Neurotrophin-3 is the third neurotrophic factor, characterized after
nerve growth factor (NGF) and brain-derived neurotrophic
factor (BDNF). NT-3 is a polypeptide consisting of 119
amino acid residues, and forms a homodimer. NT-3 binds
to tropomyosin receptor kinase C (TrkC) with high affinity.
NT-3 also binds to TrkA, TrkB, and p75NTR with low
affinity. NT-3 promotes the differentiation, growth, and
survival of neurons. The distribution of NT-3 and its biological activity on a variety of neuronal populations clearly distinguish NT-3 from NGF and BDNF, indicating that NT-3
is an authentic neurotrophic factor that has its own characteristic role in vivo.