During her PhD studies, Gülberk Bayraktar researched the protein composition and organization of the axon initial segment (AIS). The AIS is composed of a highly organized protein scaffold and is where neurons generate their electrical signaling, called action potentials. An intricate interplay of sodium (Na⁺) and potassium (K⁺) ions in the AIS facilitates action potentials and set the neuronal excitability. Thus, the main active transporter of Na⁺, the sodium-potassium pump (Na⁺/K⁺-ATPase), is of interest to study in this compartment. Gülberk Bayraktar studied if the Na⁺/K⁺-ATPase isoforms are an integral part of the protein scaffold in the AIS and how they are organized in relation to other AIS components like scaffolding protein AnkyrinG.

The findings of the PhD studies of Gülberk Bayraktar contribute to the understanding of how the Na⁺/K⁺-ATPase are organized in a disorderly manner in the AIS unlike the various components that constitute the highly ordered protein scaffold of the AIS. The methods used by Gülberk Bayraktar carries the potential of unraveling new insights into the AIS structural organization.

The PhD study was completed at Department of Molecular Biology and Genetics, Faculty of Natural Sciences, Aarhus University.

This summary was prepared by the PhD student.

Time: Thursday, May 1, 2025, at 13.15
Place: Building 1324, room 011, Tvillingeauditorium, Aarhus University, Bartholins Allé 10, Aarhus University, 8000 Aarhus C
Title of PhD thesis: Characterization of the Na⁺/K⁺-ATPase Isoforms in the Axon Initial Segment
Contact information: Gülberk Bayraktar, e-mail: gulberk@mbg.au.dk, tel.: +45 31708748
Members of the assessment committee:
Assistant professor Amélie Fréal, Department of Functional Genomics, Vrije Universiteit Amsterdam, The  Netherlands
Associate professor Claire Meehan, Department of Neuroscience, University of Copenhagen, Denmark
Professor Daan Van Aalten (chair), Department of Molecular Biology and Genetics, Aarhus University, Denmark
Main supervisor: Professor Poul Nissen, Department of Molecular Biology and Genetics, Aarhus University, Denmark
Co-supervisor: 
Professor U. Valentin Nägerl, Interdisciplinary Institute for Neuroscience, University of Bordeaux, France
Associate professor Chao Sun, Department of Molecular Biology and Genetics, Aarhus University, Denmark
Language: The PhD dissertation will be defended in English

The defence is public.
The PhD thesis is available for reading at the Graduate School of Natural Sciences/GSNS, Ny Munkegade 120, building 1521, 8000 Aarhus C