Activin Receptor-Like Kinase 4 (ALK4)

Activin Receptor-Like Kinase 4 (ALK4), also known as ACVR1B, is a type I receptor in the TGF-beta superfamily. It functions as a transmembrane serine/threonine kinase that, upon activation by activins and type II receptors, phosphorylates SMAD2/3 proteins to regulate gene transcription. This pathway is involved in diverse processes including embryogenesis, tissue homeostasis, wound healing, extracellular matrix production, immunosuppression, and carcinogenesis. ALK4 is highly expressed in the heart, reproductive organs, pituitary gland, and neuronal tissue. Dysregulation of ALK4 is implicated in cardiovascular disease, cancer, fibrosis, and reproductive/developmental disorders.

Other names

ACVR1BActivin A receptor type IB

ALK4 is a transmembrane serine/threonine kinase that forms a complex with activin type II receptors (ACVR2A or ACVR2B). Upon ligand binding, the type II receptor phosphorylates and activates ALK4, which then phosphorylates SMAD2 and SMAD3, leading to downstream gene transcription.