scholarly journals Deletion of Tet proteins results in quantitative disparities during ESC differentiation partially attributable to alterations in gene expression

2019 ◽  
Author(s):  
Michael J Reimer ◽  
Kirthi Pulakanti ◽  
Linzheng Shi ◽  
Alex Abel ◽  
Mingyu Liang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Critical Role ◽  
Embryonic Stem ◽  
Dna Demethylation ◽  
Intermediate Phenotype ◽  
Gene Promoters ◽  
Dna Hypermethylation ◽  
Tet Proteins ◽  
Tet Protein

Abstract Background: The Tet protein family (Tet1, Tet2, and Tet3) regulate DNA methylation through conversion of 5-methylcytosine to 5-hydroxymethylcytosine which can ultimately result in DNA demethylation and play a critical role during early mammalian development and pluripotency¬. While multiple groups have generated knockouts combining loss of different Tet proteins in murine embryonic stem cells (ESCs), differences in genetic background and approaches has made it difficult to directly compare results and discern the direct mechanism by which Tet proteins regulate the transcriptome. To address this concern, we utilized genomic editing in an isogenic pluripotent background which permitted a quantitative, flow-cytometry based measurement of pluripotency in combination with genome-wide assessment of gene expression and DNA methylation changes. Our ultimate goal was to generate a resource of large-scale datasets to permit hypothesis-generating experiments. Results: We demonstrate a quantitative disparity in the differentiation ability among Tet protein deletions, with Tet2 single knockout exhibiting the most severe defect, while loss of Tet1 ¬alone or combinations of Tet genes showed a quantitatively intermediate phenotype. Using a combination of transcriptomic and epigenomic approaches we demonstrate an increase in DNA hypermethylation and a divergence of transcriptional profiles in pluripotency among Tet deletions, with loss of Tet2 having the most profound effect in undifferentiated ESCs. Conclusions: We conclude that loss of Tet2 has the most dramatic effect both on the phenotype of ESCs and the transcriptome compared to other genotypes. While loss of Tet proteins increased DNA hypermethylation, especially in gene promoters, these changes in DNA methylation did not correlate with gene expression changes. Thus, while loss of different Tet proteins alters DNA methylation, this change does not appear to be directly responsible for transcriptome changes. Thus, loss of Tet proteins likely regulates the transcriptome epigenetically both through altering 5mC but also through additional mechanisms. Nonetheless, the transcriptome changes in pluripotent Tet2-/- ESCs compared to wild-type implies that the disparities in differentiation can be partially attributed to baseline alterations in gene expression.

scholarly journals Deletion of Tet proteins results in quantitative disparities during ESC differentiation partially attributable to alterations in gene expression

2019 ◽  
Author(s):  
Michael J Reimer ◽  
Kirthi Pulakanti ◽  
Linzheng Shi ◽  
Alex Abel ◽  
Mingyu Liang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Critical Role ◽  
Embryonic Stem ◽  
Dna Demethylation ◽  
Intermediate Phenotype ◽  
Gene Promoters ◽  
Dna Hypermethylation ◽  
Tet Proteins ◽  
Tet Protein

