Meet the tardigrade, also known as the water bear—one of the toughest creatures on Earth. These microscopic organisms are practically indestructible. They can survive extreme temperatures and pressures, live without water, and even withstand harmful high-energy radiation. One of the secrets to tardigrades’ toughness is a unique protein, or large biological molecule, called Dsup. Recently, scientists in Spain discovered how this protein might work.
Normally, high levels of radiation can destroy an organism’s DNA. This molecule carries a creature’s hereditary information and all the instructions it needs to function. When a Dsup molecule encounters DNA inside a tardigrade’s cell, the flexible protein alters its shape to surround and protect the DNA. “It acts like a shield,” says Luis Fernández Pacios, a chemist at the Polytechnic University of Madrid in Spain who helped discover this process.