cis-Elements and Protein Factors Related to Regulation of Transcription of Arylsulfatase Gene during Sea Urchin Development: (sea urchin development/Ars gene/cis-elements/enhancer/protein factors).

Eight restriction fragments (I-VIII) were prepared to cover a whole span of the enhancer region in the upstream of the Ars gene of the sea urchin, Hemicentrotus pulcherrimus, and their abilities to influence on the Ars gene expression were estimated by CAT assay. Only three fragments (III, IV and V) encompassing a 0.6 kb region between -2.8 kb and -2.2 kb stimulated CAT expression. By mobility shift assays, it was found that the Ars enhancer region is composed of multiple cis-acting elements that interact with nuclear proteins in a sequence-specific manner. Among them, two sequences, a G-string and a GATCTCCCC, were determined by DNA footprinting as sites of protein-DNA interaction. The DNA-binding factor prevalence changed ontogenically in three different patterns. Possible activation of DNA-binding proteins through their modification is discussed.