Thesis Defense: Phosphorylation kinetics of cardiac gap junction regulation during stress
Thesis Defense: Phosphorylation kinetics of cardiac gap junction regulation during stress
Kari Stanley
Graduate Student, Translational Biology, Medicine, and Health
Graduate Research Assistant, Smyth and Lamouille labs
December 11, 2024, at 1:00p.m.
Room G101 A/B, 4 Riverside Circle
About this Thesis
The coordinated contraction of the heart occurs because of the propagation of action potential between the cardiomyocytes. Gap junctions consisting primarily of connexin43 (Cx43) connect cardiomyocytes at a specialized region of contact between cells known as the intercalated disc to facilitate cellular coupling. Cardiac pathologies frequently manifest with disrupted gap junctional intercellular communication which can generate potentially fatal arrhythmias, thus, it is essential to elucidate mechanisms underlying Cx43 regulation and altered intercellular communication. Phosphorylation of residues in the Cx43 carboxyl terminus can alter the subcellular localization, channel gating, and internalization of Cx43. The channel open probability of gap junctions is regulated, in part, by the phosphorylation of S368. Phosphorylation of S365 and S373 have been reported to exert gatekeeper effects on the phosphorylation of S368 and these phosphorylation events further affect protein interactions with 14-3-3 and zonula occludens-1 (ZO-1). While it is established that pS365 creates a conformational change preventing pS368, it is currently unclear precisely how pS373 regulates pS368. Further, it is unknown how alterations to these residues might impact protein binding and pathological cardiac remodeling during stress. Utilizing an ex vivo ischemia model, we find by immunofluorescent confocal microscopy that wildtype Cx43 hearts exhibit significantly decreased Cx43/N-cadherin colocalization during ischemia, while phospho-null mutant hearts retain Cx43/N-cadherin colocalization. Triton X-100 solubility assay indicates S365A/S373A mice have increased junctional Cx43 during ischemia. Additionally, we show that pS368 decay is more rapid in S373A mutants than wildtype suggesting, for the first time, that pS373 may prevent dephosphorylation at Cx43-S368 rather than promote Cx43-pS368. This knowledge could highlight potential therapies for the prevention of cardiac remodeling and arrhythmogenesis.
More About the Candidate and Project
- Education and Training
- Committee Members
- Publications and Presentations
- Honors and Awards and Service
Education
Virginia Tech, Translational Biology, Medicine, and Health, M.S. Student
Virginia Tech, B.S. Biology
Training
Graduate Research Assistant, Smyth Lab
Mentor
- James Smyth, Ph.D., Associate Professor, Center for Heart and Reparative Medicine Research
- Samy Lamouille, Ph.D., Assistant Professor, Cancer Research Center
Committee Members
- James Weger-Lucarelli, Ph.D., Research Assistant Professor, Department of Biomedical Sciences & Pathobiology
- Jessica Karch, Ph.D., Assistant Professor, Center for Vascular and Heart Research
- Yassine Sassi, Ph.D., Assistant Professor, Center for Vascular and Heart Research
Publications
Padget, R.L., Zeitz, M.J., Blair, G.A., Wu X., North, M.D., Tanenbaum, M.T., Stanley, K.E., et al. Acute adenoviral cardiac infection elicits an arrhythmogenic substrate prior to inflammatory myocardial remodeling and myocarditis. Circulation Research, 2024 Mar 29;134(7):892-912. doi: 10.1161/CIRCRESAHA.122.322437
Jubb, C.S., Stanley, K.E., Foley, J. et al. Distinguishing adult Laricobius osakensis Montgomery & Shiyake, 2011 (Coleoptera: Derodontidae) from Laricobius nigrinus Fender, 1945 and Laricobius rubidus LeConte, 1861 using pronotal morphology. The Pan-Pacific Entomologist, 99(1):30-35 (2023)
