced autophagosome formation. Furthermore, SETD7 exerts a tumor-promotive function in ovarian cancer (OC) cells in a K51 methylation-dependent manner. Collectively, our data define a novel modification of LC3B and highlight the oncogenic effect of SETD7 via mediating LC3B methylation and degradation.

Urinary DNA-methylation and protein biomarkers identify urothelial carcinoma among other genitourinary diseases and cancer-free individuals

BackgroundFor more than 80 years, cystoscopy has been the gold standard for identification of urothelial carcinoma (UCa). Because of many factors, such as pain of the patients during this procedure or the costs involved, non-invasive detection of UCa remains a challenge. Herein, we verify our previously identified urinary biomarkers C-X-C Motif Chemokine Ligand 16 (CXCL16) and transforming growth-factor beta induced protein (TGFBI) on the protein level as well as the CpG sites ALOX5, TRPS1 and an intergenic region on Chromosome 16 on DNA methylation level in an independent cross-sectional study.MethodsWe collected N = 1119 urines from individuals coming to urological and gynecological check-ups, follow-up care or patients suspicious for UCa or already diagnosed for different urologic or gynecologic cancer entities. We performed methylation analysis of various CpG sites with DNA isolated from urine sediment and quantified the concentration of the protein markers CXCL16 and TGFBI in the corresponding urine supernatant using ELISA. We tested for patient-group differences with two-sided Wilcoxon rank sum tests and examined the performance with receiver operating characteristic curves. For verification, we analyzed the marker performance with previously set cutoff-values and marker combinations with established and experimental algorithms (with logical OR-conjunction, iterative threshold-based biomarker and score combining algorithm “PanelomiX”).ResultsEvaluation confirmed that our previously identified protein and DNA methylation biomarkers can distinguish UCa from frequent urological and gynecological cancers. CXCL16 and TGFBI discriminated UCa cases with a sensitivity of 31% and 56% and a specificity of 94% and 85%, respectively. Combining methylation markers resulted in UCa detection in men with a sensitivity of 54% and a specificity of 94%. Extending analysis by combining all methylation and protein markers (up to five markers in total) yielded a convincingly high specificity of 97% at a sensitivity of 72% for the identification of UCa patients within a heterogeneous collective of cancer-free individuals and patients suffering from urological or gynecological cancers.ConclusionCombining various biomarkers at protein and DNA level demonstrates a new option of non-invasive UCa diagnosis in urine, and thus might help to reduce the number of unnecessary cystoscopies, especially in patients without a history of UCa.

Lumbrokinase (LK) ameliorates diabetic kidney disease renal fibrosis through regulating snail via m6A RNA methyltransferase 3

The present study was undertaken to investigate the therapeutic effect and underlying mechanisms of lumbrokinase (LK) on diabetic kidney disease (DKD). Kidney tissue samples from DKD patients and normal controls were collected from hospitals. The type 2 diabetic nephropathy model was induced in db/db mice. The mice were then randomly divided into a model group (DM group) and an LK group. db/m mice were used as the control group (Con group). After 12 weeks of treatment with LK (234 KU/kg/day), biochemical parameters were tested, and pathological changes in the kidney were observed under a light microscope. The epithelial-to-mesenchymal transition (EMT), mRNA m6A methylation proteins, and activated TGF-β1/Smad pathway components were assessed by western blot or immunofluorescence in DKD patients, model mice, and high glucose-stimulated HK-2 cells. We found that the m6A eraser METTL3 was expressed at low levels in DKD patients, model mice, and high glucose-stimulated HK-2 cells. METTL3 overexpression reversed the high glucose-induced activation of the TGF-β1/Smad pathway and EMT through snail in vitro. However, LK can restore the expression of the m6A-modifying enzyme METTL3 in vivo and in vitro, suppressed EMT, and alleviated renal interstitial fibrosis by downregulating snail. Overall, LK ameliorated renal fibrosis through the regulation of Snail via m6A RNA METTL3.

Magnesium and Longevity

Magnesium (Mg) is not prominent among the list of well known anti-aging agents. Yet the signs and symptoms of aging mimic those of Mg deficiency. Mg is required for nearly a thousand enzymatic reactions. This narrative review does not correlate Mg status with clinical data on agents linked to longevity. The approach is more novel and highlights specific Mg dependent physiologic reactions required by these longevity linked biomarkers. Many of these share common pathways to extend healthspan. Mg is a required cofactor in the synthesis of vitamin D and melatonin and activation of six of the eight B vitamins. It is a required cofactor for all CYP450 enzymes. It is directly responsible for the appropriate methylation of proteins and DNA, which control the epigenome. The MTHFR (methylenetetrahydrofolate reductase) 677T allele that compromises methylation is present in a majority of Americans. Aberrant methylation predicts the severity of Covid-19 and its persistence into long Covid. Mg is a silent benefactor that may indirectly link these longevity agents, but only if viewed in context with calcium (Ca), i.e., Ca:Mg. Both compete for the same receptor. To fully exploit these longevity agents sufficient Mg is required. The pertinent physiology is presented, although cause and effect awaits publication of supporting clinical data.

