IPiB Thesis Defense Aug. 24: Dana Dahhan

IPiB graduate student Dana Dahhan sits at a desk in the labIPiB graduate student Dana Dahhan studies how proteins are trafficked into and out of cells. Such protein transport supports basic cellular functions and responses, including the ability of a cell to grow in one direction, the construction of new plasma membrane and cell walls during cell division, and delivery and recycling of proteins at cellular interfaces.

Dahhan’s Ph.D. research in the Bednarek Lab specifically focuses on the instances and contexts in which protein transport in plants diverge from other multi-celled organisms. Her experiments using cells from Arabidopsis thaliana, a small flowering plant native to Eurasia and Africa, culminate a ten-year effort across five institutions to catalog the plant protein contents of structures called clathrin-coated vesicles. These vesicles internalize protein and membrane cargo at a cell’s plasma membrane and at specific intracellular structures to create compartments that transport the cargo.

Dahhan and her close collaborator, IPiB Ph.D. graduate Gregory Reynolds, observed an unexpected low abundance and apparent depletion of a known protein that’s essential to clathrin-mediated endocytosis. Subsequent experiments showed that the protein is located outside the clathrin-coated vesicle in some cases rather than inside, where such proteins are typically found. Their results are published in The Plant Cell.

How protein transport supports essential cellular functions fascinates Dahhan for more than its intrinsic importance. Understanding what proteins facilitate the movement of cargo expands our knowledge of how both plants and other multi-celled organisms develop.

“It’s certainly important to understand how plant cells expand, divide, and respond to extracellular cues and to theorize how experimental results obtained in one land plant might apply to another,” Dahhan says. “But a lot of the underlying transport mechanisms and identities and functions of protein players are shared between different types of eukaryotic organisms…I think it will be fascinating to understand in the future how protein transport pathways have evolved.”

During Dahhan’s time in IPiB, she held several elected leadership roles in the Student-Faculty Liaison Committee (now the Graduate Leadership & Development Committee), including chair, vice chair, treasurer, and professional development chair. She was also a 2021 Denton Award for Graduate Student Excellence in Teaching and Mentoring recipient and a 2019 Department Biochemistry Graduate Fellowship awardee.

To learn more about Dahhan’s research, attend her Ph.D. defense on Monday, August 24 at 1:00 p.m. CT in Room 1211 of the DeLuca Biochemical Sciences Building.

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