Phospho-p44/42 MAPK (Erk1) (Tyr204)/(Erk2) (Tyr187) (D1H6G) Mouse mAb

• 产品编号：CST-5726S      品牌：CST       原厂货号：5726S
• 产品分类：抗体 > 一抗 > 磷酸化抗体
• 应用分类：

描述：

Phospho-p44/42 MAPK (Erk1) (Tyr204)/(Erk2) (Tyr187) (D1H6G)Mouse mAb鼠单抗能够识别p44 MAPK/Erk1 (Tyr187 of p42 MAPK/Erk2的Tyr204被磷酸化的内源性总的p44/42 MAPK/Erk蛋白。抗体可以识别双磷酸化的p44 MAPK/Erk1 (Thr202/Tyr204)/p42 MAPK/Erk2 (Thr185/Tyr187)，但是不能检测到苏氨酸单磷酸化的phosphorylated p44/42 MAPK/Erk.抗体与其他的MAP激酶没有反应性。该单克隆抗体是采用合成的与人源Erk2蛋白Tyr187周围序列相一致的肽段免疫动物而产生的。丝裂原活化蛋白激酶(MAPKs)是一个具有广泛保守性的丝氨酸/苏氨酸蛋白激酶家族，在许多细胞过程中起作用，比如细胞增殖、分化、运动和死亡。p44/42 MAPK (Erk1/2)信号转导通路能在应答各种胞外刺激后被激活，这些刺激因子包括有丝分裂原、生长因子和细胞因子(1-3)，并且被研究者认为是诊断和治疗癌症的重要靶点(4)。受到刺激后，三个不同层次的蛋白激酶级联反应就连续被开启，这三个层次的分子包含MAPKKK（MAP3K）、MAPKK（MAP2K）、MAPK。多种p44/42 MAP3Ks已经被鉴定出来，包括Raf家族成员，以及Mos、Tpl2/Cot。MEK1、MEK2是该通路中主要的MAPKKs(5,6)。MEK1、MEK2通过分别磷酸化p44和p42蛋白的活化环内的Thr202/Tyr204位点和Thr185位点/Tyr187位点，从而激活p44、p42。目前已经鉴定出p44/42的一些下游靶点，包括p90RSK (7) 和下游转录因子Elk-1 (8,9)。双特异性(Thr/Tyr) MAPK磷酸酶家族成员DUSPs、MKPs (10)，以及MEK抑制子如U0126、 PD98059，可以负调节p44/42。MAPK家族成员的活化环内有两个磷酸化位点，通常是被单个氨基酸分隔开的一个苏氨酸和一个酪氨酸残基，标记为T-x-Y基序。两个位点的同时磷酸化，已被证明是激酶活性充分活化所必须的，但研究也发现有时T-x-Y基序的单磷酸化会导致催化活性的部分激活，随后引起双磷酸化（11,12）。非磷酸化、单磷酸化及双磷酸化的MAPK/Erk的晶体结构表明每种磷酸化异构体都有独立的构象（13）。另外，MAPK/Erk2的Tyr187位点单磷酸化表明该位点被磷酸化后可以形成ATP的结合位点，而Tyr和Thr的同时磷酸化是彻底稳定底物结合位点所必需的（14）。而且，对Erk和p38 MAPK的T-x-Y基序突变分析似乎显示，T-x-Y基序中的单磷酸化带来了不同的活性和底物偏好性（15,16）。综上所述，这些数据都暗示MAPK中的T-x-Y基序的Thr-和Tyr-位点的单磷酸化有重要而被低估的作用。

1. Roux, P.P. and Blenis, J. (2004) Microbiol Mol Biol Rev 68, 320-44.
2. Baccarini, M. (2005) FEBS Lett 579, 3271-7.
3. Meloche, S. and Pouysségur, J. (2007) Oncogene 26, 3227-39.
4. Roberts, P.J. and Der, C.J. (2007) Oncogene 26, 3291-310.
5. Rubinfeld, H. and Seger, R. (2005) Mol Biotechnol 31, 151-74.
6. Murphy, L.O. and Blenis, J. (2006) Trends Biochem Sci 31, 268-75.
7. Dalby, K.N. et al. (1998) J Biol Chem 273, 1496-505.
8. Marais, R. et al. (1993) Cell 73, 381-93.
9. Kortenjann, M. et al. (1994) Mol Cell Biol 14, 4815-24.
10. Owens, D.M. and Keyse, S.M. (2007) Oncogene 26, 3203-13.
11. Seger, R. et al. (1991) Proc Natl Acad Sci U S A 88, 6142-6.
12. Robbins, D.J. et al. (1993) J Biol Chem 268, 5097-106.
13. Kinoshita, T. et al. (2008) Biochem Biophys Res Commun 377, 1123-7.
14. Prowse, C.N. et al. (2001) J Biol Chem 276, 40817-23.
15. Zhou, B. and Zhang, Z.Y. (2002) J Biol Chem 277, 13889-99.
16. Zhang, Y.Y. et al. (2008) J Biol Chem 283, 26591-601.

