Dataset Information

Active enhancers strengthen insulation by RNA-mediated CTCF binding at chromatin domain boundaries.

ABSTRACT: Vertebrate genomes are partitioned into chromatin domains or topologically associating domains (TADs), which are typically bound by head-to-head pairs of CTCF binding sites. Transcription at domain boundaries correlates with better insulation; however, it is not known whether the boundary transcripts themselves contribute to boundary function. Here we characterize boundary-associated RNAs genome-wide, focusing on the disease-relevant INK4a/ARF and MYC TAD. Using CTCF site deletions and boundary-associated RNA knockdowns, we observe that boundary-associated RNAs facilitate recruitment and clustering of CTCF at TAD borders. The resulting CTCF enrichment enhances TAD insulation, enhancer-promoter interactions, and TAD gene expression. Importantly, knockdown of boundary-associated RNAs results in loss of boundary insulation function. Using enhancer deletions and CRISPRi of promoters, we show that active TAD enhancers, but not promoters, induce boundary-associated RNA transcription, thus defining a novel class of regulatory enhancer RNAs.

SUBMITTER: Islam Z

PROVIDER: S-EPMC9977152 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Active enhancers strengthen insulation by RNA-mediated CTCF binding at chromatin domain boundaries.

Islam Zubairul Z Saravanan Bharath B Walavalkar Kaivalya K Farooq Umer U Singh Anurag Kumar AK Radhakrishnan Sabarinathan S Thakur Jitendra J Pandit Awadhesh A Henikoff Steven S Notani Dimple D

Genome research 20230117 1

Vertebrate genomes are partitioned into chromatin domains or topologically associating domains (TADs), which are typically bound by head-to-head pairs of CTCF binding sites. Transcription at domain boundaries correlates with better insulation; however, it is not known whether the boundary transcripts themselves contribute to boundary function. Here we characterize boundary-associated RNAs genome-wide, focusing on the disease-relevant <i>INK4a/ARF</i> and <i>MYC</i> TAD. Using CTCF site deletions ...[more]

PMID: 36650052

Similar Datasets

Project description:The genome is partitioned into Topologically Associating Domains (TADs). About half of the boundaries of these TADs exhibit transcriptional activity and are correlated with better TAD insulation. However, the association between these transcripts and TAD insulation, enhancer:promoter interactions and transcription of genes remains unknown. Here we investigate the functional roles of these bRNAs (boundary-RNA) in boundary insulation and consequent effects on enhancer-promoter interactions and TAD transcription genome-wide and more specifically on the disease relevant INK4a/ARF TAD. Using a series of CTCF site deletions and bRNA knockdown experiments at this TAD boundary, we show a direct association of CTCF with the bidirectional bRNAs where the loss of bRNA triggers the concomitant loss of: CTCF at the TAD boundary, its insulation, enhancer:promoter interactions and gene transcription within the targeted TAD. We used another series of enhancer deletions and CRISPRi on promoters within INK4a/ARF TAD to better understand the regulation and origins of bRNA itself. We observe that the enhancers interact with boundaries and positively regulate the bRNA transcription at TAD boundaries. In return, the bRNAs recruit/stabilize the CTCF even on weak motifs within these boundaries and supports CTCF binding in clusters, therefore enhancing TAD insulation. This favors the intra-TAD enhancer:promoter interactions and leads to robust gene transcription. Functionally, bRNAs are more stable than eRNAs and their knockdown exactly mimics the CTCF site deletion. Furthermore, transcribing boundaries exhibit high TAD transcription in TCGA tumour datasets. Together, these results show that active enhancers directly mediate better insulation of TADs by activating the transcription at TAD boundaries triggering CTCF clustering at the boundary which results in better insulation and favours robust intra-TAD enhancer:promoter interactions to activate the gene transcription.

Dataset Information

Active enhancers strengthen insulation by RNA-mediated CTCF binding at chromatin domain boundaries.

Publications

Active enhancers strengthen insulation by RNA-mediated CTCF binding at chromatin domain boundaries.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets