Diana Zagirova, Anna Kononkova, Nikita Vaulin, Ekaterina Khrameeva
{"title":"From compartments to loops: understanding the unique chromatin organization in neuronal cells.","authors":"Diana Zagirova, Anna Kononkova, Nikita Vaulin, Ekaterina Khrameeva","doi":"10.1186/s13072-024-00538-6","DOIUrl":"10.1186/s13072-024-00538-6","url":null,"abstract":"<p><p>The three-dimensional organization of the genome plays a central role in the regulation of cellular functions, particularly in the human brain. This review explores the intricacies of chromatin organization, highlighting the distinct structural patterns observed between neuronal and non-neuronal brain cells. We integrate findings from recent studies to elucidate the characteristics of various levels of chromatin organization, from differential compartmentalization and topologically associating domains (TADs) to chromatin loop formation. By defining the unique chromatin landscapes of neuronal and non-neuronal brain cells, these distinct structures contribute to the regulation of gene expression specific to each cell type. In particular, we discuss potential functional implications of unique neuronal chromatin organization characteristics, such as weaker compartmentalization, neuron-specific TAD boundaries enriched with active histone marks, and an increased number of chromatin loops. Additionally, we explore the role of Polycomb group (PcG) proteins in shaping cell-type-specific chromatin patterns. This review further emphasizes the impact of variations in chromatin architecture between neuronal and non-neuronal cells on brain development and the onset of neurological disorders. It highlights the need for further research to elucidate the details of chromatin organization in the human brain in order to unravel the complexities of brain function and the genetic mechanisms underlying neurological disorders. This research will help bridge a significant gap in our comprehension of the interplay between chromatin structure and cell functions.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"17 1","pages":"18"},"PeriodicalIF":4.2,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11112951/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141089231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chromatin profiling and state predictions reveal insights into epigenetic regulation during early porcine development.","authors":"Sarah M Innis, Ryan A Cabot","doi":"10.1186/s13072-024-00542-w","DOIUrl":"10.1186/s13072-024-00542-w","url":null,"abstract":"<p><strong>Background: </strong>Given their physiological similarities to humans, pigs are increasingly used as model organisms in human-oriented biomedical studies. Additionally, their value to animal agriculture across the globe has led to the development of numerous studies to investigate how to improve livestock welfare and production efficiency. As such, pigs are uniquely poised as compelling models that can yield findings with potential implications in both human and animal contexts. Despite this, many gaps remain in our knowledge about the foundational mechanisms that govern gene expression in swine across different developmental stages, particularly in early development. To address some of these gaps, we profiled the histone marks H3K4me3, H3K27ac, and H3K27me3 and the SWI/SNF central ATPase BRG1 in two porcine cell lines representing discrete early developmental time points and used the resulting information to construct predicted chromatin state maps for these cells. We combined this approach with analysis of publicly available RNA-seq data to examine the relationship between epigenetic status and gene expression in these cell types.</p><p><strong>Results: </strong>In porcine fetal fibroblast (PFF) and trophectoderm cells (PTr2), we saw expected patterns of enrichment for each of the profiled epigenetic features relative to specific genomic regions. H3K4me3 was primarily enriched at and around global gene promoters, H3K27ac was enriched in promoter and intergenic regions, H3K27me3 had broad stretches of enrichment across the genome and narrower enrichment patterns in and around the promoter regions of some genes, and BRG1 primarily had detectable enrichment at and around promoter regions and in intergenic stretches, with many instances of H3K27ac co-enrichment. We used this information to perform genome-wide chromatin state predictions for 10 different states using ChromHMM. Using the predicted chromatin state maps, we identified a subset of genomic regions marked by broad H3K4me3 enrichment, and annotation of these regions revealed that they were highly associated with essential developmental processes and consisted largely of expressed genes. We then compared the identities of the genes marked by these regions to genes identified as cell-type-specific using transcriptome data and saw that a subset of broad H3K4me3-marked genes was also specifically expressed in either PFF or PTr2 cells.</p><p><strong>Conclusions: </strong>These findings enhance our understanding of the epigenetic landscape present in early swine development and provide insight into how variabilities in chromatin state are linked to cell identity. Furthermore, this data captures foundational epigenetic details in two valuable porcine cell lines and contributes to the growing body of knowledge surrounding the epigenetic landscape in this species.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"17 1","pages":"16"},"PeriodicalIF":3.9,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11106951/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141077184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nadezhda E Vorobyeva, Alexey N Krasnov, Maksim Erokhin, Darya Chetverina, Marina Mazina
