Naturally occurring tubulin-containing paracrystals in Allogromia: immunocytochemical identification and functional significance.
Naturally occurring tubulin-containing paracrystals in Allogromia: immunocytochemical identification and functional significance.
复制标题
异体中天然存在的含微管蛋白的副晶体：免疫细胞化学鉴定和功能意义。
DOI：
10.1002/cm.970060403
复制
发表时间：
1986
影响因子：
--
通讯作者：
Rieder,CL
中科院分区：
文献类型：
--
作者：
Rupp,G;Bowser,SS;Mannella,CA;Rieder,CL
在有孔虫原生动物anallogromiasp高度扁平的网状足部，通过视频显微镜很容易在体内观察到微管束。NF。在本报告中，我们使用视频显微镜、免疫细胞化学和高压电子显微镜来描述在足网肌诱导退出和随后的再延伸期间，广泛的MT细胞骨架和相关的细胞质运输发生的动态变化。在应用戒断刺激（用MgCl2制成高渗透性海水替代品）后的几秒钟内，沿着线性含MT原纤维的细胞内双向运输停止，取而代之的是沿着原纤维向内的、等速的细胞质流动。随着撤退的继续，大多数原纤维变成波浪状并合并形成相密集的池。这些波状原纤维和相密集池含有一种准晶物质和少量的MTs。同切片相关免疫荧光和高压电子显微镜显示，准晶物质含有微管蛋白。在恢复过程中，线性原纤维（MTs）迅速从相密集池（准晶）中延伸出来，同时缩小尺寸，从而重建正常的网络形态和运动。我们得出结论，allogromiareticulopodia的MT细胞骨架在退出过程中转化为含有微管蛋白的副晶体，作为MT蛋白的临时储存库和MT再生的起始位点。
Bundles of microtubules (MTs) are readily visualized in vivo by videomicroscopy in highly flattened reticulopodia of the foraminiferan protozoanAllogromiasp. strain NF. In this report we use videomicroscopy, immunocytochemistry, and high‐voltage electron microscopy to characterize the dynamic changes that occur in this extensive MT cytoskeleton, and in the associated cytoplasmic transport, during induced withdrawal and subsequent reextension of reticulopodia. Within seconds after application of the withdrawal stimulus (seawater substitute made hypertonic with MgCl2) intracellular bidirectional transport along linear MT‐containing fibrils ceases and is replaced by an inward, constant‐velocity flow of cytoplasm along the fibrils. As withdrawal continues, most fibrils become wavy and coalesce to form phase‐dense pools. These wavy fibrils and phase‐dense pools contain a paracrystalline material and few if any MTs. Same‐section correlative immunofluorescence and high‐voltage electron microscopy reveal that the paracrystalline material contains tubulin. During recovery linear fibrils (MTs) rapidly extend from the phase‐dense pools (paracrystals), which concurrently shrink in size, thus reestablishing normal network morphology and motility. We conclude that the MT cytoskeleton inAllogromiareticulopodia is transfonned during withdrawal into a tubulin‐containing paracrystal, which serves as a temporary reservoir of MT protein and an initiation site for MT regrowth.