2005-01-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/699868摘要：位移至focal contacts是FAK活化及調控其功能的必要條件；但非充分條件。之前的研究包括我們的報告建議：破壞FAK的N端區域與其激化脢區域的分子內之交互作用為FAK全面活化的要件。然而，消除FAK分子內此一抑制作用的機轉仍無任何報導。在我們的先期研究中，FAK的N端類似FERM區域與其他FERM區域蛋白具有高度結合磷酸酯的特性非常的相似。除此之外，FAK 的N端區域已被報導能與一些膜蛋白結合。例如，integrin β1 tail 和EGFR。顯示此區域能夠接受上游的訊息刺激；進而導致後來的磷酸化及活性。因此，我們提出FAK活化的分子機轉類似於ERM蛋白（為一群具有FERM區域的蛋白）。它們於磷酸酯結合其FERM區域後可造成結構的改變，使之進一步可允許結合其他的蛋白並被磷酸化。為了證明此一假設，我們計劃進一步探討那一種類磷酸酯可專一性的與FAK結合，並建造一個磷酸酯結合缺陷的FAK突變株。之後，此一突變株的磷酸化及活性會被進一步的與正常FAK做比較。而磷酸酯結合至FAK所導致的相關性細胞功能也會被評估。除此之外，其他可結合至FAK的N端區域之蛋白也將被探索；並了解其如何調控F<br> Abstract: Localization of FAK at focal adhesions is necessary but not sufficient to activate its activity and functions. Previous studies including ours have suggested that disruption of an intramolecular interaction between FAK’s amino-terminus and its kinase domain is required for the fully activation and function. However, there is no molecular mechanism provided to elucidate the release of this intramolecular inhibition in the process of FAK activation. A FERM-domain like region within FAK amino-terminus is resemble with other FERM domains, which exhibits a high affinity with phospholipids in vitro and in vivo in our preliminary studies. In addition, the amino-terminus of FAK is reported to interact with several membrane proteins including integrin β1 tail and EGFR, which implicated that this region can perceive upstream signal stimuli and cause consequent phosphorylation and activation. Hence, we hypothesize a molecular mechanism of FAK activation similar to ERM proteins, FERM domain containing proteins, in which an interaction between the FERM domain and phospholipids enables a conformational change to allow further binding with other molecules and consequent phosphorylation. To test the hypothesis, we are planning to identify the phospholipid species binding to FAK and create a phospholipid-binding deficient mutant of FAK. Moreover, the phosphorylation states and activity of FAK and the phospholipid-binding deficient mutant will be examined and compared. The functional relevance of phospholipid binding to FAK interaction will be evaluated as well. Additionally, we will also explore the potential protein-protein interaction(s) of FAK amino-terminus in the regulation of FAK activation and functions. These findings will provide a complete molecular mechanism in the process of FAK activation and functions.磷酸酯FAKN端區域FERM區域分子內之交互作用ERM蛋白phospholipidsFAKN-terminusFERM domainintramolecular interactionERM proteins