A cytoplasmic form of EHMT1N methylates viral proteins to enable inclusion body maturation and efficient viral replication.

Protein lysine methyltransferases (PKMTs) methylate histone and non-histone proteins to regulate biological outcomes such as development and disease including viral infection. While PKMTs have been extensively studied for modulating the antiviral responses via host gene regulation, their role in methylation of proteins encoded by viruses and its impact on host-pathogen interactions remain poorly understood. In this study, we discovered distinct nucleo-cytoplasmic form of euchromatic histone methyltransferase 1 (EHMT1N/C), a PKMT, that phase separates into viral inclusion bodies (IBs) upon cytoplasmic RNA-virus infection (Sendai Virus). EHMT1N/C interacts with cytoplasmic EHMT2 and methylates SeV-Nucleoprotein upon infection. Elevated nucleoprotein methylation during infection correlated with coalescence of small IBs into large mature platforms for efficient replication. Inhibition of EHMT activity by pharmacological inhibitors or genetic depletion of EHMT1N/C reduced the size of IBs with a concomitant reduction in replication. Additionally, we also found that EHMT1 condensation is not restricted to SeV alone but was also seen upon pathogenic RNA viral infections caused by Chandipura and Dengue virus. Collectively, our work elucidates a new mechanism by which cytoplasmic EHMT1 acts as proviral host factor to regulate host-pathogen interaction.

TNF-alpha gene promoter's hypomethylation mediates a pro-inflammatory phenotype in peripheral blood monocytes from apical periodontitis individuals.

Epigenetic regulation of the key inflammatory genes plays a crucial role in controlling monocyte/macrophage-mediated local and systemic responses to bacterial challenges. However, it has not been addressed in apical periodontitis (AP). We aimed to explore the methylation pattern of the TNF-α gene promoter and its association with the inflammatory phenotype of peripheral blood monocytes from individuals with AP and controls. A cross-sectional study was conducted, including otherwise healthy individuals with AP (n = 25) and controls (n = 29). Monocytes were isolated from the volunteer's blood samples using a Ficoll gradient followed by negative immunoselection. RNA and DNA were extracted. The DNA methylation profiles of the TNF-α gene promoter region were analyzed using bisulfite sequencing PCR. The mRNA expression levels of DNA methyltransferases 3a (DNMT3a) and Ten Eleven Translocation enzymes 1(TET1) were assessed by qPCR. A fraction of primary monocytes was also cultured for 24 h, and the supernatant was collected to measure cytokine levels through a Luminex assay. Generalized structural equation models (GSEM) evaluated the association between AP, DNA methylation, and TNF-α protein expression controlled for potential covariates. Models included the effect of the methylation of TNF-α gene promoter as a mediator of the association between AP and TNF-α protein expression levels. Monocytes from AP individuals exhibited a heightened secretion of TNF-α and IL-1β and hypomethylation of the TNF gene promoter (p < .05). AP diagnosis was associated with the TNF-α gene promoter´s hypomethylated profile and enhanced pro-inflammatory cytokine levels, while lower methylation of the gene promoter region and -163 CpG single site mediated TNF-α overexpression (p < .05). DNA hypomethylation at the TNF-α gene mediates a proinflammatory phenotype in monocytes from AP patients, supporting a role in the systemic response.

A computational analysis of the oncogenic and anti-tumor immunity role of P4HA3 in human cancers

Prolyl-4-hydroxylase subunit alpha3 (P4HA3) is a triple helical procollagen synthesis protein. The role of P4HA3 in cancer development is not well known and lacks comprehensive analyses among human cancers. This study aimed to investigate the relationship between P4HA3 expression and anti-tumor immunity and its prognostic value in pan-cancer. P4HA3 expression was analyzed from TIMER2.0, GTEx, GEPIA2.0 and TCGA databases. Genetic and DNA methylation alterations, survival analysis and proteins co-expression analysis of P4HA3 in cBio Cancer Genomics Portal, TCGA, GSCA and TIMER2.0. The correlation between P4HA3 expression and immune infiltration was analyzed by TIDE, XCELL, MCPCOUNTER, and EPIC. We performed EdU and transwell experiments to evaluate the influence of P4HA3 on the proliferation, migration and invasion abilities of different tumors. Patients derived xenograft (PDX) and subcutaneous transplantation models were utilized to explore the correlation between P4HA3 and immunotherapy response in triple-negative breast cancer (TNBC). Among 33 types of cancers, P4HA3 had generally different expression between different tumors, further analysis showed that the expression of P4HA3 was correlated with the cells infiltration of the tumor microenvironment (TME). The expression of P4HA3 was positively with the cell proliferation markers and epithelial-mesenchymal transition (EMT) markers. Moreover, P4HA3 deficiency inhibited the proliferation, migration and invasion abilities of tumor cells, and promoted anti-tumor immunotherapy of PD-1/PD-L1 inhibitor. This pan-cancer analysis of P4HA3 provides a comprehensive understanding of its oncogenic and prognosis role in different cancers, P4HA3 abnormal expression could be a useful biomarker for predicting the effectiveness of immunotherapy in cancer patients.

