Actin cytoskeleton disassembly affects conductive properties of stretch-activated cation channels in leukaemia cells.

Mechanosensitive channels in various eucaryotic cells are thought to be functionally and structurally coupled to the cortical cytoskeleton. However, the results of electrophysiological studies are rather controversial and the functional impact of cytoskeleton assembly-disassembly on stretch-activated channel properties remains unclear. Here, the possible involvement of cytoskeletal elements in the regulation of stretch-activated Ca2+-permeable channels was studied in human leukaemia K562 cells with the use of agents that selectively modify the actin or tubulin system. F-actin disassembly resulted in a considerable reduction of the amplitude of stretch-activated currents without significant change in channel open probability. The effects of treatments with cytochalasins or latrunculin were principally similar, developed gradually and consisted a strong decrease of single channel conductance. Microtubule disruption did not affect stretch-activated channels. The data presented here are in principal agreement with the general conclusion that mechanosensitive channel functions are largely dependent on the integrity of the cortical actin cytoskeleton. Specifically, changes in conductive properties of the pore may provide an essential mechanism of channel regulation underlying functional modulation of membrane currents. Our results allow one to speculate that microfilament organization may be an important determinant in modulating biophysical characteristics of stretch-activated cation channels in cells of blood origin.

[1]  E. A. Vedernikova,et al.  Disruption of actin filaments increases the activity of sodium-conducting channels in human myeloid leukemia cells. , 1996, Molecular biology of the cell.

[2]  E. A. Vedernikova,et al.  Several types of sodium-conducting channel in human carcinoma A-431 cells. , 1994, Biochimica et biophysica acta.

[3]  O. Hamill,et al.  Induced membrane hypo/hyper-mechanosensitivity: a limitation of patch-clamp recording. , 1997, Annual review of physiology.

[4]  D. W. McBride,et al.  The pharmacology of mechanogated membrane ion channels. , 1996, Pharmacological reviews.

[5]  Y. Marunaka,et al.  Blocking action of cytochalasin D on protein kinase A stimulation of a stretch-activated cation channel in renal epithelial A6 cells. , 2001, Biochemical pharmacology.

[6]  Frederick Sachs,et al.  Dynamic regulation of mechanosensitive channels: capacitance used to monitor patch tension in real time , 2004, Physical biology.

[7]  D. Benos,et al.  Immunopurification and functional reconstitution of a Na+ channel complex from rat lymphocytes. , 1995, The American journal of physiology.

[8]  S. Arkin,et al.  Taxol and anti-stathmin therapy: a synergistic combination that targets the mitotic spindle. , 2000, Cancer research.

[9]  K. Hruska,et al.  Reconstitution of stretch-activated cation channels by expression of the alpha-subunit of the epithelial sodium channel cloned from osteoblasts. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[10]  E. A. Vedernikova,et al.  Sodium-selective channels in membranes of rat macrophages , 1994, The Journal of Membrane Biology.

[11]  A. Parekh,et al.  Arf-1 (ADP-ribosylation factor-1) is involved in the activation of a mammalian Na+-selective current. , 2004, The Biochemical journal.

[12]  B. Sakmann,et al.  Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches , 1981, Pflügers Archiv.

[13]  S. Schultz,et al.  Volume regulatory responses of basolateral membrane vesicles from Necturus enterocytes: role of the cytoskeleton. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[14]  A. Parekh.  Nonhydrolyzable Analogues of GTP Activate a New Na+ Current in a Rat Mast Cell Line* , 1996, The Journal of Biological Chemistry.

[15]  D. Benos,et al.  Stretch modulates amiloride sensitivity and cation selectivity of sodium channels in human B lymphocytes. , 1996, The American journal of physiology.

[16]  C. Morris,et al.  Activation of mechanosensitive currents in traumatized membrane. , 1999, American journal of physiology. Cell physiology.

[17]  Robert E. Buxbaum,et al.  Cell Crawling: First the Motor, Now the Transmission , 1998, The Journal of cell biology.

[18]  C. Morris,et al.  Delayed activation of single mechanosensitive channels in Lymnaea neurons. , 1994, The American journal of physiology.

[19]  P. Janmey.  The cytoskeleton and cell signaling: component localization and mechanical coupling. , 1998, Physiological reviews.

[20]  O. Hamill,et al.  Molecular basis of mechanotransduction in living cells. , 2001, Physiological reviews.

[21]  Uhtaek Oh,et al.  Mechanosensitive Ion Channels in Cultured Sensory Neurons of Neonatal Rats , 2002, The Journal of Neuroscience.

[22]  D P Corey,et al.  Mechanosensation and the DEG/ENaC Ion Channels , 1996, Science.

[23]  E. A. Vedernikova,et al.  Voltage-insensitive Na channels of different selectivity in human leukemic cells. , 1997, General physiology and biophysics.

[24]  W. Ho,et al.  Actin filaments regulate the stretch sensitivity of large-conductance, Ca2+-activated K+ channels in coronary artery smooth muscle cells , 2003, Pflügers Archiv.

[25]  E. A. Vedernikova,et al.  Sodium Channel Activity in Leukemia Cells Is Directly Controlled by Actin Polymerization* , 2000, The Journal of Biological Chemistry.

[26]  F Sachs,et al.  Stretch‐activated single ion channel currents in tissue‐cultured embryonic chick skeletal muscle. , 1984, The Journal of physiology.

[27]  E. A. Vedernikova,et al.  Ca‐dependent regulation of Na+‐selective channels via actin cytoskeleton modification in leukemia cells , 1997, FEBS letters.

[28]  M. Shigekawa,et al.  Stretch-activated cation channels in skeletal muscle myotubes from sarcoglycan-deficient hamsters. , 2001, American journal of physiology. Cell physiology.

[29]  A. Staruschenko,et al.  Mechanosensitive cation channels in human leukaemia cells: calcium permeation and blocking effect , 2002, The Journal of physiology.

[30]  M. Lazdunski,et al.  TRAAK Is a Mammalian Neuronal Mechano-gated K+Channel* , 1999, The Journal of Biological Chemistry.

[31]  E. Shumilina,et al.  Regulation of sodium channel activity by capping of actin filaments. , 2003, Molecular biology of the cell.

[32]  D. Warnock,et al.  Amiloride-sensitive sodium conductance in human B lymphoid cells. , 1993, The American journal of physiology.

[33]  F Sachs,et al.  Mechanosensitive ion channels in nonspecialized cells. , 1998, Reviews of physiology, biochemistry and pharmacology.

[34]  A. Kamkin,et al.  Ion selectivity of stretch-activated cation currents in mouse ventricular myocytes , 2003, Pflügers Archiv.

[35]  L. Schild,et al.  Epithelial sodium channel/degenerin family of ion channels: a variety of functions for a shared structure. , 2002, Physiological reviews.