Mus musculus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA371775 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR5237690.fastq.gz | Fastqsanger.gz | |||
| SRR5237700.fastq.gz | Fastqsanger.gz | |||
| SRR5237691.fastq.gz | Fastqsanger.gz | |||
| SRR5237701.fastq.gz | Fastqsanger.gz | |||
| SRR5237692.fastq.gz | Fastqsanger.gz |
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Project description:Activation induced cytidine deaminase (AID) initiates antibody gene diversification by creating U:G mismatches. However, AID is not specific for antibody genes. Off-target lesions can activate oncogenes or cause chromosome translocations. Despite its importance in these key transactions little is known about how AID finds its target sites. To examine AID regulation we performed an shRNA screen. We found that Spt5, a factor associated with paused RNA polymerase II (Pol II) and single stranded DNA (ssDNA), is required for class switch recombination (CSR). Spt5 interacts with AID, it is required for the association of AID and Pol II, and for AID recruitment to switch regions. ChIP-seq experiments reveal that Spt5 co-localizes with AID and stalled Pol II. Further, Spt5 accumulation at sites of Pol II pausing is predictive of AID-induced mutation. Our data suggest that Spt5 acts as an adaptor, which brings AID to Pol II on target DNA. PolII, AID, and Spt5 were immunoprecipitated from in vitro activated B cells. For Spt5 and AID, two different antibodies were used in separate, biological replicates
2010-10-05 | E-GEOD-24178 | biostudies-arrayexpress
Project description:Class switch recombination generates antibody distinct isotypes critical to a robust adaptive immune system and defects are associated with auto-immune disorders and lymphomagenesis. Transcription is required during class switch to recruit the cytidine deaminase AID—an essential step for the formation of DNA doublestrand breaks—and strongly induces the formation of R loops within the immunoglobulin heavy chain locus. However, the impact of R loops on double-strand break formation and repair during class switch recombination remains unclear. Here we report that cells lacking two enzymes involved in R loop removal— Senataxin and RNase H2—exhibit increased R loop formation and genome instability at the immunoglobulin heavy chain locus without impacting class switch recombination efficiency, transcriptional activity, or AID recruitment. Senataxin and RNase H2-deficient cells also exhibit increased insertion mutations at switch junctions, a hallmark of alternative end joining. Importantly, these phenotypes were not observed in cells lacking Senataxin or RNase H2B alone. We propose that Senataxin acts redundantly with RNase H2 to mediate timely R loop removal, promoting efficient repair while suppressing AID-dependent genome instability and insertional mutagenesis.
2022-12-14 | GSE201210 | GEO
Project description:Activation induced cytidine deaminase (AID) initiates antibody gene diversification by creating U:G mismatches. However, AID is not specific for antibody genes. Off-target lesions can activate oncogenes or cause chromosome translocations. Despite its importance in these key transactions little is known about how AID finds its target sites. To examine AID regulation we performed an shRNA screen. We found that Spt5, a factor associated with paused RNA polymerase II (Pol II) and single stranded DNA (ssDNA), is required for class switch recombination (CSR). Spt5 interacts with AID, it is required for the association of AID and Pol II, and for AID recruitment to switch regions. ChIP-seq experiments reveal that Spt5 co-localizes with AID and stalled Pol II. Further, Spt5 accumulation at sites of Pol II pausing is predictive of AID-induced mutation. Our data suggest that Spt5 acts as an adaptor, which brings AID to Pol II on target DNA.
2010-10-05 | GSE24178 | GEO
Project description:The RNA binding protein Bcas2 is necessary for antibody class switch in mammalian genomes
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Project description:After immunization or infection, activation-induced cytidine deaminase (AID) initiates diversification of immunoglobulin (Ig) genes in B cells, introducing mutations within the antigen binding V regions (somatic hypermutation, SHM) and double-strand DNA breaks (DSBs) into switch (S) regions, leading to antibody class switch recombination (CSR). Using a candidate approach, AID has been shown to initiate mutations at numerous non-Ig genes in B cells in Peyer’s patches. However, it is not known if during B cell activation, AID also induces DNA breaks at genes other than IgH genes, which would lead to genomic instability and malignancy. Using a non-biased genome-wide approach, we have identified hundreds of reproducible AID-dependent DSBs in mouse splenic B cells shortly after induction of CSR in culture. Most interestingly, AID induces DSBs at sites syntenic with sites of translocations, deletions, and amplifications found in human B cell lymphomas, including within the oncogene B cell lymphoma11a (bcl11a)/evi9. The AID-dependent DSBs are not restricted to transcribed regions, and they frequently occur within repeated sequence elements, including CA and non-CA repeats, and SINEs. Comparison of Nbs1 binding sites in wild-type vs. aid-/- splenic B cells induced to undergo CSR; aid-dependent Nbs1 sites correlated with gene transcription (RNA Pol2).
