Isolation and cloning of a novel cDNA LDBl encoding human LIM domain binding protein

Primers for screening cDNA library have been designed according to EST AA453734 which is corresponding to the mouse LIM domain binding protein Ldb1. Arrayed human fetal brain cDNA library has been screened by PCR and routine hybridization method. A 2398 bp-cD-NA clone has been obtained. The cDNA encodes a 347 amino acids protein highly homologous to the mouse Ldb1, Xenopus Xldb1 and Drosophila Chip. It also contains an LIM binding domain and a nuclear localization signal. It has been named LDB1 (LIM domain binding protein 1), GenBank accession number is AF052389. Northern blot showed a 2.4 kb band, and the expression amounts of LDB1 in heart, brain and lung were considerably higher than those in other tissues.