Dress V M, Yi H, Musal M R, Williams N E
Department of Biology, University of Iowa, Iowa City 52242.
J Struct Biol. 1992 May-Jun;108(3):187-94. doi: 10.1016/1047-8477(92)90018-6.
There is a complex system of 2- to 5-nm filaments in the oral apparatus of Tetrahymena. Four major subunit proteins, called tetrins, have been isolated from the filaments. These proteins, showing apparent molecular weights in polyacrylamide gels of 79-89 kDa, will assemble in vitro into 2- to 5-nm filaments. Tetrin filaments in vivo show different packing arrangements in different regions of the oral apparatus. We sought to determine the distributions of tetrin polypeptides within the complex oral structure by obtaining monoclonal antibodies specific for individual tetrins, then mapping their distributions within the oral apparatus using standard fluorescence microscopy, confocal laser scanning fluorescence microscopy, and electron microscopy. The results indicate that the four tetrin polypeptides are colocalized everywhere within the oral apparatus of Tetrahymena. Tetrin-binding proteins or specific nucleating structures may need to be invoked to explain the complex organization of the tetrin network. The 16 monoclonal antibodies obtained were also used to search for evidence of immunological relationships between tetrin and cytoskeletal proteins in multicellular organisms. None was found.
四膜虫的口器中存在一个由2到5纳米细丝组成的复杂系统。已从这些细丝中分离出四种主要的亚基蛋白，称为四膜虫素。这些蛋白质在聚丙烯酰胺凝胶中的表观分子量为79至89 kDa，它们在体外会组装成2到5纳米的细丝。四膜虫素细丝在体内口器的不同区域呈现出不同的堆积排列方式。我们试图通过获得针对单个四膜虫素的单克隆抗体，然后使用标准荧光显微镜、共聚焦激光扫描荧光显微镜和电子显微镜绘制它们在口器内的分布，来确定四膜虫素多肽在复杂口器结构中的分布。结果表明，四种四膜虫素多肽在四膜虫口器内的各处都共定位。可能需要引入四膜虫素结合蛋白或特定的成核结构来解释四膜虫素网络的复杂组织。所获得的16种单克隆抗体还被用于寻找多细胞生物中四膜虫素与细胞骨架蛋白之间免疫关系的证据，但未发现相关证据。
