TrkA receptor

TrkA receptor (also known as Tropomyosin receptor kinase A) is a protein that in humans is encoded by the NTRK1 gene. It is a member of the neurotrophic tyrosine kinase receptor (NTRK) family. This kinase is a membrane-bound receptor that, upon neurotrophin binding, phosphorylates itself and members of the MAPK pathway.

Function

The TrkA receptor is part of the large family of receptor tyrosine kinases. It has high affinity binding to nerve growth factor (NGF), neurotrophin-3 and neurotrophin-4/5, but not brain-derived neurotrophic factor (BDNF). Overexpression of the TrkA receptor can lead to neoplasia, which could serve as a therapeutic target for some types of cancer.

Structure

The TrkA receptor is a single-pass type I membrane protein. It contains two Ig-like C2-type (immunoglobulin-like) domains, two leucine-rich repeat domains, and one protein kinase domain. The protein kinase domain is located in the cytoplasmic part of the receptor.

Clinical significance

Mutations in the TrkA receptor gene have been associated with congenital insensitivity to pain with anhidrosis, a rare disorder characterized by insensitivity to pain, anhidrosis (absence of sweating), and intellectual disability. TrkA receptor has also been implicated in several types of cancer, including colorectal cancer, pancreatic cancer, and breast cancer.

See also

• Nerve growth factor
• Neurotrophin
• Receptor tyrosine kinase