An oncogene that is formed through a somatic rearrangement of the neighbouring genes for neurotrophic tyrosine kinase receptor type 1 (NTRK1) and tropomyosin-3. The trkA gene product (790 aa) is a receptor for NGF, that of trkB for neurotrophin 4 (NT-4) and BDNF, and that of trkC for NT-3. The trk-fused gene product (400 aa) associates with NTRK1 tyrosine kinase in generating the thyroid trk-T3 oncogene found in papillary thyroid carcinoma. There are several chimeric genes in tumours in which the tyrosine kinase domain of trk has become linked to 5′ sequences from unrelated loci, yielding products with ectopic, constitutive tyrosine kinase activity.
Subjects: Chemistry — Medicine and Health.