Function
Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium.
Biological Context
Subcellular Location: Membrane (Multi-pass membrane protein)
Tissue Specificity: Islets, exocrine pancreas and heart. Expressed in the adrenal cortex, particularly the zona glomerulosa
Disease Association: Long QT syndrome 13 (LQT13) : A heart disorder characterized by a prolonged QT interval on the ECG and polymorphic ventricular arrhythmias. They cause syncope and sudden death in response to exercise or emotional stress, and can present with a sentinel event of sudden cardiac death in infancy. [The disease is caused by variants affecting the gene represented in this entry] | Hyperaldosteronism, familial, 3 (HALD3) : A form of hyperaldosteronism characterized by hypertension secondary to massive adrenal mineralocorticoid production. HALD3 patients present with childhood hypertension, elevated aldosteronism levels, and high levels of the hybrid steroids 18-oxocortisol and 18-hydroxycortisol. Hypertension and aldosteronism are not reversed by administration of exogenous glucocorticoids and patients require adrenalectomy to control hypertension. [The disease is caused by variants affecting the gene represented in this entry] | [Somatic mutations in KCNJ5 have been found in aldosterone-producing adrenal adenomas and can be responsible for aldosteronism associated with cell autonomous proliferation. APAs are typically solitary, well circumscribed tumors diagnosed between ages 30 and 70. They come to medical attention due to new or worsening hypertension, often with hypokalemia. The precise role of KCNJ5 mutations in APA is under debate. They produce increased sodium conductance and cell depolarization, which in adrenal glomerulosa cells produces calcium entry, the signal for aldosterone production and cell proliferation. However, they may not be causative of APA development but may be a consequence of tumorigenesis, playing only a contributory role toward aldosterone overproduction and tumor growth. Somatic mutations in KCNJ5 have not been found in non-aldosterone secreting adrenal adenomas suggesting that they are specifically associated with APA ] | [Mutations in KCNJ5 are involved in the pathogenesis of hypertension without primary aldosteronism but with increased aldosterone response to ACTH stimulation]
Product Specifications
Recombinant Human G protein-activated inward rectifier potassium channel 4 (KCNJ5) Protein is a recombinant protein from Homo sapiens (Human), expressed in in vitro E.coli expression system, covering amino acids 1-419aa, with N-terminal 10xHis-tagged tag, molecular weight 53.7kDa, purity Greater than 90% as determined by SDS-PAGE.. Suitable for ELISA and Western Blot applications.
