N6-methyl-adenosine modification in messenger and long non-coding RNA

N6-methyl-adenosine (m6A) is the most abundant modification in mammalian mRNA and long non-coding RNA. First discovered in the 1970s, m6A modification has been proposed to function in mRNA splicing, export, stability, and immune tolerance. Interest and excitement in m6A modification has recently been revived based on the discovery of a mammalian enzyme that removes m6A and the application of deep sequencing to localize modification sites. The m6A demethylase fat mass and obesity associated protein (FTO) controls cellular energy homeostasis and is the first enzyme discovered that reverses an RNA modification. m6A Sequencing demonstrates cell-type- and cell-state-dependent m6A patterns, indicating that m6A modifications are highly regulated. This review describes the current knowledge of mammalian m6A modifications and future perspectives on how to push the field forward.