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Increased histone mRNA levels during inhibition of protein synthesis

E Stimac, V E Groppi, P Coffino

    Biochemical and Biophysical Research Communications
    |July 18, 1983
    PubMed

    Insights

    Inhibition of protein synthesis rapidly increases histone mRNA levels in HeLa cells. This suggests a short-lived regulatory protein controls histone mRNA, independent of DNA replication.

    Area of Science:

    • Molecular Biology
    • Cell Biology
    • Biochemistry

    Background:

    • Histone mRNA levels are tightly regulated during the cell cycle.
    • Histone synthesis is coupled to DNA replication.
    • The precise regulatory mechanisms controlling histone mRNA stability are not fully understood.

    Purpose of the Study:

    • To investigate the role of protein synthesis in regulating histone mRNA levels.
    • To determine if histone gene expression is dependent on DNA replication.

    Main Methods:

    • Treatment of exponentially growing and synchronous G1 HeLa cells with protein synthesis inhibitors (cycloheximide or puromycin).
    • Quantification of translatable histone mRNA levels using established molecular biology techniques.
    • Analysis of the relationship between histone mRNA levels and DNA replication.

    Main Results:

    • Inhibition of protein synthesis led to a specific 5-fold increase in translatable histone mRNA within 3 hours.
    • This increase occurred in both exponentially growing and G1-phase synchronized HeLa cells.
    • Histone gene expression was effectively uncoupled from DNA replication under these conditions.

    Conclusions:

    • Histone mRNA levels are regulated by a labile (short-lived) protein.
    • Histone mRNA regulation is indirectly dependent on DNA synthesis, not directly controlled by it.
    • A post-transcriptional regulatory mechanism involving protein degradation likely controls histone mRNA abundance.

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