ActRIIA (ACVR2A) and ActRIIB (ACVR2B) are members of the transforming growth factor β (TGF-β) receptor family, including activins A and B, as well as BMP7, BMP9, BMP10, GDF1, GDF8 (myostatin), GDF11, and Nodal among other TGF-β family members as type II receptors. ALK4 and ALK7 are the main type I TGF-β receptor family members for activin A and activin B, respectively. Bimagrumab is a human monoclonal antibody that can block the activin II type receptor (ActRII), thereby regulating skeletal muscle growth. Research has shown that Bimagrumab has affinity for both ActRIIB and ActRIIA, but its affinity for ActRIIB is at least 200 times stronger than for ActRIIA.The ACVR2B Reporter Cell Line is a luciferase reporter gene cell line. On the basis of the Activin A Reporter Cell Line, the ACVR2A gene has been knocked out, allowing proteins like GDF8 to only bind to ACVR2B and activate downstream signaling pathways. By introducing specific antagonistic antibodies to block the downstream signaling pathways activated by this, followed by measuring fluorescence signals to determine luciferase expression, the extent of the antagonist’s impact on the signaling pathway can be indirectly assessed. Therefore, this cell line enables convenient, sensitive, and specific screening and validation of antagonistic drugs targeting ActRIIB.
