Activin A 蛋白, Mouse (HEK 293, His)

Activin A, a multifunctional cytokine, is a member of TGF-β superfamily. Activin A first binds to the type II activin receptors (ActIIRA or ActRIIB) on the member surface, and then recruits and phosphorylates type I activin receptors (ActRI). Activin A primarily signal through SMAD2/3 proteins to regulate a variety of functions, including inflammation, fibrosis, and tumorigenesis^[1]. Activin A Protein, Mouse (HEK293, His) is produced in HEK293 cellswith a C-Terminal His-tag. It  consists of 424 amino acids (M1-S424).

激活素是转化生长因子-β (TGF-β) 超家族的成员，由两个通过二硫键连接的抑制素 β 亚基组成。激活素A广泛表达于多种组织和细胞，具有很强的生物活性，是研究最多的激活素^[1]。
不同物种的激活素A蛋白的氨基酸序列非常稳定，由此得出的结论是，在进化过程中，激活素A仅发生了轻微的改变，并且无论在人类还是在动物中，其功能都是相似的。
激活素以由两个抑制素β组成的三种基本分子形式存在亚基：激活素 A (βAβA)、激活素 B (βBβB) 和激活素 AB (βAβB)。激活素 A 以高亲和力与激活素 II 型受体结合，后者招募 I 型受体，并且是激活 Smad2/3 信号传导所必需的。磷酸化的 ActRI 激活 Smad2 和 Smad3，它们与 Smad4 形成复合物并易位至细胞核。激活素和 TGF-β 在 Smad2/3/4 水平上共享相同的信号通路。激活素 A 发挥多种生物学功能，包括调节造血细胞增殖、神经元分化、垂体激素分泌和组织修复。它还参与许多疾病的发生过程，例如炎症、纤维化和肿瘤发生^[1][2]。
Activin A具有亲和作用抗肿瘤功能取决于肿瘤类型。在乳腺癌、肝癌和结肠癌中，激活素信号被证明可以抑制肿瘤细胞的生长。此外，肿瘤组织的激活素 A 水平降低，激活素拮抗剂水平升高，或者激活素受体或 Smad 蛋白下调。此外，其作用还包括胚胎分化、妊娠早期滋养层对子宫壁的侵袭以及缺氧条件下胎儿/新生儿的脑保护。激活素 A 还调节骨形成和再生，增强类风湿性关节炎的关节炎症，并触发呼吸系统的致病机制^[1][2]。

Recombinant Activin A (-1 ng/mL; for 12 and 24 h) inhibits the proliferation of myeloma cell line NS-1 cells and induces NS-1 cell apoptosis. Activin A upregulates the expression of CHOP, GADD34, caspase-3, and caspase-12. Moreover, both Smad3 and p-Smad3 levels are increased with treatment of activin A in NS-1 cells^[1].

Recombinant Activin A (2 ng/1 µL; intratumoral injection; for 6 days) inhibits the growth of solid tumors in tumor-bearing mice with NS-1 cells^[1].

1.Measured in a cell proliferation assay using HT-29 human colon cancer cell. The ED₅₀ for this effect is 6.407 ng/mL, corresponding to a specific activity is 1.561×10⁵ units/mg.
2.Measured by its ability to inhibit proliferation of MPC-11 cells. The ED₅₀ for this effect is typically 0.8-4 μg/mL.
3.Measured by its ability in a ELISA.
3.1. Immobilized human ACVR2B at 10 μg/mL (100 μl/well) can bind biotinylated mouse INHBA-His, The EC₅₀ of biotinylated mouse INHBA-His is 0.161 μg/mL.
3.2 Immobilized mouse INHBA-his at 10 μg/mL (100 μl/well) can bind human Follistatin Protein, The EC₅₀ of human Follistatin Protein is 0.39 μg/mL.

Mouse

HEK293

C-His

Q3UY39 (S21-S424)

16323  [NCBI]

Approximately 18&43 kDa

Greater than 90% as determined by reducing SDS-PAGE

无菌粉末

Lyophilized from a 0.2 μm filtered solution of PBS or 20 mM PB, 150 mM NaCl, pH 7.4

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.

• [1]. Ge J, et al. Involvement of CHOP in activin A induced myeloma NS 1 cell apoptosis. Oncol Rep. 2019;42(6):2644-2654.  [Content Brief]

  [2]. Enrrico Bloise, et al. Activin A in Mammalian Physiology. Physiol Rev. 2019 Jan 1;99(1):739-780.  [Content Brief]