M⁶A mRNA modifications are deposited in nascent pre-mRNA and are not required for splicing but do specify cytoplasmic turnover.

ABSTRACT: Understanding the biologic role of N⁶-methyladenosine (m⁶A) RNA modifications in mRNA requires an understanding of when and where in the life of a pre-mRNA transcript the modifications are made. We found that HeLa cell chromatin-associated nascent pre-mRNA (CA-RNA) contains many unspliced introns and m⁶A in exons but very rarely in introns. The m⁶A methylation is essentially completed upon the release of mRNA into the nucleoplasm. Furthermore, the content and location of each m⁶A modification in steady-state cytoplasmic mRNA are largely indistinguishable from those in the newly synthesized CA-RNA or nucleoplasmic mRNA. This result suggests that quantitatively little methylation or demethylation occurs in cytoplasmic mRNA. In add

SUBMITTER: Ke S 

PROVIDER: S-EPMC5495127 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature