Abstract
The pioneer round of translation plays a role in translation initiation of newly spliced and exon junction complex (EJC)-bound mRNAs. Nuclear cap-binding protein complex CBP80/20 binds to those mRNAs at the 5′-end, recruiting translation initiation complex. As a consequence of the pioneer round of translation, the bound EJCs are dissociated from mRNAs and CBP80/20 is replaced by the cytoplasmic cap-binding protein eIF4E. Steady-state translation directed by eIF4E allows for an immediate and rapid response to changes in physiological conditions. Here, we show that nonsense-mediated mRNA decay (NMD), which restricts only to the pioneer round of translation but not to steady-state translation, efficiently occurs even during serum starvation, in which steady-state translation is drastically abolished. Accordingly, CBP80 remains in the nucleus and processing bodies are unaffected in their abundance and number in serum-starved conditions. These results suggest that mRNAs enter the pioneer round of translation during serum starvation and are targeted for NMD if they contain premature termination codons.
Original language | English |
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Pages (from-to) | 145-151 |
Number of pages | 7 |
Journal | Biochemical and biophysical research communications |
Volume | 362 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2007 Oct 12 |
Keywords
- CBP80
- Nonsense-mediated mRNA decay
- Pioneer round of translation
- Processing body
- Serum starvation
- Steady-state translation
- Stress granule
- eIF4E
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology