Wapl repression by Pax5 promotes loop extrusion and V gene recombination at the Igh locus
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE140975 | GEO | 2020/07/01
REPOSITORIES: GEO
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Project description:Extended loop extrusion across the immunoglobulin heavy-chain (Igh) locus facilitates VH-DJH recombination in pro-B cells by aligning the VH and DJH segments for RAG-mediated cleavage. This cohesin-mediated process, resulting in global changes of the chromosome architecture in pro-B cells, depends on a 3-fold downregulation of the cohesin-release factor Wapl by Pax5-induced repression of the Wapl promoter. Here, we demonstrate that chromatin looping and VK-JK recombination at the Igk locus was insensitive to a 3-fold Wapl increase in pre-B cells. Given the equally low Wapl mRNA levels in pro-B and pre-B cells, the Wapl protein was unexpectedly expressed at a 2.2-fold higher level in pre-B cells compared to pro-B cells, which resulted in a distinct chromosomal architecture with normalized loop sizes in pre-B cells. High-resolution analysis of the Igk locus identified multiple internal loops, which likely juxtapose VK and JK elements to facilitate VK-JK recombination. The higher Wapl expression in Igm-transgenic pre-B cells prevented extended loop extrusion at the Igh locus, leading to recombination of only the 6 most 3’ proximal VH genes and to allelic exclusion of all other VH genes in pre-B cells. Hence, the different chromosomal architectures in pro-B and pre-B cells forced the Igh and Igk loci to assume distinct folding principles to undergo V gene recombination.
2023-01-15 | GSE210289 | GEO
Project description:Immunoglobulin heavy chain locus (Igh) VH, D, and JH gene segments are developmentally assembled into V(D)J exons. RAG endonuclease initiates V(D)J recombination by binding a JH-recombination signal sequence (RSS) within a chromatin-based recombination center (RC) and then, in an orientation-dependent process, scans upstream D-containing chromatin presented by cohesin-mediated loop extrusion for convergent D-RSSs to initiate DJH-RC formation. In primary pro-B cells, 100s of upstream VH-associated RSSs, embedded in convergent orientation to the DJH-RC-RSS, gain proximity to the DJH-RC for VH-to-DJH joining via a mechanistically-undefined VH-locus contraction process. Here, we report that a 2.4 mega-base VH locus inversion in primary pro-B cells nearly abrogates rearrangements of normally convergent VH-RSSs and cryptic RSSs, even though locus contraction per se is maintained. Moreover, this inversion activated rearrangement of both cryptic VH-locus RSSs normally in the opposite orientation and, unexpectedly, of normally-oriented cryptic RSSs within multiple, sequential upstream convergent-CBE domains. Primary pro-B cells had significantly reduced transcription of Wapl, a cohesin-unloading factor, versus levels in v-Abl pro-B lines that lack marked locus contraction or distal VH rearrangements. Correspondingly, Wapl depletion in v-Abl lines activated VH-locus contraction and orientation-specific RAG-scanning across the VH-locus. Our findings indicate that locus contraction and physiological VH-to-DJH joining both are regulated via circumvention of CBE scanning impediments.
2020-11-08 | GSE151908 | GEO
Project description:Immunoglobulin heavy chain locus (Igh) VH, D, and JH gene segments are developmentally assembled into V(D)J exons. RAG endonuclease initiates V(D)J recombination by binding a JH-recombination signal sequence (RSS) within a chromatin-based recombination center (RC) and then, in an orientation-dependent process, scans upstream D-containing chromatin presented by cohesin-mediated loop extrusion for convergent D-RSSs to initiate DJH-RC formation. In primary pro-B cells, 100s of upstream VH-associated RSSs, embedded in convergent orientation to the DJH-RC-RSS, gain proximity to the DJH-RC for VH-to-DJH joining via a mechanistically-undefined VH-locus contraction process. Here, we report that a 2.4 mega-base VH locus inversion in primary pro-B cells nearly abrogates rearrangements of normally convergent VH-RSSs and cryptic RSSs, even though locus contraction per se is maintained. Moreover, this inversion activated rearrangement of both cryptic VH-locus RSSs normally in the opposite orientation and, unexpectedly, of normally-oriented cryptic RSSs within multiple, sequential upstream convergent-CBE domains. Primary pro-B cells had significantly reduced transcription of Wapl, a cohesin-unloading factor, versus levels in v-Abl pro-B lines that lack marked locus contraction or distal VH rearrangements. Correspondingly, Wapl depletion in v-Abl lines activated VH-locus contraction and orientation-specific RAG-scanning across the VH-locus. Our findings indicate that locus contraction and physiological VH-to-DJH joining both are regulated via circumvention of CBE scanning impediments.
