Search

The gene encoding arylsulfatase (Ars; EC 3.1.6.1) as well as two Ars pseudogenes were isolated from sea urchin genomic libraries. The Ars gene was 20-kbp long and contained six exons interrupted by five introns. Four polypyrimidine repetitive sequences were dispersed in its upstream-flanking region. Comparison of the amino acid sequence of sea-urchin arylsulfatase with those of human sterol sulfatase, human arylsulfatase A and bacterial arylsulfatase revealed that they have two similar sequences in common. The position of the transcription-start site of the A rs gene was determined to be approximately 40-bp upstream from the 5' end of the protein-coding region, and the nucleotide sequence of the 5'-flanking region was determined up to 3.3 kbp upstream from the transcription start point. Putative TATAA box and CCAAT consensus sequences were located at positions -28 and -82, respectively. A highly conserved hexamer motif, CTCTTT, localized near the transcription-start site of the sea-urchin Ars gene, was also detected in similar regions of other sea urchin genes such as CyIIIa, Spec 1, Spec 2a, Spec 2c, Spec 2d, and SM50, but not in the histone genes. [ABSTRACT FROM AUTHOR]

Arylsulfatase is known to be synthesized in large amounts at the early gastrula stage of sea urchin development. We determined the amino acid sequence of a portion of the purified sea urchin embryonic arylsulfatase, and then isolated a cDNA clone for arylsulfatase by screening a sea urchin plutei λgtl0 cDNA library with an oligodeoxynucleotide probe synthesized according to the determined amino acid sequence. The longest cDNA clones were selected and the nucleotide sequence determined. The cDNA is 2422 nucleotides long and encodes 551 amino acids. The deduced amino acid sequence has no sequence similarity with any of the peptides registered in NBRF peptide databank. Northern blot analysis revealed that the arylsulfatase cDNA hybridizes to a 2.9-kb mRNA. This mRNA exists in the unfertilized egg in small amounts, but markedly increases after the blastula stage preceding the increase of the arylsulfatase activity. [ABSTRACT FROM AUTHOR]