STKR

STKR denotes the serine/threonine kinase receptor family of the TKL group — the TGF-beta superfamily type I and type II receptors such as TGFBR1/2, ACVR1, BMPR1/2, and ACVRL1. Type II receptors bind ligands (TGF-betas, BMPs, activins) and phosphorylate the GS box of type I receptors, whose activated kinases then phosphorylate SMAD1/5 or SMAD2/3 to control proliferation, differentiation, immunity, and development. Mutations cause hereditary hemorrhagic telangiectasia (ACVRL1, ACVR1), pulmonary arterial hypertension (BMPR2), and Marfan-like syndromes, while TGF-beta receptor signaling is a major fibrosis and immuno-oncology target. Recombinant STKR ectodomains and kinase domains serve these programs.