Acts as an activator of both rRNA/tRNA and protein methyltransferases (   ). Together with methyltransferase BUD23, methylates the N(7) position of a guanine in 18S rRNA . The heterodimer with N6AMT1/HEMK2 catalyzes N5-methylation of ETF1 on 'Gln-185', using S-adenosyl L-methionine as methyl donor ( ). The heterodimer with N6AMT1/HEMK2 also monomethylates 'Lys-12' of histone H4 (H4K12me1) . The heterodimer with ALKBH8 catalyzes the methylation of 5-carboxymethyl uridine to 5-methylcarboxymethyl uridine at the wobble position of the anticodon loop in target tRNA species . Together with methyltransferase THUMPD3, catalyzes the formation of N(2)-methylguanosine at position 6 in a broad range of tRNA substrates and at position 7 of tRNA(Trp) . Involved in the pre-rRNA processing steps leading to small-subunit rRNA production . Together with methyltransferase METTL5, specifically methylates the 6th position of adenine in position 1832 of 18S rRNA ( ).
Subcellular locations: Nucleus, Nucleoplasm, Cytoplasm, Perinuclear region
Localizes to a polarized perinuclear structure, overlapping partially with the Golgi and lysosomes .