Prestin is expressed on the whole outer hair cell basolateral surface

Yu, Ning; Zhu, Meng-Lei; Zhao, Hong-Bo

doi:10.1016/j.brainres.2006.04.017

Cited by 52 publications

(55 citation statements)

References 31 publications

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“…As previously reported (Yu et al, 2006), animals were anesthetized with pentobarbital and decapitated. The temporal bone was then removed.…”

Section: Animal Preparation and Cochlear Tissue Isolationmentioning

confidence: 99%

“…The pixels of Cx26 and Cx30 labeling in 100-μm long epithelium were calculated in each section and then summed. The staining intensities of Cx26 and Cx30 were also measured by use of the "plot profile" function in ImageJ (NIH, Bethesda, MD; Yu et al, 2006). Data were plotted in SigmaPlot (SPSS Inc., Chicago, IL).…”

Section: Quantitative Analysis and Image Presentationmentioning

confidence: 99%

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Distinct and gradient distributions of connexin26 and connexin30 in the cochlear sensory epithelium of guinea pigs

Zhao

2006

J of Comparative Neurology

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Connexin26 (Cx26) and Cx30 are predominant isoforms of gap junction channels in the cochlea and play a critical role in hearing. In this study, the cellular distributions of Cx26 and Cx30 in the cochlear sensory epithelium of guinea pigs were examined by immunofluorescent staining and confocal microscopy in whole mounts of the cochlear sensory epithelium and dissociated cell preparations. The expression of Cx26 and Cx30 demonstrated a longitudinal gradient distribution in the epithelium and was reduced threefold from the cochlear apex to base. The reduction was more pronounced in the Deiters cells and pillar cells than in the Hensen cells. Cx26 was expressed in all types of supporting cells, but little Cx30 labeling was seen in the Hensen cells. Cx26 expression in the Hensen cells was concentrated mainly in the second and third rows, forming a distinct band along the sensory epithelium at its outer region. In the dissociated Deiters cells and pillar cells, Cx30 showed dense labeling at the cell bodies and processes in the reticular lamina. Cx26 labeling largely overlapped that of Cx30 in these regions. Cx26 and Cx30 were also coexpressed in the gap junctional plaques between Claudius cells. Neither Cx26 nor Cx30 labeling was seen in the hair cells and spiral ganglion neurons. These observations demonstrate that Cx26 and Cx30 have a longitudinal gradient distribution and distinct cellular expression in the auditory sensory epithelium. This further supports our previous reports that Cx26 and Cx30 can solely and concertedly perform different functions in the cochlea. Indexing termsgap junction; cochlear supporting cells; reticular lamina; spiral ganglion; inner ear; nonsyndromic hearing lossThe connexin gene family encodes gap junction channels in mammals. So far, more than 20 connexin genes and their corresponding isoforms have been identified . Each connexin shows tissue-or cell-specific expression, and most organs and tissues express more than one connexin (for reviews see Harris, 2001; Evans and Martin, 2002;Willecke et al., 2002). Connexin gap junctions perform electronic and metabolic communications between cells and play important roles in many aspects of cellular and physiological functions. In particular, gap junctions are known to play a critical role in hearing function. Connexin mutations can cause hearing loss and account for 70 -80% of nonsyndromic hearing loss in children (Kelsell et al., 1997;Denoyelle et al., 1997;Grifa et al., 1999 The mammalian cochlea is the auditory organ and contains sensory hair cells and nonsensory supporting cells. Gap junctional coupling is extensive in the cochlea (for reviews see Kikuchi et al., 2000;Zhao et al., 2006). In early histological studies, electron microscopy and dye injection demonstrated that intercellular communications existed in the organ of Corti (Jahnke, 1975;Gulley and Reese, 1976;Iurato et al., 1976Iurato et al., , 1977Hama and Saito, 1977;Santos-Sacchi and Dallos, 1983;Santos-Sacchi, 1987;Zwislocki et al., 1992). Kikuchi et al. (1995), using ...

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“…As previously reported (Yu et al, 2006), animals were anesthetized with pentobarbital and decapitated. The temporal bone was then removed.…”

Section: Animal Preparation and Cochlear Tissue Isolationmentioning

confidence: 99%

Section: Quantitative Analysis and Image Presentationmentioning

confidence: 99%

Distinct and gradient distributions of connexin26 and connexin30 in the cochlear sensory epithelium of guinea pigs

Zhao

2006

J of Comparative Neurology

Self Cite

108

144

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“…Prestin locates on the lateral membrane of the OHC in high densities (19,20) and in much lower densities on the rest of the membrane, including the basal membrane (21). It has been observed as highly accumulated membrane integral proteins (2,500 particles/m 2 ) about 11 nm in diameter by using the freeze-fracture technique (22) and atomic force microscopy (AFM) (23).…”