Abstract Background: The Tet protein family (Tet1, Tet2, and Tet3) regulate DNA methylation through conversion of 5-methylcytosine to 5-hydroxymethylcytosine which can ultimately result in DNA demethylation and play a critical role during early mammalian development and pluripotency¬. While multiple groups have generated knockouts combining loss of different Tet proteins in murine embryonic stem cells (ESCs), differences in genetic background and approaches has made it difficult to directly compare results and discern the direct mechanism by which Tet proteins regulate the transcriptome. To address this concern, we utilized genomic editing in an isogenic pluripotent background which permitted a quantitative, flow-cytometry based measurement of pluripotency in combination with genome-wide assessment of gene expression and DNA methylation changes. Our ultimate goal was to generate a resource of large-scale datasets to permit hypothesis-generating experiments. Results: We demonstrate a quantitative disparity in the differentiation ability among Tet protein deletions, with Tet2 single knockout exhibiting the most severe defect, while loss of Tet1 ¬alone or combinations of Tet genes showed a quantitatively intermediate phenotype. Using a combination of transcriptomic and epigenomic approaches we demonstrate an increase in DNA hypermethylation and a divergence of transcriptional profiles in pluripotency among Tet deletions, with loss of Tet2 having the most profound effect in undifferentiated ESCs. Conclusions: We conclude that loss of Tet2 has the most dramatic effect both on the phenotype of ESCs and the transcriptome compared to other genotypes. While loss of Tet proteins increased DNA hypermethylation, especially in gene promoters, these changes in DNA methylation did not correlate with gene expression changes. Thus, while loss of different Tet proteins alters DNA methylation, this change does not appear to be directly responsible for transcriptome changes. Thus, loss of Tet proteins likely regulates the transcriptome epigenetically both through altering 5mC but also through additional mechanisms. Nonetheless, the transcriptome changes in pluripotent Tet2-/- ESCs compared to wild-type implies that the disparities in differentiation can be partially attributed to baseline alterations in gene expression.

scholarly journals Deletion of Tet proteins results in quantitative disparities during ESC differentiation partially attributable to differences in gene expression

2019 ◽  
Author(s):  
Michael J Reimer ◽  
Kirthi Pulakanti ◽  
Linzheng Shi ◽  
Alex Abel ◽  
Mingyu Liang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Critical Role ◽  
Embryonic Stem ◽  
Dna Demethylation ◽  
Intermediate Phenotype ◽  
Gene Promoters ◽  
Dna Hypermethylation ◽  
Tet Proteins ◽  
Tet Protein

Abstract Background: The Tet protein family (Tet1, Tet2, and Tet3) regulate DNA methylation through conversion of 5-methylcytosine to 5-hydroxymethylcytosine which can ultimately result in DNA demethylation and play a critical role during early mammalian development and pluripotency¬. While multiple groups have generated knockouts combining loss of different Tet proteins in murine embryonic stem cells (ESCs), differences in genetic background and approaches has made it difficult to directly compare results and discern the direct mechanism by which Tet proteins regulate the transcriptome. To address this concern, we utilized genomic editing in an isogenic pluripotent background which permitted a quantitative, flow-cytometry based measurement of pluripotency in combination with genome-wide assessment of gene expression and DNA methylation changes. Our ultimate goal was to generate a resource of large-scale datasets to permit hypothesis-generating experiments. Results: We demonstrate a quantitative disparity in the differentiation ability among Tet protein deletions, with Tet2 single knockout exhibiting the most severe defect, while loss of Tet1 ¬alone or combinations of Tet genes showed a quantitatively intermediate phenotype. Using a combination of transcriptomic and epigenomic approaches we demonstrate an increase in DNA hypermethylation and a divergence of transcriptional profiles in pluripotency among Tet deletions, with loss of Tet2 having the most profound effect in undifferentiated ESCs. Conclusions: We conclude that loss of Tet2 has the most dramatic effect both on the phenotype of ESCs and the transcriptome compared to other genotypes. While loss of Tet proteins increased DNA hypermethylation, especially in gene promoters, these changes in DNA methylation did not correlate with gene expression changes. Thus, while loss of different Tet proteins alters DNA methylation, this change does not appear to be directly responsible for transcriptome changes. Thus, loss of Tet proteins likely regulates the transcriptome epigenetically both through altering 5mC but also through additional mechanisms. Nonetheless, the transcriptome changes in pluripotent Tet2-/- ESCs compared to wild-type implies that the disparities in differentiation can be partially attributed to baseline alterations in gene expression.

scholarly journals PROSER1 mediates TET2 O-GlcNAcylation to regulate DNA demethylation on UTX-dependent enhancers and CpG islands

2021 ◽  
Vol 5 (1) ◽  
pp. e202101228
Author(s):  
Xiaokang Wang ◽  
Wojciech Rosikiewicz ◽  
Yurii Sedkov ◽  
Tanner Martinez ◽  
Baranda S Hansen ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Target Genes ◽  
Cpg Islands ◽  
Dna Demethylation ◽  
Dna Hypermethylation ◽  
Genome Wide ◽  
Associated Proteins ◽  
Tet Enzymes ◽  
Tet Protein ◽  
First Time

