SignalSilence? Cbl-b siRNA II

• 产品编号：CST-12122S      品牌：CST       原厂货号：12122S
• 产品分类：DNA和RNA纯化 > RNA干扰 > RNAi Oligos > siRNA
• 应用分类：

描述：

来自Cell Signaling Technology (CST)的SignalSilence^® Cbl-b siRNA II可以帮助研究者通过RNA干扰特异性地抑制 Cbl-b的表达，这种方法可以通过将双链RNA分子传递到细胞内从而使基因表达有选择的沉默。来自CST的所有的SignalSilence^® siRNA产品都是经过内部严格检测的，并且通过Western blot 分析证明确实能够减少目的蛋白的表达。通过三苯甲基分析每个碱基以监测寡核苷酸的合成，确保合适的配对效率。随后寡核苷酸通过亲和固相萃取法纯化。退火的RNA双链通过质谱分析来证实其精确的组成。每一批产品都通过质谱分析与前面的产品进行比较，来保证不同批次之间的最大一致性。CST推荐使用100 nM SignalSilence^® Cbl-b siRNA II 进行转染，48到72小时后对细胞进行裂解。转染步骤按照转染试剂说明书提供的步骤进行。遇到任何使用方面的问题，请随时联系CST。每小瓶可供100次转染，每次转染量相当于在转染24孔板时，每孔总体积为300μl培养基中siRNA的终浓度为100nM。Cbl蛋白（在哺乳动物中为c-Cbl, Cbl-b, 和Cbl-c）是一个具有单亚基环指蛋白-泛素E3连接酶家族，其包含多种蛋白相互作用模序(1)。所有的Cbl蛋白具有高度保守的N-末端酪氨酸激酶结合(TKB)结构域，该结构域可以介导Cbl蛋白与磷酸化后Cbl底物酪氨酸残基之间的相互作用。环指的C-末端，Cbl蛋白具有富含脯氨酸的结构域，可介导与含有SH3结构域蛋白的相互作用。对酪氨酸残基的磷酸化可介导与含有SH2结构域的蛋白相互作用，诸如PI3K 的p85亚基。这些蛋白-蛋白相互作用模序，赋予了Cbl家族蛋白具有调节蛋白的功能(2)。通过对特殊底物的泛素化作用和分解作用，这一调节功能促成了Cbl 蛋白的E3-依赖活性。这一调节功能也促成了非-E3依赖活性，诸如受体酪氨酸激酶内化作用中对蛋白的募集作用、Cbl蛋白在特殊亚细胞组分的定位作用、以及离散的信号转导途径的激活作用(1)。Cbl-b是一种E3泛素连接酶，具有与c-Cbl几乎相同的结构域。Cbl-b在造血细胞生理学的作用已经被报道。Cbl-b的表达对于抗原识别过程中TCR表达的下调很重要(2)。Cbl-b通过对PI3K的调节亚基p85的泛素化(3,4)，实现CD28信号级联放大到Vav 和Rac1的负向调节作用。作为T淋巴细胞克隆无反应的一种重要的调节剂，Cbl-b mRNA和蛋白在钙动员和神经钙蛋白活化后，对T细胞进行增量调节(5)。Cbl-b缺乏的T细胞对无反应诱导有抵抗作用(5)。分子事件控制的这一表型被认为与PLCγ1和PKCθ泛素化作用有关，由于野生型无反应T细胞重新刺激后出现这些信号分子的降解，在Cbl-b缺乏的T细胞中并不出现(5)。

1. Schmidt, M.H. and Dikic, I. (2005) Nat Rev Mol Cell Biol 6, 907-18.
2. Naramura, M. et al. (2002) Nat Immunol 3, 1192-9.
3. Chiang, Y.J. et al. (2000) Nature 403, 216-20.
4. Fang, D. and Liu, Y.C. (2001) Nat Immunol 2, 870-5.
5. Heissmeyer, V. et al. (2004) Nat Immunol 5, 255-65.