2020-11-08 | GSE151907 | GEO
Project description:Immunoglobulin heavy chain locus (Igh) VH, D, and JH gene segments are developmentally assembled into V(D)J exons. RAG endonuclease initiates V(D)J recombination by binding a JH-recombination signal sequence (RSS) within a chromatin-based recombination center (RC) and then, in an orientation-dependent process, scans upstream D-containing chromatin presented by cohesin-mediated loop extrusion for convergent D-RSSs to initiate DJH-RC formation. In primary pro-B cells, 100s of upstream VH-associated RSSs, embedded in convergent orientation to the DJH-RC-RSS, gain proximity to the DJH-RC for VH-to-DJH joining via a mechanistically-undefined VH-locus contraction process. Here, we report that a 2.4 mega-base VH locus inversion in primary pro-B cells nearly abrogates rearrangements of normally convergent VH-RSSs and cryptic RSSs, even though locus contraction per se is maintained. Moreover, this inversion activated rearrangement of both cryptic VH-locus RSSs normally in the opposite orientation and, unexpectedly, of normally-oriented cryptic RSSs within multiple, sequential upstream convergent-CBE domains. Primary pro-B cells had significantly reduced transcription of Wapl, a cohesin-unloading factor, versus levels in v-Abl pro-B lines that lack marked locus contraction or distal VH rearrangements. Correspondingly, Wapl depletion in v-Abl lines activated VH-locus contraction and orientation-specific RAG-scanning across the VH-locus. Our findings indicate that locus contraction and physiological VH-to-DJH joining both are regulated via circumvention of CBE scanning impediments.
2020-11-08 | GSE151906 | GEO
Project description:Immunoglobulin heavy chain locus (Igh) VH, D, and JH gene segments are developmentally assembled into V(D)J exons. RAG endonuclease initiates V(D)J recombination by binding a JH-recombination signal sequence (RSS) within a chromatin-based recombination center (RC) and then, in an orientation-dependent process, scans upstream D-containing chromatin presented by cohesin-mediated loop extrusion for convergent D-RSSs to initiate DJH-RC formation. In primary pro-B cells, 100s of upstream VH-associated RSSs, embedded in convergent orientation to the DJH-RC-RSS, gain proximity to the DJH-RC for VH-to-DJH joining via a mechanistically-undefined VH-locus contraction process. Here, we report that a 2.4 mega-base VH locus inversion in primary pro-B cells nearly abrogates rearrangements of normally convergent VH-RSSs and cryptic RSSs, even though locus contraction per se is maintained. Moreover, this inversion activated rearrangement of both cryptic VH-locus RSSs normally in the opposite orientation and, unexpectedly, of normally-oriented cryptic RSSs within multiple, sequential upstream convergent-CBE domains. Primary pro-B cells had significantly reduced transcription of Wapl, a cohesin-unloading factor, versus levels in v-Abl pro-B lines that lack marked locus contraction or distal VH rearrangements. Correspondingly, Wapl depletion in v-Abl lines activated VH-locus contraction and orientation-specific RAG-scanning across the VH-locus. Our findings indicate that locus contraction and physiological VH-to-DJH joining both are regulated via circumvention of CBE scanning impediments.
