CLDN16
Description
The CLDN16 (claudin 16) is a protein-coding gene located on chromosome 3.
Claudin-16 is a protein encoded by the CLDN16 gene in humans. It belongs to the claudin family, integral membrane proteins that are components of tight junctions. These junctions are critical for maintaining the integrity of epithelial and endothelial cell sheets by forming continuous seals that prevent the free passage of solutes and water. CLDN16 is primarily found in the kidneys, specifically in the thick ascending limb of Henle, where it regulates the paracellular resorption of magnesium ions. It is believed to act either as an intercellular pore or an ion concentration sensor. Defects in the CLDN16 gene can lead to primary hypomagnesemia, a condition characterized by excessive renal magnesium loss, hypomagnesemia, hypercalciuria, and ultimately nephrocalcinosis and kidney failure.
CLDN16, also known as Paracellin-1, plays a critical role in maintaining the integrity of tight junctions, the specialized cell junctions that regulate the passage of molecules between cells. It achieves this by contributing to the obliteration of the intercellular space, a process that is independent of calcium. Its function is essential for the paracellular reabsorption of magnesium, ensuring the selective passage of ions. CLDN16 may form an intercellular pore that allows the movement of magnesium and calcium ions down their electrochemical gradients, effectively acting as a gatekeeper for these ions. Alternatively, it could serve as a sensor for magnesium concentration, modulating the paracellular permeability controlled by other factors.
CLDN16 is also known as HOMG3, PCLN1.
