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Histone mRNAs contain blocked and methylated 5' terminal sequences but lack methylated nucleosides at internal

B Moss, A Gershowitz, L A Weber

    Cell
    |January 1, 1977
    PubMed

    Insights

    Histone messenger RNA (mRNA) 5' terminals were analyzed in HeLa cells. Distinct methylation patterns were identified, differing from bulk mRNA.

    Area of Science:

    • Molecular Biology
    • Biochemistry
    • Cell Biology

    Background:

    • Histone mRNA is crucial for DNA replication and cell division.
    • Understanding mRNA structure, particularly 5' termini, is key to gene expression regulation.

    Purpose of the Study:

    • To characterize the 5' terminal structures of histone mRNA.
    • To compare histone mRNA 5' termini with those of bulk polyadenylylated mRNA.

    Main Methods:

    • HeLa cells were synchronized and labeled during S phase.
    • Histone mRNA was isolated from polyribosomes and purified via sucrose gradient sedimentation.
    • 5' terminal oligonucleotides were analyzed for methylation patterns.

    Main Results:

    • Two distinct 5' terminal structures were identified: m7G(5 étaire)pppNmpN and m7G(5 étaire)pppNm-pNmpN.
    • The first methylated nucleoside is 7-methylguanosine.
    • Histone mRNA 5' termini showed unique methylation patterns, lacking specific modifications found in bulk mRNA.

    Conclusions:

    • Histone mRNA possesses unique 5' terminal methylation patterns.
    • These structural differences may influence histone mRNA stability or translation.
    • The findings contribute to understanding mRNA processing and regulation in eukaryotic cells.

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