The phrase seeing is believing doesn’t just apply to supernatural phenomenon; biochemists often say the same thing when imaging proteins or other molecules for the first time.
Imaging is a powerful tool in many biochemists’ repertoire. The Department of Biochemistry at the University of Wisconsin–Madison is home to a large collection of equipment and facilities, including the Biochemistry Optical Core (BOC) and upcoming UW–Madison cryo-electron microscopy (cryo-EM) facility, that allows scientists to pursue their many imaging endeavors. The department’s goal is simple: to provide faculty, researchers, and students from the department and all across campus with access to these resources and the training to operate them, even if they’ve never used them before.
Elle Kielar-Grevstad, the director of the BOC and supervisor to the department’s core facility staff, serves to promote and facilitate the department’s mission by helping researchers with their light and fluorescent microscopy needs.
“Imaging is really capturing a state of being,” she says. “That can mean a lot of things depending on what resolution you require. Whether you are looking at a whole animal, a tissue, a single cell, or a single protein, you’re still capturing a state of being, or in many cases multiple states of being. Your research question will determine the resolution requirements and that in turn dictates what type of equipment you need. The great thing about all the core facilities at Biochemistry is that we can likely help you meet your imaging or experimental needs, and if we can’t, it is our job to connect you with others on campus that can.”
Context is Key in Biochemistry and More
Imaging provides something very important in molecular biology, cellular biology, and biochemistry: context. While laboratory techniques in a test tube can measure the reaction of an enzyme of interest, what imaging provides is the context of where that reaction is taking place within an organism or within a cell. This can lead to a richer understanding of a biological process, which can then lead to the development of new products, tools, drugs and treatments.
“Molecules are not static objects within cells and understanding the dynamics of a protein can lead to greater understanding of its function or functions within a complex environment,” Kielar-Grevstad explains. “At the BOC you can easily alter conditions and watch what happens in real time, whether that is seeing your molecule move from the nucleus into the cytoplasm or watching it affect a specific signaling cascade. The outcomes and questions you can ask are endless.”
Researchers in the Department of Biochemistry as well as the Department of Biomolecular Chemistry utilize the facilities often. The two departments make up the joint graduate program, the Integrated Program in Biochemistry (IPiB).
The lab of biochemistry professor Tom Martin studies the process of vesicle exocytosis, where tiny structures, or vesicles, in the cell exit through the plasma membrane. BOC microscopes allow him to see what’s taking place on the cell surface via live cell imaging, a powerful and important technique. Among many other users, Professor Sebastian Bednarek uses imaging to get a look at trafficking pathways in plants at the cellular level, while the lab of Professor Alan Attie images insulin-secreting beta cells involved in diabetes.
“What imaging can give you is localization information,” Martin says. “You can determine where a molecule of interest resides in the cell, and establishing that location is a very important thing to be able to do.”
Scott Messenger, a postdoctoral researcher in the Martin Lab in Biochemistry, is a frequent user of the optical core. He studies cancer cells and how they communicate with other cells. In particular, he focuses on a process where a cancer cell takes a tiny membrane structure and delivers it to another cell, where that other cell may take it up and become a cancer cell itself.
“We’ve been imaging the little pieces of membrane going from one cell to another in this rare event,” Messenger says. “With the microscopes in the BOC, we are able to do it in live cells and just watch these membranes budding off. It’s pretty amazing and very useful for the research. I actually think we are the first to see this happening in a live cell.”
He adds that the microscopes allow him to take a focused view of the plasma membrane but also a deeper view of the entire cell to see the structure forming inside the cell and making its way to the membrane to be released. Without this type of information, researchers can’t begin to think about how to disrupt this process and pursue this avenue of cancer treatment.
“As soon as I was ready, I talked to Elle and she trained me to use the microscope and I now have essentially unlimited access to them,” he explains. “I have undergraduates in the lab that are able to do a quick training and take publication quality images. I don’t think experienced researchers elsewhere have that kind of access, and these are undergraduates.”
Imaging for All
The history of a shared imaging facility in the department goes back to a commitment the UW–Madison Department of Biochemistry made in 2012 to invest in expanding its imaging capabilities. Five years ago, Martin worked to encourage this investment. He believed that the next wave of research in biochemistry would be performed under microscopes where scientists can directly visualize single protein molecules, their interactions with one another, and how they perform their roles in cells.
“The advances in microscopy and optical imaging were coming fast and furious at that time, and still are, and I wanted the department to stay ahead of that,” he says. “Our goal was two-fold: to add microscopes and equipment we didn’t already have and to make it more useful for Biochemistry, as well as open as a resource to the entire campus.”
Out of this initiative, the BOC was formed and Kielar-Grevstad became its first director. Under Kielar-Grevstad’s direction the BOC’s impact has gone beyond the department and IPiB. Across campus, Kielar-Grevstad assists scientists from numerous disciplines — about 173 different researchers from 71 faculty members labs in 23 unique departments across five colleges overall.
“Facilities like this are invaluable and an irreplaceable resource that can lead to a whole new perspective on your research program,” Martin says. “The upcoming cryo-EM facility also has researchers excited about investigating at even higher resolution. We are continuing to push the boundaries of imaging.”
Kielar-Grevstad says her day-to-day work is always interesting, pulling from many different disciplines. She works to cultivate a community where a diverse cross-section of researchers uses the instruments in slightly different ways to address very different questions. She tries to push scientific boundaries by providing a platform to share knowledge across those disciplines.
“A day in the life of the Biochemistry Optical Core is always fascinating,” she says. “Just the other day I was helping someone from engineering image RNA in wastewater treatment sludge. They are engineering bacteria to operate under lower oxygen levels to make wastewater treatment less expensive. The next person was imaging American cheese to look at its fat content. The distribution of the fat affects mouthfeel and taste. On that same day, a group of biochemists were imaging live immune cells and assessing responses to antigen activation.”
Staying Ahead of the Curve
Kielar-Grevstad’s hope is that all researchers at UW–Madison — especially students — know they can come to the core facility staff members for assistance with imaging or instrumentation needs, even if they’ve never used that equipment or technology before.
“The reason the core facilities were developed was to give everyone easy access to high-end instrumentation and the technical expertise to use that instrumentation effectively,” she explains. “This allows anyone — students, postdocs, faculty, research staff — the opportunity to walk into our offices, talk about research, and get the help they need to push their innovative research forward.”
Kielar-Grevstad adds that this open access, community building mission will be especially important because the new high-resolution cryo-EM instrument — expected to be in place in late 2018 or early 2019 — will help open new avenues for obtaining advanced structural biology data. The department has ensured this mission with the hire of a cryo-EM technical expert, Desiree Benefield, who joined the department in September 2017.
“It is our job as facility staff scientists to stay abreast in the current cutting-edge methods and to ask the researchers the right questions so that we fully understand what the experimental goals are,” Kielar-Grevstad explains. “This allows us to educate and then guide researchers from Biochemistry and elsewhere to the resources, tools, instruments, and techniques they need to be successful.”
This article was originally published on the UW–Madison Department of Biochemistry’s website. Photos: Robin Davies.