title: Cell membrane tethers generate mechanical force in response to electrical stimulation.
abstract: Living cells maintain a huge transmembrane electric field across their membranes. This electric field exerts a force on the membrane because the membrane surfaces are highly charged. We have measured electromechanical force generation by cell membranes using optically trapped beads to detach the plasma membrane from the cytoskeleton and form long thin cylinders (tethers). Hyperpolarizing potentials increased and depolarizing potentials decreased the force required to pull a tether. The membrane tether force in response to sinusoidal voltage signals was a function of holding potential, tether diameter, and tether length. Membrane electromechanical force production can occur at speeds exceeding those of ATP-based protein motors. By harnessing the energy in the transmembrane electric field, cell membranes may contribute to processes as diverse as outer hair cell electromotility, ion channel gating, and transport.
authors.affiliation: Bobby R. Alford Department of Otolaryngology, Head & Neck Surgery, and Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA. brownell@bcm.tmc.edu
authors.forename: William E
authors.initials: WE
authors.lastname: Brownell
authors.forename: Feng
authors.initials: F
authors.lastname: Qian
authors.forename: Bahman
authors.initials: B
authors.lastname: Anvari
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology*; D004558:Electric Stimulation; D006801:Humans; D008564:Membrane Potentials / Q000502:physiology