INTERMEDIATE FILAMENTS IN MUSCLE AND EPITHELIAL-CELLS OF NEMATODES
INTERMEDIATE FILAMENTS IN MUSCLE AND EPITHELIAL-CELLS OF NEMATODES
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DOI：
10.1083/jcb.102.6.2033
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发表时间：
1986-06-01
影响因子：
7.8
通讯作者：
WEBER, K
中科院分区：
文献类型：
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作者：
BARNIK, E;OSBORN, M;WEBER, K
目前的概念，发展控制的多基因家族的中间丝（IF）蛋白质的起源，其复杂性的进化前体之前的所有脊椎动物类。然而，在无脊椎动物中，公司的超微结构以及IFs的分子文件仅限于一些巨大的轴突和上皮的一些软体动物和环节动物。由于蛔虫是很容易解剖成干净的组织，IF在这个大的线虫表达进行了分析，通过电子显微镜和生化程序和单克隆抗体与所有哺乳动物IF蛋白反应。我们的文件首次在肌肉细胞的无脊椎动物的IF的存在。它们发生在三种肌肉类型中（不规则横纹咽肌、斜横纹体肌、子宫平滑肌）。在研究的上皮细胞（合胞体表皮、肠、卵巢、睾丸）中也发现了IFs。肌肉，咽，肠，子宫和表皮上的免疫印迹鉴定出一对多肽（表观分子量为71和63 kD）作为IF成分。在体外重建细丝获得与蛋白质从身体肌肉。在小线虫秀丽隐杆线虫IF蛋白是迄今为止只发现在大量的桥粒锚定的张力丝束穿过一个特殊的上皮细胞类型，咽的边缘细胞。我们推测，IFs可能发生在大多数，但也许不是所有的无脊椎动物，他们可能不会发生在所有细胞中大量。作为电子显微镜的表皮的一个成员的扁形虫揭示IFs，这种细胞质结构的进化起源可以预期的最低的后生动物之间或已经在一些单细胞真核生物。
Current concepts of the developmentally controlled multigene family of intermediate filament (IF) proteins expect the origin of their complexity in evolutionary precursors preceding all vertebrate classes. Among invertebrates, however, firm ultrastructural as well as molecular documentation of IFs is restricted to some giant axons and to epithelia of a few molluscs and annelids. As Ascaris lumbricoides is easily dissected into clean tissues, IF expression in this large nematode was analyzed by electron microscopic and biochemical procedures and a monoclonal antibody reacting with all mammalian IF proteins. We document for the first time the presence of IFs in muscle cells of an invertebrate. They occur in three muscle types (irregular striated pharynx muscle, obliquely striated body muscle, uterus smooth muscle). IFs are also found in the epithelia studied (syncytial epidermis, intestine, ovary, testis). Immunoblots on muscles, pharynx, intestine, uterus, and epidermis identify a pair of polypeptides (with apparent molecular masses of 71 and 63 kD) as IF constituents. In vitro reconstitution of filaments was obtained with the proteins from body muscle. In the small nematode Caenorhabditis elegans IF proteins are so far found only in the massive desmosome-anchored tonofilament bundles which traverse a special epithelial cell type, the marginal cells of the pharynx. We speculate that IFs may occur in most but perhaps not all invertebrates and that they may not occur in all cells in large amounts. As electron micrographs of the epidermis of a planaria-a member of the platyhelminthes-reveal IFs, the evolutionary origin of this cytoplasmic structure can be expected either among the lowest metazoa or already in some unicellular eukaryotes.