Date of Completion

2023

Document Type

Honors College Thesis

Department

DEPARTMENT OF BIOCHEMISTRY

Thesis Type

Honors College, College of Arts and Science Honors

First Advisor

DR. ALAN HOWE

Keywords

Focal adhesions, Talin, Protein Kinase A, Computational image processing

Abstract

Focal adhesions (FAs) are specialized structures that link the extracellular matrix (ECM) to actin cytoskeleton, playing essential roles in regulating cell migration and adhesion. Talin is a key protein resided in FAs and serves as a link between integrins and actomyosin II cytoskeleton. Recently, talin has been identified as an A-kinase anchoring protein (AKAP) that binds to protein kinase A (PKA). However, the effects of talin-PKA interaction on FA morphology and dynamics are not fully understood. In this study, a computational tool using FIJI was established to analyze FAs in rat embryo fibroblast cells (REF52s). The effects of disrupted talin-PKA interaction on the number, area, circularity, and aspect ratio of FA were investigated by comparing the point mutation AV1806DD in mouse talin 1 (mTLN1) to wildtype (WT), E1770A mutant, and the double mutant E1770A/AV1806DD. The FA analysis tool enabled accurate quantification of adhesion morphologic properties with raw images and provided insights into the role of PKA in regulating FA formation and turnover through talin interaction. The results of the study demonstrate that disrupted talin-PKA interaction alters FA morphology in REF52s, specifically resulting in a decrease in the total number of FA per cell and a more elongated shape compared to the WT (p<0.05). Although the biochemical mechanism underlying the phenotypes remains unknown, it is suggested that talin phosphorylation by PKA is likely involved, leading to alterations in talin’s interaction with integrins and/or other proteins. These findings suggest an important role for talin-PKA interaction in FA morphology and dynamics.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

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