The science would not be easy. There were going to be long days and nights in the lab, countless tests to run and techniques to be tweaked. But the end game was intriguing; identify opportunities to affect modifications in the Francisella proteome, a bacterium categorized as a class “A” bioterrorism agent. Unlike its cousin, the more well-researched E. coli bacteria, many aspects of the Francisella proteome are not fully understood. Due to its potentially virulent nature, it is important to research and document the biochemistry of this organism to in order to develop new therapies or vaccines.
While the van Hoek lab at the Mason Sci-Tech campus has been studying Francisella since 2005, they were interested to learn more about post-translational modifications (PTMs) – changes undergone by the protein when certain chemical groups are added. Specifically, Dr. Monique van Hoek, a professor in the School of Systems Biology, with a joint appointment to the National Center for Biodefense and Infectious Diseases at Mason, was interested in how the Francisella bacterium changes the activity of its proteins with the addition of the acetyl chemical group. Although van Hoek had years of experience in Francisella research, for this particular project she recognized that while her lab could make the protein/peptide samples, it was necessary to run a thorough molecular analysis of the samples to measure acetylation. That, she saw, could be done through a collaboration with another 4-VA partner university – Virginia Commonwealth, in their Chemical and Proteomics Mass Spectrometry Core Facility. It was that connection which paved the way for yet another groundbreaking 4-VA research project – “Critical post-translational modifications of the Francisella proteome.”
As van Hoek explains, not only did the research produce results, the grant also had a positive effect on students in her lab and faculty at VCU. “Real lives were changed — two great students graduated and went on to get good jobs,” notes Van Hoek. The first student, Ekaterina (Kate) Marakosova, was a PhD student at Mason who began the project with van Hoek working with the more virulent forms of Francisella. “Kate started on this project with me and developed techniques to identify protein acetylation. Kate has since gotten her doctorate and gone on to get a great job at the Food and Drug Administration,” says Van Hoek. “Alex Ii is now working as a laboratory technician with me,” adds van Hoek. “In May, Alex defended her master’s on another aspect of this project ‘Acetylation as a regulatory mechanism of chitinase activity in Francisella tularensis subsp. novidica.’”
Ii came to the van Hoek lab after starting her degree at VCU in Bioinformatics. “Once I got into this lab, I realized I really liked the work,” says Ii. “When I first started here, I was working with Kate and immediately jumped into the project. We were coming in at 5:00 am and often didn’t leave until 8:00 pm. The sample preparation was difficult, and we had to do a lot of troubleshooting, but it was worth it!” Ii was not only all in for the lab work, but with anything else that needed to be done, even driving samples to the lab in Richmond late at night.
Van Hoek also notes that her collaborator at VCU, Dr. Kristina Nelson, points to the project as furthering her own research. Nelson received a 4-VA Complementary Grant for her part in the project. “With the complementary funding, we were able to purchase standards and columns in order to ensure that the instrument was operating at peak performance, to give the best data possible,” explains Nelson. “It was fascinating to be able to visualize the changes in the protein acetylation profile.”
“The new collaboration with Kristina was certainly another positive outcome of the 4-VA Grant,” says van Hoek.
In addition to furthering the education and professional tracks of those on the project, the research was fruitful. The team has identified multiple Francisella proteins that are acetylated and look to be important in Francisella’s ability to infect hosts. To share the research, a poster was presented at the American Society for Microbiology meeting on biofilms and the manuscript has been submitted for potential publication.
While, van Hoek notes there is still much more to be researched with regard to the Francisella bacterium, which causes human disease in the US and in Europe, she credits the 4-VA grant for delivering these important results, and making such positive effects on the people and the science. Van Hoek continues to study important questions of Francisella biology, such as which proteins are secreted by this bacterium and how they are exported. In fact, van Hoek and Nelson are now at work on another 4-VA collaborative research project on this very subject “Secreted Proteins of Francisella – a new understanding.” Stay tuned!