| Autor: |
Kim J; Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA., Diaz LF; Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.; Oregon Health and Sciences University, Portland, OR 97239., Miller MJ; Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.; University of Iowa Medical School, Iowa City, IA 52242., Leadem B; Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.; GeneDx, Gaithersburg, MD 20877., Krivega I; Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.; Sonothera, South San Francisco, CA 94080., Dean A; Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA. |
| Abstrakt: |
The Myb proto-oncogene encodes the transcription factor c-MYB, which is critical for hematopoiesis. Distant enhancers of Myb form a hub of interactions with the Myb promoter. We identified a long non-coding RNA ( Myrlin ) originating from the -81 kb murine Myb enhancer. Myrlin and Myb are coordinately regulated during erythroid differentiation. Myrlin TSS deletion using CRISPR/Cas9 reduced Myrlin and Myb expression and LDB1 complex occupancy at the Myb enhancers, compromising enhancer contacts and reducing RNA Pol II occupancy in the locus. In contrast, CRISPRi silencing of Myrlin left LDB1 and the Myb enhancer hub unperturbed, although Myrlin and Myb expression were downregulated, decoupling transcription and chromatin looping. Myrlin interacts with the MLL1 complex. Myrlin CRISPRi compromised MLL1 occupancy in the Myb locus, decreasing CDK9 and RNA Pol II binding and resulting in Pol II pausing in the Myb first exon/intron. Thus, Myrlin directly participates in activating Myb transcription by recruiting MLL1. |
