Date of Presentation
5-4-2023 12:00 AM
College
School of Osteopathic Medicine
Poster Abstract
The Cdk8 Kinase Module is a dissociable regulator of cellular stress response genes, with degradation of its components Med13 and cyclin C eventually determining cell fate decisions such as engaging cell survival or cell death mechanisms. We aimed to explore the roles of ubiquitin in degradation of the Cdk8 Kinase Module following nitrogen starvation, with respect to the potential involvement of deubiquitinating enzyme Doa4, lysine linkage at position K63, and E2 ubiquitin conjugating enzymes Ubc4 and Ubc5. We utilized Western blot analysis to observe nitrogen starvation-induced degradation of Med13-HA in wild-type, doa4 mutant, and K63R yeast strains; degradation of cyclin C-MYC in wild-type and K63R strains; and Atg8-GFP activity in wild-type and ubc4/5 mutant strains, with Pgk1-GFP as a loading control. Results indicated that Med13 was degraded in doa4 mutant and K63R yeast strains, while cyclin C was stabilized in K63R strains. Additionally, GFP was cleaved from Atg8 in both wild-type and ubc4/5 mutant strains. We therefore determined that Med13 degradation does not require Doa4 or K63, and that Ubc4 and Ubc5 are specific to Med13 autophagy. However, K63 ubiquitin linkage is implicated in cyclin C degradation following nitrogen starvation, warranting further investigation.
Keywords
Ubiquitin, Cyclin C, Phosphotransferases, Kinases, Mediator Complex, Med13, Cell Death
Disciplines
Biological Phenomena, Cell Phenomena, and Immunity | Cell Biology | Laboratory and Basic Science Research | Medical Cell Biology | Medical Molecular Biology | Medicine and Health Sciences | Molecular Biology
Document Type
Poster
Included in
Biological Phenomena, Cell Phenomena, and Immunity Commons, Cell Biology Commons, Laboratory and Basic Science Research Commons, Medical Cell Biology Commons, Medical Molecular Biology Commons, Molecular Biology Commons
The Involvement of Ubiquitin in Med13 Cyclin C Degradation Following Cellular Stress
The Cdk8 Kinase Module is a dissociable regulator of cellular stress response genes, with degradation of its components Med13 and cyclin C eventually determining cell fate decisions such as engaging cell survival or cell death mechanisms. We aimed to explore the roles of ubiquitin in degradation of the Cdk8 Kinase Module following nitrogen starvation, with respect to the potential involvement of deubiquitinating enzyme Doa4, lysine linkage at position K63, and E2 ubiquitin conjugating enzymes Ubc4 and Ubc5. We utilized Western blot analysis to observe nitrogen starvation-induced degradation of Med13-HA in wild-type, doa4 mutant, and K63R yeast strains; degradation of cyclin C-MYC in wild-type and K63R strains; and Atg8-GFP activity in wild-type and ubc4/5 mutant strains, with Pgk1-GFP as a loading control. Results indicated that Med13 was degraded in doa4 mutant and K63R yeast strains, while cyclin C was stabilized in K63R strains. Additionally, GFP was cleaved from Atg8 in both wild-type and ubc4/5 mutant strains. We therefore determined that Med13 degradation does not require Doa4 or K63, and that Ubc4 and Ubc5 are specific to Med13 autophagy. However, K63 ubiquitin linkage is implicated in cyclin C degradation following nitrogen starvation, warranting further investigation.