Abstract
Genomic imprinting is a critical developmental process characteristic of parent of origin-specific gene expression. It is well accepted that differentially DNA-methylated regions (DMRs) and enhancers are two major classes of ciselements determining parent of origin-specific gene expression, with each recruiting different sets of transcription factors. Previously, we identified the AF4/FMR2 (AFF) family protein AFF3 within the transcription elongation complex SEC-L3. Here, we report that AFF3 can specifically bind both gametic DMRs (gDMRs) and enhancers within imprinted loci in an allele-specific manner. We identify the molecular regulators involved in the recruitment of AFF3 to gDMRs and provide mechanistic insight into the requirement of AFF3 at an enhancer for the expression of an ∼200-kb polycistronic transcript within the imprinted Dlk1-Dio3 locus. Our data suggest that the heterochromatic environment at the gDMR reinforces silencing of its related enhancer by controlling the binding and activity of AFF3 in an allele-specific manner. In summary, this study provides molecular details about the regulation of dosage-critical imprinted gene expression through the regulated binding of the transcription elongation factor AFF3 between a DMR and an enhancer.
Original language | English (US) |
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Pages (from-to) | 92-101 |
Number of pages | 10 |
Journal | Genes and Development |
Volume | 30 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 2016 |
Funding
We are grateful to Professor Didier Trono, Professor Stuart Orkin, Professor Colin Stewart, Professor Xiajun Li, and Professor Matthew Lorincz for providing cell lines for this study.We also thank the Molecular Biology core facility at the Stowers Institute for creating and sequencing libraries for next-generation sequencing, and the Stowers Tissue Culture facility for cell culture. We are also thankful to Laura Shilatifard for editorial assistance. Z.L. was supported as a Fellow of the Leukemia and Lymphoma Society. The study was supported in part by grant R01GM069905 from the National Institute of Health to A.S.
Keywords
- Elongation control
- Enhancers
- Transcription
ASJC Scopus subject areas
- General Medicine