NT-3 is a member of the structurally related neurotrophin family of proteins, which includes β-NGF, BDNF and NT-4 (1). NT-3 is expressed in a number of cell types including neuronal cells, eosinophils, and melanocytes (1-3). NT-3 is required for the development of peripheral sensory neurons (4). NT-3 is secreted from cells as a precursor protein, which is proteolytically cleaved into the mature form (1). NT-3 signaling is mediated through two distinct receptors, the neurotrophin receptor p75NTR and the Trk tyrosine kinase receptor TrkC. While all neurotrophins bind to the p75NTR receptor, NT-3 preferentially binds to TrkC and, with lesser affinity, TrkB (1).
