Evolutionary approach to identify putative control elements in the Hepatoma Up-Regulated Protein (HURP) gene

• Main Authors: Ching Yin Chang, 張靜尹
• Other Authors: C. K. Chou
• Format: Others
• Online Access: http://ndltd.ncl.edu.tw/handle/82134113983380350795

碩士 === 長庚大學 === 基礎醫學研究所 === 96 === To identify key regulatory gene in human liver cancer, our laboratory has used EST and cDNAs microarray database to found “Hepatoma Up- Regulated Protein (HURP)” gene which is over-expressed in human hepatoma cells. The minimal sequence carries promoter activity of HURP has been mapped in the region of -55 to +88. A putative regulatory element was also identified in the intron 1 region of HURP gene. In order to identify putative control element in the HURP gene, I took an evolutio- nary approach. The rational behind this approach is any important control element should be conserved during evolution. I first dissected HURP gene into three parts: coding sequence, promoter region and intron 1 and compared sequence divergence among different species during evolution. The results shows the conservation of coding sequence of HURP gene is 33.0% to 98.0%, and three regions of amino acid residues 88~ 121 (78.6~ 100.0%, unknown structure), 306~ 340 (60.0~ 100.0%, containing F-box binding sequence) and 471~ 520 (86.0~ 100.0%, containing microtubule binding domain) are highly conserved. The promoter of human HURP gene (-55~ +88 bps) is highly conserved in the seven species (67.1~ 99.3%), especially in two region: -27~ +20 bps, 85.1~ 100.0% and +39~ +84 bps, 80.4~ 100.0%. The two regions contain Y box binding factor element and cell cycle dependent element (CDE), pointing out that the function of HURP gene is cell cycle-regulated. The intron 1 of HURP gene sequences diverse in eight species, and the evolutionary gap appears between primates and other organisms. It suggests that the control element in intron 1 of human HURP gene is recently evolved. Though the intron 1 sequences of HURP in eight species diverse greatly, there are still two conserved region in the 5’ and 3’ terminal of intron 1 sequence, the nucleotide 212~235 and 1731~1921. The overall results show that HURP gene was recorded in the evolution history when complicate eukaryotic organism appeared. The protein and promoter region are highly conserved and pointing out HURP protein’s major function---microtubule binding, and the conserved intron 1 region of HURP gene appeared to settle at the two terminals.