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Ca‐dependent regulation of Na + ‐selective channels via actin cytoskeleton modification in leukemia cells
Author(s) -
Maximov Anton V,
Vedernikova Elena A,
Hinssen Horst,
Khaitlina Sofia Y,
Negulyaev Yuri A
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)00754-0
Subject(s) - gelsolin , actin , cytoskeleton , cytoplasm , actin cytoskeleton , microbiology and biotechnology , biophysics , chemistry , actin binding protein , diacylglycerol kinase , biology , cell , biochemistry , protein kinase c , signal transduction
With the use of the patch‐clamp technique, physiological mechanisms of Na + channel regulation involving submembranous actin rearrangements were examined in human myeloid leukemia K562 cells. We found that the actin‐severing protein gelsolin applied to cytoplasmic surface of membrane fragments at a high level of [Ca 2+ ] i (1 μ M) increased drastically the activity of Na‐selective channels of 12 pS unitary conductance. In the experiments on intact cells, the elevation of [Ca 2+ ] i using the ionophore 4Br‐A23187 also resulted in Na + channel activation. Addition of actin to the cytoplasmic surface of membrane patches reduced this activity to background level, likely due to actin polymerization. Our data imply that Ca‐dependent modulations of the actin cytoskeleton may represent one of the general mechanisms of channel regulation and cell signalling.