NGF

NGF Background

The NGF gene provides instructions for making a protein called nerve growth factor beta (NGFβ). As its name suggests, NGF is involved primarily in the growth, as well as the maintenance, proliferation, and survival of nerve cells (neurons). In fact, NGF is critical for the survival and maintenance of sympathetic and sensory neurons, as they undergo apoptosis in its absence ^[1]. The NGFβ protein functions by binding to its receptors, which initiates signaling pathways inside the cell. The NGFβ protein can bind to two different receptors, the NTRK1 receptor or the p75NTR receptor. Both receptors are found on the surface of sensory neurons and other types of neurons. The binding of the NGFβ protein to the NTRK1 receptor signals these neurons to grow and to mature and take on specialized functions (differentiate). This binding also blocks signals that initiate the process of self-destruction (apoptosis). Additionally, NGFβ signaling through NTRK1 plays a role in pain sensation. It is less clear what binding with the p75NTR receptor signals. Studies suggest that p75NTR signaling can help sensory neurons grow and differentiate but can also trigger apoptosis. However, several recent studies suggest that NGF is also involved in pathways regulating the life cycle of neurons.

[1] Freeman RS, Burch RL, et al. NGF deprivation-induced gene expression: after ten years, where do we stand [J]? Progress in Brain Research. 2004, 146: 111–26.