The University of Missouri recently had three faculty members named 2018 Fellows of the American Association for the Advancement of Science (AAAS). Two of those faculty members, Scott Peck and Shi-Jie Chen, have ties to the Department of Biochemistry at MU.
Peck is a professor of biochemistry and investigator in the Bond Life Sciences Center. Chen is an MU Curators Distinguished Professor of Physics in the MU College of Arts and Science, a Joint Curators Distinguished Professor of Biochemistry in the MU College of Agriculture, Food and Natural Resources, and a core faculty member in the MU Informatics Institute.
Putting Together a Puzzle
Peck was honored for his “distinguished contributions to the field of plant-microbe interactions and disease resistance in plants with major contributions to proteomics technology.” It was that research that put Peck on MU’s radar nearly 15 years ago.
“I’m very thankful for this honor,” Peck said. “I’m also thankful for the people in my lab, as I really rely on them. It’s so rewarding to work with them. Nothing comes easily – but those moments when you have been working late into the day and make a discovery – that’s what makes this so exciting.”
Peck was invited to speak during the MU Interdisciplinary Plant Group’s annual symposium in 2003, while working at the Sainsbury Laboratory at the Norwich Research Park in England. Peck’s talk was focused on protein phosphorylation – a process that changes the structure of the protein and modifies its function.
“It was an incredible circumstance of timing,” Peck said. “My wife and I were looking to come back to the United States at the time, and I got an opportunity to speak at MU. With the great plant community here, we knew we had found a great fit.
“You have to work hard to make sure you’re prepared for the opportunities that come your way – but sometimes things just come together.”“It takes someone to nominate you for this honor, and that’s the cool thing about Mizzou. People want to rise up together. This award isn’t about me – it’s about us. Someone took the time to gather the information and fill out the paperwork. It won’t be long until I get the chance to do this for somebody else, and I’m already looking forward to it.”
Peck’s wife is Antje Heese, an associate professor of biochemistry. The two officially joined Mizzou in 2005.
Peck’s work at the Sainsbury Laboratory focused on proteomics in plants. Proteomics is the study of proteomes – a set of proteins produced in an organism, system or biological context – and their functions. He started his research group right when the technology related to proteomics really took off.
“Plants have to respond to changes in light, temperature, water availability and many other stresses,” Peck said. “One of the main ways that cells process information is by modifying proteins. There are multiple ways proteins can be modified, including phosphorylation.”
To survive attacks by potential bacterial pathogens, plants must prioritize and integrate the incoming information. It’s an incredibly complex system – one that Peck and his lab at MU are working to gain a deeper understanding of.
“We have ways to chemically or genetically enhance resistance to these pathogens,” Peck said. “However, there can be a tradeoff that happens, such as the plants ending up being smaller. As the plant is trying to raise its immune response, all of the energy goes there instead of growth. So while we can have plants that are more resistant, there can be a tradeoff in overall plant production.
“We’re working to understand the recognition signaling pathways. We want the plant to be more resistant – but without the penalty.”
Peck describes his work as putting together a puzzle. The pieces are phosphorylated proteins, and it is Peck’s job to find where the pieces go.
“We use reverse genetics to find out what responses the proteins are altering,” Peck said. “That process helps us put the puzzle back together.”
Peck and his lab have made many breakthroughs during his tenure at MU. They have uncovered a number of important proteins that hadn’t come to light for various reasons. He is currently working with a mutant plant that is a “stealth” plant.
“When bacterial pathogens land on a plant, they inject 20 to 30 proteins that shut down the plant’s immune system,” Peck said. “The pathogens live out in the environment but only turn on this invasion program when they recognize that they’re on a host. We’ve found this plant that when the pathogen lands on it, the pathogen doesn’t produce or inject the toxic proteins.
“We’ve identified the plant chemicals that are important, but we don’t know how the plant controls the levels of these signals. I think we’re really close to figuring out the pathway. We think that this is a very early aspect of resistance that basically controls the war between the bacteria and the plant. It’s been a nice piece of detective work.”
Peck and Heese were able to enjoy Peck’s AAAS award together when they first found out about it. With an embargo on publicizing the award, the two of them were able to celebrate the honor before anyone else knew about it.
“Antje really understands the impact of this award, so it was really great to be able to share the news with her,” Peck said. “She is somebody who really appreciates the honor. In the world of instant media, it was nice that we were able to enjoy the moment as a family.
