NTHU Alumnus Thao Nguyen-Researchers Revise Model of Important Plant Cell Pump's Activity
【Dr. Ha Nguyen】
Education And Positions Held
Institute of Molecular and Cellular Biology, National Tsing Hua University, 2009
Research Assistant in Academia Sinica, 2009 to 2012
Ph.D., Integrated in Biochemistry, The University of Wisconsin, Madison, 2013-2019
Postdoc Researcher in a Joint Project on Protein Science at the School of Pharmacy and the School of Medicine, the University of Maryland in Baltimore, November 2020 to present
PUBLICATION SPOTLIGHT: One project in the lab of biochemistry professor Michael Sussman investigates a proton pump present in plant cells. The pump moves protons to the outside of the cell, which creates an electrochemical gradient by which essential molecules can be moved in and out of the cell. This has important consequences; for example, the pump is involved in how stomata, the pores in leaves that facilitate gas exchange, open and close. It also plays an essential role in how plant cells elongate and grow.
IPiB graduate student Thao Nguyen recently published a paper in the Journal of Biological Chemistry (published by the American Society for Biochemistry and Molecular Biology) answering a longstanding question about how this pump is regulated. It was assumed that the C-terminal part of the pump — the end of the protein — was folding in and interacting with another part of the enzyme. This would mean it was autoinhibitory, having an effect on itself. However, their work showed that the enzyme is most likely acting with other pumps next to it, forming dimers or trimers. This work also provides the first direct evidence that the actuator domain is the target of the C-terminal domain.
Nguyen and her team put forth a new model of “head-to-tail” organization for this enzyme's activity that can be applied for future work on other enzymes. Techniques using incorporation of a photoactivatable amino acid into the protein combined with mass spectrometry allowed them to perform this work in vivo in living cells so it reflects the natural environment of the enzyme.
Nguyen is part of the Integrated Program in Biochemistry (IPiB), the joint graduate program of the Department of Biochemistry and Department of Biomolecular Chemistry. Get more info on the program here: www.ipib.wisc.edu.
Original Content Source: UW-Madison Integrated Program in Biochemistry