原厂资料：

Homology

Species predicted to react based on 100% sequence homology: Monkey

Description

SignalSilence® Cbl-b siRNA II from Cell Signaling Technology (CST) allows the researcher to specifically inhibit Cbl-b expression using RNA interference, a method whereby gene expression can be selectively silenced through the delivery of double stranded RNA molecules into the cell. All SignalSilence® siRNA products from CST are rigorously tested in-house and have been shown to reduce target protein expression by western analysis.

Quality Control

Oligonucleotide synthesis is monitored base by base through trityl analysis to ensure appropriate coupling efficiency. The oligo is subsequently purified by affinity-solid phase extraction. The annealed RNA duplex is further analyzed by mass spectrometry to verify the exact composition of the duplex. Each lot is compared to the previous lot by mass spectrometry to ensure maximum lot-to-lot consistency.

Directions for Use

CST recommends transfection with 100 nM SignalSilence® Cbl-b siRNA II 48 to 72 hours prior to cell lysis. For transfection procedure, follow protocol provided by the transfection reagent manufacturer. Please feel free to contact CST with any questions on use. 
 Each vial contains the equivalent of 100 transfections, which corresponds to a final siRNA concentration of 100 nM per transfection in a 24-well plate with a total volume of 300 μl per well.

Background

The Casitas B lineage lymphoma (Cbl) proteins (in mammals these are c-Cbl, Cbl-b, and Cbl-c) are a family of single subunit RING finger protein-ubiquitin E3 ligases that contain multiple protein interaction motifs (1). All Cbl proteins have a highly conserved N-terminal tyrosine kinase-binding (TKB) domain that mediates interactions between Cbl proteins and phosphorylated tyrosine residues on Cbl substrates. C-terminal to the RING finger, Cbl proteins have proline-rich domains that mediate interactions with SH3 domain-containing proteins. Phosphorylated tyrosine residues mediate interactions with SH2 domain-containing proteins such as the p85 subunit of PI3K. These protein-protein interaction motifs allow Cbl family proteins to function as adaptor proteins (2). This adaptor function contributes to the E3-dependent activities of Cbl proteins by targeting specific substrates for ubiquitination and degradation. The adaptor function also contributes to non-E3-dependent activities, such as the recruitment of proteins involved in receptor tyrosine kinase internalization, localization of Cbl proteins to specific subcellular compartments, and activation of discrete signaling pathways (1).Cbl-b是一种E3泛素连接酶，具有与c-Cbl几乎相同的结构域。Cbl-b在造血细胞生理学的作用已经被报道。Cbl-b的表达对于抗原识别过程中TCR表达的下调很重要(2)。Cbl-b通过对PI3K的调节亚基p85的泛素化(3,4)，实现CD28信号级联放大到Vav 和Rac1的负向调节作用。作为T淋巴细胞克隆无反应的一种重要的调节剂，Cbl-b mRNA和蛋白在钙动员和神经钙蛋白活化后，对T细胞进行增量调节(5)。Cbl-b缺乏的T细胞对无反应诱导有抵抗作用(5)。分子事件控制的这一表型被认为与PLCγ1和PKCθ泛素化作用有关，由于野生型无反应T细胞重新刺激后出现这些信号分子的降解，在Cbl-b缺乏的T细胞中并不出现(5)。

1. Schmidt, M.H. and Dikic, I. (2005) Nat Rev Mol Cell Biol 6, 907-18.
2. Naramura, M. et al. (2002) Nat Immunol 3, 1192-9.
3. Chiang, Y.J. et al. (2000) Nature 403, 216-20.
4. Fang, D. and Liu, Y.C. (2001) Nat Immunol 2, 870-5.
5. Heissmeyer, V. et al. (2004) Nat Immunol 5, 255-65.

注意事项：

Storage: Cbl-b siRNA II is supplied in RNAse-free water. Aliquot
and store at -20ºC.