{"title":"Su(Hw) interacts with Combgap to establish long-range chromatin contacts.","authors":"Nadezhda E Vorobyeva, Alexey N Krasnov, Maksim Erokhin, Darya Chetverina, Marina Mazina","doi":"10.1186/s13072-024-00541-x","DOIUrl":"10.1186/s13072-024-00541-x","url":null,"abstract":"<p><strong>Background: </strong>Insulator-binding proteins (IBPs) play a critical role in genome architecture by forming and maintaining contact domains. While the involvement of several IBPs in organising chromatin architecture in Drosophila has been described, the specific contribution of the Suppressor of Hairy wings (Su(Hw)) insulator-binding protein to genome topology remains unclear.</p><p><strong>Results: </strong>In this study, we provide evidence for the existence of long-range interactions between chromatin bound Su(Hw) and Combgap, which was first characterised as Polycomb response elements binding protein. Loss of Su(Hw) binding to chromatin results in the disappearance of Su(Hw)-Combgap long-range interactions and in a decrease in spatial self-interactions among a subset of Su(Hw)-bound genome sites. Our findings suggest that Su(Hw)-Combgap long-range interactions are associated with active chromatin rather than Polycomb-directed repression. Furthermore, we observe that the majority of transcription start sites that are down-regulated upon loss of Su(Hw) binding to chromatin are located within 2 kb of Combgap peaks and exhibit Su(Hw)-dependent changes in Combgap and transcriptional regulators' binding.</p><p><strong>Conclusions: </strong>This study demonstrates that Su(Hw) insulator binding protein can form long-range interactions with Combgap, Polycomb response elements binding protein, and that these interactions are associated with active chromatin factors rather than with Polycomb dependent repression.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"17 1","pages":"17"},"PeriodicalIF":3.9,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11106861/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141077188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Roles of post-translational modifications of UHRF1 in cancer.","authors":"Lili Gu, Yongming Fu, Xiong Li","doi":"10.1186/s13072-024-00540-y","DOIUrl":"10.1186/s13072-024-00540-y","url":null,"abstract":"<p><p>UHRF1 as a member of RING-finger type E3 ubiquitin ligases family, is an epigenetic regulator with five structural domains. It has been involved in the regulation of a series of biological functions, such as DNA replication, DNA methylation, and DNA damage repair. Additionally, aberrant overexpression of UHRF1 has been observed in over ten cancer types, indicating that UHRF1 is a typical oncogene. The overexpression of UHRF1 repressed the transcription of such tumor-suppressor genes as CDKN2A, BRCA1, and CDH1 through DNMT1-mediated DNA methylation. In addition to the upstream transcription factors regulating gene transcription, post-translational modifications (PTMs) also contribute to abnormal overexpression of UHRF1 in cancerous tissues. The types of PTM include phosphorylation, acetylation, methylationand ubiquitination, which regulate protein stability, histone methyltransferase activity, intracellular localization and the interaction with binding partners. Recently, several novel PTM types of UHRF1 have been reported, but the detailed mechanisms remain unclear. This comprehensive review summarized the types of UHRF1 PTMs, as well as their biological functions. A deep understanding of these crucial mechanisms of UHRF1 is pivotal for the development of novel UHRF1-targeted anti-cancer therapeutic strategies in the future.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"17 1","pages":"15"},"PeriodicalIF":3.9,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11080273/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140900024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ouzna Dali, Jose Antonio Muriel-Muriel, Ana Vargas-Baco, Sergei Tevosian, Jasenka Zubcevic, Fatima Smagulova, Linda F Hayward
