Abstract
Nonsense-mediated mRNA decay (NMD) is the best-characterized mRNA surveillance mechanism; this process removes faulty mRNAs harboring premature termination codons (PTCs). NMD targets newly synthesized mRNAs bound by nuclear cap-binding proteins 80/20 (CBP80/20) and exon junction complex (EJC), the former of which is thought to recruit the ribosome to initiate the pioneer round of translation. After completion of the pioneer round of translation, CBP80/20 is replaced by the cytoplasmic cap-binding protein eIF4E, which mediates steady-state translation in the cytoplasm. Here, we show that overexpression of eIF4E-T preferentially inhibits cap-dependent steady-state translation, but not the pioneer round of translation. We also demonstrate that overexpression of eIF4E-T or Dcp1a triggers the movement of eIF4E into the processing bodies. These results suggest that the pioneer round of translation differs from steady-state translation in terms of ribosome recruitment.
Original language | English |
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Pages (from-to) | 1160-1165 |
Number of pages | 6 |
Journal | Biochemical and biophysical research communications |
Volume | 369 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2008 May 16 |
Bibliographical note
Funding Information:We thank Dr. Lynne E. Maquat for providing the NMD reporter constructs, Dr. Robin Reed for α-CBP80 antibody, Dr. Sung Key Jang for dicistronic reporter plasmids, and Dr. Jens Lykke-Andersen for pcDNA3-FLAG-Dcp1a. This work was supported by the Korea Science and Engineering Foundation (KOSEF) Grant funded by the Korea government (MOST) (R01-2006-000-10194-0), a Grant of Seoul R&BD Program (NT070112), and a Grant (20070301034003) from BioGreen 21 Program, Rural Development Administration, Republic of Korea.
Keywords
- CBP80
- Internal ribosome entry site
- Nonsense-mediated mRNA decay
- Processing bodies
- Steady-state translation
- The pioneer round of translation
- eIF4E
- eIF4E-T
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology