Please use this identifier to cite or link to this item:
標題: 擬南芥中E3 RING Finger基因之分子選殖及特性分析
Molecular Cloning and Functional Analysis of E3 RING Finger Genes from Arabidopsis thaliana
作者: 劉祥欽
Chin, Liu Hsiang
關鍵字: 蛋白降解
RING finger
出版社: 生物科技學研究所
摘要: 摘要 E3 RING finger在與ubiquitin相關的蛋白降解過程中扮演了重要的角色,而與ubiquitin相關的蛋白降解在植物發育過程中參與了重要的調控。E3 RING finger蛋白具有一個保守的RING finger motif,這類的motif會與E2蛋白做專一性的結合。為了研究E3 RING finger基因在植物中的功能而從擬南芥中選殖出AtRING1及AtRING2兩個基因並分析其功能。AtRING1可轉譯成一個由181個氨基酸所組成的蛋白而AtRING2則轉譯成一個由158個氨基酸所組成的蛋白,AtRING1及AtRING2兩者的mRNA在擬南芥的發育過程中皆有表現。在擬南芥開花之後,AtRING1的mRNA表現量在花、花軸及根比在營養葉及花序葉來的高,相較之下AtRING2在營養葉及花序葉的mRNA表現量比其他器官高出許多。異位大量表現AtRING1的轉基因植物與野生種相比並沒有明顯的性狀產生,但是異位大量表現反義AtRING1使得轉基因植株早期的生長發育出現異常的情況,植株的營養葉無法正常發育而根的生長明顯受阻。除此之外,異位表現反義AtRING1及反義AtRING2的轉基因植物亦使莖頂分生組織的部位發生異常,植物的花序出現異常生長的情形。這個結果顯示了AtRING1及AtRING2應該參與了擬南芥之生長發育尤其是莖頂分生組織分裂分化相關的調控。為了研究AtRING1, 2的調控機制,故利用Yeast two-hybrid系統來篩選出與AtRING1, 2有特殊結合關係的蛋白,目前已鑑定出三個蛋白:COR47、At1g27730 、At1g13930與AtRING1有結合關係,另外亦鑑定出NAC2與AtRING2有結合關係。進一步分析這些蛋白及其基因應該可以更深入的瞭解E3 RING finger蛋白如何經由ubiquitination pathway來調控植物的生長及發育。
ABSTRACT E3 RING finger genes played key roles in the ubiquitin-mediated proteolysis which has a central role in many processes of plant development. E3 RING finger proteins contained a conserved RING motif specifically bound to E2 protein. To investigate the function of E3 RING finger genes, AtRING1 and AtRING2 from Arabidopsis were isolated and characterized. AtRING1 encodes a 181 amino acid protein whereas AtRING2 encodes a 158 amino acid protein. Both AtRING1 and AtRING2 mRNA are expressed throughout the development. After flowering, AtRING1 mRNA was expressed higher in flowers, inflorescence shoot and root than in rosette and cauline leaves. By contrast, AtRING2 mRNA was expressed higher in rosette leaf and cauline leaf than in other organs. Transgenic Arabidopsis plants ectopically expressed AtRING1 were phenotypically indistinguishable from wild-type plants. By contrast, shoot apical meristem formation was severe altered in Arabidopsis plants ectopically expressed antisense of AtRING1 or AtRING2. The inflorescence were either not produced or generated abnormally in these antisense transgenic plants. In addition, the leaf morphology was also severely altered. This result indicated that AtRING1 and AtRING2 should be involve in the regulation of shoot apical meristematic activity in Arabidopsis. To investigate the function of AtRING1 and AtRING2 action, yeast two-hybrid assays screening library using AtRING1 or AtRING2 as a bait was carried out. Three proteins (COR47, At1g27730 and At1g13930) that interacted with AtRING1 and one protein (NAC2) that interacted with AtRING2 were identified. Further analysis of these proteins should lead a deeper understanding of the function for E3 RING finger genes in the ubiquitination pathway in regulating plant development.
Appears in Collections:生物科技學研究所



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.