{"title":"Prenatal nicotine exposure leads to epigenetic alterations in peripheral nervous system signaling genes in the testis of the rat.","authors":"Ouzna Dali, Jose Antonio Muriel-Muriel, Ana Vargas-Baco, Sergei Tevosian, Jasenka Zubcevic, Fatima Smagulova, Linda F Hayward","doi":"10.1186/s13072-024-00539-5","DOIUrl":"10.1186/s13072-024-00539-5","url":null,"abstract":"<p><strong>Background: </strong>Prenatal nicotine exposure (PNE) has been documented to cause numerous deleterious effects on fetal development. However, the epigenetic changes promoted by nicotine exposure on germ cells are still not well understood.</p><p><strong>Objectives: </strong>In this study, we focused on elucidating the impact of prenatal nicotine exposure on regulatory epigenetic mechanisms important for germ cell development.</p><p><strong>Methods: </strong>Sprague-Dawley rats were exposed to nicotine during pregnancy and male progeny was analyzed at 11 weeks of age. Testis morphology was analyzed using frozen testis sections and expression of germ cell markers was examined by RT-qPCR; histone modifications were assessed by Western Blot (WB). DNA methylation analysis was performed by methylation-specific PCR of bisulfite converted DNA. Genome-wide DNA methylation was analyzed using Methylated DNA immunoprecipitation (MeDIP)-seq. We also carried out transcriptomics analysis of pituitary glands by RNA-seq.</p><p><strong>Results: </strong>We show that gestational exposure to nicotine reduces germ cell numbers, perturbs meiosis, affects the expression of germ line reprogramming responsive genes, and impacts the DNA methylation of nervous system genes in the testis. PNE also causes perturbation of gene expression in the pituitary gland of the brain.</p><p><strong>Conclusions: </strong>Our data demonstrate that PNE leads to perturbation of male spermatogenesis, and the observed effects are associated with changes of peripheral nervous system signaling pathways. Alterations in the expression of genes associated with diverse biological activities such as cell migration, cell adhesion and GABA signaling in the pituitary gland underscore the complexity of the effects of nicotine exposure during pregnancy.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"17 1","pages":"14"},"PeriodicalIF":3.9,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11075221/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140877795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander Y Afanasyev, Yoonjin Kim, Igor S Tolokh, Igor V Sharakhov, Alexey V Onufriev
{"title":"The probability of chromatin to be at the nuclear lamina has no systematic effect on its transcription level in fruit flies.","authors":"Alexander Y Afanasyev, Yoonjin Kim, Igor S Tolokh, Igor V Sharakhov, Alexey V Onufriev","doi":"10.1186/s13072-024-00528-8","DOIUrl":"10.1186/s13072-024-00528-8","url":null,"abstract":"<p><strong>Background: </strong>Multiple studies have demonstrated a negative correlation between gene expression and positioning of genes at the nuclear envelope (NE) lined by nuclear lamina, but the exact relationship remains unclear, especially in light of the highly stochastic, transient nature of the gene association with the NE.</p><p><strong>Results: </strong>In this paper, we ask whether there is a causal, systematic, genome-wide relationship between the expression levels of the groups of genes in topologically associating domains (TADs) of Drosophila nuclei and the probabilities of TADs to be found at the NE. To investigate the nature of this possible relationship, we combine a coarse-grained dynamic model of the entire Drosophila nucleus with genome-wide gene expression data; we analyze the TAD averaged transcription levels of genes against the probabilities of individual TADs to be in contact with the NE in the control and lamins-depleted nuclei. Our findings demonstrate that, within the statistical error margin, the stochastic positioning of Drosophila melanogaster TADs at the NE does not, by itself, systematically affect the mean level of gene expression in these TADs, while the expected negative correlation is confirmed. The correlation is weak and disappears completely for TADs not containing lamina-associated domains (LADs) or TADs containing LADs, considered separately. Verifiable hypotheses regarding the underlying mechanism for the presence of the correlation without causality are discussed. These include the possibility that the epigenetic marks and affinity to the NE of a TAD are determined by various non-mutually exclusive mechanisms and remain relatively stable during interphase.</p><p><strong>Conclusions: </strong>At the level of TADs, the probability of chromatin being in contact with the nuclear envelope has no systematic, causal effect on the transcription level in Drosophila. The conclusion is reached by combining model-derived time-evolution of TAD locations within the nucleus with their experimental gene expression levels.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"17 1","pages":"13"},"PeriodicalIF":3.9,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11071202/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140870899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bethany C. Taylor, Loic H. Steinthal, Michelle Dias, Hari Krishna Yalamanchili, Scott A. Ochsner, Gladys E. Zapata, Nitesh R. Mehta, Neil J. McKenna, Nicolas L. Young, Alli M. Nuotio-Antar
