water transmembrane transporter activity

Definition

Target type: molecularfunction

Enables the transfer of water (H2O) from one side of a membrane to the other. [GOC:ai]

Water transmembrane transporter activity refers to the movement of water molecules across biological membranes. This crucial process is facilitated by specialized proteins known as aquaporins. Aquaporins are integral membrane proteins that form channels through which water can pass rapidly and selectively. The molecular mechanism underlying water transport by aquaporins involves a series of intricate interactions between water molecules and the protein's amino acid residues. The aquaporin channel is typically lined by hydrophilic residues, which attract water molecules and allow them to move through the channel. However, the channel also contains a narrow constriction point, known as the "selectivity filter," which prevents the passage of larger molecules such as ions and solutes. This selectivity filter ensures that only water molecules can traverse the channel, maintaining the integrity of cellular and organellar compartments. The movement of water through aquaporins is driven by the osmotic gradient across the membrane. This gradient arises from differences in the concentration of solutes between the two compartments. Water molecules flow from areas of high water concentration (low solute concentration) to areas of low water concentration (high solute concentration), driven by the tendency to equalize the solute concentration. This process is essential for numerous physiological functions, including maintaining cell volume, regulating blood pressure, and facilitating nutrient transport. Aquaporin-mediated water transport is highly regulated and influenced by factors such as pH, temperature, and the presence of specific ligands. The dysregulation of aquaporin activity has been implicated in various diseases, including diabetes, kidney disease, and neurological disorders.'
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Proteins (2)

Compounds (16)