Neurotrophic tyrosine kinase receptor (NTRK receptor (or Trk receptor))

Neurotrophic tyrosine kinase receptors, also known as Trk receptors or NTRK receptors, are a family of single-pass transmembrane receptor tyrosine kinases including TrkA (NTRK1), TrkB (NTRK2), and TrkC (NTRK3)[1][3][4][6]. These receptors bind neurotrophins—a family of growth factors essential for the survival, development, and function of neurons—each with their corresponding primary ligand: TrkA for nerve growth factor (NGF), TrkB for brain-derived neurotrophic factor (BDNF) and neurotrophin-4, and TrkC for neurotrophin-3[6]. Upon ligand binding, Trk receptors dimerize, autophosphorylate, and activate multiple intracellular signaling pathways such as Ras/MAPK, PI3K-AKT, and PLCγ, regulating neuronal differentiation, survival, and plasticity[3][7]. Gene fusions involving NTRK genes can result in constitutively active chimeric kinases, promoting oncogenesis in a variety of cancers and making them therapeutic targets for selective kinase inhibitors[2][5]. Trk inhibitors like larotrectinib and entrectinib have achieved regulatory approval for cancers with NTRK gene fusions, marking NTRK receptors as clinically established pan-tumor targets[2][5]. Detection of NTRK gene fusions is a critical biomarker for targeted therapy selection. Caveats: The term "neurotrophic tyrosine kinase receptors" refers to the NTRK family collectively; for specificity, individual forms such as TrkA (NTRK1), TrkB (NTRK2), or TrkC (NTRK3) should be used where appropriate[3][7].

Other names

Trk receptortropomyosin receptor kinaseTrkA (NTRK1)TrkB (NTRK2)TrkC (NTRK3)neurotrophic receptor tyrosine kinaseTRK1TRK2TRK3high affinity nerve growth factor receptor (TrkA)BDNF/TRKB receptorNT-3 receptor (TrkC)

Inhibition of ATP-binding site of abnormal NTRK fusion proteins - Inhibition of autophosphorylation and downstream signaling (MAPK, PI3K-AKT, PKC, STAT3 pathways) - Antagonism of oncogenic fusion kinase signaling