Sodium/potassium/calcium exchanger 4

Sodium/potassium/calcium exchanger 4 (NCKX4) is a protein that in humans is encoded by the SLC24A4 gene. This protein is part of the solute carrier family 24 (sodium/potassium/calcium exchanger), which plays a critical role in calcium (Ca2+) homeostasis in various tissues, including the kidney, brain, and skin.

Function

NCKX4 functions as an antiporter that facilitates the exchange of sodium (Na+) and potassium (K+) ions for calcium ions across the cell membrane. This exchange process is vital for maintaining the proper function of cells, particularly in the regulation of neurotransmitter release in neurons, muscle contraction, and the maintenance of skin barrier function. The activity of NCKX4 is crucial for the reuptake of calcium ions into the cell, helping to regulate intracellular calcium levels and thus contributing to cellular signaling and homeostasis.

Structure

The structure of NCKX4, like other members of the solute carrier family, consists of multiple transmembrane domains that span the cell membrane. These domains form a pathway that allows for the selective exchange of ions between the intracellular and extracellular environments. The exact structure and the number of transmembrane domains in NCKX4 are subjects of ongoing research, but it is known that the function of the exchanger is highly dependent on its structural integrity.

Clinical Significance

Alterations in the SLC24A4 gene or the malfunctioning of NCKX4 can lead to various health issues. For instance, mutations in SLC24A4 have been associated with amelogenesis imperfecta, a condition affecting dental enamel formation, indicating the importance of NCKX4 in the mineralization processes. Furthermore, due to its role in calcium homeostasis, NCKX4 is also being studied for its potential involvement in neurological disorders, where dysregulated calcium signaling is a common feature.

Genetic

The SLC24A4 gene is located on chromosome 14 in humans. Genetic studies have aimed to understand the variations within this gene and their association with disease phenotypes. Such research is crucial for developing targeted therapies that can modulate the function of NCKX4 in pathological conditions.

See Also

• Solute carrier family
• Calcium signaling
• Amelogenesis imperfecta
• Homeostasis

External Links

• NCBI Gene: SLC24A4