Membrane composition modulates prestin-associated charge movement

J Biol Chem. 2008 Aug 15;283(33):22473-81. doi: 10.1074/jbc.M803722200. Epub 2008 Jun 20.


The lateral membrane of the cochlear outer hair cell (OHC) is the site of a membrane-based motor that powers OHC electromotility, enabling amplification and fine-tuning of auditory signals. The OHC membrane protein prestin plays a central role in this process. We have previously shown that membrane cholesterol modulates the peak voltage of prestin-associated nonlinear capacitance in vivo and in vitro. The present study explores the effects of membrane cholesterol and docosahexaenoic acid content on the peak and magnitude of prestin-associated charge movement in a human embryonic kidney (HEK 293) cell model. Increasing membrane cholesterol results in a hyperpolarizing shift in the peak voltage of the nonlinear capacitance (Vpkc) and a decrease in the total charge movement. Both measures depend linearly on membrane cholesterol concentration. Incubation of cholesterol-loaded cells in cholesterol-free media partially restores the Vpkc toward normal values but does not have a compensatory effect on the total charge movement. Decreasing membrane cholesterol results in a depolarizing shift in Vpkc that is restored toward normal values upon incubation in cholesterol-free media. However, cholesterol depletion does not alter the magnitude of charge movement. In contrast, increasing membrane docosahexaenoic acid results in a hyperpolarizing shift in Vpkc that is accompanied by an increase in total charge movement. Our results quantify the relation between membrane cholesterol concentration and prestin-associated charge movement and enhance our understanding of how membrane composition modulates prestin function.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Anion Transport Proteins / genetics
  • Anion Transport Proteins / physiology*
  • Cell Line
  • Cell Membrane / physiology
  • Cell Movement
  • Cholesterol / metabolism
  • Cloning, Molecular
  • Cochlea / physiology*
  • Electric Conductivity
  • Electrophysiology
  • Gerbillinae
  • Humans
  • Membrane Lipids / metabolism
  • Patch-Clamp Techniques
  • Sulfate Transporters


  • Anion Transport Proteins
  • Membrane Lipids
  • SLC26A5 protein, human
  • Sulfate Transporters
  • Cholesterol