Abstract
In eukaryotic protein synthesis the translation initiation factor 3 (eIF3) is a key player in the recruitment and assembly of the translation initiation machinery. Mammalian eIF3 consists of 13 subunits, including the loosely associated eIF3j subunit that plays a stabilizing role in the eIF3 complex formation and interaction with the 40S ribosomal subunit. By means of both co-immunoprecipitation and mass spectrometry analyses we demonstrate that the protein kinase CK2 interacts with and phosphorylates eIF3j at Ser127. Inhibition of CK2 activity by CX-4945 or down-regulation of the expression of CK2 catalytic subunit by siRNA cause the dissociation of j-subunit from the eIF3 complex as judged from glycerol gradient sedimentation. This finding proves that CK2-phosphorylation of eIF3j is a prerequisite for its association with the eIF3 complex. Expression of Ser127Ala-eIF3j mutant impairs both the interaction of mutated j-subunit with the other eIF3 subunits and the overall protein synthesis. Taken together our data demonstrate that CK2-phosphorylation of eIF3j at Ser127 promotes the assembly of the eIF3 complex, a crucial step in the activation of the translation initiation machinery.
| Original language | English |
|---|---|
| Pages (from-to) | 1693-1701 |
| Number of pages | 9 |
| Journal | Biochimica et Biophysica Acta - Molecular Cell Research |
| Volume | 1853 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - Jul 1 2015 |
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Keywords
- EIF3 assembly
- EIF3 complex
- EIF3j phosphorylation
- Protein kinase CK2
- Translation initiation activation
ASJC Scopus subject areas
- Cell Biology
- Molecular Biology
- Medicine(all)
Cite this
Protein kinase CK2 potentiates translation efficiency by phosphorylating eIF3j at Ser127. / Borgo, Christian; Franchin, Cinzia; Salizzato, Valentina; Cesaro, Luca; Arrigoni, Giorgio; Matricardi, Laura; Pinna, Lorenzo A.; Donella-Deana, Arianna.
In: Biochimica et Biophysica Acta - Molecular Cell Research, Vol. 1853, No. 7, 01.07.2015, p. 1693-1701.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Protein kinase CK2 potentiates translation efficiency by phosphorylating eIF3j at Ser127
AU - Borgo, Christian
AU - Franchin, Cinzia
AU - Salizzato, Valentina
AU - Cesaro, Luca
AU - Arrigoni, Giorgio
AU - Matricardi, Laura
AU - Pinna, Lorenzo A.
AU - Donella-Deana, Arianna
PY - 2015/7/1
Y1 - 2015/7/1
N2 - In eukaryotic protein synthesis the translation initiation factor 3 (eIF3) is a key player in the recruitment and assembly of the translation initiation machinery. Mammalian eIF3 consists of 13 subunits, including the loosely associated eIF3j subunit that plays a stabilizing role in the eIF3 complex formation and interaction with the 40S ribosomal subunit. By means of both co-immunoprecipitation and mass spectrometry analyses we demonstrate that the protein kinase CK2 interacts with and phosphorylates eIF3j at Ser127. Inhibition of CK2 activity by CX-4945 or down-regulation of the expression of CK2 catalytic subunit by siRNA cause the dissociation of j-subunit from the eIF3 complex as judged from glycerol gradient sedimentation. This finding proves that CK2-phosphorylation of eIF3j is a prerequisite for its association with the eIF3 complex. Expression of Ser127Ala-eIF3j mutant impairs both the interaction of mutated j-subunit with the other eIF3 subunits and the overall protein synthesis. Taken together our data demonstrate that CK2-phosphorylation of eIF3j at Ser127 promotes the assembly of the eIF3 complex, a crucial step in the activation of the translation initiation machinery.
AB - In eukaryotic protein synthesis the translation initiation factor 3 (eIF3) is a key player in the recruitment and assembly of the translation initiation machinery. Mammalian eIF3 consists of 13 subunits, including the loosely associated eIF3j subunit that plays a stabilizing role in the eIF3 complex formation and interaction with the 40S ribosomal subunit. By means of both co-immunoprecipitation and mass spectrometry analyses we demonstrate that the protein kinase CK2 interacts with and phosphorylates eIF3j at Ser127. Inhibition of CK2 activity by CX-4945 or down-regulation of the expression of CK2 catalytic subunit by siRNA cause the dissociation of j-subunit from the eIF3 complex as judged from glycerol gradient sedimentation. This finding proves that CK2-phosphorylation of eIF3j is a prerequisite for its association with the eIF3 complex. Expression of Ser127Ala-eIF3j mutant impairs both the interaction of mutated j-subunit with the other eIF3 subunits and the overall protein synthesis. Taken together our data demonstrate that CK2-phosphorylation of eIF3j at Ser127 promotes the assembly of the eIF3 complex, a crucial step in the activation of the translation initiation machinery.
KW - EIF3 assembly
KW - EIF3 complex
KW - EIF3j phosphorylation
KW - Protein kinase CK2
KW - Translation initiation activation
UR - http://www.scopus.com/inward/record.url?scp=84928248292&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84928248292&partnerID=8YFLogxK
U2 - 10.1016/j.bbamcr.2015.04.004
DO - 10.1016/j.bbamcr.2015.04.004
M3 - Article
VL - 1853
SP - 1693
EP - 1701
JO - Biochimica et Biophysica Acta - Molecular Cell Research
JF - Biochimica et Biophysica Acta - Molecular Cell Research
SN - 0167-4889
IS - 7
ER -