A NOVEL FAMILY OF DEVELOPMENTALLY-REGULATED MAMMALIAN TRANSCRIPTION FACTORS CONTAINING THE TEA ATTS DNA-BINDING DOMAIN/

We describe the molecular cloning of two novel human and murine transc ription factors containing the TEA/ATTS DNA binding domain and related to transcriptional enhancer factor-1 (TEF-1). These factors bind to t he consensus TEA/ATTS cognate binding site exemplified by the GT-IIC a nd Sph enhansons of the SV40 enhancer but differ in their ability to b ind cooperatively to tandemly repeated sites. The human TEFs are diffe rentially expressed in cultured cell lines and the mouse (m)TEFs are d ifferentially expressed in embryonic and extra-embryonic tissues in ea rly post-implantation embryos, Strikingly, at later stages of embryoge nesis, mTEF-3 is specifically expressed in skeletal muscle precursors, whereas mTEF-1 is expressed not only in developing skeletal muscle bu t also in the myocardium. Together with previous data, these results p oint to important, partially redundant, roles for these TEF proteins i n myogenesis and cardiogenesis. In addition, mTEF-1 is strongly coexpr essed with mTEF-4 in mitotic neuroblasts, while accentuated mTEF-4 exp ression is also observed in the gut and the nephrogenic region of the kidney. These observations suggest additional roles for the TEF protei ns in central nervous system development and organogenesis.