{"title":"Histone proteoform analysis reveals epigenetic changes in adult mouse brown adipose tissue in response to cold stress","authors":"Bethany C. Taylor, Loic H. Steinthal, Michelle Dias, Hari Krishna Yalamanchili, Scott A. Ochsner, Gladys E. Zapata, Nitesh R. Mehta, Neil J. McKenna, Nicolas L. Young, Alli M. Nuotio-Antar","doi":"10.1186/s13072-024-00536-8","DOIUrl":"https://doi.org/10.1186/s13072-024-00536-8","url":null,"abstract":"Regulation of the thermogenic response by brown adipose tissue (BAT) is an important component of energy homeostasis with implications for the treatment of obesity and diabetes. Our preliminary analyses of RNA-Seq data uncovered many nodes representing epigenetic modifiers that are altered in BAT in response to chronic thermogenic activation. Thus, we hypothesized that chronic thermogenic activation broadly alters epigenetic modifications of DNA and histones in BAT. Motivated to understand how BAT function is regulated epigenetically, we developed a novel method for the first-ever unbiased top-down proteomic quantitation of histone modifications in BAT and validated our results with a multi-omic approach. To test our hypothesis, wildtype male C57BL/6J mice were housed under chronic conditions of thermoneutral temperature (TN, 28°C), mild cold/room temperature (RT, 22°C), or severe cold (SC, 8°C) and BAT was analyzed for DNA methylation and histone modifications. Methylation of promoters and intragenic regions in genomic DNA decrease in response to chronic cold exposure. Integration of DNA methylation and RNA expression datasets suggest a role for epigenetic modification of DNA in regulation of gene expression in response to cold. In response to cold housing, we observe increased bulk acetylation of histones H3.2 and H4, increased histone H3.2 proteoforms with di- and trimethylation of lysine 9 (K9me2 and K9me3), and increased histone H4 proteoforms with acetylation of lysine 16 (K16ac) in BAT. Our results reveal global epigenetically-regulated transcriptional “on” and “off” signals in murine BAT in response to varying degrees of chronic cold stimuli and establish a novel methodology to quantitatively study histones in BAT, allowing for direct comparisons to decipher mechanistic changes during the thermogenic response. Additionally, we make histone PTM and proteoform quantitation, RNA splicing, RRBS, and transcriptional footprint datasets available as a resource for future research.","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"19 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140798594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reinforcement of repressive marks in the chicken primordial germ cell epigenetic signature: divergence from basal state resetting in mammals","authors":"Clémence Kress, Luc Jouneau, Bertrand Pain","doi":"10.1186/s13072-024-00537-7","DOIUrl":"https://doi.org/10.1186/s13072-024-00537-7","url":null,"abstract":"In mammals, primordial germ cells (PGCs), the embryonic precursors of the germline, arise from embryonic or extra-embryonic cells upon induction by the surrounding tissues during gastrulation, according to mechanisms which are elucidated in mice but remain controversial in primates. They undergo genome-wide epigenetic reprogramming, consisting of extensive DNA demethylation and histone post-translational modification (PTM) changes, toward a basal, euchromatinized state. In contrast, chicken PGCs are specified by preformation before gastrulation based on maternally-inherited factors. They can be isolated from the bloodstream during their migration to the genital ridges. Our prior research highlighted differences in the global epigenetic profile of cultured chicken PGCs compared with chicken somatic cells and mammalian PGCs. This study investigates the acquisition and evolution of this profile during development. Quantitative analysis of global DNA methylation and histone PTMs, including their distribution, during key stages of chicken early development revealed divergent PGC epigenetic changes compared with mammals. Unlike mammalian PGCs, chicken PGCs do not undergo genome-wide DNA demethylation or exhibit a decrease in histone H3 lysine 9 dimethylation. However, chicken PGCs show 5‑hydroxymethylcytosine loss, macroH2A redistribution, and chromatin decompaction, mirroring mammalian processes. Chicken PGCs initiate their epigenetic signature during migration, progressively accumulating high global levels of H3K9me3, with preferential enrichment in inactive genome regions. Despite apparent global chromatin decompaction, abundant heterochromatin marks, including repressive histone PTMs, HP1 variants, and DNA methylation, persists in chicken PGCs, contrasting with mammalian PGCs. Chicken PGCs’ epigenetic signature does not align with the basal chromatin state observed in mammals, suggesting a departure from extensive epigenetic reprogramming. Despite disparities in early PGC development, the persistence of several epigenetic features shared with mammals implies their involvement in chromatin-regulated germ cell properties, with the distinctive elevation of chicken-specific H3K9me3 potentially participating in these processes.","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"233 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140798614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Analysis of long-range chromatin contacts, compartments and looping between mouse embryonic stem cells, lens epithelium and lens fibers","authors":"Michael Camerino, William Chang, Ales Cvekl","doi":"10.1186/s13072-024-00533-x","DOIUrl":"https://doi.org/10.1186/s13072-024-00533-x","url":null,"abstract":"Nuclear organization of interphase chromosomes involves individual chromosome territories, “open” and “closed” chromatin compartments, topologically