title: N(6)-Methyladenosine: a conformational marker that regulates the substrate specificity of human demethylases FTO and ALKBH5.
abstract: N(6)-Methyladenosine (m6A) is currently one of the most intensively studied post-transcriptional modifications in RNA. Due to its critical role in epigenetics and physiological links to several human diseases, it is also of tremendous biological and medical interest. The m6A mark is dynamically reversed by human demethylases FTO and ALKBH5, however the mechanism by which these enzymes selectively recognise their target transcripts remains unclear. Here, we report combined biophysical and biochemical studies on the specificity determinants of m6A demethylases, which led to the identification of an m6A-mediated substrate discrimination mechanism. Our results reveal that m6A itself serves as a 'conformational marker', which induces different conformational outcomes in RNAs depending on sequence context. This critically impacts its interactions with several m6A-recognising proteins, including FTO and ALKBH5. Remarkably, through the RNA-remodelling effects of m6A, the demethylases were able to discriminate substrates with very similar nucleotide sequences. Our findings provide novel insights into the biological functions of m6A modifications. The mechanism identified in this work is likely of significance to other m6A-recognising proteins.
authors.affiliation: Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Singapore 117 543, Singapore.
authors.forename: Shui
authors.initials: S
authors.lastname: Zou
authors.affiliation: Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Singapore 117 543, Singapore.|Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138 673, Singapore.
authors.forename: Joel D W
authors.initials: JD
authors.lastname: Toh
authors.affiliation: Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Singapore 117 543, Singapore.
authors.forename: Kendra H Q
authors.initials: KH
authors.lastname: Wong
authors.affiliation: Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138 673, Singapore.|School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637 551, Singapore.
authors.forename: Yong-Gui
authors.initials: YG
authors.lastname: Gao
authors.affiliation: Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138 673, Singapore.
authors.forename: Wanjin
authors.initials: W
authors.lastname: Hong
authors.affiliation: Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Singapore 117 543, Singapore.
authors.forename: Esther C Y
authors.initials: EC
authors.lastname: Woon
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D000071502:AlkB Homolog 5, RNA Demethylase / Q000737:chemistry* / Q000378:metabolism*; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO / Q000737:chemistry* / Q000378:metabolism*; D020816:Amino Acid Motifs; D001483:Base Sequence; D055162:Biocatalysis; D016384:Consensus Sequence; D000073398:Demethylation; D006801:Humans; D010084:Oxidation-Reduction; D011487:Protein Conformation; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D020871:RNA Stability; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D012313:RNA; C010223:N-methyladenosine; C559920:ALKBH5 protein, human; D000071502:AlkB Homolog 5, RNA Demethylase; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; C526492:FTO protein, human; D000241:Adenosine