Enables mRNA m(6)A methyltransferase activity. Involved in several processes, including RNA metabolic process; forebrain radial glial cell differentiation; and mRNA destabilization. Located in nucleus. Part of RNA N6-methyladenosine methyltransferase complex. Is expressed in brain; genitourinary system; hindlimb; intestine; and liver. Orthologous to human METTL3 (methyltransferase 3, N6-adenosine-methyltransferase complex catalytic subunit).
