Abstract 9870839 Graber This research is aimed at determining how various receptors activate specific G proteins. G proteins are coupled to a number of hormone and neurotransmitter receptors, and they consist of 3 subunits: alpha, beta and gamma. The subunit determines the type of reaction that will occur. The research here is attempting to identify the residues and regions on the alpha subunits that interact with the 5HT1 and muscarinc receptors. Amino acids in a region which is required for coupling to the 5-HT receptors will be mutated and then functional assays of the receptor binding will be performed. Truncation of the alpha 1 subunit will also be examined to determine the minimal residues involved in the coupling. Similar studies will be done with the muscarinc receptors and the alpha q subunits. Other experiments will be done to see if physical interactions occur in the absence of function. These studies will aid in our understanding of how many different receptors interact with G proteins to result in different biological activities. Heterotrimeric G proteins interact with a number of different hormone and neurotransmitter receptors to bring about different biological activities. This research is aimed at determining how one of the major subunits of the G proteins interacts with the receptors to determine the specificity of the reaction. Since G proteins are important for many biological functions, these studies will be important for understanding of the basic mechanisms involved in determining which reactions will occur.
