Methyl-ß-cyclodextrin reversibly alters the gating of lipid rafts-associated Kv1.3 channels in Jurkat T lymphocytes
You are here
Pottosin, II and Valencia-Cruz, G and Bonales-Alatorre, E and Shabala, SN and Dobrovinskaya, OR, Methyl-s-cyclodextrin reversibly alters the gating of lipid rafts-associated Kv1.3 channels in Jurkat T lymphocytes, Pfluegers Archiv: European Journal of Physiology, 454, (2) pp. 235-244. ISSN 0031-6768 (2007) [Refereed Article]
The voltage-dependent Kv1.3 potassium channels mediate a variety of physiological functions in human T lymphocytes. These channels, along with their multiple regulatory components, are localized in cholesterol-enriched microdomains of plasma membrane (lipid rafts). In this study, patch-clamp technique was applied to explore the impact of the lipid-raft integrity on the Kv1.3 channel functional characteristics. T lymphoma Jurkat cells were treated for 1 h with cholesterol-binding oligosaccharide methyl-Î²-cyclodextrin (MÎ²CD) in 1 or 2 mM concentration, resulting in depletion of cholesterol by 63Â±5 or 75Â±4%, respectively. Treatment with 2 mM MÎ²CD did not affect the cells viability but retarded the cell proliferation. The latter treatment caused a depolarizing shift of the Kv1.3 channel activation and inactivation by 11 and 6 mV, respectively, and more than twofold decrease in the steady-state activity at depolarizing potentials. Altogether, these changes underlie the depolarization of membrane potential, recorded in a current-clamp mode. The effects of MÎ²CD were concentration- and time-dependent and reversible. Both development and recovery of the MÎ²CD effects were completed within 1-2 h. Therefore, cholesterol depletion causes significant alterations in the Kv1.3 channel function, whereas T cells possess a potential to reverse these changes. Â© 2007 Springer-Verlag.
Repository Staff Only:
item control page