Genomic structure, alternative transcripts and chromosome location of the human LIM domain binding protein 1 gene LDB1

By protein interaction screening using a radioactive LMO2 protein probe we have isolated a LIM domain binding protein. The gene shows high homology to independently isolated genes from mouse, Xenopus and Drosophila called Ldb 1/Nli/Clim-2, Xldb1 and Chip, respectively. The human and mouse genes diffe r by only two amino acids, suggesting that the gene that we have isolated i s the human homologue. Here we describe the genomic organization, alternati ve transcript forms and the chromosome mapping of the human gene LDB1 (alia s NLI). The gene is spread over at least 12 kb and has 11 exons. Preceding the described ATG initiation site in the mouse a highly conserved region be tween mouse, chicken and human was detected with a second possible in frame initiation site coding for further 36 amino acids. An alternative splice s ite adding six nucleotides corresponding to the addition of two amino acids at the end of exon 10 was found. The gene was mapped to chromosome 10q24-- >q25 by in situ hybridization, a region frequently deleted in many types of cancer. Fine mapping with a radiation hybrid panel localized the gene in t he interval between the markers D10S603 and D10S540. Copyright (C) 1999 S. Karger AG, Basel.