DNA methylation at enhancers and CpG islands usually leads to gene repression, which is counteracted by DNA demethylation through the TET protein family. However, how TET enzymes are recruited and regulated at these genomic loci is not fully understood. Here, we identify TET2, the glycosyltransferase OGT and a previously undescribed proline and serine rich protein, PROSER1 as interactors of UTX, a component of the enhancer-associated MLL3/4 complexes. We find that PROSER1 mediates the interaction between OGT and TET2, thus promoting TET2 O-GlcNAcylation and protein stability. In addition, PROSER1, UTX, TET1/2, and OGT colocalize on many genomic elements genome-wide. Loss of PROSER1 results in lower enrichment of UTX, TET1/2, and OGT at enhancers and CpG islands, with a concomitant increase in DNA methylation and transcriptional down-regulation of associated target genes and increased DNA hypermethylation encroachment at H3K4me1-predisposed CpG islands. Furthermore, we provide evidence that PROSER1 acts as a more general regulator of OGT activity by controlling O-GlcNAcylation of multiple other chromatin signaling pathways. Taken together, this study describes for the first time a regulator of TET2 O-GlcNAcylation and its implications in mediating DNA demethylation at UTX-dependent enhancers and CpG islands and supports an important role for PROSER1 in regulating the function of various chromatin-associated proteins via OGT-mediated O-GlcNAcylation.

scholarly journals Advances in the DNA methylation hydroxylase TET1

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Wenzheng Liu ◽  
Guanhua Wu ◽  
Fei Xiong ◽  
Yongjun Chen
Keyword(s):  
Dna Methylation ◽  
Stem Cells ◽  
Cpg Islands ◽  
Embryonic Stem ◽  
Dna Demethylation ◽  
Research Progress ◽  
Malignant Tumours ◽  
Key Factor ◽  
Tet Protein ◽  
Genomic Methylation

Abstract Background The ten-eleven translocation 1 (TET1) protein is a 5-methylcytosine hydroxylase that belongs to the TET protein family of human α-ketoglutarate oxygenases. TET1 recognizes and binds to regions of high genomic 5′-CpG-3′ dinucleotide density, such as CpG islands, initiates the DNA demethylation program, and maintains DNA methylation and demethylation balance to maintain genomic methylation homeostasis and achieve epigenetic regulation. This article reviews the recent research progress of TET1 in the mechanism of demethylation, stem cells and immunity, various malignant tumours and other clinical diseases. Conclusion TET1 acts as a key factor mediating demethylation, the mechanism of which still remains to be investigated in detail. TET1 is also critical in maintaining the differentiation pluripotency of embryonic stem cells and plays anti- or oncogenic roles in combination with different signalling pathways in different tumours. In certain tumours, its role is still controversial. In addition, the noncatalytic activity of TET1 has gradually attracted attention and has become a new direction of research in recent years.

scholarly journals VHL inactivation without hypoxia is sufficient to achieve genome hypermethylation

2016 ◽  
Author(s):  
Artem V. Artemov ◽  
Nadezhda Zhigalova ◽  
Svetlana Zhenilo ◽  
Alexander M. Mazur ◽  
Egor B. Prokhortchouk
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Binding Sites ◽  
Promoter Hypermethylation ◽  
Gene Promoters ◽  
Dna Hypermethylation ◽  
Hypoxic Conditions ◽  
Transcription Regulators

AbstractVHL inactivation is a key oncogenic event for renal carcinomas. In normoxia, VHL suppresses HIF1a-mediated response to hypoxia. It has previously been shown that hypoxic conditions inhibit TET-dependent hydroxymethylation of cytosines and cause DNA hypermethylation at gene promoters. In this work, we performed VHL inactivation by CRISPR/Cas9 and studied its effects on gene expression and DNA methylation. We showed that even without hypoxia, VHL inactivation leads to hypermethylation of the genome which mainly occurred in AP-1 and TRIM28 binding sites. We also observed promoter hypermethylation of several transcription regulators associated with decreased gene expression.

