NOP2/Sun Domain Family, Member 2 (NSUN2)

NSUN2 encodes a methyltransferase that catalyzes the intron-dependent formation of 5-methylcytosine at C34 of tRNA-leu(CAA). The full-length human protein contains 767 amino acids and has a SUN domain. One variant lacks exon 3, resulting in a 35-amino acid deletion, and the other 2 variants encode smaller proteins lacking the SUN domain. RT-PCR detected predominant expression of full-length MISU and lower expression of the MISU variant lacking exon 3 in all human cell lines examined. Northern blot analysis detected ubiquitous expression of Misu in mouse tissues. MISU was distributed throughout the nucleus during S phase, when the number and size of nucleoli increase. In G2 phase, some MISU was detected in cytoplasmic vesicles, and MISU localized to the spindle during mitosis.