Activin RIA Protein, Human (HEK293, Fc)

Activin A receptor, type I (ACVR1), also known as ALK-2, is a bone morphogenetic protein (BMP) type I receptor. ACVR1 is involved in a wide variety of biological processes, including bone, heart, cartilage, nervous, and reproductive system development and regulation^[1]. Activin RIA Protein, Human (HEK293, Fc) is produced in HEK293 cells with a C-Terminal Fc-tag. It consists of 102 amino acids (D23-V124).

Activin A receptor type I (ACVR1) gene, also known as ALK-2, is located in chromosome 2q23-q24 and encodes for the 509 amino acid protein. The ACVR1 protein product is initially described as an activin type I receptor, and it is found to be expressed in several tissues and different human cell lines^[1].
The sequence of amino acids in ACVR1 proteins from different species is very stable, which leads to the conclusion that in the process of evolution, ACVR1 has been only slightly altered, and that both in humans and in animals, its function is similar.
As a member of the BMP/TGFβ receptor family, the ACVR1 protein contains an extracellular N-terminal ligand-binding domain, a transmembrane (TM) domain, an intracellular glycine-serine-rich (GS) domain, and a protein kinase (PK) domain. The loop positioned in the helix-loop-helix of the GS domain contains the key residues responsible for ACVR1 activation upon phosphorylation. As a type I receptor, ACVR1 forms heterotetrameric receptor complexes with the type II receptors BMPR2, ACVR2A, and ACVR2B. Such complexes consist of two type I and two type II receptors. Upon binding of ligands to the heteromeric complexes, type II receptors transphosphorylate the GS domain of type I receptors. As a result, the kinase domain of type I receptors is activated and subsequently phosphorylates SMAD1/5/8 proteins that transduce the signal. ACVR1 is first described to bind to activin A, a member of the BMP/TGFβ family that usually triggers phosphorylation and activation of SMAD2/3 upon complex formation with type II receptors. Later, ACVR1 is also found to bind several BMPs with distinct affinities, triggering SMAD1/5/8 signalling. Besides canonical SMAD signalling, ACVR1 can activate non-canonical signalling pathways, such as p38 mitogen-activated protein kinases/MAPKs^[1].
ACVR1 is involved in a wide variety of biological processes, including bone, heart, cartilage, nervous, and reproductive system development and regulation. Moreover, ACVR1 has been extensively studied for its causal role in fibrodysplasia ossificans progressiva (FOP). ACVR1 is linked to different pathologies, including cardiac malformations and alterations in the reproductive system. More recently, ACVR1 has been experimentally validated as a cancer driver gene in diffuse intrinsic pontine glioma (DIPG)^[1].

Recombinant human ACVR1 (2.5-5 μg/mL) robustly down-regulates phosphorylated Smad1/5/8 and p38 MAPK levels in the HUVEC^R206H cells. ACVR1 also inhibits chondro-osseous differentiation in HUVEC^R206H cells^[2].

Measured by its binding ability in a functional ELISA. When Recombinant Human BMP-6 is used at 0.25 μg/mL can bind Human Activin RIA. The ED₅₀ for this effect is 4.46 μg/mL.

Human

HEK293

C-hFc

Q53SV1 (D23-V124)

/

DEKPKVNPKLYMCVCEGLSCGNEDHCEGQQCFSSLSINDGFHVYQKGCFQVYEQGKMTCKTPPSPGQAVECCQGDWCNRNITAQLPTKGKSFPGTQNFHLEV

38-45 kDa

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

Lyophilized powder.

Lyophilized from a 0.2 μm filtered solution of PBS, 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]. José Antonio Valer, et al. ACVR1 Function in Health and Disease. Cells. 2019 Oct 31;8(11):1366.  [Content Brief]

  [2]. Jing Pang, et al. ACVR1-Fc suppresses BMP signaling and chondro-osseous differentiation in an in vitro model of Fibrodysplasia ossificans progressive. Bone. 2016 Nov;92:29-36.  [Content Brief]