Post-transcriptional regulation of histone gene expression in a mouse mastocytoma cell cycle mutant (21-Tb) depends largely on conserved DNA sequences that are essential for RNA 3' processing. We have analyzed whether this regulation occurs at the level of RNA 3' processing. We show, by RNase mapping, that nuclear H4 mRNA precursors, which are hardly detectable in total RNA from exponentially dividing cells, accumulate in Gl-arrested cells, i.e. when mature mRNAs are drastically reduced. Furthermore, we show that a heat-labile component of the processing apparatus, recently identified in HeLa cell nuclear extracts, is limiting in extracts from Gl-arrested 21-Tb cells. In contrast, this activity is in excess in extracts from exponentially dividing cells, whereas both extracts contain similar amounts of snRNPs of the Sm serotype. These fluctuations in the heatlabile activity may generally contribute to proliferation or cell cycle dependent histone gene regulation.
|Original language||English (US)|
|Number of pages||6|
|State||Published - Jun 1987|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Biochemistry, Genetics and Molecular Biology(all)
- Immunology and Microbiology(all)