کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1936487 | 1050692 | 2007 | 7 صفحه PDF | دانلود رایگان |
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.
Journal: Biochemical and Biophysical Research Communications - Volume 362, Issue 1, 12 October 2007, Pages 145–151