Role of Dot1L and H3K79 methylation in regulating somatic hypermutation of immunoglobulin genes
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ABSTRACT:
PROVIDER: PRJNA705367 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR13801706_1.fastq.gz | Fastqsanger.gz | |||
| SRR13801706_2.fastq.gz | Fastqsanger.gz | |||
| SRR13801707_1.fastq.gz | Fastqsanger.gz | |||
| SRR13801707_2.fastq.gz | Fastqsanger.gz | |||
| SRR13801708_1.fastq.gz | Fastqsanger.gz |
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Similar Datasets
Project description:Somatic hypermutation (SHM) and class switch recombination (CSR) of the immunoglobulin (Ig) genes allow B cells to make antibodies that protect us against a wide variety of pathogens. SHM is mediated by activation induced deaminase (AID), occurs at a million times higher frequency than other mutations in the mammalian genome and is largely restricted to the variable (V) and switch (S) regions of Ig genes. Using the Ramos human Burkitt’s lymphoma cell line, we find that H3K79me2/3 and its methyltransferase Dot1L are more abundant on the V region than the constant (C) region which does not undergo mutation. In primary naïve mouse B cells examined ex vivo, the H3K79me2/3 modification appears constitutively in the donor Sμ and is inducible in the recipient Sγ1 upon CSR stimulation. Knockout (KO) and inhibition of Dot1L in Ramos cells significantly reduces V region mutation and the abundance of H3K79me2/3 on the V region and is associated with a decrease of Pol II and its S2 phosphorylated form at the IgH locus. KO of Dot1L also decreases the abundance of BRD4 and CDK9 (a subunit of P-TEFb complex) on the V region and this is accompanied by decreased nascent transcripts throughout the IgH gene. Treatment with JQ1 (inhibitor of BRD4) or DRB (inhibitor of CDK9) decreased SHM and the abundance of Pol II S2P at the IgH locus. With all these factors playing a role in transcription elongation, our studies extend our insights into the chromatin context and dynamics of transcription required for SHM.
2021-02-28 | GSE167873 | GEO
Project description:Somatic hypermutation (SHM) and class-switch recombination (CSR) of the immunoglobulin (Ig) genes allow B cells to make antibodies that protect us against a wide variety of pathogens. SHM is mediated by activation-induced deaminase (AID), occurs at a million times higher frequency than other mutations in the mammalian genome, and is largely restricted to the variable (V) and switch (S) regions of Ig genes. Using the Ramos human Burkitt's lymphoma cell line, we find that H3K79me2/3 and its methyltransferase Dot1L are more abundant on the V region than on the constant (C) region, which does not undergo mutation. In primary naïve mouse B cells examined ex vivo, the H3K79me2/3 modification appears constitutively in the donor Sμ and is inducible in the recipient Sγ1 upon CSR stimulation. Knockout and inhibition of Dot1L in Ramos cells significantly reduces V region mutation and the abundance of H3K79me2/3 on the V region and is associated with a decrease of polymerase II (Pol II) and its S2 phosphorylated form at the IgH locus. Knockout of Dot1L also decreases the abundance of BRD4 and CDK9 (a subunit of the P-TEFb complex) on the V region, and this is accompanied by decreased nascent transcripts throughout the IgH gene. Treatment with JQ1 (inhibitor of BRD4) or DRB (inhibitor of CDK9) decreases SHM and the abundance of Pol II S2P at the IgH locus. Since all these factors play a role in transcription elongation, our studies reinforce the idea that the chromatin context and dynamics of transcription are critical for SHM.
| S-EPMC8307847 | biostudies-literature
Project description:Activation induced deaminase (AID) initiates class switch recombination (CSR) and somatic hypermutation of the antibody genes but also mutates other genes, with oncogenic consequences, as a side effect. It is important to understand the mechanisms that render the antibody genes and off-target genomic loci susceptible to AID. We identify the H3K79 histone methyltransferase DOT1L as nuclear AID-proximal factor required for CSR, as well as off-target AID activity, including IgH-cMyc translocations. Mechanistically, we find that DOT1L activity restricts transcriptional pause release, as evidenced by reduced promoter-proximal RNA polymerase II (RNAPII) and increased RNAPII Serine 2 phosphorylation into the gene bodies of all H3K79-modified genes. Additional evidence suggests that widespread pause release results in abnormal transcription elongation, which can explain the variable effect of DOT1L-deficiency on H3K79-methylated gene transcript levels, depending on their original transcriptional activity and gene length. Thus, we propose that DOT1L limits transcriptional pause release, which enables AID activity genome-wide.
