Abstract
摘要:ATP 合成酶是細胞中重要的酵素,它能產生「能量貨幣分子」—ATP。Paul D. Boyer和John E. Walker因為釐清ATP合成的酵素機制而在1997年獲頒諾貝爾化學獎。長時間以來,ATP 合成酶一直被認為只出現在動物的粒線體內膜上,然而愈來愈多的證據顯示ATP 合成酶也會表現在癌組織的表皮細胞、乳癌及肺癌細胞的細胞膜上,這一類的ATP 合成酶被稱作「細胞膜異位表達ATP合成酶」。除了我們在2008年和2012年分別發表於J. Proteome Res.和Cancer Research的文章中,證明阻斷細胞膜異位表達ATP合成酶的活性可以有效地抑制癌細胞生長外,也有許多報導指出細胞膜異位表達ATP合成酶具有可當作抗腫瘤及抑制血管新生藥物標靶的潛力。細胞膜異位表達ATP合成酶是一個重要的蛋白質,但是它為何出現在細胞膜? 以及它在細胞膜上的功能為何? 目前仍不是很清楚。因此本計畫的主要目標是要結合蛋白質體學和網路生物學探討細胞膜異位表達ATP合成酶的反應路徑。
特定目標:
1. 分析細胞膜異位表達ATP合成酶的差異性交互作用體。
2. 重建細胞膜異位表達ATP合成酶的蛋白質交互作用網路。
3. 解析細胞膜異位表達ATP合成酶的動態磷酸化蛋白質體。
4. 建構細胞膜異位表達ATP合成酶的磷酸化動態網路。
5. 實驗證實細胞膜異位表達ATP合成酶的反應路徑。
在本研究計畫中,我們期望能夠了解細胞膜異位表達ATP合成酶的反應路徑,進而釐清為何它會表現於癌細胞膜上。此研究將有助於提供重要的資訊以利肺癌治療。
Abstract: ATP synthase is a multimeric protein complex that catalyzes the synthesis of ATP. It is essential for almost all organisms because ATP is the common “energy currency” of cells. The Nobel Prize in Chemistry 1997 was awarded to Paul D. Boyer and John E. Walker "for their elucidation of the enzymatic mechanism underlying the synthesis of adenosine triphosphate (ATP)". Boyer proposed the “binding-change hypothesis,” a detailed elucidation of the mechanism by which ATP synthase catalyzes the synthesis of ATP. John E. Walker determined the DNA sequence of the genes encoding the proteins in ATP synthase and the first X-ray structure of F1, soluble fraction of ATP synthase. For a long time, animal ATP synthase was believed to be found only in mitochondria, where most cellular ATP synthesis takes place. However, in recent studies ATP synthase was also found on the extracellular surface of endothelial cells in some cancer tissues, lymphocytes, hepatocytes, proliferating cell lines, breast and lung cancer cells. With the property of facing out-side the cell, this kind of ATP synthase is called ectopic ATP synthase. Ectopic ATP synthase not only functions as energy generators but also as proton channels and receptors for various ligands, which are involved in numerous biological processes including the mediation of intracellular pH, cholesterol homeostasis, the regulation of the proliferation and differentiation of endothelial cells, and the recognition of immune responses of tumor cells. Ectopic ATP synthase together with the whole respiratory chain are localized on C6 glioma and lung cancer cell surface has been reported. Ectopic ATP synthase is expressed on the surfaces of various cancer cells, but not on the normal or normal-like cells, therefore, the researchers suggest that ectopic ATP synthase is a potential molecular target for anti-tumor and anti-angiogenesis therapies. ATP synthase is an important protein; however, a role for ectopic ATP synthase on the plasma membrane of cancer cells remains uncertain. Our major objective is to elucidate the response pathways of ectopic ATP synthase in lung cancer cells by combining proteomics and network biology. Our specific aims are:
1. To profile the differential interactome of ectopic ATP synthase.
2. To construct the rewired protein interaction networks of ectopic ATP synthase.
3. Dynamic profiling phosphoproteome of ectopic ATP synthase-inhibited lung cancer cells.
4. To analyze phosphorylation network dynamics.
5. To validate the key regulatory pathway of ectopic ATP synthase.
With the proposed study, we expect to understand the response pathways of ectopic ATP synthase and why it arises not only in mitochondria but also on the plasma membrane of cancer cells. It may provide in-depth information on the impact and importance of lung cancer therapy.
Keyword(s)
細胞膜異位表達ATP合成酶
網路生物學
蛋白質體學
蛋白質交互作用網路
磷酸化網路動態
反應路徑
ectopic ATP synthase
network biology
proteomics
protein interaction networks
phosphorylation network dynamics
response pathways