The cortical actin-membrane cytoskeleton of unfertilized sea urchin eggs: analysis of the spatial organization and relationship of filamentous actin, nonfilamentous actin, and egg spectrin.
The cortical actin-membrane cytoskeleton of unfertilized sea urchin eggs: analysis of the spatial organization and relationship of filamentous actin, nonfilamentous actin, and egg spectrin.
复制标题
未受精海胆卵的皮质肌动蛋白-膜细胞骨架：丝状肌动蛋白、非丝状肌动蛋白和卵血影蛋白的空间组织和关系分析。
DOI：
10.1016/0012-1606(89)90105-x
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发表时间：
1989
影响因子：
2.7
通讯作者：
Begg,DA
中科院分区：
文献类型：
--
作者：
Bonder,EM;Fishkind,DJ;Cotran,NM;Begg,DA
用荧光phalloidin、抗肌动蛋白抗体和抗卵谱蛋白抗体对未受精海胆卵的整个坐垫、冷冻切片和分离皮质进行探针检测，以研究皮质相关肌动蛋白膜细胞骨架的组织状态。丝状肌动蛋白和卵谱蛋白定位于质膜、微绒毛和非微绒毛结构域。非微绒毛丝状肌动蛋白位于微绒毛旁边，沿着质膜的内表面形成广泛的互联网络。这种丝状肌动蛋白网络的组织与底层皮质颗粒的定位精确相关。皮质细胞质不含任何可检测到的丝状肌动蛋白，而是含有非丝状肌动蛋白的隔离结构域。Spectrin定位于质膜的细胞质表面，集中病灶与微绒毛中的丝状肌动蛋白共定位。Spectrin也被观察到覆盖在皮质颗粒和其他细胞内囊泡的表面。根据光镜形态、细胞内分布以及与卵皮质的共分离，其中一些谱膜细胞器代表酸性囊泡。确定肌动蛋白（丝状和非丝状）和谱蛋白形成皮质膜细胞骨架的相互关联结构域的复杂组织，有助于深入了解胚胎发生过程中早期膜重构的基本机制。此外，spectrin在细胞内囊泡表面的定位表明它在膜运输、膜生物发生和细胞分化中具有新发现的功能作用。
Whole mounts, cryosections, and isolated cortices of unfertilized sea urchin eggs were probed with fluorescent phalloidin, anti-actin and anti-egg spectrin antibodies to investigate the organizational state of the cortically associated actin-membrane cytoskeleton. Filamentous actin and egg spectrin were localized to the plasma membrane, within microvillar and nonmicrovillar domains. The nonmicrovillar filamentous actin was located immediately subjacent to the microvilli forming an extensive interconnecting network along the inner surface of the plasma membrane. The organization of this filamentous actin network precisely correlated with the positioning of the underlying cortical granules. The cortical cytoplasm did not contain any detectable filamentous actin, but instead contained a sequestered domain of nonfilamentous actin. Spectrin was localized to the cytoplasmic surface of the plasma membrane with concentrated foci co-localized with the filamentous actin present in microvilli. Spectrin was also observed to coat the surfaces of cortical granules as well as other populations of intracellular vesicles. On the basis of light microscopic morphology, intracellular distribution, and co-isolation with the egg cortex, some of these spectrin-coated organelles represent acidic vesicles. Identification of an elaborate organization of inter-related domains of actin (filamentous and nonfilamentous) and spectrin forming the cortical membrane cytoskeleton provides insight into the fundamental mechanisms for early membrane restructuring during embryogenesis. Additionally, the localization of spectrin to the surface of intracellular vesicles is indicative of its newly identified functional roles in membrane trafficking, membrane biogenesis and cellular differentiation.