Characterization of a Human Cardiac Gene Which Encodes for a LIM Domain Protein and is Developmentally Expressed in Myocardial Development

A clone with high sequence homology to a rat muscle LIM protein has been isolated from a human fetal heart cDNA library. The isolated cDNA is 887 bp in length, with an open reading frame of 194 amino acid residues. Northern blot analysis revealed that it is predominantly expressed in fetal and neonatal hearts, with a low level of expression in adult heart and slow-twitch skeletal muscle (soleus). No detectable expression of this transcript was found in other tissues. Its cardiac expression and structural similarity to the rat homolog implied a regulatory role in human cardiac muscle. The biological property was confirmed by zinc binding assay, demonstrating its zinc-binding affinity. Homology of CLP to a rat muscle LIM protein and its predominantly differential expression in cardiac tissue imply its significant putative role in the development and growth of the human heart.