2020-11-08 | GSE151909 | GEO
Project description:VH-DJH recombination of the immunoglobulin heavy-chain (Igh) locus is temporally and spatially controlled during early B-cell development, and yet no regulatory elements other than the VH gene promoters have been identified throughout the entire 2.5-Mb VH gene cluster. Here we discovered novel regulatory sequences that are interspersed in the distal VH gene region. These conserved repeat elements were characterized by the presence of Pax5-dependent active chromatin, the binding of Pax5, E2A, CTCF and Rad21 as well as by Pax5-dependent antisense transcription in pro-B cells. The Pax5-activated intergenic repeat (PAIR) elements were no longer bound by Pax5 in pre-B and B cells consistent with the loss of antisense transcription, whereas E2A and CTCF interacted with PAIR elements throughout early B-cell development. The pro-B-cell-specific and Pax5-dependent activity of the PAIR elements suggests that they are involved in the regulation of distal VH-DJH recombination at the Igh locus. Analysis of chromatin and TF binding in rag2-/- and pax5-/- rag2-/- pro-B cells. Chip-Chip with one experiment for each antibody, 12 samples.
2011-02-11 | E-GEOD-27074 | biostudies-arrayexpress
Project description:VH-DJH recombination of the immunoglobulin heavy-chain (Igh) locus is temporally and spatially controlled during early B-cell development, and yet no regulatory elements other than the VH gene promoters have been identified throughout the entire 2.5-Mb VH gene cluster. Here we discovered novel regulatory sequences that are interspersed in the distal VH gene region. These conserved repeat elements were characterized by the presence of Pax5-dependent active chromatin, the binding of Pax5, E2A, CTCF and Rad21 as well as by Pax5-dependent antisense transcription in pro-B cells. The Pax5-activated intergenic repeat (PAIR) elements were no longer bound by Pax5 in pre-B and B cells consistent with the loss of antisense transcription, whereas E2A and CTCF interacted with PAIR elements throughout early B-cell development. The pro-B-cell-specific and Pax5-dependent activity of the PAIR elements suggests that they are involved in the regulation of distal VH-DJH recombination at the Igh locus. Analysis of chromatin and TF binding in rag2-/- and wt pro-B, DP T and Mature B cells. Chip-Seq of CTCF and Rad21. The provided data is in mm8 coordinates.
2011-02-11 | E-GEOD-27214 | biostudies-arrayexpress
Project description:Immunoglobulin heavy chain variable region exons are assembled in progenitor-B cells, from VH, D, and JH gene segments located in separate clusters across the Igh locus. RAG endonuclease orchestrates V(D)J recombination from a JH-based recombination center (RC). Cohesin-mediated extrusion of upstream chromatin past RC-bound RAG presents Ds for joining to JHs to form a DJHRC, from which RAG scans upstream for VHs to assemble VHDJH exons in an ordered recombination process. Cohesin-mediated chromatin loop extrusion is impeded by CTCF-bound elements (CBEs), with extrusion between two CBEs, particularly if convergently-oriented, forming chromatin-contact loops genome-wide. Igh has provocative CBE organization, with two divergently-oriented CBEs (CBE1 and CBE2) in the IGCR1 element between the VH and D/JH domains, dozens of VH domain CBEs convergent to CBE1, and 10 3'Igh-CBEs convergent to CBE2. IGCR1 CBEs segregate D/JH and VH domains by impeding RAG-scanning. After DJH formation, down-regulation of WAPL, a cohesin unloader, neutralizes IGCR1 and VH-domain CBEs, allowing RAG to scan the VH domain. To elucidate potential mechanisms underlying the developmental transition from D-to-JH to VH-to-DJH recombination and potential roles of IGCR1-based CBEs and 3'Igh-CBEs in regulating RAG-scanning, we tested effects of deleting or inverting IGCR1 or 3'Igh-CBEs in mice and/or progenitor-B cell lines. These studies revealed that normal IGCR1 CBE orientation augments its RAG-scanning impediment activity and that the 3'Igh-CBEs reinforce RC activity as a dynamic loop extrusion impediment, thereby, increasing its ability to support V(D)J recombination. Finally, our findings implicate a mechanism by which developmental WAPL down-regulation contributes to ordered V(D)J recombination.
