利用發光基團輔助之光導去活化法驗證受損細胞膜的細胞自噬清除機制

Identification of autophagic clearance for damaged plasma membrane using chromophore-assisted light inactivation (CALI) methodology

洪聿賢(Yu-Hsien Hung)

指導教授 ： 楊維元

國立臺灣大學/生命科學院/生化科學研究所/博士(2016年)

https://doi.org/10.6342/NTU201603248

摘要

細胞膜扮演細胞邊界的功能將細胞的內含物與周遭的環境區隔。細胞膜受損會造成細胞內外的物質能夠自由交換，這可能導致細胞死亡，所以細胞需要適當地修復細胞膜來維持細胞內環境的穩定。
我們建立了發光機團輔助之光導去活化法，能夠精確地在特定時間和特定地方造成細胞膜損壞，而且細胞膜受損的程度也可以很容易控制。利用這個方法，我們發現細胞會根據細胞膜受損的程度內吞帶有損壞的物質的囊泡和直接切除受損的區域來進行細胞膜修復。藉由內吞作用進到細胞質帶有受損膜的囊泡會選擇性的被泛素修飾，接著泛素會被細胞自嗜受體辨認並最終將這些囊泡送入細胞自嗜體內。我們的研究發現細胞膜透過選擇性的細胞自嗜清除壞掉的細胞膜來進行品質管制。最後，由於發光機團輔助之光導去活化法提供了時間上空間上和細胞膜受損程度上的可操控性，因此未來可以更進一步用來研究細胞膜修復的機制

關鍵字

細胞膜修復 ； CALI ； 鈣離子 ； 泛素 ； LC3 ； 選擇性細胞自噬

並列摘要

Cell membrane works as a barrier that separates the contents of a cell from the sur-rounding space. Damage of cell membrane causes freely exchange of materials between intra- and extra-cellular spaces which would lead to cell death. Therefore, appropriate plasma membrane repairing is required for maintaining cellular homeostasis.
Here, we develop a chromophore-assisted light inactivation (CALI)-based method-ology allowing spatiotemporal and selective induction of plasma membrane damage. This scheme accomplishes a simple control of the membrane damage extent. By applying this approach, we report that cells undergo endocytosis of vesicles carrying damaged components and/or shedding of the damaged part to mediate plasma membrane repair process according to the extent of injury. Additionally, we further elucidate that the en-docytosed wound vesicles are selectively ubiquitinated, then recognized by autophagy receptors and finally taken up by autophagosomes. Our research provides new insights into selective autophagy as a quality control mechanism to facilitate degradation of im-paired plasma membrane. Furthermore, the CALI-based approach with enhanced opera-bility in time, place, size and extent of damage can be extended over further studies in plasma membrane damage responses.

並列關鍵字

plasma membrane repair ； CALI ； Calcium ion ； ubiquitin ； LC3 ； selective autophagy

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