A fundamental feature of cell signaling is the conversion of extracellular signals into adaptive transcriptional responses. The role of RNA modifications in this process is poorly understood. The small nuclear RNA 7SK prevents transcriptional elongation by sequestering the cyclin dependent kinase 9/cyclin T1 (CDK9/CCNT1) positive transcription elongation factor (P-TEFb) complex. We found that epidermal growth factor signaling induces phosphorylation of the enzyme methyltransferase 3 (METTL3), leading to METTL3-mediated methylation of 7SK. 7SK methylation enhanced its binding to heterogeneous nuclear ribonucleoproteins, causing the release of the HEXIM1 P-TEFb complex subunit1 (HEXIM1)/P-TEFb complex and inducing transcriptional elongation. Our findings establish the mechanism underlying 7SK activation and uncover a previously unknown function for the mA modification in converting growth factor signaling events into a regulatory transcriptional response via an RNA methylation-dependent switch.
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http://dx.doi.org/10.1126/sciadv.ade7500 | DOI Listing |
m A RNA methylation suppresses the immunostimulatory potential of endogenous RNA. Deficiency of m A provokes inflammatory responses and cell death, but the underlying mechanisms remain elusive. Here we showed that the noncoding RNA 7SK gains immunostimulatory potential upon m A depletion and subsequently activates the RIG-I/MAVS axis to spark interferon (IFN) signaling cascades.
View Article and Find Full Text PDFSci Adv
May 2023
Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA.
A fundamental feature of cell signaling is the conversion of extracellular signals into adaptive transcriptional responses. The role of RNA modifications in this process is poorly understood. The small nuclear RNA 7SK prevents transcriptional elongation by sequestering the cyclin dependent kinase 9/cyclin T1 (CDK9/CCNT1) positive transcription elongation factor (P-TEFb) complex.
View Article and Find Full Text PDFMar Drugs
February 2023
Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
Marine toxins (MTs) are a group of structurally complex natural products with unique toxicological and pharmacological activities. In the present study, two common shellfish toxins, okadaic acid (OA) () and OA methyl ester (), were isolated from the cultured microalgae strain PL11. OA can significantly activate the latent HIV but has severe toxicity.
View Article and Find Full Text PDFMethods Enzymol
September 2021
Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, United States. Electronic address:
RNAs from various cells and tissues are modified in nearly 200 chemically distinct ways. These modifications can be deposited either on the 5' or 3' ends, or internally on the nucleobases or sugar backbone. 5'-end modifications are crucial for protecting RNAs from untimely degradation/processing, regulating their cellular functions, or discriminating endogenous RNAs from pathogenic RNAs.
View Article and Find Full Text PDFElife
February 2020
Department of Biomedical Research, National Jewish Health, Denver, United States.
More than 30% of genes in higher eukaryotes are regulated by promoter-proximal pausing of RNA polymerase II (Pol II). Phosphorylation of Pol II CTD by positive transcription elongation factor b (P-TEFb) is a necessary precursor event that enables productive transcription elongation. The exact mechanism on how the sequestered P-TEFb is released from the 7SK snRNP complex and recruited to Pol II CTD remains unknown.
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