2023-05-30 | GSE230251 | GEO
Project description:Immunoglobulin heavy chain variable region exons are assembled in progenitor-B cells, from VH, D, and JH gene segments located in separate clusters across the Igh locus. RAG endonuclease orchestrates V(D)J recombination from a JH-based recombination center (RC). Cohesin-mediated extrusion of upstream chromatin past RC-bound RAG presents Ds for joining to JHs to form a DJHRC, from which RAG scans upstream for VHs to assemble VHDJH exons in an ordered recombination process. Cohesin-mediated chromatin loop extrusion is impeded by CTCF-bound elements (CBEs), with extrusion between two CBEs, particularly if convergently-oriented, forming chromatin-contact loops genome-wide. Igh has provocative CBE organization, with two divergently-oriented CBEs (CBE1 and CBE2) in the IGCR1 element between the VH and D/JH domains, dozens of VH domain CBEs convergent to CBE1, and 10 3'Igh-CBEs convergent to CBE2. IGCR1 CBEs segregate D/JH and VH domains by impeding RAG-scanning. After DJH formation, down-regulation of WAPL, a cohesin unloader, neutralizes IGCR1 and VH-domain CBEs, allowing RAG to scan the VH domain. To elucidate potential mechanisms underlying the developmental transition from D-to-JH to VH-to-DJH recombination and potential roles of IGCR1-based CBEs and 3'Igh-CBEs in regulating RAG-scanning, we tested effects of deleting or inverting IGCR1 or 3'Igh-CBEs in mice and/or progenitor-B cell lines. These studies revealed that normal IGCR1 CBE orientation augments its RAG-scanning impediment activity and that the 3'Igh-CBEs reinforce RC activity as a dynamic loop extrusion impediment, thereby, increasing its ability to support V(D)J recombination. Finally, our findings implicate a mechanism by which developmental WAPL down-regulation contributes to ordered V(D)J recombination.
2023-05-30 | GSE230249 | GEO
Project description:Immunoglobulin heavy chain variable region exons are assembled in progenitor-B cells, from VH, D, and JH gene segments located in separate clusters across the Igh locus. RAG endonuclease orchestrates V(D)J recombination from a JH-based recombination center (RC). Cohesin-mediated extrusion of upstream chromatin past RC-bound RAG presents Ds for joining to JHs to form a DJHRC, from which RAG scans upstream for VHs to assemble VHDJH exons in an ordered recombination process. Cohesin-mediated chromatin loop extrusion is impeded by CTCF-bound elements (CBEs), with extrusion between two CBEs, particularly if convergently-oriented, forming chromatin-contact loops genome-wide. Igh has provocative CBE organization, with two divergently-oriented CBEs (CBE1 and CBE2) in the IGCR1 element between the VH and D/JH domains, dozens of VH domain CBEs convergent to CBE1, and 10 3'Igh-CBEs convergent to CBE2. IGCR1 CBEs segregate D/JH and VH domains by impeding RAG-scanning. After DJH formation, down-regulation of WAPL, a cohesin unloader, neutralizes IGCR1 and VH-domain CBEs, allowing RAG to scan the VH domain. To elucidate potential mechanisms underlying the developmental transition from D-to-JH to VH-to-DJH recombination and potential roles of IGCR1-based CBEs and 3'Igh-CBEs in regulating RAG-scanning, we tested effects of deleting or inverting IGCR1 or 3'Igh-CBEs in mice and/or progenitor-B cell lines. These studies revealed that normal IGCR1 CBE orientation augments its RAG-scanning impediment activity and that the 3'Igh-CBEs reinforce RC activity as a dynamic loop extrusion impediment, thereby, increasing its ability to support V(D)J recombination. Finally, our findings implicate a mechanism by which developmental WAPL down-regulation contributes to ordered V(D)J recombination.
2023-05-30 | GSE230604 | GEO