Phospho-eIF4B (Ser422) Antibody

• 产品编号：CST-3591P      品牌：Cell Signaling Technology       原厂货号：3591P
• 产品分类：抗体 > 一抗 > 磷酸化抗体
• 应用分类：

描述：

Phospho-eIF4B (Ser422) Antibody检测仅在Ser422位点磷酸化的内源性eIF4B蛋白。通过人工合成人源eIF4B蛋白Ser422位点周围序列相应的磷酸化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。真核生物起始因子4B (eIF4B)被认为在蛋白质翻译起始阶段协助eIF4F复合物。在植物中，已知eIF4B蛋白和poly-(A)结合蛋白相互作用，从而增加它与poly-(A)结合活性(1)。虽然eIF4B在胰岛素刺激下发生磷酸化和蛋白质翻译增加保持很大的相关性，但是热休克和血清饥饿能够引起eIF4B在多个位点去磷酸化，这类似一些翻译抑制的动力学特征(2-5)。许多激酶包括p70 S6 激酶能够在体外使eIF4B磷酸化，同时至少一个血清诱导的eIF4B磷酸化位点对rapamycin和LY294002敏感(6)。最近研究证明Ser406位点是通过有丝分裂素调节的新型磷酸化位点(7)，同时这个磷酸化位点是依赖于MEK和mTOR通路的活化(7)。因此，这个位点的磷酸化对eIF4B翻译活性起着至关重要的作用(7)。研究证明p70 S6激酶能够在体内使eIF4B蛋白在rapamycin敏感位点Ser422发生磷酸化，而eIF4B蛋白的Ser422Ala突变体在体外翻译实验中显示活性消失(7)。

1. Le, H. et al. (1997) J. Biol. Chem. 272, 16247-16255.
2. Duncan, R.F. and Hershey, J.W. (1989) J. Cell Biol. 109, 1467-1481.
3. Duncan, R.F. and Hershey, J.W. (1984) J. Biol. Chem. 259, 11882-11889.
4. Duncan, R. and Hershey, J.W. (1985) J. Biol. Chem. 260, 5493-5497.
5. Manzella, J.M. et al. (1991) J. Biol. Chem. 266, 2383-2389.
6. Gingras, A.C. et al. (2001) Genes Dev. 15, 807-826.
7. van Gorp, A.G. et al. (2009) Oncogene 28, 95-106.
8. Raught, B. et al. (2004) EMBO J. 23, 1761-1769.

原厂资料：

Specificity / Sensitivity

Phospho-eIF4B (Ser422) Antibody detects eIF4B only when phosphorylated at Ser422.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser422 of human eIF4B. Antibodies are purified by protein A and peptide affinity chromatography.

Background

Eukaryotic initiation factor 4B (eIF4B) is thought to assist the eIF4F complex in translation initiation. In plants, eIF4B is known to interact with the poly-(A) binding protein, increasing its poly-(A) binding activity (1). Heat shock and serum starvation cause dephosphorylation of eIF4B at multiple sites with kinetics similar to those of the corresponding inhibition of translation, while phosphorylation of eIF4B following insulin treatment correlates well with an observed increase in translation (2-5). Multiple kinases, including p70 S6 kinase, can phosphorylate eIF4B in vitro, and at least one serum-inducible eIF4B phosphorylation site is sensitive to rapamycin and LY294002 (6). Recently Ser406 was identified as a novel phosphorylation site regulated by mitogens (7), and the phosphorylation of this site is dependent on the MEK and mTOR activity (7). This phosphorylation is shown to be essential for the translational activity of eIF4B (7).

p70 S6 Kinase has been shown to phosphorylate eIF4B at the rapamycin-sensitive site Ser422 in vivo, and a Ser422Ala mutant of eIF4B shows deminished activity in an in vitro translation assay (7).

1. Le, H. et al. (1997) J. Biol. Chem. 272, 16247-16255.
2. Duncan, R.F. and Hershey, J.W. (1989) J. Cell Biol. 109, 1467-1481.
3. Duncan, R.F. and Hershey, J.W. (1984) J. Biol. Chem. 259, 11882-11889.
4. Duncan, R. and Hershey, J.W. (1985) J. Biol. Chem. 260, 5493-5497.
5. Manzella, J.M. et al. (1991) J. Biol. Chem. 266, 2383-2389.
6. Gingras, A.C. et al. (2001) Genes Dev. 15, 807-826.
7. van Gorp, A.G. et al. (2009) Oncogene 28, 95-106.
8. Raught, B. et al. (2004) EMBO J. 23, 1761-1769.

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.