Slepecky N B, Ulfendahl M
Institute for Sensory Research, Syracuse University, New York 13244-5290.
Hear Res. 1992 Jan;57(2):201-15. doi: 10.1016/0378-5955(92)90152-d.
Actin-binding and microtubule-associated proteins regulate microfilament and microtubule number, length, organization and location in cells. In freeze-dried preparations of the guinea pig cochlea, both actin and tubulin are found in the sensory and supporting cells of the organ of Corti. Fodrin (brain spectrin) co-localized with actin in the cuticular plates of both inner and outer hair cells and along the lateral wall of the outer hair cells. Alpha-actinin co-localized with actin in the cuticular plates of the hair cells and in the head and foot plates of the supporting cells. It was also found in the junctional regions between hair cells and supporting cells. Profilin co-localized with actin in the cuticular plates of the sensory hair cells. Myosin was detected only in the cuticular plates of the outer hair cells and in the supporting cells in the region facing endolymph. Gelsolin was found in the region of the nerve fibers. Tubulin is found in microtubules in all cells of the organ of Corti. In supporting cells, microtubules are bundled together with actin microfilaments and tropomyosin, as well as being present as individual microtubules arranged in networks. An intensely stained network of microtubules is found in both outer and inner sensory hair cells. The microtubules in the outer hair cells appear to course throughout the entire length of the cells, and based on their staining with antibodies to the tyrosinated form of tubulin they appear to be more dynamic structures than the microtubules in the supporting cells. The microtubule-associated protein MAP-2 is present only in outer hair cells within the organ of Corti and co-localizes with tubulin in these cells. No other MAPs (1,3,4,5) are present. Tau is found in the nerve fibers below both inner and outer hair cells and in the osseous spiral lamina. It is clear that the actin-binding and microtubule-associated proteins present in the cochlea co-localize with actin and tubulin and that they modulate microfilament and microtubule structure and function in a manner similar to that seen in other cell types. The location of some of these proteins in outer hair cells suggests a role for microfilaments and microtubules in outer hair cell motility.
肌动蛋白结合蛋白和微管相关蛋白可调节细胞中微丝和微管的数量、长度、组织方式及位置。在豚鼠耳蜗的冻干制剂中，肌动蛋白和微管蛋白存在于柯蒂氏器的感觉细胞和支持细胞中。血影蛋白（脑血影蛋白）在内、外毛细胞的表皮板以及外毛细胞的侧壁上与肌动蛋白共定位。α - 辅肌动蛋白在毛细胞的表皮板以及支持细胞的顶板和底板中与肌动蛋白共定位。在毛细胞与支持细胞之间的连接区域也能发现它。胸腺素β4在感觉毛细胞的表皮板中与肌动蛋白共定位。肌球蛋白仅在外毛细胞的表皮板以及面向内淋巴的支持细胞区域中被检测到。凝溶胶蛋白存在于神经纤维区域。微管蛋白存在于柯蒂氏器所有细胞的微管中。在支持细胞中，微管与肌动蛋白微丝和原肌球蛋白捆绑在一起，同时也以单个微管的形式排列成网络状。在外、内感觉毛细胞中均发现有密集染色的微管网。外毛细胞中的微管似乎贯穿细胞的整个长度，基于它们用抗酪氨酸化微管蛋白抗体的染色情况，它们似乎比支持细胞中的微管结构更具动态性。微管相关蛋白MAP - 2仅存在于柯蒂氏器内的外毛细胞中，并在这些细胞中与微管蛋白共定位。不存在其他微管相关蛋白（MAP - 1、MAP - 3、MAP - 4、MAP - 5）。微管相关蛋白Tau存在于内、外毛细胞下方的神经纤维以及骨螺旋板中。很明显，耳蜗中存在的肌动蛋白结合蛋白和微管相关蛋白与肌动蛋白和微管蛋白共定位，并且它们以与其他细胞类型类似的方式调节微丝和微管的结构及功能。这些蛋白中的一些在外毛细胞中的定位表明微丝和微管在外毛细胞运动中发挥作用。
