Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/63122
標題: 油體膜上特有蛋白質的演化研究
Evolutionary Studies on Unique Proteins of Oil Bodies
作者: 曾志正
關鍵字: 生物科學類;oil body;油體;oleosin;caleosin;steroleosin;油體膜蛋白;油體鈣蛋白;油體固醇蛋白;基礎研究
摘要: 
本實驗室過去十餘年於國科會計畫長期支持下選擇芝麻種子油體當模型系統(model system)從事油體蛋白質之研究。油體構造是一團三酸甘油酯包在一層磷脂質(phospholipid)內,此磷脂質層鑲滿豐富的構造蛋白質叫油體膜蛋白(oleosin)及二種微量蛋白質名為油體鈣蛋白(caleosin)與油體固醇蛋白(steroleosin)。被子植物種子油體膜蛋白有兩個同功蛋白(oleosin-H and -L),油體固醇蛋白也有兩個同功蛋白(isoform A and B)。2007年我們首次從百合花粉中純化到穩定的油體,並找到另一個油體膜蛋白同功蛋白(oleosin-P)。裸子植物松(Pinus koraitusis)、銀杏(Ginkgo biloba)的油體中僅存在一種油體膜蛋白,為oleosin-L;然而蘇鐵(Cycas revoluta)油體並無油體膜蛋白,卻含有分子量約為30 kDa的蛋白質,本研究室初步結果顯示極可能是油體鈣蛋白。本計畫擬研究油體蛋白質的演化關係。第一年擬探討花粉油體中是否含有油體鈣蛋白與油體固醇蛋白,或是其他未知蛋白質,並篩選定序其對應基因。此外,將構築蘇鐵種子形成過程中油體累積時期之cDNA library以供尋找並定序蘇鐵油體蛋白基因。第二年擬篩選定序蘇鐵油體蛋白質對應基因,證實油體鈣蛋白為蘇鐵油體之最大量蛋白質,並對蘇鐵油體做較深入的生化分析。此外,擬找尋比松更高等的裸子植物(例如,麻黃)及較原始的被子植物(例如,八角)的油體,以便瞭解oleosin-H在演化上何時從oleosin-L複製分出。第三年擬篩選定序麻黃或八角油體膜蛋白對應基因,同時檢測蘇鐵、麻黃、八角及演化上更早期的生物(例如,蕨類、藻類)是否有油體固醇蛋白或其他未知蛋白質。期許提供更多實驗數據,推論油體蛋白質的演化關係。

In the past decade, our group worked on sesame oil body proteins under the support of NSC grants. Seed oil bodies contain a triacylglycerol matrix surrounded by a layer of phospholipids and unique proteins. Three classes of oil body proteins termed oleosin, caleosin, and steroleosin have been identified in sesame oil bodies. Isoforms were found in oleosin (H and L forms) and in steroleosin (A and B forms). In 2007, we first isolated stable oil bodies from lily pollen and identified a new class of oleosin (P-isoform). Only L-oleosin but not H-oleosin was found in oil bodies from pine and ginkgo seeds. While no oleosin was detected, a putative caleosin of 30 kDa was found in cycas seed oil bodies. In this proposal, we plan to investigate the evolution of oil-body proteins. In the first year, we intend to detect proteins other than oleosin-P in pollen oil bodies and to clone their corresponding genes. In addition, a cDNA library will be constructed with mRNA extracted from maturing cycas seed. In the second year, we intend to clone the corresponding gene for the putative caleosin found in cycas seed oil bodies, and characterize these oil bodies in depth. To know the splitting of oleosin-H from oleosin-L, we schedule to analyze oil bodies and their proteins in Ephedra or Illicium. In the third year, we intend to clone and sequence genes encoding putative oil-body proteins from cycas, Ephedra, Illicium, or other primitive species such as ferm and algue. We expect to provide more experimental evidence for the analyses of evolution in oil-body proteins.
URI: http://hdl.handle.net/11455/63122
其他識別: NSC97-2313-B005-026-MY3
Appears in Collections:生物科技學研究所

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