Characterization of structure and function of human spot 14

• Main Author: 鄭伊珊
• Other Authors: 周慰遠
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/57529453343569968987

碩士 === 國防醫學院 === 生物化學研究所 === 92 === Spot 14 is an acidic 17kDa protein and tissue-specific expression regulated in lipogenesis. In liver, messenger RNA（mRNA）level of Spot 14 and its protein were raised rapidly by T3 and dietary carbohydrate. Conversely, Spot 14 expression is curtailed in response to fasting. Recent studies purpose that Spot 14 is a transcription activator that acts as a homodimer to modulate gene expression. There are many current studies on rat Spot 14, but its physiology function is not well defined. In this study, the biochemical methods such as analytical ultracentrifugation、native gel system and glutaraldehyde cross-linking were used to identify that Spot 14 form a homodimer in vitro. However, the homodimer is not formed by the disulfide bond. In mammalian two hybrid system demonstrated that Spot 14 exists as a homodimer in vivo. The possibility of physiology function of human Spot 14 was analyzed in malic enzyme promoter and some nuclear receptors. In the malic enzyme promoter analysis, human Spot 14 might serve as coactivator or corepressor for thyroid receptor depending on the cell lines. The similar dual functional roles were found in GRIP1- or Zac1- induced nuclear receptor transcriptional activators that depended on the type of nuclear receptors and cell lines. Thus, this study provide a novel regulation mechanism of human Spot 14 in some gene expressions.