title: miR-34 activity is modulated through 5'-end phosphorylation in response to DNA damage.
abstract: MicroRNA (miRNA) expression is tightly regulated by several mechanisms, including transcription and cleavage of the miRNA precursor RNAs, to generate a mature miRNA, which is thought to be directly correlated with activity. MiR-34 is a tumour-suppressor miRNA important in cell survival, that is transcriptionally upregulated by p53 in response to DNA damage. Here, we show for the first time that there is a pool of mature miR-34 in cells that lacks a 5'-phosphate and is inactive. Following exposure to a DNA-damaging stimulus, the inactive pool of miR-34 is rapidly activated through 5'-end phosphorylation in an ATM- and Clp1-dependent manner, enabling loading into Ago2. Importantly, this mechanism of miR-34 activation occurs faster than, and independently of, de novo p53-mediated transcription and processing. Our study reveals a novel mechanism of rapid miRNA activation in response to environmental stimuli occurring at the mature miRNA level.
authors.affiliation: Department of Therapeutic Radiology, Yale School of Medicine, 15 York Street, New Haven, Connecticut 06502, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Salzman
authors.affiliation: Department of Radiation Oncology, David Geffen School of Medicine, Los Angeles, California 90024, USA.
authors.forename: Kotoka
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Therapeutic Radiology, Yale School of Medicine, 15 York Street, New Haven, Connecticut 06502, USA.
authors.forename: Sunitha
authors.initials: S
authors.lastname: Nallur
authors.affiliation: Department of Therapeutic Radiology, Yale School of Medicine, 15 York Street, New Haven, Connecticut 06502, USA.
authors.forename: Michelle T
authors.initials: MT
authors.lastname: Dookwah
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, Yale University, PO Box 208103, New Haven, Connecticut 06502, USA.
authors.forename: Chanatip
authors.initials: C
authors.lastname: Metheetrairut
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, Yale University, PO Box 208103, New Haven, Connecticut 06502, USA.|Department of Pathology, Beth Israel Deaconess Medical Center, Institute for RNA Medicine, Harvard Medical School, 330 Brookline Avenue, Boston, Massachusetts 02215, USA.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Slack
authors.affiliation: Department of Radiation Oncology, David Geffen School of Medicine, Los Angeles, California 90024, USA.
authors.forename: Joanne B
authors.initials: JB
authors.lastname: Weidhaas
mesh_terms: D060565:Argonaute Proteins / Q000378:metabolism; D064007:Ataxia Telangiectasia Mutated Proteins / Q000378:metabolism; D002460:Cell Line; D004249:DNA Damage / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009687:Nuclear Proteins; D010766:Phosphorylation; D010770:Phosphotransferases; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: C466422:AGO2 protein, human; D060565:Argonaute Proteins; C522425:MIRN34 microRNA, human; D035683:MicroRNAs; D009687:Nuclear Proteins; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; C520030:CLP1 protein, human; D010770:Phosphotransferases; D064007:Ataxia Telangiectasia Mutated Proteins