Traveling across the globe to study a tiny protein

Olivierre

Doctoral candidate Jaylene Ollivierre works with a small bacterial protein that regulates the activity of larger DNA repair complexes in Northeastern’s DNA Damage Recognition and Tolerance Laboratory led by chemistry and chemical biology assistant professor Penny Beuning.

That protein, called UmuD (pronounced yoo-myoo-d), has been studied for 20 years, Ollivierre said, “but it keeps surprising us.”

DNA damage response proteins, Ollivierre explained, are error-prone and frequently cause mutations, which can make bacteria unsusceptible to antibiotics. “This work is important for understanding and potentially combatting antibiotic resistance,” said Beuning.

Earlier this month, Ollivierre received an East Asia and Pacific Summer Institutes fellowship from the National Science Foundation to continue studying UmuD at the University of Wollongong in Australia.

She views the two-month experience as a unique opportunity to use what she’s learned about UmuD to tackle questions related to DNA replication.

“A big part of the program is to expose students to science policy, infrastructure and culture while forming collaborations that will help us through grad school and beyond,” Ollivierre said.

She will collaborate with University of Wollongong biological chemistry professor Nick Dixon, whom she met in 2008 at a Northeastern seminar on his research. The technology used in Dixon’s lab, which Ollivierre said “utilizes a host of biophysical techniques to study multiprotein DNA replication complexes,” complements the tools used in Beuning’s lab.

For example, Ollivierre will use a technique called native mass spectrometry to study how UmuD interacts with the protein components of a cellular machine called DNA Pol III, which is responsible for DNA replication. The technique, she said, “is especially useful for analyzing complexes that contain dynamic proteins like UmuD.”

When a strand of DNA becomes damaged — because of either spontaneous mutations or impact by external factors, such as viruses, UV radiation or toxic chemicals — Pol III temporarily shuts down operations, while another set of cellular machines, translesion synthesis polymerases, begin the process of DNA repair.

“We will explore the hypothesis that UmuD has a role in this switch from replication to repair,” Ollivierre said. “We believe that UmuD somehow regulates communication between the two processes.”

Beuning praised Ollivierre’s dedication to the research. “She has been intrepid in her pursuits to understand UmuD function at a very high level,” Beuning said. “The fellowship is a fitting recognition for her truly creative work and allows her to take her research to the next level.”