The functional role of the brain finger protein, ZNF179, in neural differentiation

• Main Authors: Ping-Chieh Pao, 包秉潔
• Other Authors: Wen-Chang Chang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/54356704190596259707

碩士 === 國立成功大學 === 藥理學研究所 === 96 === ZNF179, also known as brain finger protein, is a member of RING finger family. After analyzed the gene expression profile obtained from Gene Expression Omnibus (GEO), we found that ZNF179 was down-regulated in R6/2 Huntington’s disease transgenic mice. In addition to Huntington’s disease, the expression of ZNF179 was also reported to be decreased in other neurodegererated diseases, Amyotrophic Lateral Sclerosis (ALS). The expression of ZNF179 was gradually increased during mouse embryogenesis and maintained a high expression level in the adult brain. These all indicate that the ZNF179 is important to the functions of the brain. Therefore, the functional role of ZNF179 in neural cells is worthwhile for further investigation. P19 cell line is mouse pluripotent embryonic carcinoma cells. It could be induced to differentiate into neurons, glial cells and fibroblasts when aggregated in the presence of retinoic acid, and is a well-established cell model to investigate the important cellular mechanism during neural differentiation. Using P19 cell line as a neural differentiation cell model, we found that the expression of ZNF179 was noticeably increased in the RA-induced neural differentiated P19 cells. To evaluate the cellular distribution of ZNF179, we created EGFP-ZNF179 fusion protein expression construct and found that the EGFP-ZNF179 fusion protein was distributed in the cytosol of undifferentiated P19 cells. Interestingly, in neural differentiated P19 cells the EGFP-ZNF179 fusion protein translocated from the cytosol into the nucleus. The different cellular distribution patterns imply that the ZNF179 may play its role in the nucleus. Then the ZNF179 knock-down stable cell lines were established to further dissect the exact role and function of ZNF179. Our data showed that knock-down of ZNF179 significantly attenuated the P19 cell neural differentiation. We further investigated the cellular mechanism of ZNF179 in neural differentiation and found that the phosphorylation of PKB/AKT Ser473 but not Thr308 was dramatically increased in the aggregated ZNF179 knock-down stable cell lines after treating with RA 4 days. These results indicate that abnormal phosphorylation of PKB/AKT Ser473 could be involved in the cellular mechanism of ZNF179 in neural differentiation.