title: Expression of prestin, a membrane motor protein, in the mammalian auditory and vestibular periphery.
abstract: Hair cells are specialized mechanoreceptors common to auditory and vestibular sensory organs of mammalian and non-mammalian species. Different hair cells are believed to share common features related to their mechanosensory function. It has been shown that hair cells possess various forms of motile properties that enhance their receptor function. Membrane-based electromotility is a form of hair cell motility observed in isolated outer hair cells (OHCs) of the cochlea. A novel membrane protein, prestin, recently cloned from gerbil and rat tissues, is presumably responsible for electromotility. We cloned prestin from mouse organ of Corti and confirmed strong homology of this protein among different rodent species. We explored whether or not prestin is present in hair cells of the vestibular system. Using reverse transcription-polymerase chain reaction, we demonstrated that prestin is expressed in mouse and rat auditory and vestibular organs, but not in chicken auditory periphery. In situ hybridization and immunolocalization studies confirmed the presence of prestin in OHCs as well as in vestibular hair cells (VHCs) of rodent saccule, utricle and crista ampullaris. However, in the VHCs, staining of varying intensity with anti-prestin antibodies was observed in the cytoplasm, but not in the lateral plasma membrane or in the stereociliary membrane. Whole-cell patch-clamp recordings showed that VHCs do not possess the voltage-dependent capacitance associated with membrane-based electromotility. We conclude that although prestin is expressed in VHCs, it is unlikely that it supports the form of somatic motility observed in OHCs.
authors.affiliation: Section on Structural Cell Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bldg. 50, Room 4249, Bethesda, MD 20892-8027, USA. adlerh@nidcd.nih.gov
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Adler
authors.forename: Inna A
authors.initials: IA
authors.lastname: Belyantseva
authors.forename: Raymond C
authors.initials: RC
authors.lastname: Merritt
authors.forename: Gregory I
authors.initials: GI
authors.lastname: Frolenkov
authors.forename: Gerard W
authors.initials: GW
authors.lastname: Dougherty
authors.forename: Bechara
authors.initials: B
authors.lastname: Kachar
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D027321:Anion Transport Proteins; D001306:Auditory Pathways / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology; D002645:Chickens; D003001:Cloning, Molecular; D025802:Electric Capacitance; D004594:Electrophysiology; D006198:Hair Cells, Auditory / Q000502:physiology; D018072:Hair Cells, Auditory, Outer / Q000502:physiology; D051379:Mice / Q000378:metabolism*; D020409:Molecular Motor Proteins; D008969:Molecular Sequence Data; D009925:Organ of Corti / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D000076988:Sulfate Transporters; D014722:Vestibule, Labyrinth / Q000378:metabolism*
chemical_list: D027321:Anion Transport Proteins; D020409:Molecular Motor Proteins; C498720:Pres protein, mouse; D011506:Proteins; C409207:Slc26a5 protein, rat; D000076988:Sulfate Transporters