METTL16 exerts an m6A-independent function to facilitate translation and tumorigenesis

Nat Cell Biol. 2022 Feb;24(2):205-216. doi: 10.1038/s41556-021-00835-2. Epub 2022 Feb 10.

Abstract

METTL16 has recently been identified as an RNA methyltransferase responsible for the deposition of N6-methyladenosine (m6A) in a few transcripts. Whether METTL16 methylates a large set of transcripts, similar to METTL3 and METTL14, remains unclear. Here we show that METTL16 exerts both methyltransferase activity-dependent and -independent functions in gene regulation. In the cell nucleus, METTL16 functions as an m6A writer to deposit m6A into hundreds of its specific messenger RNA targets. In the cytosol, METTL16 promotes translation in an m6A-independent manner. More specifically, METTL16 directly interacts with the eukaryotic initiation factors 3a and -b as well as ribosomal RNA through its Mtase domain, thereby facilitating the assembly of the translation-initiation complex and promoting the translation of over 4,000 mRNA transcripts. Moreover, we demonstrate that METTL16 is critical for the tumorigenesis of hepatocellular carcinoma. Collectively, our studies reveal previously unappreciated dual functions of METTL16 as an m6A writer and a translation-initiation facilitator, which together contribute to its essential function in tumorigenesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine / analogs & derivatives*
  • Adenosine / metabolism
  • Animals
  • Carcinogenesis / genetics
  • Carcinogenesis / metabolism*
  • Carcinogenesis / pathology
  • Carcinoma, Hepatocellular / enzymology*
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / pathology
  • Cytosol / enzymology
  • Eukaryotic Initiation Factor-3 / genetics
  • Eukaryotic Initiation Factor-3 / metabolism
  • Gene Expression Regulation, Neoplastic
  • HEK293 Cells
  • Hep G2 Cells
  • Humans
  • Liver Neoplasms / enzymology*
  • Liver Neoplasms / genetics
  • Liver Neoplasms / pathology
  • Methyltransferases / genetics
  • Methyltransferases / metabolism*
  • Mice, Inbred NOD
  • Mice, SCID
  • Protein Biosynthesis*
  • RNA Processing, Post-Transcriptional*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism*
  • RNA, Ribosomal / genetics
  • RNA, Ribosomal / metabolism
  • Signal Transduction
  • Tumor Burden

Substances

  • EIF3A protein, human
  • EIF3B protein, human
  • Eukaryotic Initiation Factor-3
  • RNA, Messenger
  • RNA, Ribosomal
  • N-methyladenosine
  • METTL16 protein, human
  • Methyltransferases
  • Adenosine