https://scholars.lib.ntu.edu.tw/handle/123456789/160140
標題: | 果蠅神經樹突中內吞系統的分布及Nak調控 Localization and Nak regulation of endocytic machineries in Drosophila da dendrites |
作者: | 索先 Suo, Hsien |
關鍵字: | Nak;Rab4;Rab5;Rab11;內吞;樹突;果蠅;endocytosis;dendrite;drosophila | 公開日期: | 2009 | 摘要: | 複雜的樹突型態對於神經細胞的正常生理功能是非常重要的。儘管調控樹突發育的細胞機制尚不清楚,但最近已有研究指出外泌系統 (secretory system) 和內吞系統 (endocytic system) 扮演了重要角色。Numb-associated kinase (Nak) 是一個和內吞系統相關的磷酸激酶,並且調控樹突的型態生成。利用核酸干擾技術在果蠅樹狀神經細胞降低Nak蛋白的表現量時,會導致樹突分支減少。在過去利用融合螢光蛋白的方式,已經知道YFP-Nak會和Clathrin light chain-GFP有很好的共位現象,然而,對於Nak調控樹突發育的分子機制仍不明瞭。在本篇研究中,我檢驗象徵內吞作用不同路徑的螢光融合蛋白 (包括: Rab4mRFP, Rab5GFP, Rab11GFP及 ManIIGFP)在樹突中的數量及分布情形,發現不同的內吞胞器在樹突中會有不同且極性的分布,如: Rab4mRFP主要位在靠近神經細胞體的樹突中,然而Rab11GFP則相反,主要位在遠離細胞體的樹突內。這項結果暗示了不同的樹突區域可能需要不同的內吞系統活性。接著,我發現這些螢光蛋白在樹狀神經的樹突分支點,都和YFPNak有相當好的共位現象。然而,當我利用核酸干擾技術抑制Nak蛋白表現時,這些螢光蛋白的分布和數量都不受影響。還有,活體影像顯示YFPNak和Rab5GFP在樹突中具有不同的移動行為。總的來說,本篇研究的實驗數據顯示Nak不調控Rab4mRFP、 Rab5GFP、Rab11GFP及ManIIGFP 等內吞系統胞器蛋白的數量及極性分布之建立。 The great complexity of dendrites is important for their proper functions on receiving and integrating signals. Although the cellular mechanisms regulating dendrite development are largely unknown, secretory and endocytic pathways were recently shown to be involved. Numb-associated kinase (Nak) is an endocytic kinase required for dendrite morphogenesis. Nak depleted da neurons showed decreased numbers of dendritic branches. YFP-Nak is highly co-localized with clathrin light chain (Clc)-GFP at the tips of growing dendrites; however, the molecular mechanisms of Nak in dendrites are still unclear. I am interested in dissecting the endocytic steps that Nak participates in. In this study, I demonstrated the differential distribution of Rab4-mRFP, Rab5-GFP, Rab11-GFP, and ManII-GFP along the dendritic processes, in which Rab4-mRFP and Rab11-GFP preferentially distributed in proximal or distal dendrites, respectively. This data suggest the distinct requirements of cellular activities in different regions of dendrites. Although YFP-Nak colocalized largely with all the examined endocytic markers, knocked-down Nak by RNAi did not exert significant effects on the numbers and distributions of these markers. Moreover, YFP-Nak showed different dynamics with Rab5-GFP and Rab4-mRFP. Collectively, Nak is not functioning in the establishment and maintenance of the polarized distributions of Rab4-mRFP, Rab5-GFP, Rab11-GFP, and ManII-GFP. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/178727 |
顯示於: | 分子醫學研究所 |
檔案 | 描述 | 大小 | 格式 | |
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ntu-98-R96448008-1.pdf | 23.32 kB | Adobe PDF | 檢視/開啟 |
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