N6-methyladenosine (m6A) is an endogenous A3 adenosine receptor ligand

Abstract

About 150 post-transcriptional RNA modifications have been identified in all kingdoms of life. During RNA catabolism, most modified nucleosides are resistant to degradation and are released into the extracellular space. In this study, we explored the physiological role of these extracellular modified nucleosides and found that N6-methyladenosine (m6A), widely known as an epigenetic mark in RNA, acts as a ligand for the adenosine A3 receptor, for which it has greater affinity than unmodified adenosine. Structural modeling defined the amino acids required for specific binding of m6A to the A3 receptor. m6A is dynamically released in response to cytotoxic stimuli and facilitates type I allergy. Our findings shed light on m6A as a signaling molecule with the ability to activate GPCRs, a previously unreported property of RNA modifications.