scholarly journals Tet Proteins Can Convert 5-Methylcytosine to 5-Formylcytosine and 5-Carboxylcytosine

Science ◽  
2011 ◽  
Vol 333 (6047) ◽  
pp. 1300-1303 ◽  
Author(s):  
Shinsuke Ito ◽  
Li Shen ◽  
Qing Dai ◽  
Susan C. Wu ◽  
Leonard B. Collins ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Enzymatic Activity ◽  
Genomic Dna ◽  
Embryonic Stem ◽  
Dna Demethylation ◽  
Dependent Manner ◽  
Tet Proteins ◽  
Activity Dependent ◽  
Catalyzed Oxidation

5-methylcytosine (5mC) in DNA plays an important role in gene expression, genomic imprinting, and suppression of transposable elements. 5mC can be converted to 5-hydroxymethylcytosine (5hmC) by the Tet (ten eleven translocation) proteins. Here, we show that, in addition to 5hmC, the Tet proteins can generate 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) from 5mC in an enzymatic activity–dependent manner. Furthermore, we reveal the presence of 5fC and 5caC in genomic DNA of mouse embryonic stem cells and mouse organs. The genomic content of 5hmC, 5fC, and 5caC can be increased or reduced through overexpression or depletion of Tet proteins. Thus, we identify two previously unknown cytosine derivatives in genomic DNA as the products of Tet proteins. Our study raises the possibility that DNA demethylation may occur through Tet-catalyzed oxidation followed by decarboxylation.

scholarly journals Tet proteins: on track towards DNA demethylation?

2012 ◽  
Vol 3 (5) ◽  
pp. 395-402 ◽  
Author(s):  
Nathalie Véron
Keyword(s):  
Dna Methylation ◽  
Enzymatic Activity ◽  
Dna Demethylation ◽  
Epigenetic Mark ◽  
Developmental Processes ◽  
Tet Proteins ◽  
Active Dna Demethylation ◽  
Demethylation Pathway ◽  
Cellular Integrity ◽  
Tet Protein

AbstractDynamic DNA methylation is a prerequisite for many developmental processes and maintenance of cellular integrity. In mammals however, mechanisms of active DNA demethylation have for long been elusive. The discovery of the ten-eleven translocation (Tet) family of enzymes that oxidize 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) or 5-carboxylcytosine (5caC) provided new means by which DNA methylation could actively be reversed. This review focuses on the possible mechanisms of DNA demethylation via Tet proteins and their metabolites 5hmC, 5fC and 5caC. Additionally, it discusses the roles of the three Tet protein family members Tet1, Tet2 and Tet3 as developmental regulators, probably in part independent of their enzymatic activity. By contrast, recent evidence suggests a function of 5hmC as an epigenetic mark on its own, going beyond the expectation of only acting as an intermediate in an active DNA demethylation pathway.

scholarly journals A novel protein complex that regulates active DNA demethylation in Arabidopsis

2020 ◽  
Author(s):  
Pan Liu ◽  
Wen-Feng Nie ◽  
Xiansong Xiong ◽  
Yuhua Wang ◽  
Yuwei Jiang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Protein Complex ◽  
Excision Repair ◽  
Dna Demethylation ◽  
Loss Of Function ◽  
Dna Hypermethylation ◽  
Active Dna Demethylation ◽  
Domain Protein ◽  
Genomic Regions

