Nerve growth factor

Nerve Growth Factor (NGF) is a neurotrophic factor and neuropeptide primarily involved in the regulation of growth, maintenance, proliferation, and survival of certain target neurons. It is perhaps the prototypical growth factor, in that it was one of the first to be described. Since it was first isolated by Nobel Laureates Rita Levi-Montalcini and Stanley Cohen in 1956, numerous biological processes involving NGF have been identified, two of them being the survival of pancreatic beta cells and the regulation of the immune system.

Structure

NGF is initially in a 7S, 130-kDa complex of 3 proteins - Alpha-NGF, Beta-NGF, and Gamma-NGF (2:2:2 ratio) when expressed. This form of NGF is also referred to as proNGF. The gamma subunit of this complex acts as a serine protease, and cleaves the N-terminal of the beta subunit, thereby activating the protein into functional NGF.

Function

NGF is critical for the survival and maintenance of sympathetic and sensory neurons, as they undergo apoptosis in its absence. However, several recent studies suggest that NGF is also involved in pathways besides those regulating the life cycle of neurons.

Clinical significance

NGF appears to promote myelin repair. Hence, NGF could potentiate the regeneration of the spinal cord and peripheral nerves. NGF could also promote the differentiation and survival of oligodendrocytes, cells which myelinate neurons of the central nervous system.

See also

• Neurotrophin
• Nerve growth factor receptor
• Nerve growth factor (human)

References

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External links

• NGF: Gene from National Center for Biotechnology Information
• NGF: Protein from Alzheimer Research Forum