Protein- and lipid-reactive agents alter outer hair cell lateral membrane motor charge movement.
Outer hair cells from the mamma*lian cochlea are mechanically active cells that rely on charged voltage sensors within their lateral plasma membrane to gate the integral membrane motor protein, prestin, into one of two area states. Here we use protein and lipid reactive reagents to probe the influence of these bilayer components on motor-induced nonlinear membrane capacitance. Of the protein-reactive reagents tested, cross-linking and sulfhydryl reagents were most effective in altering steady state and time-varying motor activity. Of the lipid-altering agents, chloroform and HePC were most effective. Chloroform, in particular, drastically modified the susceptibility of the motor to prior voltage (initial conditions). Our data suggest that outer hair cell motor activity derives substantially from interactions with its lipid environment.
Santos-Sacchi
J
J
Sections of Otolaryngology and Neurobiology, Yale University School of Medicine, New Haven, CT 06510, USA. joseph.santos-sacchi@ yale.edu
Wu
M
M
D000818:Animals; D002462:Cell Membrane / Q000502:physiology*; D002725:Chloroform / Q000494:pharmacology; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004553:Electric Conductivity; D004594:Electrophysiology; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000502:physiology*; D015640:Ion Channel Gating / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D018408:Patch-Clamp Techniques; D011506:Proteins / Q000378:metabolism*; D012997:Solvents / Q000494:pharmacology; D013439:Sulfhydryl Reagents / Q000494:pharmacology
D003432:Cross-Linking Reagents; C498722:Pres protein, Cavia porcellus; D011506:Proteins; D012997:Solvents; D013439:Sulfhydryl Reagents; D002725:Chloroform