Here’s what you’ll learn when you read this story:

• Tardigrades are the hardiest creatures on Earth, capable of surviving extreme cold and heat, and able to handle 1,000 times more radiation than humans.
• A new study aims to describe the biochemistry and structure of one of its most well-known defenses—a damage suppressor protein known as Dsup.
• Scientists discovered that this protein adheres to DNA and partially unwinds it, providing increased protection against radiation.

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There’s no animal on Earth (or in space, for that matter) quite like a tardigrade. In some ways, this is literally true, as tardigrades—also known as “water bears” because of their pudgy, bear-like appearance—represent their own phylum. But they also have some of the most extreme biology ever observed in the animal kingdom. No bigger than half a millimeter, tardigrades can endure extreme cold and heat, can enter in a protective state known as biostasis, and can withstand 1,000 times more radiation than a human.

This last remarkable factoid is of particular interest to Tyler Woodward from the University of Iowa, who—along with his co-author, Todd Washington—published a new study in the Journal of Molecular Biology that attempts to unpack the structure and biochemical attributes of one of the tradigrade’s greatest molecular weapons: a damage suppressor protein known simply as “Dsup.” Using an array of techniques, including mass photometry, biolayer interferometry, small-angle X-ray scattering, and microfluidic modulation spectroscopy, the authors discovered that this protein binds to DNA and partially unwinds it, which reduces its capacity for damage.

“It clings tightly to DNA—not just at one spot of the molecule but along its entirety,” Woodward wrote in a recent article for The Conversation. “Dsup doesn’t have a fixed shape. Instead, it behaves more like a spaghetti noodle in water, constantly shifting, bending and adopting many different shapes.”

This Dsup protein isn’t a new discovery—a team of Japanese scientists first discovered the protein back in 2016. According to Woodward, Dsup comes from a “gene with a sequence unlike any other known to exist in nature that makes a protein found only in tardigrades.” So, it’s no wonder that many scientists have explored its properties to potentially harden our own, much more fragile human biology.

There’s also a chance that Dsup could be used for cancer treatments. Because radiation is a key tool for nearly all types of cancers, developing a therapy laced with the Dsup protein could protect patients from some of the damaging side effects of these treatments.

Earlier this year, the University of Iowa published a study in the journal Nature Biomedical Engineering revealing that polymer-lipid based nanoparticles could deliver mRNA instructions to produce the Dsup protein. These nanoparticles target oral and rectal cells in mice, which are often damaged during radiation therapy, and found that the treatment produced enough of the Dsup protein to protect cells from radiation damage.

“This is an entirely novel approach for protecting healthy tissue and may eventually offer a way to optimize radiation therapy for patients while minimizing these debilitating side effects,” James Byrne, a co-author of the study from the University of Iowa, said in a press statement at the time.

However, this is only one important scientific avenue for Dsup. Woodward notes that scientists have investigated ways to use the protein to make plants more radiation resistant and to make astronauts safer during interplanetary travel. After all, tardigrades are the only known species that can survive in the vacuum of space.

For 500 million years, tardigrades have called Earth home, and they’ve been patiently waiting for a big-brained species like us to take notice and discover all of their incredible secrets.

Darren lives in Portland, has a cat, and writes/edits about sci-fi and how our world works. You can find his previous stuff at Gizmodo and Paste if you look hard enough.