The structure of the human LIM protein ACT gene and its expression in tumor cell lines

We describe the human ACT genomic and cDNA sequence which like its murine c ounterpart contains the defining secondary structure of the FHL (Four-and-a -Half LIM-domain) LIM-protein family. The coding region of the human ACT ge ne spans five exons. This distribution is very similar to the FHL1 gene and includes the arrangement of split codons across exon boundaries suggesting that these genes share a common ancestor. The human ACT gene was not detec ted by Northern analysis in the adult testis although this is the only know n site of expression found with its murine counterpart. However, the human ACT gene was found to be expressed in a panel of human tumor cell lines der ived from squamous cell carcinomas, melanomas, and leukemias, Interestingly , FHL1, FHL2, and FHL3 were also found to be expressed in some of these cel l lines and the results suggest an important role for FHLs in tumor biology . (C) 2000 Academic Press.