aquaporiinien

Aquaporins are a family of integral membrane proteins that form pores in the cell membrane. They function as selective channels, primarily facilitating the transport of water molecules across biological membranes. Discovered by Peter Agre in 1992, who was awarded the Nobel Prize in Chemistry in 2003 for this work, aquaporins are found in virtually all living organisms, from bacteria to plants and animals.

These proteins are crucial for maintaining cell hydration and osmotic balance. In mammals, aquaporins are particularly abundant in tissues with high water transport rates, such as the kidneys, where they play a vital role in reabsorbing water and concentrating urine. In plants, aquaporins are essential for water uptake by roots, transport through the xylem, and transpiration from leaves.

The structure of aquaporins is characterized by a conserved motif that allows them to recognize and transport water while excluding ions and other small molecules. This selectivity is a key feature that differentiates them from other ion channels. While water transport is their primary function, some aquaporins have been found to transport small uncharged molecules like glycerol or urea, leading to the broader classification of aquaglyceroporins. Dysfunctional aquaporins are implicated in various diseases, including kidney disorders, neurological conditions, and diabetes insipidus, highlighting their critical role in physiological processes.