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confidence: 99%

The Motor Protein Prestin Is a Bullet-shaped Molecule with Inner Cavities

Mio

Kubo

Ogura

et al. 2008

Journal of Biological Chemistry

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Prestin is a transmembrane motor protein localized at the outer hair cells (OHCs) of the mammalian inner ear. Voltage-dependent conformational changes in prestin generate changes in the length of OHCs. A loss of prestin function is reported to induce severe auditory deficiencies, suggesting prestin-dependent changes of OHC length may be at least a part of cochlear amplification. Here we expressed the recombinant FLAG-fused prestin proteins in Sf9 cells and purified to particles of a uniform size in EM. The square-shaped top view of purified prestin, the binding of multiple anti-FLAG antibodies to each prestin particle, the native-PAGE analysis, and the much larger molecular weight obtained from size exclusion chromatography than the estimation for the monomer all support that prestin is a tetramer (Zheng, J., Du, G. G., Anderson, C. T., Keller, J. P., Orem, A., Dallos, P., and Cheatham, M. (2006) J. Biol. Chem. 281, 19916 -19924). From negatively stained prestin particles, the three-dimensional structure was reconstructed at 2 nm resolution assuming 4-fold symmetry. Prestin is shown to be a bulletshaped particle with a large cytoplasmic domain. The surface representation demonstrates indentations on the molecule, and the slice images indicate the inner cavities of sparse densities. The dimensions, 77 ؋ 77 ؋ 115 Å , are consistent with the previously reported sizes of motor proteins on the surface of OHCs.The mammalian ear has specialized function in collecting sound signals and transmitting them to the nerve. Several amplifying systems are developed for sound collection. The pinna and ear canal funnel have suitable shapes for effective sound collection and condensation. The bones of the middle ear (malleus, incus, and stapes) convert the sound energy in the eardrum to the pressure waves in the fluid of the cochlea with 20 -40-fold amplification.In the inner ear, a positive feedback loop generates synchronous force by sensing the vibrations within the organ of Corti, which amplifies gained sound signals more than 100 times, although the mechanisms are not clearly understood (1, 2). One of the hypotheses is that voltage-dependent changes in the length of the outer hair cells (OHCs) 2 generate the lateral membrane motility and amplify the sound (3-5). These changes are proposed to be caused by prestin (SLC26A5) (6, 7), which is a membrane integral protein and is categorized to the solute linked carrier (SLC) 26 family of anion transporters. It has been also reported that prestin responds to the membrane potential by harboring cytoplasmic anions (Cl Ϫ or HCO 3 Ϫ ), as extrinsic voltage sensors, and changes its structure (8). Because prestin is densely embedded in the plasma membrane of the OHCs, the total length of the cell also changes as much as 5% as follows: decreases by depolarization and increases by hyperpolarization (9, 10). A voltage-dependent structural change was also observed in heterologously expressed cells, which strongly supports that prestin is a motor protein (6).The prestin gene (81.4 kDa, 744 a...

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“…The OHCs were freshly isolated from adult guinea pigs (250-400 g) as previously described [10,15,[26][27]. Briefly, the temporal bones were removed after decapitation.…”

Section: Outer Hair Cell Preparationmentioning

confidence: 99%

ATP activates P2x receptors and requires extracellular Ca++ participation to modify outer hair cell nonlinear capacitance

Zhao

2008

Pflugers Arch - Eur J Physiol

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Intracochlear ATP is an important mediator in regulating hearing function. ATP can activate ionotropic purinergic (P2x) and metabotropic purinergic (P2y) receptors to influence cell functions. In this paper, we report that ATP can activate P2x receptors directly to modify outer hair cell (OHC) electromotility, which is an active cochlear amplifier determining hearing sensitivity and frequency selectivity in mammals. We found that ATP, but not UTP, a P2y receptor agonist, reduced the OHC electromotility-associated nonlinear capacitance (NLC) and shifted its voltage dependence to the right (depolarizing) direction. Blockage of the activation of P2x receptors by pyridox-alphosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS), suramin, and 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS) could block the ATP effect. This modification also required extracellular Ca ++ participation. Removal of extracellular Ca ++ abolished the ATP effect. However, chelation of intracellular Ca ++ concentration by a fast calciumchelating reagent 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA, 10 mM) did not affect the effect of ATP on NLC. The effect is also independent of K + ions. Substitution of Cs + for intracellular or extracellular K + did not affect the ATP effect. Our findings indicate that ATP activates P2x receptors instead of P2y receptors to modify OHC electromotility. Extracellular Ca ++ is required for this modification.

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Prestin is expressed on the whole outer hair cell basolateral surface

Cited by 52 publications

References 31 publications

Distinct and gradient distributions of connexin26 and connexin30 in the cochlear sensory epithelium of guinea pigs

Distinct and gradient distributions of connexin26 and connexin30 in the cochlear sensory epithelium of guinea pigs

The Motor Protein Prestin Is a Bullet-shaped Molecule with Inner Cavities

ATP activates P2x receptors and requires extracellular Ca++ participation to modify outer hair cell nonlinear capacitance

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