SUMMARYActive DNA demethylation is critical for altering DNA methylation patterns and regulating gene expression. The 5-methylcytosine DNA glycosylase/lyase ROS1 initiates a base excision repair pathway for active DNA demethylation and is required for the prevention of DNA hypermethylation at thousands of genomic regions in Arabidopsis. How ROS1 is regulated and targeted to specific genomic regions is not well understood. Here, we report the discovery of an Arabidopsis protein complex that contains ROS1, regulates ROS1 gene expression, and likely targets the ROS1 protein to specific genomic regions. ROS1 physically interacts with a WD40 domain protein (RWD40), which in turn interacts with a methyl-DNA binding protein (RMB1) as well as with a zinc finger and homeobox domain protein (RHD1). RMB1 binds to DNA that is methylated in any sequence context, and this binding is necessary for its function in vivo.Loss-of-function mutations in RWD40, RMB1, or RHD1 cause DNA hypermethylation at several tested genomic regions independently of the known ROS1 regulator IDM1. Because the hypermethylated genomic regions include the DNA methylation monitoring sequence in the ROS1 promoter, plants mutated in RWD40, RMB1, or RHD1 show increased ROS1 expression. Importantly, ROS1 binding to the ROS1 promoter requires RWD40, RMB1, and RHD1, suggesting that this complex dictates ROS1 targeting to this locus. Our results demonstrate that ROS1 forms a protein complex with RWD40, RMB1, and RHD1, and that this novel complex regulates active DNA demethylation at several endogenous loci in Arabidopsis.

scholarly journals Bivalent chromatin protects reversibly repressed genes from irreversible silencing

2020 ◽  
Author(s):  
Dhirendra Kumar ◽  
Raja Jothi
Keyword(s):  
Dna Methylation ◽  
Regulatory Mechanism ◽  
De Novo ◽  
Embryonic Stem ◽  
Cell Types ◽  
List Type ◽  
Gene Promoters ◽  
Dna Hypermethylation ◽  
Rapid Activation ◽  
Bivalent Gene

ABSTRACTBivalent chromatin is characterized by the simultaneous presence of H3K4me3 and H3K27me3, histone modifications generally associated with transcriptionally active and repressed chromatin, respectively. Prevalent in embryonic stem cells, bivalency is postulated to poise lineage-controlling developmental genes for rapid activation during embryogenesis while maintaining a transcriptionally repressed state in the absence of activation cues, but its function in development and disease remains a mystery. Here we show that bivalency does not poise genes for rapid activation but protects reversibly repressed genes from irreversible silencing. We find that H3K4me3 at bivalent gene promoters—a product of the underlying DNA sequence—persists in nearly all cell types irrespective of gene expression and confers protection from de novo DNA methylation. Accordingly, loss of H3K4me3 at bivalent promoters is strongly associated with aberrant hypermethylation and irreversible silencing in adult human cancers. Bivalency may thus represent a distinct regulatory mechanism for maintaining epigenetic plasticity.HIGHLIGHTSBivalent chromatin does not poise genes for rapid activationH3K4me3 at bivalent promoters is not instructive for transcription activationH3K4me3 at bivalent promoters protects reversibly repressed genes from de novo DNA methylationLoss of H3K4me3/bivalency is associated with aberrant DNA hypermethylation in cancer

scholarly journals Thousand words about cervical cancer and epigenetics

2016 ◽  
Vol 85 (3) ◽  
pp. 216 ◽  
Author(s):  
Dorota Ewa Bronowicka-Kłys ◽  
Patrycja Pawlik ◽  
Paweł Piotr Jagodziński
Keyword(s):  
Dna Methylation ◽  
Regulation Of Gene Expression ◽  
Epigenetic Modifications ◽  
Dna Demethylation ◽  
Cancer Development ◽  
Tet Proteins ◽  
And Function ◽  
Tet Protein ◽  
The Impact ◽  
Role And Function

Epigenetic modifications include DNA methylation, DNA demethylation along with the major role fulfilled by TET protein. Epigenetic modifications refer to the regulation of gene expression without the alteration of the DNA sequence. Some of the most common epigenetic modifications include DNA methylation and demethylation, as well as the functional role of TET proteins. Epigenetic alterations are heritable traits, therefore one of the key elements to understanding the mechanisms of cancer development is to further our knowledge on the role and function of epigenetic modifications.This mini‑review takes into consideration the overview of the literature on the impact of epigenetic changes in cancer development, especially in the development of CC. Researchers believe that certain compounds are capable of inhibiting the process of DNA methylation and may play an important role in future cancer therapy.

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