Dr. Mingyi Xie, assistant professor in the Department of Biochemistry and Molecular Biology, is exploring tiny molecules with big influence over cells - microRNAs (miRNAs). These miRNAs have important roles in how our cells develop and function differently, despite having the same copy of DNA in each nucleus.
Dr. Xie earned his PhD from Arizona State University and did his postdoctoral research on miRNA biogenesis at Yale. He joined the University of Florida faculty and became a member of the UFGI in 2016. His academic interests, however, started in a very different field than his current research.
“When I was a kid, I was a big animal lover. The weirdest animal I kept was an owl. I was very inspired to go into biology, and later on, ecology.”
Dr. Xie grew up in southeastern China, where he did his undergraduate research on preserving local mangrove forests in the face of increasing urban development.
“How could we repopulate these forests and restore the population? [The research] took a lot of effort and I feel that these large scale projects could not be controlled as well as if I had done it on a micro scale, like in a lab. There are so many moving parts to consider, therefore a decisive conclusion could not be drawn easily.”
Dr. Xie's experience with fieldwork led him to discover his passion for working in a laboratory setting. He transitioned to molecular biology research during his time in graduate school at Arizona State. From there, his research interests further focused on his current research on miRNAs and their biogenesis, function, and degradation.
Biogenesis and Degradation of microRNA
Gene regulation is a tightly controlled process, allowing cells to differentiate in their development and adapt to their environment. Even though this process is integral for cell and organism function, it is still not fully understood. Dr. Xie is working to change this.
When gene regulation is done improperly and protein production is mismanaged, issues can arise for the individual ranging in severity from benign to very dangerous.
Noncoding RNAs like miRNA are a part of this puzzle, even though they don’t explicitly code for proteins. They are abundant and useful during gene regulation, but how and why they are used is still being defined. He explained that they play a role with mRNA translational output.
Dr. Xie is specifically interested in the processes that regulate these important molecules, particularly how miRNA levels are regulated within the cell.
“For certain miRNAs, biogenesis is not the primary way that their levels are regulated. We are now venturing into a new area- miRNA degradation.”
Given that miRNAs are a type of long-lived RNA, it is important to have ways to manage their levels within cells through this degradation process.
“Recently, it was discovered that mRNAs that are normally targeted by miRNAs for degradation can actually turn the tables on miRNA and cause them to degrade.” In some cases, there is a specific mRNA that can be used to clear out miRNAs. This can rescue the other mRNAs from being repressed by the miRNA and keep them functional.
“When miRNAs are made, they are very stable. We need to have an active way to get rid of them. Our goal is to find out how this detailed mechanism can be active when we want it to be active, and deactivate it, based on the need.”
Mentoring and Education in the Lab
Like other great instructors, Dr. Xie’s success is measured by more than just his research.
In 2020, Dr. Xie was awarded the UF College of Medicine's Exemplary Teacher Award, celebrating his tireless dedication to his students and their success.
“I really like teaching, so I am very proud of the Exemplary Teacher Award. Throughout my career, I have mentored many students. I was a teaching assistant for five years in graduate school, so I got a lot of educational experience early on. I actually mentored four undergrads as a graduate student too.”
He went on to explain that he enjoys working with students because of the “interesting, probing ‘beginner’ questions they ask that make you rethink the topics at hand”.
“My postdoc advisor Dr. Joan Steitz always told me that even though we may lead a research focused career, we still should do classroom teaching. You will benefit a lot from that in your own research.”
The Xie Lab currently has one assistant research scientist, two postdocs, three graduate students, three undergraduates, and one lab technician.
“We have a pretty diverse team, which I think is really good,” he commented.
On campus, Dr. Xie can often be seen riding his electric skateboard to his lab.
“I picked it up while at Arizona State as a graduate student. I am definitely open to new things!” ∎