Incubator for Innovation

As a postdoctoral fellow at the European Molecular Biology Laboratory, Mosalaganti honed his expertise in the burgeoning field of cryo-electron tomography (cryo-ET). This technique involves flash-freezing cells and then using specialized microscopes that beam electrons at the sample to reveal the three-dimensional structure of complex biological machines in their native cellular environment.

As he began planning for his own lab, Mosalaganti got the itch to expand beyond the types of protein complexes he’d studied as a postdoctoral fellow. Instead, he wanted to use cryo-ET to investigate organelles — specialized compartments of the cell that perform specific tasks. He was particularly interested in lysosomes, organelles that break down unnecessary and malfunctioning biomolecules to be recycled or removed from the cell.

“Changing research topics like that is a bit of a risk when launching a lab, because the larger funding agencies want to see that you already have some experience or preliminary data,” says Mosalaganti, who is now an assistant professor at the U-M Medical School and College of Literature, Science, and the Arts, in addition to his LSI appointment. “But with the advanced instrumentation and connections across disciplines, the LSI just felt like a place where I could already see my research growing and being successful.

By October 2022, Mosalaganti had secured his first major funding award to advance his research program: the highly competitive NIH Director’s New Innovator Award (or DP2 Award), which supports early-career investigators to pursue bold, creative research projects.

With the five-year award, he hopes to figure out how various organelles, including lysosomes, connect with each other to regulate processes that are essential for the life of all cells.

In the initial phase of this project, Mosalaganti first had to develop a pipeline of microscopes, software and data analysis tools that could capture dynamic organelles coming together, in high resolution. With all the pieces in place now, Mosalaganti says the pipeline can swiftly be adapted for a range of projects while also moving the DP2 work forward.

“It’s a good platform for asking new questions, or asking questions differently, because we can look inside cells and see what’s happening in unprecedented detail,” he says. “Already we’re finding evidence that contradicts some long-held beliefs in the field.”

That platform also serves as the foundation for other projects in his lab, including a collaboration to unearth new understandings of neurodegeneration.

A common feature across neurodegenerative disorders — Alzheimer’s disease, Parkinson’s disease, frontotemporal dementia and others — is abnormal protein aggregation, primarily within neurons. These are proteins that a healthy cell would normally clear out, like taking out the garbage. Genetic abnormalities, risk factors and aging can slow or halt the clearing processes, allowing the garbage to pile up until it eventually chokes the cell.

“One way to inhibit the formation of these aggregates would be to determine their structure so you can target them,” Mosalaganti explains. “But neither conventional microscopy nor patient tissues can show us where within the cell these proteins are aggregating and what they look like during the formation process, before it’s too late to intervene.”

He hypothesized that cryo-ET could uncover what the aggregates look like within patient-derived neurons in various stages of aggregation. Even before he arrived in Ann Arbor, one of Mosalaganti’s soon-to-be colleagues connected him with a neurologist on campus who could help him test this theory.

LSI professor Lois Weisman, who studies how cellular cargo is transported within neurons, heard about Mosalaganti’s postdoctoral research and thought his structural biology expertise would be a good addition to a consortium of U-M faculty who study protein folding and trafficking. That’s where Mosalaganti met physician-scientist Sami Barmada, an associate professor of neurology in the Medical School and the director of the Michigan Brain Bank.

He and Mosalaganti quickly hatched a plan to use cryo-ET to peer directly into neurons and determine where and how these proteins were aggregating. To get started, they applied for seed funding from the LSI’s Klatskin-Sutker Discovery Fund. This philanthropic award supports early-stage research that has high potential to positively impact human health. That funding allowed them to visualize the protein aggregates directly in patient-derived neurons, providing enough data to demonstrate their proof of concept.

Less than four years after their first meeting, the team now has a grant from the Kissick Family Foundation and Milken Institute, and the project is expanding in scope and detail. They next plan to apply their approach to neurons that carry specific genetic mutations associated with frontotemporal dementia. They will also use patient tissue to map the detailed structure and location of the proteins in unprecedented detail.

The research has the potential to identify more effective therapeutic avenues for frontotemporal dementia. The team has already uncovered data indicating that one prominent strategy others are using to develop treatments is unlikely to work, based on where they are finding the protein aggregates within the cell. 

 “I think, in retrospect, this project would have taken much longer if Lois had not introduced me to this consortium — and now we already have a full team working on this with exciting new discoveries,” Mosalaganti says.

“That’s the benefit of being somewhere like the LSI. As scientists, we each have a finite amount of time to make an everlasting impact and address outstanding, difficult-to-tackle questions in biology. It really helps to be at a place like the LSI, where you have access to excellent resources and connections across disciplines that allow you to address these big questions.”

Mosalaganti was one of two U-M faculty members to receive the NIH Director’s New Innovator Award in 2022. (Prior to that, no U-M faculty had received the award since 2016, and only five had received it in the past decade.) The second recipient was his colleague and upstairs neighbor at the LSI, Wenjing Wang.

Wang joined the LSI faculty as an assistant professor in 2018 with a plan to engineer cellular proteins for studying cell activity. Her lab develops specific types of genetically encoded tools called chemogenetic and optogenetic tools.

In general, genetically encoded tools work by delivering a small sequence of extra DNA to the nucleus, prompting the cell to produce the protein encoded in the DNA — like sending a factory a new set of instructions to build one extra type of machine part, with the thousands of parts it’s already building. Once that new protein is built, it begins performing the job it was designed for, such as activating a cellular process, targeting an unwanted protein or even silencing the whole cell. But Wang’s tools also incorporate an extra on/off switch.

“With chemogenetics and optogenetics, we’re basically adding another layer of control,” says Wang, now an associate research professor at the LSI and associate professor of chemistry in the College of Literature, Science, and the Arts. “Instead of becoming active as soon as they are built, these proteins do not turn on until we add a chemical or light to the cell. So we can remotely control when they start or stop the function we want to see.”

The tools are a powerful platform for fundamental discovery science, allowing researchers to uncover how specific cellular functions contribute to health and disease. With the DP2 Award, for example, Wang hopes to create tools that will unlock new understandings of G protein-coupled receptors (GPCRs) — a large family of proteins that sit on the surface of every cell to receive messages and inform cellular behavior.

While Wang is developing these tools to help advance her own research questions, her lab is certainly not the only one benefiting. Other LSI labs are now implementing these tools to investigate how different neurons control breathing and how proteins found in one brain region can regulate food intake in mice. And recently, she’s partnered with LSI faculty member Bing Ye to customize her tools for fruit flies.