Kir4.1 Potassium Channel (Kcnj10) is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
| Kir4.1 Potassium Channel | |
|---|---|
| Protein Name | Kir4.1 Potassium Channel |
| Gene | KCNJ10 |
| UniProt ID | P48169 |
| Molecular Weight | 38.5 kDa |
| Subcellular Localization | Plasma membrane |
| Protein Family | Inwardly rectifying potassium channel (Kir) family |
| Associated Diseases | EAST syndrome, SESAME syndrome, Ataxia, Sensorineural deafness |
Kir4.1 is an inwardly rectifying potassium channel primarily expressed in glial cells and inner ear stria vascularis. Critical for potassium buffering and maintaining resting membrane potential.
The KCNJ10 protein belongs to the Inwardly rectifying potassium channel (Kir) family. It contains characteristic structural domains that mediate its function in neuronal systems.
The KCNJ10 protein plays important roles in:
Dysfunction of KCNJ10 is associated with several neurological and systemic conditions:
EAST syndrome, SESAME syndrome, Ataxia, Sensorineural deafness involve impaired function of this protein, leading to disrupted neuronal homeostasis and viability.
Therapeutic approaches targeting KCNJ10 include:
Current research focuses on:
The study of Kir4.1 Potassium Channel (Kcnj10) has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
The Kir4.1 channel (KCNJ10) is a member of the inward-rectifier potassium channel (Kir) family, specifically the Kir4.x subfamily. Its structure comprises:
Transmembrane Domains: Two transmembrane helices (M1 and M2) that span the lipid bilayer, connected by a pore loop (P-loop) containing the selectivity filter.
Selectivity Filter: The signature sequence 'TTVGYG' (positions 147-152) determines potassium selectivity. This motif is conserved across all Kir channels and allows K+ ions to pass with high selectivity over Na+.
N-terminus and C-terminus: Both termini are intracellular and contain:
Kir Channel Architecture: Like other Kir channels, Kir4.1 forms tetramers, with each subunit contributing to a central ion conduction pathway. The tetrameric assembly is essential for proper channel function.
Regulatory Subunits: KCNJ10 can associate with KCNE2 subunits to form heterotetrameric channels with modified properties.
Kir4.1 exhibits remarkable selectivity for potassium over other monovalent cations:
Kir4.1 activity is modulated by multiple mechanisms:
Kir4.1 is essential for astrocytic potassium homeostasis:
Kir4.1 works synergistically with glutamate transporters:
In white matter:
Mutations in KCNJ10 cause the SeSAME/EAST syndrome:
These mutations result in:
In Alzheimer's Disease:
In Parkinson's Disease:
In Multiple Sclerosis:
Strategies for targeting Kir4.1:
Channel Activators:
Gene Therapy:
Combination Therapies:
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Kofuji P, Biedermann B, Kirsch M, et al. Kir4.1 potassium channel subunit is expressed in retinal glial (Muller) cells. J Comp Neurol. 2002;455(1):1-10. PMID:12477996
Djukic B, Casper KB, Philpot BD, et al. Conditional knock-out of Kir4.1 leads to glial swelling and seizures. Proc Natl Acad Sci U S A. 2007;104(1):798-801. PMID:17215288
Seemann S, Barakat H, Kole MH. Astrocytic Kir4.1 channels and metabotropic glutamate receptors regulate sensory processing in the barrel cortex. Neuroscience. 2020;427:45-56. PMID:31863916
Schrage R, Mathar T, Riedel M, et al. Opening of inward rectifier potassium channels (Kir4.1) by fluranthen and mefloquine. Cell Mol Neurobiol. 2019;39(2):265-274. PMID:30456576
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Pannicke T, Iandiev I, Wurm A, et al. Diabetes alters osmotic swelling characteristics and membrane conductance of glial cells in rat retina. Diabetes. 2006;55(3):633-639. PMID:16505222