Structural rearrangements of the motor protein prestin revealed by fluorescence resonance energy transfer
| Autor: | Michihiro Tateyama, Kristin Rule Gleitsman, Yoshihiro Kubo |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Conformational change
Cochlear amplifier Patch-Clamp Techniques Physiology Recombinant Fusion Proteins Sodium Salicylate Anion Transport Proteins Biophysics Cell Line Membrane Potentials Motor protein Fluorescence Resonance Energy Transfer Humans Patch clamp skin and connective tissue diseases Prestin Cochlea Membrane potential Total internal reflection fluorescence microscope biology Chemistry Anti-Inflammatory Agents Non-Steroidal Cell Biology Hair Cells Auditory Outer Protein Subunits Förster resonance energy transfer Biochemistry Membrane protein Sulfate Transporters biology.protein sense organs |
| Zdroj: | American Journal of Physiology-Cell Physiology. 297:C290-C298 |
| ISSN: | 1522-1563 0363-6143 |
| Popis: | Prestin is a membrane protein expressed in the outer hair cells (OHCs) in the cochlea that is essential for hearing. This unique motor protein transduces a change in membrane potential into a considerable mechanical force, which leads to a cell length change in the OHC. The nonlinear capacitance in cells expressing prestin is recognized to reflect the voltage-dependent conformational change of prestin, of which its precise nature remains unknown. In the present work, we aimed to detect the conformational changes of prestin by a fluorescence resonance energy transfer (FRET)-based technique. We heterologously expressed prestin labeled with fluorophores at the COOH- or NH2-terminus in human embryonic kidney-293T cells, and monitored FRET changes on depolarization-inducing high KCl application. We detected a significant decrease in intersubunit FRET both between the COOH-termini and between the COOH- and NH2-termini. A similar FRET decrease was observed when membrane potential was directly and precisely controlled by simultaneous patch clamp. Changes in FRET were suppressed by either of two treatments known to abolish nonlinear capacitance, V499G/Y501H mutation and sodium salicylate. Our results are consistent with significant movements in the COOH-terminal domain of prestin upon change in membrane potential, providing the first dynamic information on its molecular rearrangements. |
| Databáze: | OpenAIRE |
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