“It takes someone to nominate you for this honor, and that’s the cool thing about Mizzou. People want to rise up together. This award isn’t about me – it’s about us. Someone took the time to gather the information and fill out the paperwork. It won’t be long until I get the chance to do this for somebody else, and I’m already looking forward to it.”
A Major Contribution
After completing his Ph.D. in physics from the University of California, San Diego, Shi-Jie Chen was contemplating future post-doctoral research. A seminar about how proteins can be folded into three-dimensional structures gave Chen the perfect field of research to pursue.
Chen joined MU in 1999 after completing a five-year post-doc at the University of California, San Francisco. Chen’s lab develops computer models for biomolecular structure and function with a main focus on ribonucleic acid (RNA) molecules.
“I thought I could make a contribution in the protein folding area,” Chen said. “I was interested in entering the bio field anyway, and that was the sole focus of my post-doc. I worked on how proteins are folded into three-dimensional structures.”
Chen earned his AAAS Fellows honor for his “distinguished contributions to the field of computational and theoretical biological physics, particularly for theoretical modeling and computational predictions of RNA folding and function.”
“I am honored to receive this award,” Chen said. “It’s a nice recognition of hard work – and also a recognition of the students and post-docs in my lab. I hope that this helps them get more future recognition.”
All of Chen’s research is centered on the RNA molecule and its functions. He describes his pedigree as “quite unusual” as his research is more related to biochemistry and his Ph.D. is in physics. His tenure home is the College of Arts and Science as he teaches physics.
“When I came to MU for an interview, the department was in the process of building the biophysics program,” Chen said. “I could feel the passion from the leadership, which was very exciting. It’s been extremely rewarding to teach and do research with my colleagues at Mizzou.”
Chen said that he works in three general areas when it comes to RNA. The first is related to using a computer to predict a three-dimensional structure.
“This problem is critically important for biology because structure determines function,” Chen said. “We can use X-ray to measure and determine the structure, but given the vast number of sequences coming out, the experimental methods alone cannot stay up with the rapid pace. We need a more efficient method – a computational method.“I thought I could make a contribution in the protein folding area. I was interested in entering the bio field anyway, and that was the sole focus of my post-doc. I worked on how proteins are folded into three-dimensional structures.”
“We’re trying to develop the best computational methods possible to predict RNA structures, and we’re working to understand how RNA molecules change the structures to regulate gene expression.”
Chen said that they use physical methods to predict the structures as well.
“RNA and DNA molecules are highly charged,” Chen said. “In the cell, the positive charge is attracted to the negative charge. The charges on RNA and DNA can be neutralized by metal ions and the molecules become more flexible. That allows them to form different functional structures.
“In the cell, you have metal ions. We use a computer to predict where these metal ions bind and how tightly they bind to the molecules, which is the second area of my research.”
The third area of RNA research Chen works on is related to biomedical applications. His lab works with Professor Xiao Heng in the Department of Biochemistry on structure-based understanding of HCV and HIV gene expression. Through collaboration with Professor Dongsheng Duan in the Department of Molecular Microbiology and Immunology, Chen’s lab works on CRISPR technology to understand the mechanism of gene editing and applications to gene therapy. In collaboration with Professor Li-Qun (Andrew) Gu in the Department of Bioengineering and Dalton Cardiovascular Research Center, the Chen lab also develops computational approaches to RNA folding and RNA-targeted therapeutic design with nanopore-based single-molecule technology.
Chen grew up in China and earned an undergraduate degree in physics at Zhejiang University. He came to the United States in 1988 through the China-U.S. Physics Examination and Application (CUSPEA) program. The program was used by American universities to recruit top physics graduate students from China.
“There were multiple written tests and interviews,” Chen said. “They put together an evaluation and sent it to the top 100 research universities. The top 75 or so students were chosen from a large pool of students.”
Chen met his wife, Xiaoqin Zou, through the CUSPEA program. Zou is a professor of physics and a professor of biochemistry at MU as well.
“We had never been in Missouri before coming to Mizzou,” Chen said. “My office-mate was very confused as to why we were leaving the nice California weather for Missouri. We love it here, though.”
Chen will continue to work with the RNA molecule, and hopes to keep providing new research findings as he goes along.
“RNA molecules used to be the kind of molecule that people weren’t that interested in,” Chen said. “Historically, people were more interested in DNA and proteins. The reason, I think, was that we had extremely limited knowledge about RNA molecules, especially the cellular functions of noncoding RNAs. Currently, the field is moving rapidly as more and more emerging discoveries in biomedical sciences and new biotechnologies all point to the key roles of RNA. We are excited to be able to solve some hard problems and provide answers to some important biology questions.”