Sutton, Laurie PDarira, Shradha2025-02-132025-02-132024-01-0112974http://hdl.handle.net/11603/37627G protein coupled receptors (GPCRs) are the largest class of membrane proteins. They act as signaling molecules that transmit extracellular signals into the cell, thereby regulating various physiological functions. Upon activation by an extracellular signal, GPCRs can initiate distinct intracellular events via interaction with G proteins. Given their role in regulating almost all physiological functions and their presence on the plasma membrane, GPCRs make for attractive therapeutic targets. Through my dissertation work, I have advanced our understanding of these prospects to aid the pursuit of GPCR based drug discovery. The major focus of my dissertation was understanding biased signaling. Bias is defined as the tendency of certain receptors to be able to activate to more than one G protein depending on the nature of the activating ligand. To understand these processes, we made use of the kinin receptor system as a model. These GPCRs namely, Bradykinin 1(B1R) and Bradykinin 2(B2R) are major regulators of aspects such as pain, inflammation and cardiovascular homeostasis. However, the molecular mechanisms underlying this regulation are not well understood. To better understand these mechanisms, we generated a comprehensive G protein activation map of these receptors when activated by each of the four different peptide ligands (bradykinin, kallidin, des-arg9-bradykinin and des-arg10-kallidin). Forming a major group of understudied GPCRs are the orphan GPCRs whose functions remain unknown, and their endogenous ligand have not been identified. GPR162 is one such orphan receptor that has been implicated in regulating hedonic tone or an individual’s liking of rewarding stimuli. This part of my dissertation project was focused on the design and use of two different chimeric GPCR constructs of GPR162. This approach enables us to activate these chimeric constructs using known ligands in vitro allowing us to discern these intracellular signaling events. Next, to understand the involvement of GPR162 in regulating hedonic tone, we created and validated a novel global GPR162 knock-out (KO) mouse model. Overall, this thesis is focused on understudied aspects of GPCR signaling through the development and optimization of novel molecular tools to understand the intracellular signaling capabilities of the orphan receptor GPR162 and provides novel insights into the unconventional signaling mechanisms of the kinin receptors.application:pdfThis item may be protected under Title 17 of the U.S. Copyright Law. It is made available by UMBC for non-commercial research and education. For permission to publish or reproduce, please see http://aok.lib.umbc.edu/specoll/repro.php or contact Special Collections at speccoll(at)umbc.edu or contact Special Collections at speccoll(at)umbc.eduBiased SignalingBradykininGPCRGPR162Orphan ReceptorsText