2011-01-21 | E-GEOD-24827 | biostudies-arrayexpress
Project description:After immunization or infection, activation-induced cytidine deaminase (AID) initiates diversification of immunoglobulin (Ig) genes in B cells, introducing mutations within the antigen binding V regions (somatic hypermutation, SHM) and double-strand DNA breaks (DSBs) into switch (S) regions, leading to antibody class switch recombination (CSR). Using a candidate approach, AID has been shown to initiate mutations at numerous non-Ig genes in B cells in Peyer’s patches. However, it is not known if during B cell activation, AID also induces DNA breaks at genes other than IgH genes, which would lead to genomic instability and malignancy. Using a non-biased genome-wide approach, we have identified hundreds of reproducible AID-dependent DSBs in mouse splenic B cells shortly after induction of CSR in culture. Most interestingly, AID induces DSBs at sites syntenic with sites of translocations, deletions, and amplifications found in human B cell lymphomas, including within the oncogene B cell lymphoma11a (bcl11a)/evi9. The AID-dependent DSBs are not restricted to transcribed regions, and they frequently occur within repeated sequence elements, including CA and non-CA repeats, and SINEs.
2011-01-21 | GSE24827 | GEO
Project description:Class Switch Recombination (CSR) is a DNA recombination reaction that diversifies the effector component of antibody responses. CSR is initiated by activation-induced cytidine deaminase (AID), which targets transcriptionally active immunoglobulin heavy chain (Igh) switch donor and acceptor DNA. The 3’ Igh super-enhancer, 3’ Regulatory Region (3’RR), is essential for acceptor region transcription, but how this function is regulated is unknown. Here we identify the chromatin reader ZMYND8 as an essential regulator of the 3’RR and CSR. In B cells, ZMYND8 binds promoters and super-enhancers, including the 3’RR, and controls its activity by modulating the enhancer transcriptional status. In its absence, there is increased 3’RR polymerase loading, and decreased acceptor region transcription and CSR. In addition to CSR, ZMYND8 deficiency impairs somatic hypermutation (SHM) of Igh, which is also dependent on the 3’RR. Thus ZMYND8 controls Igh diversification in mature B lymphocytes by regulating the activity of the 3’ Igh super-enhancer.
2018-10-04 | GSE118794 | GEO
Project description:Previous studies have demonstrated that E-proteins induce AID expression in activated B cells. Here we have examined the role of Id3 in germinal center (GC) cells. We found that Id3 expression is high in follicular B-lineage cells but declines in GC cells. Immunized mice depleted for Id3 expression displayed a block in germinal center B cell maturation, showed reduced numbers of marginal zone B cells and class switched cells, were associated with decreased antibody titers and lower numbers of plasma cells. In vitro Id3-depleted B cells displayed a defect in class switch recombination. Whereas AID levels were not altered in Id3-depleted activated B cells, the expression of a subset of genes encoding for signaling components of antigen receptor, cytokine receptor and chemokine receptor mediated signaling was significantly impaired. We propose that during the GC reaction Id3 levels decline to activate the expression of genes encoding for signaling components that mediate B cell receptor and or cytokine-mediated signaling to promote the differentiation of GC B cells.
2016-08-18 | GSE84374 | GEO
Project description:Activation-induced cytidine deaminase (AID) initiates both somatic hypermutation (SHM) for antibody affinity maturation and DNA breakage for antibody class switch recombination (CSR) via transcription-dependent cytidine deamination of single stranded DNA targets. While largely specific for immunglobulin genes, AID also acts on a limited set of off-targets, generating oncogenic translocations and mutations that contribute to B cell lymphoma. How AID is recruited to off-targets has been a long-standing mystery. Based on deep GRO-Seq studies of mouse and human B lineage cells activated for CSR or SHM, we report that most robust AID off-target translocations occur within highly focal regions of target genes in which sense and antisense transcription converge. Moreover, we found that such AID-targeting "convergent" transcription arises from antisense transcription that emanates from Super-Enhancers within sense transcribed gene bodies. Our findings provide a mechanistic explanation for AID off-targeting to a small subset of mostly lineage-specific genes in activated B cells.
2014-12-04 | GSE62296 | GEO
Project description:Activation-induced cytidine deaminase (AID) is required for initiation of Ig class switch recombination (CSR) and somatic hypermutation (SHM) of antibody genes during immune responses. AID has also been shown to induce chromosomal translocations, mutations, and DNA double-strand breaks (DSBs) involving non-Ig genes in activated B cells. To determine what makes a DNA site a target for AID-induced DSBs, we identify off-target DSBs induced by AID by performing chromatin immunoprecipitation (ChIP) for Nbs1, a protein that binds DSBs, followed by deep sequencing (ChIP-Seq). We detect and characterize hundreds of off-target AID-dependent DSBs. Two types of tandem repeats are highly enriched within the Nbs1-binding sites: long CA repeats, which can form Z-DNA, and tandem pentamers containing the AID target hotspot WGCW. These tandem repeats are not nearly as enriched at AID-independent DSBs, which we also identified. Msh2, a component of the mismatch repair pathway and important for genome stability, increases off-target DSBs, similar to its effect on Ig switch region DSBs, which are required intermediates during CSR. Most of the off-target DSBs are two-ended, consistent with generation during G1 phase, similar to DSBs in Ig switch regions. However, a minority are one-ended, presumably due to conversion of single-strand breaks to DSBs during replication. One-ended DSBs are repaired by processes involving homologous recombination, including break-induced replication repair, which can lead to genome instability. Off-target DSBs, especially those present during S phase, can lead to chromosomal translocations, deletions and gene amplifications, resulting in the high frequency of B cell lymphomas derived from cells that express or have expressed AID.
2015-07-16 | GSE66424 | GEO