Human METTL16 is a -methyladenosine (mA) methyltransferase that targets pre-mRNAs and various non-coding RNAs.

-methyladenosine (mA) is a highly dynamic RNA modification that has recently emerged as a key regulator of gene expression. While many mA modifications are installed by the METTL3-METTL14 complex, others appear to be introduced independently, implying that additional human mA methyltransferases remain to be identified. Using crosslinking and analysis of cDNA (CRAC), we reveal that the putative human mA "writer" protein METTL16 binds to the U6 snRNA and other ncRNAs as well as numerous lncRNAs and pre-mRNAs.

Tuning the ribosome: The influence of rRNA modification on eukaryotic ribosome biogenesis and function.

rRNAs are extensively modified during their transcription and subsequent maturation in the nucleolus, nucleus and cytoplasm. RNA modifications, which are installed either by snoRNA-guided or by stand-alone enzymes, generally stabilize the structure of the ribosome. However, they also cluster at functionally important sites of the ribosome, such as the peptidyltransferase center and the decoding site, where they facilitate efficient and accurate protein synthesis.

Effects of the Bowen-Conradi syndrome mutation in EMG1 on its nuclear import, stability and nucleolar recruitment.

Bowen-Conradi syndrome (BCS) is a severe genetic disorder that is characterised by various developmental abnormalities, bone marrow failure and early infant death. This disease is caused by a single mutation leading to the aspartate 86 to glycine (D86G) exchange in the essential nucleolar RNA methyltransferase EMG1. EMG1 is required for the synthesis of the small ribosomal subunit and is involved in modification of the 18S ribosomal RNA.

NSUN3 and ABH1 modify the wobble position of mt-tRNAMet to expand codon recognition in mitochondrial translation.

Mitochondrial gene expression uses a non-universal genetic code in mammals. Besides reading the conventional AUG codon, mitochondrial (mt-)tRNA mediates incorporation of methionine on AUA and AUU codons during translation initiation and on AUA codons during elongation. We show that the RNA methyltransferase NSUN3 localises to mitochondria and interacts with mt-tRNA to methylate cytosine 34 (C34) at the wobble position.

NSUN6 is a human RNA methyltransferase that catalyzes formation of m5C72 in specific tRNAs.

Many cellular RNAs require modification of specific residues for their biogenesis, structure, and function. 5-methylcytosine (m(5)C) is a common chemical modification in DNA and RNA but in contrast to the DNA modifying enzymes, only little is known about the methyltransferases that establish m(5)C modifications in RNA. The putative RNA methyltransferase NSUN6 belongs to the family of Nol1/Nop2/SUN domain (NSUN) proteins, but so far its cellular function has remained unknown.