An enhancer RNA recruits KMT2A to regulate transcription of Myb
Juhyun Kim,
Luis F. Diaz,
Matthew J. Miller,
Benjamin Leadem,
Ivan Krivega,
Ann Dean
Affiliations
Juhyun Kim
Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Corresponding author
Luis F. Diaz
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, USA
Matthew J. Miller
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, USA
Benjamin Leadem
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, USA
Ivan Krivega
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, USA
Ann Dean
Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Corresponding author
Summary: 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 expressions were downregulated, decoupling transcription and chromatin looping. Myrlin interacts with the KMT2A/MLL1 complex. Myrlin CRISPRi compromised KMT2A 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 KMT2A.
