Characterization of Two Novel Gene Products in Human Hepatoma Cells

• Main Authors: Chang Chia-wei, 詹家偉
• Other Authors: Chen-Kung Chou
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/19797813982159787751

碩士 === 國立陽明大學 === 微生物暨免疫學研究所 === 88 === The draft of human genome has been finished, and genomic sequence of several model organism has also been decoded. In the future, the most important work is to define the functions of novel genes. This study is trying to use different isolated approaches to reveal the possible functions of two novel genes from human liver cells. Base on microarray and EST database analysis, we have identified two genes from human liver tissue: FB39 and HURP, that express differently in hepatoma and hepatoma-adjacent normal tissues. FB39 is a gene codes for a protein with 276 amino acids. Microarray analysis showed that Fb39 is down regulated in human hepatoma tissues. Northern blot analysis showed that FB39 is highly expressed in normal liver、heart and thyroid. The localization of flag fusion protein of FB39 gene was found to be majorly in cytosol. The expression of mouse homolog FB39 gene showed no different during liver regeneration. We also identified two yeast homolog of FB39: NIT3 and NIT2. They share 49% and 31% identities with FB39 respectively. When both yeast genes were knockout, the yeast still viable. It suggests that FB39 may not be essential for survival of the yeast cell. On the other hand, the expression of HURP is much higher in hepatoma tissues than in hepatoma-adjacent liver tissues. It was shown that mRNA level of HURP was induced after the normal human fibroblasts was stimulated with FCS. The mRNA level of HURP gene dramatically increase after 36 hours of hepatectomy. HURP gene codes protein with 846 amino acids. The function of HURP is totally unknown. During cell cycle progression, HURP aas major localizes in cytosol in inter phase. On the other hand, in mitotic cell, HURP was found to associate with spindle fiber. When N-terminal of HURP protein (a.a 42-242) was expressed, it was localized in the nucleus and also cause micronucleation in 293T cell. All of these data indicated that HURP may play some important roles in cell cycle regulation.