Structure based development of fluorescently modified regulator of G protein signaling (RGS) as a strategy for RGS drug screening

• Main Authors: Chung-Hung Hsieh, 謝昌泓
• Other Authors: Chii-Shen Yang
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/70956721794045373974

碩士 === 國立臺灣大學 === 微生物與生化學研究所 === 97 === Heterotrimeric G-protein system mediates more than 60% of hormones in human and senses extracellular signals via G-protein coupled receptor (GPCR) which triggers cytosolic signaling cascades to respond to the environment. This signal is highly specific and regulated by a group of proteins, called regulator of G-protein signaling (RGS). RGS serves as GTPase accelerating protein (GAP) which acts specifically at corresponding Gα protein and terminates signaling pathway. Besides, RGS can distribute specifically at central nervous system, cardiovascular system or other tissues, and since it shows high specificity toward Gα protein, it becomes a promising drug target for therapeutic usage. Our goal is to develop a fluorescence-based screening system to monitor the interactions between RGS and Gα, and our data showed that the helix-loop junction at RGS proteins are the best positions for fluorescent probe modifications to serve such a purpose. This strategy was then successfully shown by using an AtRGS1domain protein with fluorescent probe modified at helix-loop junction area and a sensitive fluorescence change can be observed upon activation. A general principle to select proper residues for monitoring protein-protein interaction (PPI) was thus proposed.