Year: 2015
Type: dissertation
Abstract: Defective autophagy can lead to dysregulation of metabolic homeostasis. Previous studies in our laboratory have shown that RGS4-overexpressing HEK cells show increased autophagic activity. Herein, we study the potential role of RGS4 as a regulator of autophagy in the Min6 mouse pancreatic beta cell line, via inhibition of Gαi3, an established attenuator of autophagy. Min6 cells exposed to nutrient-deprived conditions undergo autophagic initiation demonstrated by increased expression of autophagy markers. When RGS4-YFP is ectopically expressed in Min6 cells, confocal microscopy imaging revealed colocalization between RGS4-YFP (both wild type and loss-of-function mutants), Gαi3 (RC)-CFP, and autophagy markers including Beclin1-DsRed and Atg12-RFP on intracellular punctae. Despite its colocalization with known regulators of autophagy, RGS4 was apparently unable to modulate the activity of known mediators and markers of autophagic activity (phospho-p76S6K, LC3 II, phospho-Bcl-2). We conclude that Gαi3 and RGS4 are not major factors in the regulation of autophagic flux in Min6 cells.
Source: TSpace (University of Toronto)
Author: Stephanie Alexandra Beadman
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2786103630