Neurotrophic factor receptor

Neurotrophic factor receptors or neurotrophin receptors are a group of growth factor receptors which specifically bind to neurotrophins (neurotrophic factors).

Two classes of neurotrophic factor receptors are the p75 and the "Trk" families of Tyrosine kinases receptors.

• p75 is a low affinity neurotrophin receptor, to which all neurotrophins bind. It is a member of the tumour necrosis super family. In some contexts, the phrase "x" only applies to this receptor.^[1]
• The Trk family include TrkA, TrkB, and TrkC, and will only bind with specific neurotrophins, but with a much higher affinity. The Trks mediate the functional signals of the neurotrophins.
• NGF binds to TrkA, BDNF and NT-4 bind to TrkB and NT-3 binds to TrkC. In addition NT-3 also binds to and activates TrkA and TrkB but it does so less efficiently.
• Whilst the Trk receptors have a clearly defined trophic role, p75 receptors activate signalling pathways which can also result in apoptosis.