Third in a series: Pellock studies bacterial physiology
Three Professors Receive National Institutes of Health Grants
The National Institutes of Health (NIH) has awarded grants to three Providence College professors to support their research.
The Institutional Development Award’s Network of Biomedical Research Excellence (INBRE) grants are designed to build up the research capacity of institutions that traditionally have not received much NIH funding.
This year, Dr. Christopher M. Bloom, associate professor of psychology, Dr. Brett J. Pellock, assistant professor of biology, and Dr. Jennifer L. Van Reet, assistant professor of psychology, have all received grants. In this article, PC News focuses on Pellock's research.
Pellock’s lab also received a nearly $55,000 renewable student training award for his research after completing a three-year faculty development grant. He is working to identify small, non-coding RNAs (sRNAs) in the bacterium Shewanella oneidensis, which can break down toxic heavy metals in anaerobic conditions — an important feature for bioremediation projects. These sRNAs are a group of genes that bacteria use to turn genes on or off based on changing environmental conditions.
The researcher and his students are studying physiological processes in Shewanella, including how the cells break down metals such as manganese or chromium. Much of the work has focused on the differences between their organism and E. coli, which Pellock described as the favorite laboratory test subject for researchers.
“When you talk to other researchers, we tend to think about bacterial issues through the lens of E. coli,” he said.
One student in his lab, Chris Brennan ’13 (Litchfield, N.H.), worked for more than two years to build a Shewanella mutant that lacked a protein known as HFQ, which is involved in sRNA regulation.
“A lot of what happens in genetics is we break those genes and look at what happens when we break them,” Pellock said. “Using those outcomes, we then infer what the normal functions of the gene are when the gene is intact. That’s what geneticists do. We break genes and look at what happens.”
Pellock originally estimated that it would take about six months to build the mutant. But “we had a really, really hard time making this mutant,” he said. “It suggested to me at the time, although it was just a hunch, that something different was going on.”
At the American Society of Microbiology’s annual meeting, student researcher Matt Goulet ’12 presented a poster about the Shewanella mutant, and it generated a lot of interest, Pellock said. “A lot of other people have tried and failed,” he said. “We got something that a lot of people with larger and better funded labs have been unable to get.”
HFQ “is a very well-conserved gene among bacterial species,” Pellock said, and the HFQ protein in E. coli and Shewanella appear very similar molecularly.
However, the HFQ mutants of Shewanella and E. coli behave very differently, and Pellock believes that the proteins must perform different functions in each cell.
“What we quickly realized was the mutant on its own was interesting and can tell us something about the role of the gene that is novel,” he said.
Pellock is working to publish a paper that details how to build the mutant. “In the process, it spawned a couple of other projects,” he said. “Now we’re getting a handle on what underlies these differences, and what might be different about what HFQ is doing in each system.”
Because his lab is working on publishing its findings, Pellock believes he will be able to apply for direct NIH funding in the future, rather than a portion of the INBRE pool as he has in the past.
The INBRE grant covers the costs of supplies, including media components and consumable plastics, as well as custom nucleotides for molecular cloning. It also pays stipends to some students who work in the lab during the summer, although Pellock also has volunteers.
Students often work more than the 35-hour weeks they are allotted, given the vagaries of the work. For example, students will sign up for shifts to help collect growth data over 30 consecutive hours.
“They have no problem doing that, and eagerly volunteer for the service,” he said. “There’s a lot of hours but it’s neat when you have great students. They are motivated and want to do this and are genuinely excited by it.”
Brennan, who worked at the Massachusetts Institute of Technology this summer, came back to PC for three weekends to conduct experiments himself.
Through this experience students get to understand how science works. “In addition to the technical side of things they learned how to be very rigorous about it,” Pellock said.
— Liz F. Kay
Read more about what's happening at the College at PC News.