Compound 21 Attenuates Isoflurane-Induced Injury in Neonatal Rat Hippocampal Neurons and Primary Rat Neuronal Cells by Upregulating METTL3.

Isoflurane, as an anesthetic drug, has a neurotoxic effect on the developing brain tissue. Compound 21 (C21) has been reported to be neuroprotective and ameliorate stroke effects. However, the mechanism by which C21 protects against nerve damage remains unclear. Animal and cellular models of brain injury were constructed using isoflurane (ISO) in neonatal SD rats and primary rat neuronal cells (PRNCs). After treatment with C21, the ultrastructure and morphology of the hippocampus in the model rats were assessed using the transmission electron microscope and H&E staining. Methylation or apoptosis-related genes or proteins were examined using immunohistochemistry, RT-qPCR, and Western blot. The levels of inflammatory factors were monitored using the ELISA kits. m6A modification was analyzed by Dot blot and MeRIP-qPCR. Cell proliferation and apoptosis were also tested using Edu and TUNEL staining. C21 suppresses apoptosis and inflammation and improves hippocampal morphology in ISO-induced neonatal rats. Mechanistically, C21 upregulates m6A modification, PPAR-a, BCL-2, and METTL3 in ISO-induced neonatal rats and ISO-treated PRNCs. C21 promotes cell proliferation, enhances BCL-2 m6A modification, and reduces inflammation by upregulating METTL3 by upregulating METTL3 in ISO-treated PRNCs. These findings suggest that C21 enhances neuronal cell survival and morphology and up-regulates methylation and Bc1-2 levels, potentially offering a therapeutic strategy for neuroprotection in clinical settings, particularly in cases of neurotoxic exposure. The mechanism may be related to the upregulation of METTL3.

Placental methylation and pro-inflammatory protein levels in cord blood

IntroductionThe neonates’ inflammatory response may in part be shaped during development by the placental epigenome, but evidence is scarce. We investigated the association between placental DNA methylation and pro-inflammatory proteins in cord blood. MethodsA total of 249 mother-child dyads from the Harvard Epigenetic Birth Cohort were included in this study. Genome-wide methylation in placental DNA was assessed using the Illumina Human Methylation 450 Bead Chip array and verified by pyrosequencing. Cord blood inflammation markers assessed were interleukin-6, interleukin-8 and tumor necrosis factor α, intercellular adhesion molecule 1, serum amyloid A, and C-reactive protein. ResultsWe identified differential placental DNA methylation of three loci in the HIVEP3 gene shore region that were associated with TNFα protein levels in cord blood. TNFα levels were associated with mode of delivery, gestational age and birth order. Three other loci located in the open sea region of the BCL11B gene were associated with SAA protein levels in cord blood. SAA levels were associated with birthweight, gestational age, and infant sex. ConclusionsOur results suggest a potential role for HIVEP3 and BCL11B placental DNA methylation in the acute immune response of the neonate. These immune markers were correlated with several mother and child characteristics.

Methylarginine targeting chimeras for lysosomal degradation of intracellular proteins.

A paradigm shift in drug development is the discovery of small molecules that harness the ubiquitin-proteasomal pathway to eliminate pathogenic proteins. Here we provide a modality for targeted protein degradation in lysosomes. We exploit an endogenous lysosomal pathway whereby protein arginine methyltransferases (PRMTs) initiate substrate degradation via arginine methylation. We developed a heterobifunctional small molecule, methylarginine targeting chimera (MrTAC), that recruits PRMT1 to a target protein for induced degradation in lysosomes. MrTAC compounds degraded substrates across cell lines, timescales and doses. MrTAC degradation required target protein methylation for subsequent lysosomal delivery via microautophagy. A library of MrTAC molecules exemplified the generality of MrTAC to degrade known targets and neo-substrates-glycogen synthase kinase 3β, MYC, bromodomain-containing protein 4 and histone deacetylase 6. MrTAC selectively degraded target proteins and drove biological loss-of-function phenotypes in survival, transcription and proliferation. Collectively, MrTAC demonstrates the utility of endogenous lysosomal proteolysis in the generation of a new class of small molecule degraders.

Identifying the “stripe” transcription factors and cooperative binding related to DNA methylation

DNA methylation plays a critical role in gene regulation by modulating the DNA binding of transcription factors (TFs). This study integrates TFs’ ChIP-seq profiles with WGBS profiles to investigate how DNA methylation affects protein interactions. Statistical methods and a 5-letter DNA motif calling model have been developed to characterize DNA sequences bound by proteins, while considering the effects of DNA modifications. By employing these methods, 79 significant universal “stripe” TFs and cofactors (USFs), 2360 co-binding protein pairs, and distinct protein modules associated with various DNA methylation states have been identified. The USFs hint a regulatory hierarchy within these protein interactions. Proteins preferentially bind to non-CpG sites in methylated regions, indicating binding affinity is not solely CpG-dependent. Proteins involved in methylation-specific USFs and cobinding pairs play essential roles in promoting and sustaining DNA methylation through interacting with DNMTs or inhibiting TET binding. These findings underscore the interplay between protein binding and methylation, offering insights into epigenetic regulation in cellular biology.