TrkA Protein, Rat (HEK293, Fc)

The TrkA protein, a receptor tyrosine kinase, plays a vital role in the development and maturation of the central and peripheral nervous systems by regulating the proliferation, differentiation, and survival of sympathetic and sensory neurons. Serving as a high-affinity receptor for NGF, its primary ligand, TrkA can also be activated by NTF3/neurotrophin-3, though NTF3 specifically supports axonal extension through NTRK1 without influencing neuron survival. Upon dimeric NGF ligand-binding, TrkA undergoes homodimerization, autophosphorylation, and activation, subsequently recruiting, phosphorylating, and/or activating downstream effectors such as SHC1, FRS2, SH2B1, SH2B2, and PLCG1. These effectors regulate distinct yet overlapping signaling cascades, steering cell survival and differentiation. Through SHC1 and FRS2, TrkA activates a GRB2-Ras-MAPK cascade controlling cell differentiation and survival, while through PLCG1, it modulates NF-Kappa-B activation and the transcription of genes crucial for cell survival. Additionally, through SHC1 and SH2B1, TrkA controls a Ras-PI3 kinase-AKT1 signaling cascade, further contributing to the regulation of cell survival. In the absence of ligand and activation, TrkA may promote cell death, underscoring the dependence of neuron survival on trophic factors.