BACKGROUND Neurotrophin-3 (NT-3) is a small secreted protein and a member of neurotrophin family, which also includes Brain-Derived Neurotrophic Factor (BDNF), Nerve growth factor (NGF), and Neurotrophin 4/5 (NT-4/5). All the neurotrophins are initially produced as 30–35 kDa precursor proteins containing a signal peptide, sites for glycosylation, and pairs of basic amino acids that are recognized by processing enzymes. The calcium-dependent serine protease furin and other members of the prohormone convertase family cleave each of the neurotrophins at a dibasic cleavage site in the middle of the precursor protein, releasing the biologically active 12–14 kDa C-terminal product. They activate two structurally unrelated receptors, the p75 neurotrophin receptor (NTR) and the receptor tyrosine kinases designated (Trk).1 The p75NTR binds all neurotrophins with a very similar affinity, although it binds neurotrophin precursors with high affinity and retains low affinity to the mature cleaved forms. Whereas the Trk receptors show more restricted neurotrophin-binding affinity. TrkA potently binds Nerve Growth Factor (NGF) and is involved in differentiation and survival of neurons and in control of gene expression of enzymes involved in neurotransmitter synthesis. TrkB has highest affinity for brain-derived neurotrophic factor (BDNF) and is involved in neuronal plasticity, long term potentiation and apoptosis of CNS neurons. TrkC is activated by neurotrophin-3 (NT-3) and is found on proprioceptive sensory neurons.2 Trks are single transmembrane catalytic receptors with intracellular tyrosine kinase activity. Trk receptors are coupled to the Ras, Cdc42/Rac/RhoG, MAPK, PI 3-K and PLCgamma and JNK signaling pathways. p75NTR lacks tyrosine kinase activity and signals via NF-kappaB activation.
NT-3 has approximately 50% homology to NGF, brain-derived neurotrophic factor (BDNF), and NT-4. NT-3 plays an important role in the development of the nervous system as well as in mediating the survival, synaptic plasticity, and neurotransmission of neurons in the adult nervous system. NT-3 is widely expressed in the hippocampus and facilitates hippocampal plasticity by regulating neurogenesis. In addition, NT-3 participates in various non-neuronal regulatory activities. It was reported that NT-3/Trk C signaling is functionally important in the control of hair follicle regression.3
1. Lewin, G.R. & Barde, Y.A. : Annu Rev Neurosci. 19:289-317, 1996
2. Genç, B. et al: PLoS ONE 2:e403, 2004
3. Botchkarev, V.A. et al: Am. J. Path. 153:785-99, 1998
Products are for research use only. They are not intended for human, animal, or diagnostic applications.
Target Protein Species:
15.6 pg/ml – 1000pg/ml
Cross-reactivates with NT-4 <2.5%, and no detectable cross-reactivity with any other cytokine.
Store at 4°C. Use within 6 months.
ELISA Kits are based on standard sandwich enzyme-linked immunosorbent assay technology. Freshly prepared standards, samples, and solutions are recommended for best results.