Date of Award

2020

Document Type

Thesis

Degree Name

Bachelors

Department

Natural Sciences

First Advisor

Yildirim, Necmettin

Area of Concentration

Biochemistry and Applied Mathematics

Abstract

A mathematical model was developed to study dynamics of the yeast pheromone response pathway with a focus on the roles of the yeast RGS protein Sst2 and effects of time delays on the pathway dynamics. The model considers interactions near the membrane of the receptor protein Ste2, RGS protein Sst2, and heterotrimeric G-protein, as well as the downstream of the pathway, which includes pheromone dependent upregulation of these proteins. The final model consists of a system of 6 nonlinear delay differential equations (DDEs) which incorporates inherent time delays that account for slower biological processes, such as transcription and translation. The model parameters were either collected from the literature or estimated from the experimental data by fitting the model to the data. Then the model was tested against a new experimental data set to assess the predictive power of the model. It has been observed that the model correctly captures the initial phase in the new data, but loses inaccuracy for the later dynamics. Numerical simulations for the roles of the proteins in the pathway correlate well with previous biological understanding, and the examinations of the effect of time-delay indicate the importance of time lags in the model for maintaining normal membrane-receptor abundance.

Download

Share

COinS