Membrane prestin expression correlates with the magnitude of prestin-associated charge movement.
Full expression of electromotility, generation of non-linear capacitance (NLC), and high-acuity mammalian hearing require prestin function in the lateral wall of cochlear outer hair cells (OHCs). Estimates of the number of prestin molecules in the OHC membrane vary, and a consensus has not emerged about the correlation between prestin expression and prestin-associated charge movement in the OHC. Using an inducible prestin-expressing cell line, we demonstrate that the charge density, but not the voltage at peak capacitance, directly correlates with the amount of prestin in the plasma membrane. This correlation is evident in studies involving a controlled increase of prestin expression with time after induction and inducer dose-response. Conversely, membrane prestin levels and charge density gradually decline together following the reduction of prestin levels from a steady state by removal of the inducer. Thus, charge density directly correlates with the level of membrane prestin expression, whereas changing membrane levels of prestin have no effect on the voltage at peak capacitance in this inducible prestin-expressing cell line.
Huffington Center on Aging and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: mlseymou@bcm.edu.
Michelle L
ML
Seymour
Bobby R. Alford Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, TX 77030, USA; W. M. Keck Center for Interdisciplinary Bioscience Training, Houston, TX 77005, USA. Electronic address: lavanya.rajagopalan@gmail.com.
Lavanya
L
Rajagopalan
Department of Bioengineering, Rice University, Houston, TX 77030, USA. Electronic address: gd4@rice.edu.
Guillaume
G
Duret
Bobby R. Alford Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: mvolk@unch.unc.edu.
Matthew J
MJ
Volk
Huffington Center on Aging and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: haiyingl@bcm.edu.
Haiying
H
Liu
Bobby R. Alford Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: brownell@bcm.edu.
William E
WE
Brownell
Huffington Center on Aging and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Bobby R. Alford Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: fpereira@bcm.edu.
Fred A
FA
Pereira
D000818:Animals; D027321:Anion Transport Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D003051:Cochlea / Q000378:metabolism; D004318:Doxycycline / Q000494:pharmacology; D025802:Electric Capacitance; D004594:Electrophysiology; D005786:Gene Expression Regulation; D005849:Gerbillinae; D057809:HEK293 Cells; D018072:Hair Cells, Auditory, Outer / Q000502:physiology; D006801:Humans; D017136:Ion Transport; D008564:Membrane Potentials; D051379:Mice; D008810:Mice, Inbred C57BL; D017711:Nonlinear Dynamics; D018408:Patch-Clamp Techniques; D000076988:Sulfate Transporters; D013997:Time Factors
D027321:Anion Transport Proteins; C498719:SLC26A5 protein, human; D000076988:Sulfate Transporters; D004318:Doxycycline
Charge density; Membrane; Non-linear capacitance; Prestin