Neurturin is a disulfide-linked homodimer neurotrophic factor structurally related to GDNF, Artemin, and Persephin. These proteins belong to the cysteine-knot family of growth factors that assume stable dimeric structures. Neurturin signals through a multicomponent receptor system, composed of RET and one of four GFR α (α1-α4) receptors. Neurturin promotes the development and survival of sympathetic and sensory neurons by signaling through a receptor system composed of RET and GFRα2. The functional form of human Neurturin is a disulfide-linked homodimer, of two 11.8 kDa polypeptide monomers (204 total amino acid residues). Each monomer contains seven conserved cysteine residues, one of which (Cys 69) is used for inter-chain disulfide bridging and the others are involved in intramolecular ring formation known as the cysteine knot configuration.