Type
Text
Type
Dissertation
Advisor
Rizzo, Robert | Green, David F. | MacCarthy, Thomas | Scarlata, Suzanne.
Date
2014-12-01
Keywords
Systematic biology
Department
Department of Applied Mathematics and Statistics.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/77743
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
G-protein-coupled receptor (GPCR) signaling plays an important role in converting extracellular stimuli into cellular responses. Many biological functions are regulated by GPCR signaling, and nearly 40\% of current pharmaceuticals target GPCRs. In this work, mathematical modeling is used to investigate the initial steps of GPCR signaling with two major aims: 1) to understand the causes for non-canonical signaling behaviors; 2) to understand how signaling specificity is reacted to in the individual reactions of the pathway. The classic ternary complex model describing the interaction between a single ligand, receptor and G-protein served as our basic model for the initial investigation. Dose response curves were generated using computer simulations and qualitative differences were observed due to variations in the model parameters. A systematic study on individual parameters demonstrates that the rate for the binding of ligand-receptor complex to G-protein is the key determinant. In the next step, models containing two signaling pathways were built. The two signaling pathways can be considered to interact with each other when interactions between the components of both pathways exist. When nonspecific interactions exist in both the binding of the ligand to the receptor and the binding of the receptor to the G-protein, a biphasic dose response is observed. Specificity for the steady state response and dynamics of the signal were defined and how the strength of interactions and concentration of molecules affect signaling specificity were investigated. Other processes involved in GPCRs signaling were also considered. GPCRs undergo internalization upon ligand activation; they also form homo/hetero-dimers. A double-peaked dynamical response was observed due to the internalization of the receptors, while dimerization of the receptors may produce a double-peaked steady state response. Specificity as previous defined was also calculated and shown to be affected by both internalization and dimerization. | 140 pages
Recommended Citation
JIANG, TAO, "Mathematical Modeling of G-protein-coupled Receptor Signaling Pathways" (2014). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 3528.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/3528