Histone H3.3 promotes IgV gene diversification by enhancing formation of AID‐accessible single‐stranded DNA
Immunoglobulin diversification is driven by activation‐induced deaminase (AID), which converts cytidine to uracil within the Ig variable (IgV) regions. Central to the recruitment of AID to the IgV genes are factors that regulate the generation of single‐stranded DNA (ssDNA), the enzymatic substrate...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2016
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4883027/ https://www.ncbi.nlm.nih.gov/pubmed/27220848 http://dx.doi.org/10.15252/embj.201693958 |
_version_ | 1782434208920109056 |
---|---|
author | Romanello, Marina Schiavone, Davide Frey, Alexander Sale, Julian E |
author_facet | Romanello, Marina Schiavone, Davide Frey, Alexander Sale, Julian E |
author_sort | Romanello, Marina |
collection | PubMed |
description | Immunoglobulin diversification is driven by activation‐induced deaminase (AID), which converts cytidine to uracil within the Ig variable (IgV) regions. Central to the recruitment of AID to the IgV genes are factors that regulate the generation of single‐stranded DNA (ssDNA), the enzymatic substrate of AID. Here, we report that chicken DT40 cells lacking variant histone H3.3 exhibit reduced IgV sequence diversification. We show that this results from impairment of the ability of AID to access the IgV genes due to reduced formation of ssDNA during IgV transcription. Loss of H3.3 also diminishes IgV R‐loop formation. However, reducing IgV R‐loops by RNase HI overexpression in wild‐type cells does not affect IgV diversification, showing that these structures are not necessary intermediates for AID access. Importantly, the reduction in the formation of AID‐accessible ssDNA in cells lacking H3.3 is independent of any effect on the level of transcription or the kinetics of RNAPII elongation, suggesting the presence of H3.3 in the nucleosomes of the IgV genes increases the chances of the IgV DNA becoming single‐stranded, thereby creating an effective AID substrate. |
format | Online Article Text |
id | pubmed-4883027 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-48830272016-10-06 Histone H3.3 promotes IgV gene diversification by enhancing formation of AID‐accessible single‐stranded DNA Romanello, Marina Schiavone, Davide Frey, Alexander Sale, Julian E EMBO J Articles Immunoglobulin diversification is driven by activation‐induced deaminase (AID), which converts cytidine to uracil within the Ig variable (IgV) regions. Central to the recruitment of AID to the IgV genes are factors that regulate the generation of single‐stranded DNA (ssDNA), the enzymatic substrate of AID. Here, we report that chicken DT40 cells lacking variant histone H3.3 exhibit reduced IgV sequence diversification. We show that this results from impairment of the ability of AID to access the IgV genes due to reduced formation of ssDNA during IgV transcription. Loss of H3.3 also diminishes IgV R‐loop formation. However, reducing IgV R‐loops by RNase HI overexpression in wild‐type cells does not affect IgV diversification, showing that these structures are not necessary intermediates for AID access. Importantly, the reduction in the formation of AID‐accessible ssDNA in cells lacking H3.3 is independent of any effect on the level of transcription or the kinetics of RNAPII elongation, suggesting the presence of H3.3 in the nucleosomes of the IgV genes increases the chances of the IgV DNA becoming single‐stranded, thereby creating an effective AID substrate. John Wiley and Sons Inc. 2016-05-24 2016-07-01 /pmc/articles/PMC4883027/ /pubmed/27220848 http://dx.doi.org/10.15252/embj.201693958 Text en © 2016 MRC Laboratory of Molecular Biology. Published under the terms of the CC BY 4.0 license This is an open access article under the terms of the Creative Commons Attribution 4.0 (http://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Articles Romanello, Marina Schiavone, Davide Frey, Alexander Sale, Julian E Histone H3.3 promotes IgV gene diversification by enhancing formation of AID‐accessible single‐stranded DNA |
title | Histone H3.3 promotes IgV gene diversification by enhancing formation of AID‐accessible single‐stranded DNA
|
title_full | Histone H3.3 promotes IgV gene diversification by enhancing formation of AID‐accessible single‐stranded DNA
|
title_fullStr | Histone H3.3 promotes IgV gene diversification by enhancing formation of AID‐accessible single‐stranded DNA
|
title_full_unstemmed | Histone H3.3 promotes IgV gene diversification by enhancing formation of AID‐accessible single‐stranded DNA
|
title_short | Histone H3.3 promotes IgV gene diversification by enhancing formation of AID‐accessible single‐stranded DNA
|
title_sort | histone h3.3 promotes igv gene diversification by enhancing formation of aid‐accessible single‐stranded dna |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4883027/ https://www.ncbi.nlm.nih.gov/pubmed/27220848 http://dx.doi.org/10.15252/embj.201693958 |
work_keys_str_mv | AT romanellomarina histoneh33promotesigvgenediversificationbyenhancingformationofaidaccessiblesinglestrandeddna AT schiavonedavide histoneh33promotesigvgenediversificationbyenhancingformationofaidaccessiblesinglestrandeddna AT freyalexander histoneh33promotesigvgenediversificationbyenhancingformationofaidaccessiblesinglestrandeddna AT salejuliane histoneh33promotesigvgenediversificationbyenhancingformationofaidaccessiblesinglestrandeddna |