The c-Jun NH2-terminal kinase3 (JNK3) gene: genomic structure, chromosomalassignment, and loss of expression in brain tumors

By examining 19 human cell lines derived from brain tumors for altered expr ession of expressed sequence tags (ESTs) in chromosomal hand 4q21-22, we de tected loss of expression, in 10 cell lines, of two sequences, WI6336 and W I7913. Both corresponded to the c-Jun NH2-terminal kinase (JNK) 3. In the p resent study, genomic cloning revealed that the JNK3 gene consists of 14 ex ons interrupted by 13 introns: its transcription-initiation site is within exon 3 and the termination codon lies in exon 14. Fluorescence in situ hybr idization (FISH) and radiation-hybrid mapping confirmed the gene to 4q21-22 . Together with prior evidence that, in JNK3-deficient mice, the JNK3 signa ling pathway mediates apoptosis in central nervous tissue, our results sugg est that loss of expression of the JNK3 gene may play an important role in the development of brain tumors in humans.