MOLECULAR-CLONING OF THE CDNA FOR HUMAN TRKC (NTRK3), CHROMOSOMAL ASSIGNMENT, AND EVIDENCE FOR A SPLICE VARIANT

TrkC is a receptor tyrosine kinase that is activated by neurotrophin-3 , a factor important in the development of certain areas of the centra l nervous system. We have cloned and sequenced the human trkC cDNA and found that the predicted amino acid sequence is 97 to 98% homologous to the rat and porcine trkC sequences, respectively. The rat trkC has several isoforms due to alternative splicing in the tyrosine kinase do main. We cloned one human splice variant that has a nucleic acid seque nce identical to the rat isoform with an insert of 14 amino acids. The human trkC cDNA also has a (CGG)(n) repeat in the 5'-untranslated reg ion, This sequence was not highly polymorphic in that 79 of 80 chromos omes examined had eight repeats, while 1 chromosome had four repeats. By PCR analysis of a somatic cell hybrid panel and fluorescence in sit u hybridization with the cDNA clone, human trkC was mapped to chromoso me 15q24-q25. (C) 1994 Academic Press, Inc.