THE MOUSE CREATINE-KINASE PAIRED E-BOX ELEMENT CONFERS MUSCLE-SPECIFIC EXPRESSION TO A HETEROLOGOUS PROMOTER

E-box elements, with the CANNTG sequence motif, occur in numerous prom oters and enhancers. We evaluated the tissue-specific expression prope rties of the paired murine E-box element from the mouse muscle creatin e kinase (MCK) enhancer in a minimal heterologous promoter construct. A 46-bp fragment containing the paired E-box element in its wild-type (wt) configuration confered high levels of muscle-specific expression in transfected embryonic chicken cell cultures. The expression from th is paired E-box element was similar to that of the simian virus 40 (SV 40) promoter/enhancer, but a 21-bp fragment containing a single E-box was inactive. We conclude that the paired E-box element from the MCK e nhancer is sufficient for high levels of muscle-specific expression wh en placed upstream from a non-muscle TATA element.