title: Plant actin controls membrane permeability.
abstract: The biological effects of electric pulses with low rise time, high field strength, and durations in the nanosecond range (nsPEFs) have attracted considerable biotechnological and medical interest. However, the cellular mechanisms causing membrane permeabilization by nanosecond pulsed electric fields are still far from being understood. We investigated the role of actin filaments for membrane permeability in plant cells using cell lines where different degrees of actin bundling had been introduced by genetic engineering. We demonstrate that stabilization of actin increases the stability of the plasma membrane against electric permeabilization recorded by penetration of Trypan Blue into the cytoplasm. By use of a cell line expressing the actin bundling WLIM domain under control of an inducible promotor we can activate membrane stabilization by the glucocorticoid analog dexamethasone. By total internal reflection fluorescence microscopy we can visualize a subset of the cytoskeleton that is directly adjacent to the plasma membrane. We conclude that this submembrane cytoskeleton stabilizes the plasma membrane against permeabilization through electric pulses.
authors.affiliation: Botanical Institute, Karlsruhe Institute of Technology, Kaiserstr. 2, 76128 Karlsruhe, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Hohenberger
authors.forename: Christian
authors.initials: C
authors.lastname: Eing
authors.forename: Ralf
authors.initials: R
authors.lastname: Straessner
authors.forename: Steffen
authors.initials: S
authors.lastname: Durst
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Frey
authors.forename: Peter
authors.initials: P
authors.lastname: Nick
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry*; D000199:Actins / Q000737:chemistry*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability; D003907:Dexamethasone / Q000737:chemistry; D018274:Electroporation; D005818:Genetic Engineering / Q000379:methods; D005938:Glucocorticoids / Q000737:chemistry; D008856:Microscopy, Fluorescence / Q000379:methods; D036103:Nanotechnology / Q000379:methods; D010944:Plants / Q000378:metabolism*; D011523:Protoplasts / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics; D014343:Trypan Blue / Q000494:pharmacology
chemical_list: D000199:Actins; D005938:Glucocorticoids; D003907:Dexamethasone; D014343:Trypan Blue