eIF3J Antibody

• 产品编号：CST-3261S      品牌：CST       原厂货号：3261S
• 产品分类：抗体 > 一抗 > 蛋白特异性一抗
• 应用分类：

描述：

eIF3j Antibody检测内源性eIF3j总蛋白水平。通过人工合成人源eIF3j蛋白相应序列的多肽片段去免疫动物从而制备多克隆抗体。通过蛋白A和多肽亲和层析纯化抗体。翻译起始阶段40S核糖体与mRNA结合需要一些因子帮助。由eIF4E、eIF4A和eIF4G组成的起始因子eIF4F复合物能够与mRNA5’-端帽子结构结合。eIF4F和eIF4B在mRNA5’非翻译区解开mRNA的二级结构。与40S核糖体亚单位相互作用的一些真核翻译起始因子包括elF3能够结合mRNA 的5'末端帽子结构，随后沿着mRNA寻找起始密码子。elF3是一个含有10到13不同亚基的大翻译起始复合物。eIF3a、eIF3b、eIF3c、eIF3e、eIF3f和eIF3h对复合物的功能起到关键性作用，它们为核心亚基。eIF3可能通过与eIF4G的相互作用促进mRNA与40S亚基结合(1)。eIF3可以使Met-tRNAi•eIF2•GTP三联体复合物稳定地结合到40S核糖体亚基上，并有助于在加入60S核糖体亚单位之后保持这个复合物的完整(2)。研究证明mTOR能够和eIF3直接相互作用(3,4)。当用激素或有丝分裂信号刺激细胞时，mTOR结合eIF3复合物，并且使S6K1磷酸化(3)。这个过程将导致S6K1从eIF3分离同时S6K1被激活。激活的S6K1随后磷酸化下游靶蛋白包括核糖体蛋白S6和eIF4B，从而最终促使翻译加强。进一步研究证明在胰岛素刺激之后，活化的mTOR信号通路能诱导eIF3和eIF4G相互联系(3)。eIF3j是eIF3最小的亚基之一，它在40S起始复合物组装起重要作用(5)。研究显示eIF3j与氨基酰位点和mRNA进入40S核糖体亚基的通道相联系(6)。研究也证明eIF3j在参与终止后复合物的循环过程也起到了额外的作用(7)。

1. Masutani, M. et al. (2007) EMBO J 26, 3373-83.
2. Chaudhuri, J. et al. (1999) J Biol Chem 274, 17975-80.
3. Holz, M.K. et al. (2005) Cell 123, 569-80.
4. Harris, T.E. et al. (2006) EMBO J 25, 1659-68.
5. Fraser, C.S. et al. (2004) J Biol Chem 279, 8946-56.
6. Fraser, C.S. et al. (2007) Mol Cell 26, 811-9.
7. Pisarev, A.V. et al. (2007) Cell 131, 286-99.

原厂资料：

Specificity / Sensitivity

eIF3j Antibody detects endogenous levels of total eIF3j protein.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to the sequence of human eIF3j. Antibodies are purified by protein A and peptide affinity chromatography.

Background

Translation initiation requires a set of factors to facilitate the association of the 40S ribosomal subunit with mRNA. The eIF4F complex, consisting of eIF4E, eIF4A and eIF4G, binds to the 5' cap structure of mRNA. eIF4F and eIF4B unwind the secondary structure of mRNA at its 5' untranslated region. The 40S ribosomal subunit, along with some initiation factors including eIF3, then binds to the 5' mRNA cap and searches along the mRNA for the initiation codon. eIF3 is a large translation initiation complex with 10 to 13 different subunits. eIF3a, eIF3b, eIF3c, eIF3e, eIF3f and eIF3h are the core subunits critical for the function of this complex. eIF3 physically interacts with eIF4G, which may be responsible for the association of the 40S ribosomal subunit with mRNA (1). eIF3 also stabilizes the binding of Met-tRNAf.eIF2.GTP to the 40S ribosomal subunit and helps keep the integrity of the resulting complex upon addition of the 60S ribosomal subunit (2). Studies have shown that mTOR interacts with eIF3 directly (3,4). When cells are stimulated by hormones or mitogenic signals, mTOR binds to the eIF3 complex and phosphorylates S6K1 (3). This process results in the dissociation of S6K1 from eIF3 and S6K1 activation. The activated S6K1 then phosphorylates its downstream targets including ribosomal protein S6 and eIF4B resulting in stimulation of translation. Further findings demonstrated that activated mTOR signaling induces the association of eIF3 with eIF4G upon stimulation with insulin (3).One of the smallest subunits of eIF3, eIF3j, is critical in 40S initiation complex assembly (5). eIF3j has been shown to associate with the aminoacyl site and mRNA entry channel of the 40S ribosomal subunit (6). eIF3j has also been shown to have an additional role in the recycling of post-termination complexes (7).

1. Masutani, M. et al. (2007) EMBO J 26, 3373-83.
2. Chaudhuri, J. et al. (1999) J Biol Chem 274, 17975-80.
3. Holz, M.K. et al. (2005) Cell 123, 569-80.
4. Harris, T.E. et al. (2006) EMBO J 25, 1659-68.
5. Fraser, C.S. et al. (2004) J Biol Chem 279, 8946-56.
6. Fraser, C.S. et al. (2007) Mol Cell 26, 811-9.
7. Pisarev, A.V. et al. (2007) Cell 131, 286-99.

注意事项：

Storage: Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM
NaCl, 100 µg/ml BSA and 50% glycerol. Store at –20°C.
Do not aliquot the antibody.