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  • 學位論文

Atg1在果蠅發育上的調控基因篩選分析

A Screen for modifiers of Atg1-mediated signaling in Drosophila development

指導教授 : 陳光超
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摘要


細胞自噬是具有高度保留性的過程,涉及囊泡分泌及細胞質內蛋白質和胞器的降解。Atg1是一種絲氨酸/酥氨酸激酶,並且已經知道受到Tor訊號傳遞途徑的調控。研究發現在酵母菌中,Atg1的激酶活性是CVT訊息傳遞途徑以及細胞自噬所必須。因此Atg1可能是一個可以調控細胞自噬很多步驟的一個調節點。 我利用果蠅為實驗材料,研究結果顯示大量表現Atg1,在果蠅複眼的發育上會造成細胞死亡和眼睛表面粗糙的表型。儘管目前的研究已經發現一些會與Atg1有所關聯的蛋白質,然而要鑑定出其他在細胞自噬過程中可能與Atg1有交互作用的受質仍是一個困難的任務。因此為了尋找參與在Atg1所調控細胞自噬過程中未知且新穎的基因,我利用表現Atg1 所造成粗糙眼睛的表型做了果蠅眼睛發育上的調控基因篩選分析。利用能代表果蠅百分之七十基因組的連續染色體缺陷,在測試了277株染色體缺陷的果蠅中,我發現了26個品系的染色體缺陷果蠅能有效抑制Atg1所造成的訊息傳遞途徑。我利用一系列的遺傳分析縮小候選基因的位置,並且找到了三個可能與Atg1有關聯且參與在細胞死亡訊息傳遞途徑的基因。 這些能夠與Atg1作用的調控蛋白將為細胞死亡與細胞自噬的研究帶來新的發展。我目前正在調查這些調控蛋白是否能與Atg1有物理上的交互作用,並且在細胞死亡的過程中扮演什麼樣的生物功能。

關鍵字

細胞自噬 細胞凋亡 果蠅

並列摘要


Abstracts Autophagy is a highly conserved cellular process that involves vesicle-mediated sequestration and degradation of cytoplasmic proteins and organelles. Atg1 is a Ser/Thr kinase that is regulated by TOR-dependent signaling. In yeast, studies have found the requirement for Atg1 kinase activity in both CVT and autophagy. Thus, Atg1 is representing a nodal point for controlling multiple steps in autophagic process in response to various stresses. I have examined that overexpression of Drosophila Atg1 in the developing compound eye triggers cell death and results in eye roughness. Although a number of proteins have been found to associate with Atg1, the identification of Atg1 substrates important for autophagy remains a difficult task. To identify novel genes involved in the Atg1-mediated pathway, I carried out a dominant modifier screen of the Atg1-induced rough eye phenotype using contiguous chromosomal deficiencies that represent more than 70% of the Drosophila genome. Of the 277 deficiencies tested, 26 were identified as suppressors of Atg1 signaling. I characterize a subset of autosomal regions that strongly interact with Atg1. Three novel genes will likely identify Atg1 regulators and should shed some light on how cells are regulated by the balance between cell survival and cell death. I am currently investigating whether these regulators have physical interaction with Atg1 and what is the biological function in cell death.

並列關鍵字

Autophagy Apoptosis Drosophila Atg1

參考文獻


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