Abstract
The cytoplasmic translation factor eEF1A has been implicated in the nuclear export of tRNA species in lower eukaryotes. Here we demonstrate that eEF1A plays a central role in nuclear export of proteins in mammalian cells. TD-NEM (transcription-dependent nuclear export motif), a newly characterized nuclear export signal, mediates efficient nuclear export of several proteins including the von Hippel-Lindau (VHL) tumor suppressor and the poly(A)-binding protein (PABP1) in a manner that is dependent on ongoing RNA polymerase II (RNA PolII)-dependent transcription. eEF1A interacts specifically with TD-NEM of VHL and PABP1 and disrupting this interaction, by point mutations of key TD-NEM residues or treatment with actinomycin D, an inhibitor of RNA PolII-dependent transcription, prevents assembly and nuclear export. siRNA-induced knockdown or antibody-mediated depletion of eEF1A prevents in vivo and in vitro nuclear export of TD-NEM-containing proteins. Nuclear retention experiments and inhibition of the Exportin-5 pathway suggest that eEF1A stimulates nuclear export of proteins from the cytoplasmic side of the nuclear envelope, without entering the nucleus. Together, these data identify a role for eEF1A, a cytoplasmic mediator of tRNA export in yeast, in the nuclear export of proteins in mammalian cells. These results also provide a link between the translational apparatus and subcellular trafficking machinery demonstrating that these two central pathways in basic metabolism can act cooperatively.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 5296-5308 |
| Number of pages | 13 |
| Journal | Molecular Biology of the Cell |
| Volume | 19 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 2008 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Molecular Biology
- Cell Biology
Cite this
EEF1A is a novel component of the mammalian nuclear protein export machinery. / Khacho, Mireille; Mekhail, Karim; Pilon-Larose, Karine; Pause, Arnim; Côté, Jocelyn; Lee, Stephen.
In: Molecular Biology of the Cell, Vol. 19, No. 12, 12.2008, p. 5296-5308.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - EEF1A is a novel component of the mammalian nuclear protein export machinery
AU - Khacho, Mireille
AU - Mekhail, Karim
AU - Pilon-Larose, Karine
AU - Pause, Arnim
AU - Côté, Jocelyn
AU - Lee, Stephen
PY - 2008/12
Y1 - 2008/12
N2 - The cytoplasmic translation factor eEF1A has been implicated in the nuclear export of tRNA species in lower eukaryotes. Here we demonstrate that eEF1A plays a central role in nuclear export of proteins in mammalian cells. TD-NEM (transcription-dependent nuclear export motif), a newly characterized nuclear export signal, mediates efficient nuclear export of several proteins including the von Hippel-Lindau (VHL) tumor suppressor and the poly(A)-binding protein (PABP1) in a manner that is dependent on ongoing RNA polymerase II (RNA PolII)-dependent transcription. eEF1A interacts specifically with TD-NEM of VHL and PABP1 and disrupting this interaction, by point mutations of key TD-NEM residues or treatment with actinomycin D, an inhibitor of RNA PolII-dependent transcription, prevents assembly and nuclear export. siRNA-induced knockdown or antibody-mediated depletion of eEF1A prevents in vivo and in vitro nuclear export of TD-NEM-containing proteins. Nuclear retention experiments and inhibition of the Exportin-5 pathway suggest that eEF1A stimulates nuclear export of proteins from the cytoplasmic side of the nuclear envelope, without entering the nucleus. Together, these data identify a role for eEF1A, a cytoplasmic mediator of tRNA export in yeast, in the nuclear export of proteins in mammalian cells. These results also provide a link between the translational apparatus and subcellular trafficking machinery demonstrating that these two central pathways in basic metabolism can act cooperatively.
AB - The cytoplasmic translation factor eEF1A has been implicated in the nuclear export of tRNA species in lower eukaryotes. Here we demonstrate that eEF1A plays a central role in nuclear export of proteins in mammalian cells. TD-NEM (transcription-dependent nuclear export motif), a newly characterized nuclear export signal, mediates efficient nuclear export of several proteins including the von Hippel-Lindau (VHL) tumor suppressor and the poly(A)-binding protein (PABP1) in a manner that is dependent on ongoing RNA polymerase II (RNA PolII)-dependent transcription. eEF1A interacts specifically with TD-NEM of VHL and PABP1 and disrupting this interaction, by point mutations of key TD-NEM residues or treatment with actinomycin D, an inhibitor of RNA PolII-dependent transcription, prevents assembly and nuclear export. siRNA-induced knockdown or antibody-mediated depletion of eEF1A prevents in vivo and in vitro nuclear export of TD-NEM-containing proteins. Nuclear retention experiments and inhibition of the Exportin-5 pathway suggest that eEF1A stimulates nuclear export of proteins from the cytoplasmic side of the nuclear envelope, without entering the nucleus. Together, these data identify a role for eEF1A, a cytoplasmic mediator of tRNA export in yeast, in the nuclear export of proteins in mammalian cells. These results also provide a link between the translational apparatus and subcellular trafficking machinery demonstrating that these two central pathways in basic metabolism can act cooperatively.
UR - http://www.scopus.com/inward/record.url?scp=59449087670&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=59449087670&partnerID=8YFLogxK
U2 - 10.1091/mbc.E08-06-0562
DO - 10.1091/mbc.E08-06-0562
M3 - Article
C2 - 18799616
AN - SCOPUS:59449087670
VL - 19
SP - 5296
EP - 5308
JO - Molecular Biology of the Cell
JF - Molecular Biology of the Cell
SN - 1059-1524
IS - 12
ER -