Nerve growth factor receptor

Nerve growth factor receptor

Nerve growth factor receptors are a group of growth factor receptors which specifically bind to neurotrophins.

There are two classes of receptors, p75 and the "Trk" family 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.

Contents

TrkA, B, and C receptors

TrkA is a receptor tyrosine kinase (meaning it mediates its actions by causing the addition of phosphate molecules on certain tyrosines in the cell, activating cellular signaling).

There are other related Trk receptors (TrkB and TrkC), and there are other neurotrophic factors structurally related to NGF (BDNF, NT-3, and NT-4)

  • TrkA mediates the effects of NGF
  • TrkB binds and is activated by BDNF, NT-4, and NT-3
  • TrkC binds and is activated only by NT-3

LNGFR receptor

The other NGF receptor, the LNGFR, (for Low affinity nerve growth factor receptor, commonly known as "p75", plays a less clear role.

LNGFR binds and serves as a "sink" for neurotrophins. Cells which express both the LNGFR and the Trk receptors might therefore have a greater activity - since they have a higher "microconcentration" of the neurotrophin.

However, although NGF has been classically described as promoting neuron survival and differentiation, research performed in the early 2000s suggest that NGF with its prodomain attached (proNGF) can elicit apoptosis of cells that are positive for the LNGFR and negative for TrkA.[2]

Secreted proNGF has been demonstrated in a variety of neuronal and non-neuronal cell populations. It has been proposed that secreted proNGF can elicit neuron death in a variety of neurodegenerative conditions, including Alzheimer's disease, following the observation of an increase of proNGF in the nucleus basalis of postmortem Alzheimer's brains.

References

  1. ^ MeSH Nerve+Growth+Factor+Receptor+p75
  2. ^ Ibáñez C (2002). "Jekyll-Hyde neurotrophins: the story of proNGF". Trends Neurosci 25 (6): 284–6. doi:10.1016/S0166-2236(02)02169-0. PMID 12086739. 

External links



Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Low-affinity nerve growth factor receptor — P75 redirects here. For the New Testament manuscript, see Papyrus 75. For Pentium processor at 75 MHz, see Intel P5 (microarchitecture). Nerve growth factor receptor PDB rendering based on 1sg1 …   Wikipedia

  • Low affinity nerve growth factor receptor — The Low Affinity Nerve Growth Factor Receptor (also called the LNGFR or p75 neurotrophin receptor) is one of the two receptor types for the neurotrophins, a family of protein growth factors which stimulate neuronal cells to survive and… …   Wikipedia

  • Nerve growth factor — (beta polypeptide) Rendering of NGF from PDB 1SG1 …   Wikipedia

  • Nerve Growth factor IB — Nuclear receptor subfamily 4, group A, member 1 PDB rendering based on 1cit …   Wikipedia

  • Epidermal growth factor receptor — This article is about a cell surface receptor. For estimated measure of kidney function (eGFR), see Glomerular filtration rate. Epidermal growth factor receptor …   Wikipedia

  • Fibroblast growth factor receptor 2 — PDB rendering based on 1djs …   Wikipedia

  • Fibroblast growth factor receptor 1 — PDB rendering based on 1agw …   Wikipedia

  • Platelet-derived growth factor receptor — platelet derived growth factor receptor, alpha polypeptide Identifiers Symbol PDGFRA Entrez 5156 HUGO …   Wikipedia

  • Tumor necrosis factor receptor — TNFR/NGFR cysteine rich region Structure of the soluble human 55 kd TNF receptor human TNF beta complex[1]. Identifiers Symbol …   Wikipedia

  • Growth factor — The term growth factor refers to a naturally occurring protein capable of stimulating cellular growth, [DorlandsDict|three/000038554|growth factor] proliferation and cellular differentiation. Growth factors are important for regulating a variety… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”