All living things rely on fluid balance to function. When not enough water is being moved through the cell membrane, cells can fix this with their water channels, or aquaporins, which can open and close.

Scientists from the University of Gothenburg recently found a water channel in a fish that seems to have a unique valve that closes quickly.

In the long run, this discovery could be important for making drugs to treat cancer and Alzheimer’s.

Fish live in water that has different levels of salt, and some species can stay alive on land for up to a week. This makes their aquaporins work in a very specific way so that they can control the amount of water in their cells even when they are in very different environments.

By analyzing the aquaporins in the cells of climbing perch (Anabas testudineus), a species of climbing fish that occasionally climbs out of the water and spends time on land, scientists have identified a water channel that appears to have a distinctive quick-closing valve. Life Science Alliance published their findings.

The findings, according to biochemist Kristina Hedfalk, show “the first high-resolution structural characterisation of a water channel found on the skin and gills of fish. 

“We can see that this channel,” the biochemist added, “which is in fact a protein, has a unique fold on the exterior surface of the cell, indicative of a previously unknown type of quick-closing valve in a water-specific aquaporin. The valve enables the water channel to open or close quickly, depending on the changing environment of the fish.”

Reduces pressure

Understanding how aquaporins work to control water flow could lead to the development of new drugs to treat conditions like cerebral oedema, which could save lives after an accident or the start of a disease.

When cerebral oedema happens, it is very important to be able to lower the pressure in the brain before it does any damage.

By growing the protein that makes up the valve in the fish’s water channel in the lab, researchers have found the bits that can control the fluid balance in cells when there are sudden changes.

Previous research has shown that the function of aquaporins in brain cells is reduced when Alzheimer’s disease starts. Because of this, this study could also be a good step toward making drugs for this disease.

“This is important basic research, where we can see the regulating protein at molecular level,” Kristina Hedfalk said. 

“In addition to its potential relevance to drug research, it is also important for us to understand the water channels in fish when managing them in aquaculture settings, so that the fish stay as healthy and comfortable as possible.”

Source: 10.26508/lsa.202201491

Image Credit: Shutterstock