Project summary/abstract
The long-term goal of my research is to understand how the kinetic and thermodynamic properties of
enzymes maintain metabolic homeostasis. The function of metabolic homeostasis is to maintain appropriate
levels of ATP and biosynthetic precursors. Understanding metabolic homeostasis is important as it is a
fundamental property of all cells and its dysregulation leads to metabolic syndrome, which contributes to several
common disorders, including diabetes, cardiovascular disease, cancer, and nonalcoholic fatty liver disease.
Metabolic homeostasis is achieved by controlling enzyme activity through mass action and allosteric regulation.
Studies of purified enzymes have yielded extensive knowledge of the structure, reaction mechanism, and
allosteric regulation of enzymes in several metabolic pathways. However, metabolic homeostasis is the result of
non-linear interactions between many enzymes and metabolites, which are difficult to fully understand by
studying individual enzymes in isolation. As a result, the specific functions of most allosteric regulators is not well
understood and it is largely unknown how allosteric regulation and mass action achieve metabolic homeostasis
in cells. In this proposal, our main objectives are to 1) develop mathematical models to characterize metabolic
homeostasis, and 2) develop experimental approaches to test model predictions by measuring and manipulating
metabolic homeostasis in live cells and in vitro reconstituted pathways. We will use a combination of modeling
and experiments to address key gaps in our understanding of the regulation of glycolysis, pentose phosphate
pathway, tricarboxylic acid cycle, and mitochondrial oxidative phosphorylation. The big-picture questions that we
plan to investigate are: How do glycolysis and respiration maintain cellular ATP homeostasis? How do cells
resolve the conflicting demands of ATP production and biosynthesis? How do metabolic pathways that share
products and substrates coordinate with each other? What is the role of compartmentalization and metabolite
channeling in regulating metabolic homeostasis? Our lab is well-positioned to make advances in the
understanding of metabolic homeostasis as we have extensive experience in developing and using LC-MS,
fluorescence sensors, genetically-encoded tools for manipulation of metabolism, in vitro protein characterization,
engineering cell lines using CRISPR-Cas9, and mathematical models to study metabolism.