TY - JOUR
T1 - Arabidopsis eIF3e is regulated by the COP9 signalosome and has an impact on development and protein translation
AU - Yahalom, Avital
AU - Kim, Tae Houn
AU - Roy, Bijoyita
AU - Singer, Ruth
AU - Von Arnim, Albrecht G.
AU - Chamovitz, Daniel A.
PY - 2008/1
Y1 - 2008/1
N2 - The roles of individual eukaryotic translation initiation factor 3 (eIF3) subunits are largely unclear, although some are essential, while others are thought to have regulatory roles. The 'e' subunit, also known as Int-6/Int6, is a candidate for a regulatory subunit as it is not essential for translation initiation in yeasts. eIF3e associates with the COP9 signalosome, and localizes to the nucleus in certain tissues. To further elucidate the roles of eIF3e, we have taken a genetic approach using Arabidopsis as a model system. Overexpression of eIF3e results in defects similar to mutations in the COP9 signalosome. eIF3e protein, but not transcript, over accumulates in csn mutants, and eIF3e is degraded in a proteasome-dependent fashion. In vitro and in vivo assays suggest that excess eIF3e inhibits translation. We conclude that the COP9 signalosome maintains a precise regulation of eIF3e levels, which is necessary for normal development in Arabidopsis.
AB - The roles of individual eukaryotic translation initiation factor 3 (eIF3) subunits are largely unclear, although some are essential, while others are thought to have regulatory roles. The 'e' subunit, also known as Int-6/Int6, is a candidate for a regulatory subunit as it is not essential for translation initiation in yeasts. eIF3e associates with the COP9 signalosome, and localizes to the nucleus in certain tissues. To further elucidate the roles of eIF3e, we have taken a genetic approach using Arabidopsis as a model system. Overexpression of eIF3e results in defects similar to mutations in the COP9 signalosome. eIF3e protein, but not transcript, over accumulates in csn mutants, and eIF3e is degraded in a proteasome-dependent fashion. In vitro and in vivo assays suggest that excess eIF3e inhibits translation. We conclude that the COP9 signalosome maintains a precise regulation of eIF3e levels, which is necessary for normal development in Arabidopsis.
KW - COP9 signalosome
KW - Int-6/Int6
KW - Protein translation
KW - eIF3
UR - http://www.scopus.com/inward/record.url?scp=37749042420&partnerID=8YFLogxK
U2 - 10.1111/j.1365-313X.2007.03347.x
DO - 10.1111/j.1365-313X.2007.03347.x
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C2 - 18067529
AN - SCOPUS:37749042420
SN - 0960-7412
VL - 53
SP - 300
EP - 311
JO - Plant Journal
JF - Plant Journal
IS - 2
ER -