Three different actin filament assemblies occur in every hair cell: each contains a specific actin crosslinking protein.
Three different actin filament assemblies occur in every hair cell: each contains a specific actin crosslinking protein.
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DOI：
10.1083/jcb.112.4.641
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发表时间：
1991-02
影响因子：
7.8
通讯作者：
Tilney, M
中科院分区：
文献类型：
--
作者：
Drenckhahn, D;Engel, K;Hofer, D;Merte, C;Tilney, L;Tilney, M
鸡听器毛细胞的顶端含有三种不同类型的肌动蛋白丝组装体。它们是：（a）静纤毛中具有相同极性的肌动蛋白丝的类晶体，（B）形成表皮板的肌动蛋白丝的致密凝胶状网络，以及（c）一束具有混合极性的平行肌动蛋白丝，构成附着于粘附小带（ZA）细胞质面的周向丝带。肌动蛋白丝的每一种不同的超分子组装体都含有一种特定的肌动蛋白丝交联蛋白，这对该特定的组装体来说是独一无二的。因此，fimalin似乎是负责paracrystallin包装的肌动蛋白丝在静纤毛;血影蛋白的亚型驻留在表皮板，在那里它形成的须状crossbridge，和α辅肌动蛋白是肌动蛋白交联蛋白的圆周ZA束。原肌球蛋白，稳定肌动蛋白丝，是目前在所有的肌动蛋白丝组装除了静纤毛。另一个惊人的发现是，肌球蛋白似乎是缺席的ZA环和角质板的毛细胞，但存在于ZA环的支持细胞。肌球蛋白在周围支持细胞的ZA环中的丰度意味着它可能在形成毛细胞插入其中的支持拉伸细胞框架中是重要的。
The apex of hair cells of the chicken auditory organ contains three different kinds of assemblies of actin filaments in close spatial proximity. These are (a) paracrystals of actin filaments with identical polarity in stereocilia, (b) a dense gellike meshwork of actin filaments forming the cuticular plate, and (c) a bundle of parallel actin filaments with mixed polarities that constitute the circumferential filament belt attached to the cytoplasmic aspect of the zonula adhaerens (ZA). Each different supramolecular assembly of actin filaments contains a specific actin filament cross-linking protein which is unique to that particular assembly. Thus fimbrin appears to be responsible for paracrystallin packing of actin filaments in stereocillia; an isoform of spectrin resides in the cuticular plate where it forms the whisker-like crossbridges, and alpha actinin is the actin crosslinking protein of the circumferential ZA bundle. Tropomyosin, which stabilizes actin filaments, is present in all the actin filament assemblies except for the stereocilia. Another striking finding was that myosin appears to be absent from the ZA ring and cuticular plate of hair cells although present in the ZA ring of supporting cells. The abundance of myosin in the ZA ring of the surrounding supporting cells means that it may be important in forming a supporting tensile cellular framework in which the hair cells are inserted.