Tropomyosin receptor kinase (most accurately, this refers to the family comprising Tropomyosin receptor kinase A, B, and C, commonly termed TrkA, TrkB, and TrkC) (Trk (used generically; specific members are TrkA, TrkB, TrkC))

Tropomyosin receptor kinases form a family of transmembrane receptor tyrosine kinases chiefly involved in nervous system development, synaptic transmission, and cellular survival signaling[1][2][3][4][5][7][8]. The canonical members—TrkA (NTRK1), TrkB (NTRK2), and TrkC (NTRK3)—are activated by distinct neurotrophins (nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3, respectively)[1][2][4][5][7]. Upon ligand binding, they dimerize and autophosphorylate, initiating cascades such as RAS/MAPK, PI3K/AKT, and PLCγ, leading to neuronal differentiation, survival, and proliferation[2][4][5][7]. Oncogenic activation—typically via NTRK gene fusions—can drive malignancy, making TRK kinases an important modern cancer drug target[5][8]. Approved drugs selectively inhibit these kinases, with ongoing research into resistance and CNS safety. Alternative splicing and isoform diversity complicate function and therapeutic targeting. Trk receptors also play roles in immune regulation and neurodegenerative disease biology[6][7].

Other names

Tropomyosin receptor kinasesTrk receptorsTRK familyNeurotrophic tyrosine kinase receptor familyTrkA (NTRK1, neurotrophic tyrosine kinase receptor type 1, high-affinity nerve growth factor receptor)TrkB (NTRK2, neurotrophic tyrosine kinase receptor type 2, BDNF receptor)TrkC (NTRK3, neurotrophic tyrosine kinase receptor type 3, NT-3 growth factor receptor)

Competitive inhibition of ATP binding in the kinase domain (blocks phosphorylation and signal transduction); Preventing dimerization and activation by neurotrophin ligands; Downregulation or inhibition of proliferation, survival, and anti-apoptotic pathways (RAS/MAPK, PI3K/AKT, PLCγ); Selective inhibition of oncogenic fusion proteins (NTRK fusions)