Honors Program
Honors Program: Embargoed Theses
First Advisor
Dr. Yihe Huang
Second Advisor
Dr. Tatsuya Yamada
Date of this Version
Spring 2025
Document Type
Thesis
Citation
Brink, K. 2025. Biochemical Characterization of Mammalian Sodium Calcium Exchangers. Undergraduate Honors Thesis. University of Nebraska-Lincoln
Abstract
Ca2+ is a widespread second messenger in mammalian cells. It is crucial
for various physiological processes. These include skeletal mineralization, cell
proliferation, muscle cell contraction, nerve transmission, hormonal secretion,
maintaining a regular heartbeat, and blood clotting. Na+/Ca2+ Exchangers (NCXs)
play a central role in regulating the concentration of intracellular Ca2+ homeostasis
through the high-capacity extrusion of Ca2+. In humans, three homologs of NCX
exist, each has multiple cytosolic regulatory domains. The NCXs can also function
in both monomeric and dimeric states. Dysfunction of NCXs has been associated
with various diseases, including heart disease, neurodegenerative disorders, and
cancer. This makes NCXs a highly promising therapeutic target. Despite extensive
physiological research on this protein, the molecular principles governing the
function and regulation of NCXs largely remain unknown due to limited structural
studies. This effort is further hindered by the significant challenge of expressing
and purifying both monomeric and dimeric NCXs. Using an improved mammalian
expression system developed in our lab, we successfully expressed both
monomeric and dimeric NCXs for all three homologs from both humans and rats,
which were analyzed by fluorescence-detection size exclusion chromatography
(FSEC). Additionally, we have expressed and purified 3C protease to facilitate the
subsequent structural studies by removing the fluorescence and purification tags.
Comments
Copyright Kaleb Brink 2025.