Medknow Publications on behalf of the Neurological Society of India
Vol. 59, No. 4, 2011, pp. 527-531
Bioline Code: ni11164
Full paper language: English
Document type: Research Article
Document available free of charge
Neurology India, Vol. 59, No. 4, 2011, pp. 527-531
© Copyright 2011 Neurology India.
Expression patterns of two potassium channel genes in skeletal muscle cells of patients with familial hypokalemic periodic paralysis
Kim, June-Bum; Lee, Gyung-Min; Kim, Sung-Jo; Yoon, Dong-Ho & Lee, Young-Hyuk
Background: Familial hypokalemic periodic paralysis is an autosomal-dominant disorder characterized by episodic attacks of muscle weakness with hypokalemia. The combination of sarcolemmal depolarization and hypokalemia has been attributed to abnormalities of the potassium conductance governing the membrane potential; however, the molecular mechanism that causes hypokalemia has not yet been determined.
Aim: To test the hypothesis that the expression patterns of delayed rectifier potassium channel genes in the skeletal muscle cells of patients with familial hypokalemic periodic paralysis differ from those in normal cells.
Material and Methods: We examined both mRNA and protein levels of two major delayed rectifier potassium channel genes KCNQ3 and KCNQ5 in the skeletal muscle cells from three patients with familial hypokalemic periodic paralysis and three healthy controls.
Results: When normal cells were exposed to 50 mM potassium buffer, which was used to induce depolarization, the KCNQ3 protein level significantly increased in the membrane fraction but decreased in the cytosolic fraction, whereas the opposite was true in patient cells.
Conclusion: Abnormal subcellular distribution of the KCNQ3 protein was observed in patient cells. Our results suggest that the altered expression of KCNQ3 in patient cells exposed to high extracellular potassium levels could possibly hinder normal function of the channel protein. These findings may provide an important clue to understanding the molecular mechanism of familial hypokalemic periodic paralysis.
Genetic diseases, neuromuscular diseases, paralysis
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