The detection and functions of RNA modification m⁶A based on m⁶A writers and erasers

N⁶-methyladenosine (m⁶A) is the most frequent chemical modification in eukaryotic mRNA and is known to participate in a variety of physiological processes, including cancer progression and viral infection. The reversible and dynamic m⁶A modification is installed by m⁶A methyltransferase (writer) enzymes and erased by m⁶A demethylase (eraser) enzymes. m⁶A modification recognized by m⁶A binding proteins (readers) regulates RNA processing and metabolism, leading to downstream biological effects such as promotion of stability and translation or increased degradation. The m⁶A writers and erasers determine the abundance of m⁶A modifications and play decisive roles in its distribution and function. In this review, we focused on m⁶A writers and erasers and present an overview on their known functions and enzymatic molecular mechanisms, showing how they recognize substrates and install or remove m⁶A modifications. We also summarize the current applications of m⁶A writers and erasers for m⁶A detection and highlight the merits and drawbacks of these available methods. Lastly, we describe the biological functions of m⁶A in cancers and viral infection based on research of m⁶A writers and erasers and introduce new assays for m⁶A functionality via programmable m⁶A editing tools.