原厂资料：

Homology

Species predicted to react based on 100% sequence homology: Chicken, D. melanogaster, Xenopus, Zebrafish, Bovine, C. elegans

Specificity / Sensitivity

Phospho-p44/42 MAPK (Erk1) (Tyr204)/(Erk2) (Tyr187) (D1H6G) Mouse mAb recognizes endogenous levels of p44/42 MAPK/Erk protein when phosphorylated at Tyr204 of p44 MAPK/Erk1 (Tyr187 of p42 MAPK/Erk2). This antibody detects dual-phosphorylated p44 MAPK/Erk1 (Thr202/Tyr204)/p42 MAPK/Erk2 (Thr185/Tyr187), but does not detect threonine mono-phosphorylated p44/42 MAPK/Erk. This antibody does not cross-react with any other MAP kinases.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Tyr187 of human Erk2 protein.

Background

Mitogen-activated protein kinases (MAPKs) are a widely conserved family of serine/threonine protein kinases involved in many cellular programs, such as cell proliferation, differentiation, motility, and death. The p44/42 MAPK (Erk1/2) signaling pathway can be activated in response to a diverse range of extracellular stimuli including mitogens, growth factors, and cytokines (1-3), and research investigators consider it an important target in the diagnosis and treatment of cancer (4). Upon stimulation, a sequential three-part protein kinase cascade is initiated, consisting of a MAP kinase kinase kinase (MAPKKK or MAP3K), a MAP kinase kinase (MAPKK or MAP2K), and a MAP kinase (MAPK). Multiple p44/42 MAP3Ks have been identified, including members of the Raf family, as well as Mos and Tpl2/COT. MEK1 and MEK2 are the primary MAPKKs in this pathway (5,6). MEK1 and MEK2 activate p44 and p42 through phosphorylation of activation loop residues Thr202/Tyr204 and Thr185/Tyr187, respectively. Several downstream targets of p44/42 have been identified, including p90RSK (7) and the transcription factor Elk-1 (8,9). p44/42 are negatively regulated by a family of dual-specificity (Thr/Tyr) MAPK phosphatases, known as DUSPs or MKPs (10), along with MEK inhibitors, such as U0126 and PD98059.

The "activation loop" of MAPK family members contains two phosphorylation sites, typically a threonine and a tyrosine separated by a single amino acid, designated the T-x-Y motif. Phosphorylation on both residues has been shown to be required for full activation of kinase activity, but it has been appreciated for some time that mono-phosphorylation of the T-x-Y motif occurs, resulting in partial activation of catalytic acitvity and priming for subsequent, dual-phosphorylation (11,12). The crystal structures of non-, mono-, and dual-phospho MAPK/Erk demonstrate that each phospho-isomer assumes an independent conformation (13). In addition, mono-phosphorylation of MAPK/Erk2 at Tyr187 reveals that phosphorylation at this site serves to configure the ATP binding site, while phosphorylation of both Tyr and Thr residues is required to completely stabilize the substrate binding site (14). Furthermore, T-x-Y mutational analysis of members of the Erk and p38 MAP kinases appears to suggest that mono-phosphorylation of the T-x-Y motif confers differential activity and substrate preference (15,16). Taken together, these data suggest an important and underappreciated role for Thr- and Tyr- mono-phosphorylation of the T-x-Y motif among MAP kinases.

1. Roux, P.P. and Blenis, J. (2004) Microbiol Mol Biol Rev 68, 320-44.
2. Baccarini, M. (2005) FEBS Lett 579, 3271-7.
3. Meloche, S. and Pouysségur, J. (2007) Oncogene 26, 3227-39.
4. Roberts, P.J. and Der, C.J. (2007) Oncogene 26, 3291-310.
5. Rubinfeld, H. and Seger, R. (2005) Mol Biotechnol 31, 151-74.
6. Murphy, L.O. and Blenis, J. (2006) Trends Biochem Sci 31, 268-75.
7. Dalby, K.N. et al. (1998) J Biol Chem 273, 1496-505.
8. Marais, R. et al. (1993) Cell 73, 381-93.
9. Kortenjann, M. et al. (1994) Mol Cell Biol 14, 4815-24.
10. Owens, D.M. and Keyse, S.M. (2007) Oncogene 26, 3203-13.
11. Seger, R. et al. (1991) Proc Natl Acad Sci U S A 88, 6142-6.
12. Robbins, D.J. et al. (1993) J Biol Chem 268, 5097-106.
13. Kinoshita, T. et al. (2008) Biochem Biophys Res Commun 377, 1123-7.
14. Prowse, C.N. et al. (2001) J Biol Chem 276, 40817-23.
15. Zhou, B. and Zhang, Z.Y. (2002) J Biol Chem 277, 13889-99.
16. Zhang, Y.Y. et al. (2008) J Biol Chem 283, 26591-601.

注意事项：

Storage: Supplied in 10 mM sodium HEPES (pH 7.5), 150
mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02%
sodium azide. Store at –20°C. Do not aliquot the antibody.