Neurotrophins

Artemin is a disulfide‐linked homodimeric neurotrophic factor structurally related to GDNF, neurturin and persephin. These proteins belong to the cysteine knot superfamily of growth factors that assume stable dimeric protein structures. Artemin, GDNF, persephin and neurturin all signal through a multicomponent receptor system, composed of RET (receptor tyrosine kinase) and one of the four GFRα (α1‐α4) receptors. Artemin prefers the receptor GFRα3‐RET, but will use other receptors as an alternative. Artemin supports the survival of all peripheral ganglia, such as sympathetic, neural crest and placodally‐derived sensory neurons, and dopaminergic midbrain neurons. The functional human artemin ligand is a disulfide‐linked homodimer of two 12.0 kDa polypeptide monomers. Each monomer contains seven conserved cysteine residues, one of which is used for interchain disulfide bridging and the others are involved in intramolecular ring formation known as the cysteine‐knot configuration. Recombinant Murine Artemin is a disulfide‐linked homodimer formed by two identical 113 amino acid subunits with a calculated molecular weight of 24.2 kDa.