• Species Reactivity

  Human

• Specificity

  Detects human Activin RIB/ALK‑4 in direct ELISAs. In direct ELISAs, no cross-reactivity with recombinant human Activin RIA, RIIA, or RIIB is observed.

• Source

  Monoclonal Mouse IgG2b Clone # 544310

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant human Activin RIB/ALK‑4    
  Ser24-Glu126    
  Accession # P36896

• Formulation

  Supplied 0.2 mg/mL in a saline solution containing BSA and Sodium Azide.

• Label

  Alexa Fluor 405

Applications

• Recommended    
  Concentration

  Sample

• Flow Cytometry

  0.25-1 µg/10    ⁶ cells

  PC‑3 human prostate cancer cell line

• 
  

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Preparation and Storage

• Shipping

  The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

• Stability & Storage

  Store the unopened product at 2 - 8 °C. Do not use past expiration date.

Background: Activin RIB/ALK-4

Activin RIB, also known as ALK4, is a glycosylated 58 kDa type I receptor in the superfamily of TGF-beta serine/threonine kinase receptors. Activin RIB associates with Activin RIIB to form a receptor complex for activin and inhibin molecules (1). These ligands bind to Activin RIIB which then associates with and phosphorylates the cytoplasmic domain of Activin RIB to initiate signal transduction (2, 3). Mature human Activin RIB consists of a 103 amino acid (aa) extracellular domain (ECD), a 23 aa transmembrane segment, and a 356 aa cytoplasmic region that includes the kinase domain (4). Within the ECD, human Activin RIB shares 93% and 95% aa sequence identity with mouse and rat Activin RIB, respectively. It shares 25-35% aa sequence identity with other human type I receptors Activin RIA, Activin RIC, BMPR-IA, BMPR-IB, and TGF-beta R1. Alternately spliced isoforms of Activin RIB have deletions in the cytoplasmic domain and function as dominant negative inhibitors of activin signaling (5, 6). Activin receptor signaling is modulated by the direct interaction of Activin RIB with cripto or inhibin binding protein (7-9). Activin RIB is excluded from the signaling complex if Activin RIIB first binds inhibin and betaglycan (10). Activin RIB functions in a wide variety of growth and differentiation processes, including embryonic cell fate and axis determination, cell proliferation and apoptosis, and tumorigenesis (1, 11, 12).

• References:

   

1. Chen, Y- G. et al. (2006) Exp. Biol. Med. 231:534. 

2. Attisano, L. et al. (1996) Mol. Cell. Biol. 16:1066. 

3. Tsuchida, K. et al. (1995) Endocrinology 136:5493. 

4. ten Dijke, P. et al. (1993) Oncogene 8:2879. 

5. Xu, J. et al. (1994) Proc. Natl. Acad. Sci. USA 91:7957. 

6. Zhou, Y. et al. (2000) Mol. Endocrinol. 14:2066. 

7. Chapman, S.C. and T.K. Woodruff (2001) Mol. Endocrinol. 15:668.

8. Bianco, C. et al. (2002) Mol. Cell. Biol. 22:2586.

9. Gray, P.C. et al. (2003) Proc. Natl. Acad. Sci. USA 100:5193.

10. Lewis, K.A. et al. (2000) Nature 404:411.

11. Gu, Z. et al. (1998) Genes Dev. 12:844.

12. Chen, Y. et al. (2004) Dev. Biol. 268:280.

• Long Name:

  Activin Receptor IB

• Entrez Gene IDs:

  91 (Human); 11479 (Mouse)

• Alternate Names:

  activin A receptor, type IB; Activin receptor type IB; Activin receptor-like kinase 4; Activin RIB; ActivinRIB; ACTRIB; ACVR1B; ACVRLK4ACTR-IB; ALK4; ALK-4; ALK4activin A receptor, type II-like kinase 4; EC 2.7.11; EC 2.7.11.30; Serine/threonine-protein kinase receptor R2; SKR2activin receptor type-1B