Aquaporins, long thought to be only water pores, also carry ions across species.

Scientists once thought aquaporins, or AQPs, were simple tunnels in cell membranes that stayed open just to let water pass through. But this view left out how cells handle more complex challenges. Researchers analyzed aquaporin structures across living things, comparing their building blocks, called amino acids. They found these channels work like multifunctional gates. Instead of staying constantly open, specific signals from inside and outside the cell can switch them on or off. Different parts of the protein act as filters and gates to decide what gets through. Surprisingly, at least fifteen classes of AQPs can move charged particles, called ions, along with water. These dual water-and-ion channels help living things manage nutrients, move cells, detect sensory signals, protect against stress, and communicate across tissues.

Why it matters

This matters because it reveals that aquaporins are not just passive water channels but active ion transporters. They are found in many organisms and control processes like cell movement, nutrient uptake, and signaling. Understanding this dual function could lead to new insights in medicine and agriculture.

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