Two human demethylases, the fat mass and obesity-associated (FTO) enzyme and ALKBH5, oxidatively demethylate abundant N6-methyladenosine (m6A) residues in mRNA. Achieving a method for selective inhibition of FTO over ALKBH5 remains a challenge, however. Here, we have identified meclofenamic acid (MA) as a highly selective inhibitor of FTO. MA is a non-steroidal, anti-inflammatory drug that mechanistic studies indicate competes with FTO binding for the m6A-containing nucleic acid. The structure of FTO/MA has revealed much about the inhibitory function of FTO. Our newfound understanding, revealed herein, of the part of the nucleotide recognition lid (NRL) in FTO, for example, has helped elucidate the principles behind the selectivity of FTO over ALKBH5. Treatment of HeLa cells with the ethyl ester form of MA (MA2) has led to elevated levels of m6A modification in mRNA. Our collective results highlight the development of functional probes of the FTO enzyme that will (i) enable future biological studies and (ii) pave the way for the rational design of potent and specific inhibitors of FTO for use in medicine.

An ultrasensitive microRNA assay was developed with one-step loop-mediated isothermal amplification (LAMP) initiated by the target microRNA.

Biogenic polyamines participate in regulating gene expression, activating DNA synthesis and facilitating DNA-protein interaction through interaction with DNA/RNA. The interaction of polyamines with G-quadruplexes (G4s) has been reported to modulate the structure of G4s. In this paper, we investigate the effects of polyamines on one of the properties of G4s, G4/hemin peroxidase. Three polyamines (spermine, spermidine and putrescine) are found to have positive effects on different G4/hemin DNAzymes, in which spermine exhibits the strongest enhancement efficiency. CD and UV/Vis spectral analysis suggests two reasons for the strong activity enhancement: first, spermine protects hemin from rapid degradation by H 2 O 2 ; second, spermine condenses the G4 structures and provides a favorable microenvironment for the catalytic reaction. Since G4/hemin DNAzymes have been extensively applied in various chemical sensors and biosensors, this finding would be helpful for the design of G4/hemin based sensors and widen the application range of this kind of DNAzyme.