Biochemistry majors Sharon Tsimese, '27 (Sashital lab) and Austin Petfalski, '26 (Roche lab) conducted research this summer with support from the Dean's High Impact Award. Driven by curiosity highlights the eleven recipients of this prestigious award, and includes this writeup on Sharon's work:

Sharon Tsimese (’27 biochemistry)
Mentored by Dipali Sashital, professor of biochemistry, biophysics, and molecular biology

After one year at Iowa State, Sharon Tsimese is already wholly immersed in undergraduate research as a member of the Sashital Lab in the Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology. Tsimese joined the group during the spring of 2024 as a first-year student and has continued working this summer as a funded researcher through her LAS award.

Tsimese’s research project is focused on bacterial resistance. Bacteria have evolved to develop many defense systems that protect them against viruses, Tsimese explained, and she is examining a new system named Septu, discovered in 2018. Exploring these systems may one day provide clues to fighting bacterial infections in humans.

“We know this system is effective at protecting bacteria against phages; however, we have not yet concluded how this immune system is triggered and activated in a bacterial cell,” Tsimese said. “This is the hypothesis we ought to test. Key components of immune systems in higher organisms like humans may have their origins in bacterial homologs; therefore, investigating the mechanism of this immune system may potentially revolutionize health care and offer new ways to combat bacterial infections through phage therapy.”

The Septu system contains two proteins – the ATPase PtuA and the nuclease PtuB, which form a PtuAB complex. That’s where Tsimese focused her efforts this summer.

“This summer, my successes so far include producing an accurate and reproducible Michaelis–Menten Curve for the protein complex and elucidating the activity of these various proteins through different activity assays and extensive testing, ultimately helping us narrow down our focus to the key areas to explore in this defense system.”

Congratulations to Austin and Sharon, and thank you to Dr. Roche and Dr. Sashital for their mentorship!