GDNF is a disulfide-linked, homodimeric neurotrophic factor that belongs to the cystine-knot family of growth factors. Natively glycosylated, GDNF signals through a multi-component receptor system that comprises of a RET and one of the four GFR_ receptors. In embryonic midbrain cultures, GDNF promotes the survival and morphological differentiation of dopaminergic neurons and increases their high-affinity dopamine uptake. Mature rat and human GDNF exhibit approximately 93% amino acid sequence identity and show considerable species cross-reactivity Recombinant Human GDNF is a non-glycosylated, disulfide-linked homodimer (30 kDa) consisting of 135 amino acids in each subunit.