Neurotrophin

Function

Neurotrophins (NT) are survival factors for sympathetic and sensory neurons and control a number of aspects of survival, development and function of neurons in the central and peripheral nervous systems^[1]. There are 4 mammalian NTs and they are activated by the family of the receptor tyrosine kinases TrkA (see High affinity nerve growth factor receptor), TrkB (see TrkB tyrosine kinase receptor), TrkC. NTs activate the p75 neurotrophin receptor (BDNF) which is a member of the tumor necrosis factor receptor superfamily.

• Neurotrophin 3 is released through the regulated secretory pathway and influences the development of the enteric nervous system^[2].
• Neurotrophin 4 is released through the constitutive secretory pathway ^[3].

Relevance

Alterations in NTs levels were implicated in neurodegenerative disorders such as Alzheimer disease and Huntington disease as well as psychiatric disorders including depression and substance abuse^[4].

Structural highlights

The complex between NT3 and p75 neurotrophin receptor (p75NTR) shows a . There are 3 sites of interactions between NT3 and p75NTR - site 1, site 2 and site 3^[5].

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