LOCALIZATION OF PROTEINS ASSOCIATED WITH THE OUTER HAIR CELL PLASMA-MEMBRANE IN THE GERBIL COCHLEA

There is substantial evidence that the motility of mammalian outer hai r cells is generated close to or within the plasma membrane. Several a nalogies between the outer hair cell cortical lattice and the membrane -related cytoskeleton of erythrocytes have been noted. In erythrocytes a member of the anion exchanger protein family, AE1, also known as Ba nd 3, is involved in membrane-cytoskeleton linkage via Protein 4.1. In the Following payer, the presence of these two proteins in gerbilline outer hair cells is confirmed by western blot. Furthermore, fo-locali zation of these two proteins was detected in the lateral wall of outer hair cells by immunofluorescence and postembedding electron immunohis tochemistry. Band 3 is restricted to this region: whereas Protein 4.1 has a somewhat more dispersed distribution. Thus, the structure of the se sensory receptor cells may result From an adaptation of a strategy used by other motile cells. The proteins investigated likely have a su pport function and may comprise ''pillars'' seen between the lateral p lasma membrane and the cytoskeleton in micrographs of outer hair cells . The possibility that Band 3 comprises ''protein particles'' seen in the lateral plasma membrane, or maybe directly involved in the voltage -dependent force generation in outer hair cells, is also discussed. (C ) 1997 IBRO. Published by Elsevier Science Ltd.