Nerve growth factor pathway

Nerve growth factor (NGF) is a member of the neurotrophin family of secretary proteins that are involved in cell survival, growth and differentiation. It is important for the development and maintenance of both the sympathetic and sensory nervous systems. This pathway highlights how NGF binds to p75NTR or TrkA and activates the PI3K, Ras and PLC signaling pathways.

NGF signals through at least two types of receptor; the low-affinity nerve growth factor receptor [LNGFR or p75 neurotrophin receptor (p75NTR)] and TrkA, a transmembrane tyrosine kinase.  When NGF binds to TrkA, the receptor dimerizes and autophosphorylates its tyrosine kinase domain, which leads to the activation of PI3K, Ras, and PLC signaling pathways. Alternatively, p75NTR can form a heterodimer with TrkA which has higher affinity for NGF.