Masutani Mamiko, Sonenberg Nahum, Yokoyama Shigeyuki, Imataka Hiroaki
RIKEN Genomic Sciences Center, Tsurumi-ku, Yokohama, Japan.
EMBO J. 2007 Jul 25;26(14):3373-83. doi: 10.1038/sj.emboj.7601765. Epub 2007 Jun 21.
Eukaryotic translation initiation factor (eIF)3 is the largest eIF ( approximately 650 kDa), consisting of 10-13 different polypeptide subunits in mammalian cells. To understand the role of each subunit, we successfully reconstituted a human eIF3 complex consisting of 11 subunits that promoted the recruitment of the 40S ribosomal subunit to mRNA. Strikingly, the eIF3g and eIF3i subunits, which are evolutionarily conserved between human and the yeast Saccharomyces cerevisiae are dispensable for active mammalian eIF3 complex formation. Extensive deletion analyses suggest that three evolutionarily conserved subunits (eIF3a, eIF3b, and eIF3c) and three non-conserved subunits (eIF3e, eIF3f, and eIF3h) comprise the functional core of mammalian eIF3.
真核生物翻译起始因子(eIF)3是最大的eIF(约650 kDa),在哺乳动物细胞中由10 - 13个不同的多肽亚基组成。为了解每个亚基的作用,我们成功重建了一个由11个亚基组成的人eIF3复合物,该复合物促进了40S核糖体亚基与mRNA的结合。引人注目的是,在人类和酿酒酵母之间进化保守的eIF3g和eIF3i亚基对于活性哺乳动物eIF3复合物的形成是可有可无的。广泛的缺失分析表明,三个进化保守的亚基(eIF3a、eIF3b和eIF3c)和三个非保守的亚基(eIF3e、eIF3f和eIF3h)构成了哺乳动物eIF3的功能核心。