CLONING OF THE HUMAN TWIST GENE - ITS EXPRESSION IS RETAINED IN ADULTMESODERMALLY-DERIVED TISSUES

We have previously reported on the isolation of several differentially expressed genes derived from young and senescent non growing WI-38 hu man fetal lung-derived fibroblasts. A 0.8-kb cDNA. clone, isolate EPC- A2 (early population doubling cDNA-A2), encodes the 3' end of the huma n homolog of the Twist protein. Twist genes encode basic helix-loop-he lix DNA-binding transcription factors that play crucial roles in mesod erm development. Here, we report the cloning and sequencing of the gen omic human twist gene. II encodes a protein of 201 amino acids with 96 % amino acid sequence identity to mouse Twist, and 100% sequence conse rvation in the DNA-binding region among all species in which it has be en characterized. We further show that expression of human twist is re tained in mesodermally-derived tissues and cell lines derived from adu lt donors.