PROXIMAL CIS-REGULATORY ELEMENTS OF SEA-URCHIN ARYLSULFATASE GENE

Expression of the arylsulfatase (HpArs) gene in the sea urchin, Hemice ntrotus pulcherrimus, is regulated in spatially, as well as temporary, during development. To address the cis-regulatory elements involved i n this regulation, we performed reporter assays using variously delete d or mutated promoter and regulatory elements of the HpArs gene, accom panied by gel mobility shift assay and foot printing. Results show tha t two regions, PU1 (- 72 b.p. to - 56 b.p.), which is similar to SpZ12 -1 and/or Oct-1 motif, and the PD1 site (+ 133 b.p, to + 142 b.p.), wh ich is homologous to the binding sites oi Rei family transcription fac tors and/or AGIE-BP1, are related to the regulation of expression oi t he HpArs gene. Furthermore, an HpArs enhancer element called C15, whic h is located 3 kb.p. downstream from the transcription start site, act ivates the HpArs promoter. We also report that the enhancer activity o i the C15 fragment was mediated by elements, PU1 and PD1.