2023-05-31 | MSV000092065 | MassIVE
Project description:Activation-induced deaminase (AID) initiates class switch recombination (CSR) and somatic hypermutation of immunoglobulin genes, which are required for efficient antibody responses. Collaterally, AID can also mutate a set of off-target genes with oncogenic consequences. The mechanisms that make such loci susceptible to AID are not fully understood. We find that the H3K79 histone methyltransferase DOT1L is located close to AID in the nucleus. Not only does DOT1L activity facilitate CSR, but it also facilitates AID off-target activity, including Igh-cMyc translocations. Genes mutated by AID display high DOT1L activity. DOT1L deficiency causes mostly increased nascent transcription, accompanied by a modest reduction in RNAPII occupancy. By integrating different genomic approaches, we discovered that DOT1L restricts the velocity of transcription elongation proportionally to the level of higher order H3K79 methylation (H3K79me2/3) and favors RNAPII pausing. These transcriptional conditions enhance AID occupancy and, consequently, its activity. Our data indicate a role for DOT1L and H3K79me2/3 in limiting transcription and highlight stronger RNAPII pausing and attenuated RNAPII elongation velocity as critical steps for productive AID association and mutagenesis at target loci. Furthermore, increased transcription elongation velocity could explain both upregulation and downregulation of genes in DOT1L-deficient cells.
2025-11-13 | GSE233974 | GEO
Project description:Activation-induced deaminase (AID) initiates class switch recombination (CSR) and somatic hypermutation of immunoglobulin genes, which are required for efficient antibody responses. Collaterally, AID can also mutate a set of off-target genes with oncogenic consequences. The mechanisms that make such loci susceptible to AID are not fully understood. We find that the H3K79 histone methyltransferase DOT1L is located close to AID in the nucleus. Not only does DOT1L activity facilitate CSR, but it also facilitates AID off-target activity, including Igh-cMyc translocations. Genes mutated by AID display high DOT1L activity. DOT1L deficiency causes mostly increased nascent transcription, accompanied by a modest reduction in RNAPII occupancy. By integrating different genomic approaches, we discovered that DOT1L restricts the velocity of transcription elongation proportionally to the level of higher order H3K79 methylation (H3K79me2/3) and favors RNAPII pausing. These transcriptional conditions enhance AID occupancy and, consequently, its activity. Our data indicate a role for DOT1L and H3K79me2/3 in limiting transcription and highlight stronger RNAPII pausing and attenuated RNAPII elongation velocity as critical steps for productive AID association and mutagenesis at target loci. Furthermore, increased transcription elongation velocity could explain both upregulation and downregulation of genes in DOT1L-deficient cells.
2025-11-13 | GSE233969 | GEO
Project description:Activation-induced deaminase (AID) initiates class switch recombination (CSR) and somatic hypermutation of immunoglobulin genes, which are required for efficient antibody responses. Collaterally, AID can also mutate a set of off-target genes with oncogenic consequences. The mechanisms that make such loci susceptible to AID are not fully understood. We find that the H3K79 histone methyltransferase DOT1L is located close to AID in the nucleus. Not only does DOT1L activity facilitate CSR, but it also facilitates AID off-target activity, including Igh-cMyc translocations. Genes mutated by AID display high DOT1L activity. DOT1L deficiency causes mostly increased nascent transcription, accompanied by a modest reduction in RNAPII occupancy. By integrating different genomic approaches, we discovered that DOT1L restricts the velocity of transcription elongation proportionally to the level of higher order H3K79 methylation (H3K79me2/3) and favors RNAPII pausing. These transcriptional conditions enhance AID occupancy and, consequently, its activity. Our data indicate a role for DOT1L and H3K79me2/3 in limiting transcription and highlight stronger RNAPII pausing and attenuated RNAPII elongation velocity as critical steps for productive AID association and mutagenesis at target loci. Furthermore, increased transcription elongation velocity could explain both upregulation and downregulation of genes in DOT1L-deficient cells.
