本研究發現冰花SKD1蛋白質除具有MIT domain及AAA-ATPase domain外，冰花SKD1蛋白質的胺基酸序列與二級結構相當於酵母菌的VPS4(END13)蛋白質，也間接預測到冰花SKD1蛋白質具有特殊的NACHT domain 特徵，再依據蛋白質-蛋白質交互作用的原理，透過酵母菌雙雜合系統的實驗數據資料庫，篩選到BRO1 (HEAT repeat) 與VPS4 (NACHT domain) 產生蛋白質間交互作用的候選者，相對地，BRO1_YEAST (HEAT repeat)與AIP1_YEAST (WD40 repeat), AIP1_YEAST (WD40 repeat)與ABP1_YEAST (ADF domain), ABP1_YEAST (ADF domain)與ARP2_YEAST (ACTIN domain)會互相交互作用，這些蛋白質在細胞裡作為細胞骨架的結構蛋白質，最有可能關聯到鉀離子吸收與耐鹽機制，此種研究方法亦可應用在其它真核生物中找尋與鉀離子運輸相關的功能蛋白質。

SKD1 (suppressor of potassium transport growth defect) belongs to the AAA-ATPase family and is one of the class E VPS (vacuolar protein sorting) proteins. The ATPase activity-deficient form of SKD1 leads the perturbation of mechanism transport through endosomes and lysosomes, however, the molecular mechanism behind the action of SKD1 is poorly understood. In this study, it is identified that VPS4_YEAST (Saccharomyces cerevisiae) is the homology protein of mcSKD1 (Mesembryanthemum crystallinum SKD1) employing sequence profile analysis. The full-length mcSKD1 protein possesses MIT, AAA-ATPase, and NACHT domains of VPS4_YEAST. It is investigated that VPS4_YEAST (NACHT domain) interacts to BRO1_YEAST (HEAT repeat), BRO1_YEAST (HEAT repeat) to AIP1_YEAST (WD40 repeat), AIP1_YEAST (WD40 repeat) to ABP1_YEAST (ADF domain), ABP1_YEAST (ADF domain) to ARP2_YEAST (ACTIN domain), respectively, from yeast two-hybrid system via protein-protein interaction. These proteins employ the function of cytoskeleton structural proteins in cells. Hence, mcSKD1 protein may involve the mechanisms of potassium ion uptake and salt tolerance via the function of cytoskeleton structural proteins.

中文摘要・・・・・・・・・・・・・・・・・・・・・・・・・.6
英文摘要・・・・・・・・・・・・・・・・・・・・・・・・・.7
一、前言・・・・・・・・・・・・・・・・・・・・・・・・・・・.8
1-1冰花SKD1基因的相關實驗・・・・・・・・・・・・・・・・・.8
1-2酵母菌雙雜合系統是蛋白質-蛋白質交互作用預測的依據・・・・・10
二、研究方法與材料・・・・・・・・・・・・・・・・・・・・・・12
2-1蛋白質序列輪廓分析・・・・・・・・・・・・・・・・・・・・12
2-2研究方法・・・・・・・・・・・・・・・・・・・・・・・12
2-3酵母菌雙雜合系統蛋白質-蛋白質交互作用・・・・・・・・・・15
三、結果與討論・・・・・・・・・・・・・・・・・・・・・・・・・17
3-1冰花SKD1蛋白質的一級結構分析・・・・・・・・・・・・・・・17
3-1-1冰花SKD1的MIT domain分析・・・・・・・・・・・・・・18
3-1-2冰花SKD1的AAA ATPase domain分析・・・・・・・・・・20
3-1-3全長mcSKD1的domains分析・・・・・・・・・・・・・・・・28
3-1-4酵母菌系統的同源蛋白質──VPS4_YEAST(END13)・・・・・・・41
3-1-5冰花SKD1蛋白質具有NACHT domain的特徵・・・・・・・44
3-2全長冰花SKD1蛋白質的二級、三級結構預測・・・・・・・・・・・・47
3-2-1冰花SKD1蛋白質MIT domain的二級、三級結構預測・・・・・・・・47
3-2-2冰花SKD1蛋白質AAA ATPase domain的二級、三級結構預測・・・・49
3-3與VPS4_YEAST交互作用的蛋白質預測・・・・・・・・・・・・・・52
四、結論・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・57
五、參考文獻・・・・・・・・・・・・・・・・・・・・・・・・・・・・59

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