Activin A 蛋白, Human/Mouse/Rat (HEK293)

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, Human/Mouse/Rat (HEK293) is produced in HEK293 cells, and consists of 117 amino acids (G310-S426).

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 (0-10 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 (1, 5, 50, 100, 200 ng/mL) increases the abundance of specific globin probe fragments for gamma and epsilon globins (209 nucleotides) as well as alpha (180 nucleotides), which are protected from S1 digestion, in the human erythroid cell line, K562^[3].
Recombinant Activin A (50 ng/mL; 6-72 hours) increases the cell content of FSH and total FSH (secreted plus intracellular) in rat pituitary cells^[5].

Recombinant Activin A (20 ng/1 µL; intratumoral injection; for 6 days) inhibits the growth of solid tumors in tumor-bearing mice with NS-1 cells^[1].
Recombinant Activin A (1 μg/20 μL; i.c.v.; once) reduces the neuronal loss in the hippocampal CA1/2 region, dorsolateral striatum but not in the parietal cortex in a 15-min hypoxic-ischemic (HI) injury in the rat brain. Activin A can enhance the survival of injured hippocampal and striatal neurons^[4].

1. The ED₅₀ for this effect is <8 ng/mL, as measured by its ability to inhibit proliferation of MPC-11 cells.
2. The ED₅₀ is less than 8 ng/mL, as measured by its ability to induce SMAD signaling in 293-Activin A Res cells.

• 
  The ED₅₀ for this effect is <8 ng/mL, as measured by its ability to inhibit proliferation of MPC-11 cells.

Human

HEK293

Tag Free

P08476 (G311-S426)

3624  [NCBI]

GLECDGKVNICCKKQFFVSFKDIGWNDWIIAPSGYHANYCEGECPSHIAGTSGSSLSFHSTVINHYRMRGHSPFANLKSCCVPTKLRPMSMLYYDDGQNIIKKDIQNMIVEECGCS

13-15 kDa

Greater than 95% as determined by reducing SDS-PAGE.

无菌粉末

Lyophilized from a 0.2 μm filtered solution of 4 mM HCl.

<0.01 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O or PBS.

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]

  [3]. N L Frigon Jr, et al. Regulation of globin gene expression in human K562 cells by recombinant activin A. Blood. 1992 Feb 1;79(3):765-72.  [Content Brief]

  [4]. D D Wu, et al. Expression of the activin axis and neuronal rescue effects of recombinant activin A following hypoxic-ischemic brain injury in the infant rat. Brain Res. 1999 Jul 24;835(2):369-78.  [Content Brief]

  [5]. B Attardi, et al. Rapid stimulatory effect of activin-A on messenger RNA encoding the follicle-stimulating hormone beta-subunit in rat pituitary cell cultures. Mol Endocrinol. 1990 May;4(5):721-6.  [Content Brief]