associated domains (TADs) and chromatin loops. The DNA- and RNA-binding transcription factor CTCF together with the cohesin complex serve as major organizers of chromatin architecture. Cellular differentiation is driven by temporally and spatially coordinated gene expression that requires chromatin changes of individual loci of various complexities. Lens differentiation represents an advantageous system to probe transcriptional mechanisms underlying tissue-specific gene expression including high transcriptional outputs of individual crystallin genes until the mature lens fiber cells degrade their nuclei. Chromatin organization between mouse embryonic stem (ES) cells, newborn (P0.5) lens epithelium and fiber cells were analyzed using Hi-C. Localization of CTCF in both lens chromatins was determined by ChIP-seq and compared with ES cells. Quantitative analyses show major differences between number and size of TADs and chromatin loop size between these three cell types. In depth analyses show similarities between lens samples exemplified by overlaps between compartments A and B. Lens epithelium-specific CTCF peaks are found in mostly methylated genomic regions while lens fiber-specific and shared peaks occur mostly within unmethylated DNA regions. Major differences in TADs and loops are illustrated at the ~ 500 kb Pax6 locus, encoding the critical lens regulatory transcription factor and within a larger ~ 15 Mb WAGR locus, containing Pax6 and other loci linked to human congenital diseases. Lens and ES cell Hi-C data (TADs and loops) together with ATAC-seq, CTCF, H3K27ac, H3K27me3 and ENCODE cis-regulatory sites are shown in detail for the Pax6, Sox1 and Hif1a loci, multiple crystallin genes and other important loci required for lens morphogenesis. The majority of crystallin loci are marked by unexpectedly high CTCF-binding across their transcribed regions. Our study has generated the first data on 3-dimensional (3D) nuclear organization in lens epithelium and lens fibers and directly compared these data with ES cells. These findings generate novel insights into lens-specific transcriptional gene control, open new research avenues to study transcriptional condensates in lens fiber cells, and enable studies of non-coding genetic variants linked to cataract and other lens and ocular abnormalities.","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"11 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140626733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sofia Kamalyan, Olga Kyrchanova, Natalia Klimenko, Valentin Babosha, Yulia Vasileva, Elena Belova, Dariya Fursenko, Oksana Maksimenko, Pavel Georgiev
{"title":"The N-terminal dimerization domains of human and Drosophila CTCF have similar functionality.","authors":"Sofia Kamalyan, Olga Kyrchanova, Natalia Klimenko, Valentin Babosha, Yulia Vasileva, Elena Belova, Dariya Fursenko, Oksana Maksimenko, Pavel Georgiev","doi":"10.1186/s13072-024-00534-w","DOIUrl":"10.1186/s13072-024-00534-w","url":null,"abstract":"<p><strong>Background: </strong>CTCF is highly likely to be the ancestor of proteins that contain large clusters of C2H2 zinc finger domains, and its conservation is observed across most bilaterian organisms. In mammals, CTCF is the primary architectural protein involved in organizing chromosome topology and mediating enhancer-promoter interactions over long distances. In Drosophila, CTCF (dCTCF) cooperates with other architectural proteins to establish long-range interactions and chromatin boundaries. CTCFs of various organisms contain an unstructured N-terminal dimerization domain (DD) and clusters comprising eleven zinc-finger domains of the C2H2 type. The Drosophila (dCTCF) and human (hCTCF) CTCFs share sequence homology in only five C2H2 domains that specifically bind to a conserved 15 bp motif.</p><p><strong>Results: </strong>Previously, we demonstrated that CTCFs from different organisms carry unstructured N-terminal dimerization domains (DDs) that lack sequence homology. Here we used the CTCF<sup>attP(mCh)</sup> platform to introduce desired changes in the Drosophila CTCF gene and generated a series of transgenic lines expressing dCTCF with different variants of the N-terminal domain. Our findings revealed that the functionality of dCTCF is significantly affected by the deletion of the N-terminal DD. Additionally, we observed a strong impact on the binding of the dCTCF mutant to chromatin upon deletion of the DD. However, chromatin binding was restored in transgenic flies expressing a chimeric CTCF protein with the DD of hCTCF. Although the chimeric protein exhibited lower expression levels than those of the dCTCF variants, it efficiently bound to chromatin similarly to the wild type (wt) protein.</p><p><strong>Conclusions: </strong>Our findings suggest that one of the evolutionarily conserved functions of the unstructured N-terminal dimerization domain is to recruit dCTCF to its genomic sites in vivo.</p>","PeriodicalId":49253,"journal":{"name":"Epigenetics & Chromatin","volume":"17 1","pages":"9"},"PeriodicalIF":3.9,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10983669/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140337445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}