Jubb, C.S., McAvoy, T.J., Stanley, K.E. et al. Establishment of the predator Laricobius nigrinus, introduced as a biological control agent for hemlock woolly adelgid in Virginia, USA. BioControl 66, 367–379 (2021)
Presentations
ORAL PRESENTATIONS
Stanley K., Padget R., Zeitz M., Blair G., North M., Tanenbaum M., Phillips C., King D. R., Lamouille S., Gourdie R., Swanger S., Poelzing S., Smyth J. “Elucidating mechanisms of cardiac gap junction disruption during acute adenoviral myocarditis” Oral Presentation, Biological Sciences Research Day, Virginia Tech, Blacksburg, VA., February 3, 2024
Stanley K., “Elucidating mechanisms of cardiac gap junction disruption during acute adenoviral myocarditis” Oral Presentation, Research in Progress Seminar, FBRI, Roanoke, VA., November 17, 2023
Stanley K., Padget R., Zeitz M., Blair G., North M., Tanenbaum M., King D. R., Lamouille S., Gourdie R., Swanger S., Poelzing S., Smyth J. “Elucidating mechanisms of cardiac gap junction disruption during acute adenoviral myocarditis” Fralin Biomedical Research Institute Retreat, Hot Springs, VA, June 7, 2023
Stanley K., Keynote speaker, American Heart Association STEM Goes Red, Go Red For Women, Roanoke, VA, May 19, 2023
POSTER PRESENTATIONS
Stanley K., Padget R., Zeitz M., Blair G., North M., Tanenbaum M., King D. R., Lamouille S., Gourdie R., Swanger S., Poelzing S., Smyth J. “Elucidating mechanisms of cardiac gap junction disruption during acute adenoviral myocarditis” Poster Presentation, Cardiovascular and Heart Research Symposium, Roanoke, VA, August 26, 2024
Stanley K., Padget R., Zeitz M., Blair G., North M., Tanenbaum M., Phillips C., King D. R., Lamouille S., Gourdie R., Swanger S., Poelzing S., Smyth J. “Elucidating mechanisms of cardiac gap junction disruption during acute adenoviral myocarditis” Poster Presentation, International Gap Junction Conference, Alexandria, VA., July 29, 2024
Stanley K., Padget R., Zeitz M., Blair G., North M., Tanenbaum M., Phillips C., King D. R., Lamouille S., Gourdie R., Swanger S., Poelzing S., Smyth J. “Elucidating mechanisms of cardiac gap junction disruption during acute adenoviral myocarditis” Poster Presentation, American Society for Cell Biology, Boston, MA., December 4, 2023
Stanley K., Padget R., Zeitz M., Blair G., North M., Tanenbaum M., King D. R., Lamouille S., Gourdie R., Swanger S., Poelzing S., Smyth J. “Elucidating mechanisms of cardiac gap junction disruption during acute adenoviral myocarditis” Poster Presentation, Translational Biology, Medicine, and Health Research Symposium, Roanoke, VA, January 18, 2023
Stanley K., Padget R., Zeitz M., Blair G., North M., Tanenbaum M., King D. R., Lamouille S., Gourdie R., Swanger S., Poelzing S., Smyth J. “Elucidating mechanisms of cardiac gap junction disruption during acute adenoviral myocarditis” Poster Presentation, Translational Biology, Medicine, and Health Open House, Roanoke, VA, October 20, 2023
Stanley K., Padget R., Zeitz M., Blair G., North M., Tanenbaum M., King D. R., Lamouille S., Gourdie R., Swanger S., Poelzing S., Smyth J. “Elucidating mechanisms of cardiac gap junction disruption during acute adenoviral myocarditis” Poster Presentation, Cardiovascular and Heart Research Symposium, Roanoke, VA, October 9, 2023
Honors and Awards
American Heart Association Predoctoral Fellowship 2023-2024 23PRE1025476
Breakout session oral presentation 1st place, Biological Sciences Research Day, February 3, 2024
2nd place poster presentation, Vascular and Heart Research Symposium, October 9, 2023
Keynote speaker, American Heart Association STEM Goes Red, Go Red For Women, Roanoke, VA, May 19, 2023
TBMH Student of the Year in Education 2023
Service
Coordinated a graduate student panel at the local community college to speak with students about paths to graduate education, December 16, 2022
Organized a Metabolic and Cardiovascular Science study session for first year TBMH students, December 9, 2022