Emily Knuth, an IPiB graduate student, will be defending her Ph.D. research on April 30, 2024. Her research in the Merrins Lab explored the role of the amino acid leucine in regulating secretion of glucagon, a hormone released in response to fluctuations in blood sugar.
Glucagon is produced by pancreatic alpha-cells — one of the types of cells that form clusters known as pancreatic islets — and helps maintain blood sugar during periods of fasting and hypoglycemia. It also acts as a signaling molecule, communicating with neighboring islet cells. Understanding how nutrients and signals from other islet cells control glucagon release may lead to new opportunities for treating metabolic conditions such as diabetes.
Scientists believe that glucagon secretion is regulated in two ways. Calcium levels in the cell act as an on-off switch, while the signaling molecule cyclic AMP acts as a dimmer switch to control how much glucagon is secreted. Knuth investigated the role that different amino acids play in regulating cyclic AMP levels. She found that the amino acid leucine inhibits cyclic AMP production and lowers glucagon secretion. Her research has been published in Science Advances and further work is undergoing peer review.
Knuth’s interest in studying the interconnectedness of molecules responsible for metabolic pathways stemmed from her childhood on a beef farm in Iowa. “I thought I was going to be a plant breeder and that my studies would address food security,” recalls Knuth. “But after I took a human nutrition class as an undergrad, I realized my interests lay more with what happens to food after you eat it.”
Her graduate research was further influenced by her lab’s location in the William S. Middleton Memorial Veterans Hospital, along with several labs from departments across University of Wisconsin–Madison also studying diabetes.
“When you’re with your own lab, it’s easy to forget that there are so many important aspects to diabetes research besides metabolism and alpha-cells. It’s easy to lose the forest for the trees,” Knuth reflects. “Here, we’re interacting with people who all ask questions that are based off their different specialty within diabetes research. It really helps you think about the bigger picture and real-world applications. It just really broadens your perspective and makes you think about the things that your lab isn’t focused on, which I have found really helpful.”
To learn more about Knuth’s research, attend her Ph.D. defense, “Role of Branched Chain Amino Acid Leucine in Suppressing Alpha Cell cAMP and Glucagon Secretion,” on Tuesday, April 30 at 9:00 a.m. CT in Room 1211 of Hector F. DeLuca Biochemical Sciences Building.