2025-11-13 | GSE290944 | GEO
Project description:Activation-induced deaminase (AID) initiates class switch recombination (CSR) and somatic hypermutation of immunoglobulin genes, which are required for efficient antibody responses. Collaterally, AID can also mutate a set of off-target genes with oncogenic consequences. The mechanisms that make such loci susceptible to AID are not fully understood. We find that the H3K79 histone methyltransferase DOT1L is located close to AID in the nucleus. Not only does DOT1L activity facilitate CSR, but it also facilitates AID off-target activity, including Igh-cMyc translocations. Genes mutated by AID display high DOT1L activity. DOT1L deficiency causes mostly increased nascent transcription, accompanied by a modest reduction in RNAPII occupancy. By integrating different genomic approaches, we discovered that DOT1L restricts the velocity of transcription elongation proportionally to the level of higher order H3K79 methylation (H3K79me2/3) and favors RNAPII pausing. These transcriptional conditions enhance AID occupancy and, consequently, its activity. Our data indicate a role for DOT1L and H3K79me2/3 in limiting transcription and highlight stronger RNAPII pausing and attenuated RNAPII elongation velocity as critical steps for productive AID association and mutagenesis at target loci. Furthermore, increased transcription elongation velocity could explain both upregulation and downregulation of genes in DOT1L-deficient cells.
2025-11-13 | GSE290945 | GEO
Project description:Immunoglobulin enhancers increase RNA polymerase 2 stalling at somatic hypermutation target sequences
| PRJNA746964 | ENA
Project description:The transcription factor Bach2 is required for germinal center formation and somatic hypermutation (SHM) of immunoglobulins, both central to an efficient antibody-mediated immune response. Activation-induced cytidine deaminase (AID) initiates SHM and CSR in germinal centers and has potential to induce human B cell lymphoma. To understand the role of Bach2 in AID-mediated immunoglobulin gene diversification processes, we established a Bach2-deficient DT40 B cell line. We show that in addition to allowing SHM, Bach2 drives immunoglobulin gene conversion (GCV), an important AID-dependent antibody gene diversification process. We demonstrate that Bach2 promotes GCV by increasing the expression of AID. Importantly, we found that the regulation of AID is independent of Blimp-1 and that Bach2-deficient cells have altered expression of several genes regulating AID expression, stability and function. These results demonstrate that Bach2 has a previously unappreciated role in the production of high-affinity antibodies.
2017-03-27 | GSE92430 | GEO
Project description:Actively transcribed genes in mammals are decorated by H3K79 methylation, which is correlated with transcription levels and is catalyzed by the histone methyltransferase DOT1L. DOT1L is required for mammalian development, and the inhibition of its catalytic activity has been extensively studied for cancer therapy; however, the mechanisms underlying DOT1L’s functions in normal development and cancer pathogenesis remain elusive. To dissect the relationship between H3K79 methylation, cellular differentiation, and transcription regulation, we systematically examined the role of DOT1L and its catalytic activity in embryonic stem cells (ESCs). DOT1L is dispensable for ESC self-renewal but is required for establishing the proper expression signature of neural progenitor cells, while catalytic inactivation of DOT1L has a lesser effect. Furthermore, DOT1L loss, rather than its catalytic inactivation, causes defects in glial cell specification. Although DOT1L loss by itself has no major defect in transcription elongation, transcription elongation defects seen with the super elongation complex inhibitor KL-2 are exacerbated in DOT1L knockout cells, but not in catalytically dead DOT1L cells, revealing a role of DOT1L in promoting productive transcription elongation that is independent of H3K79 methylation. Taken together, our study reveals a catalytic-independent role of DOT1L in modulating cell-fate determination and in transcriptional elongation control.
2020-10-21 | GSE134083 | GEO