Chloride potassium symporter 4

Chloride Potassium Symporter 4

The Chloride Potassium Symporter 4 (KCC4) is a member of the cation-chloride cotransporter family, which plays a crucial role in maintaining cellular ion homeostasis. This protein is encoded by the SLC12A7 gene in humans.

Structure

KCC4 is a membrane protein that facilitates the electroneutral movement of potassium (K⁺) and chloride (Cl⁻) ions across the cell membrane. It is composed of multiple transmembrane domains that form a channel through which ions can pass. The exact structure of KCC4 is still under investigation, but it shares structural similarities with other members of the cation-chloride cotransporter family.

Function

KCC4 is primarily involved in the regulation of cell volume and the maintenance of intracellular chloride concentration. It is activated under conditions of cell swelling and helps to restore normal cell volume by extruding K⁺ and Cl⁻ ions from the cell. This process is essential for various physiological functions, including:

• Neuronal signaling
• Epithelial transport
• Muscle contraction

Expression

KCC4 is expressed in a variety of tissues, including the kidney, brain, and inner ear. Its expression levels and activity can be modulated by various factors, including:

• Osmotic stress
• Hormonal regulation
• Cellular signaling pathways

Clinical Significance

Mutations or dysregulation of KCC4 have been implicated in several medical conditions. For instance, altered KCC4 function can contribute to:

• Hypertension
• Epilepsy
• Deafness

Research is ongoing to better understand the role of KCC4 in these conditions and to develop potential therapeutic interventions.

Research and Development

Recent studies have focused on the development of specific inhibitors and activators of KCC4 as potential therapeutic agents. These studies aim to modulate KCC4 activity in diseases where its function is compromised.

See Also

• Cation-chloride cotransporter
• SLC12A family
• Ion transport

External Links

• NCBI Gene: SLC12A7
• UniProt: Q9Y666