RAM/Fam103a1 is required for mRNA cap methylation

Thomas Gonatopoulos-Pournatzis, Sianadh Dunn, R. Bounds, Victoria H. Cowling (Lead / Corresponding author)

    Research output: Contribution to journalArticle

    28 Citations (Scopus)

    Abstract

    The 7-methylguanosine cap added to the 5' end of mRNA is required for efficient gene expression in eukaryotes. In mammals, methylation of the guanosine cap is catalyzed by RNMT (RNA guanine-7 methyltransferase), an enzyme previously thought to function as a monomer. We have identified an obligate component of the mammalian cap methyltransferase, RAM (RNMT-Activating Mini protein)/Fam103a1, a previously uncharacterized protein. RAM consists of an N-terminal RNMT-activating domain and a C-terminal RNA-binding domain. As monomers RNMT and RAM have a relatively weak affinity for RNA; however, together their RNA affinity is significantly increased. RAM is required for efficient cap methylation in vitro and in vivo, and is indirectly required to maintain mRNA expression levels, for mRNA translation and for cell viability. Our findings demonstrate that RAM is an essential component of the core gene expression machinery.

    Original languageEnglish
    Pages (from-to)585-596
    Number of pages12
    JournalMolecular Cell
    Volume44
    Issue number4
    DOIs
    Publication statusPublished - 18 Nov 2011

    Keywords

    • METHYLTRANSFERASE
    • BINDING
    • IDENTIFICATION
    • TRANSCRIPTION
    • TRANSLATION
    • RECRUITMENT
    • MECHANISM
    • EVOLUTION
    • ENZYMES
    • PROTEIN

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