Receptor binding characteristics initiate responses

Three Trks have been identified, Trk A, B and C. Ligand-binding induces Trk receptor homodimerization. This activates the intrinsic cytoplasmic tyrosine kinase activity, resulting in receptor autophosphorylation and initiation of an intracellular response. A characteristic feature of the Trk family of receptors is the presence of a leucine-rich region near the N-terminal (extracellular) end of the molecule. 

Once the ligand binds to the receptor, it initiates a series of biochemical reactions that induce a short-term response (e.g., phosphorylation state of an intermediate protein) and/or a longer-term response as a result of a regulated gene response. These networks respond relatively rapidly, exhibiting dynamics with characteristic time scales of seconds to minutes. A cell is often presented with multiple, competing cues, and it processes that infor-... 

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