Honts Jerry E, Williams Norman E
Department of Biology, Drake University, Des Moines, IA 50311, USA.
J Eukaryot Microbiol. 2003 Jan-Feb;50(1):9-14. doi: 10.1111/j.1550-7408.2003.tb00100.x.
An important unsolved problem lies in the mechanisms that determine overall size, shape, and the localization of subcellular structures in eukaryotic cells. The membrane skeleton must play a central role in these processes in many cell types, and the ciliate membrane skeleton, or epiplasm, offers favorable opportunities for exploring the molecular determinants of cortical organization. Among the ciliates, Tetrahymena is well suited for the application of a wide range of molecular and cellular approaches. Progress has been made in the identification and sequencing of genes and proteins that encode epiplasmic and cortical proteins. The amino acid sequences of these proteins suggest that they define new classes of cytoskeletal proteins, distinct from the articulin and epiplasmin proteins. We will also discuss recent in vivo and in vitro studies of the regulation of assembly of these cortical proteins. This will include information regarding the down-regulation of epiplasmic proteins during cleavage, their topographic regulation in the cell cycle, and the results of in vitro assembly and binding studies of the epiplasmic C protein.
一个重要的未解决问题在于决定真核细胞整体大小、形状和亚细胞结构定位的机制。在许多细胞类型中，膜骨架必定在这些过程中发挥核心作用，而纤毛虫的膜骨架，即表质，为探索皮层组织的分子决定因素提供了有利契机。在纤毛虫中，四膜虫非常适合应用多种分子和细胞方法。在编码表质和皮层蛋白的基因及蛋白质的鉴定和测序方面已取得进展。这些蛋白质的氨基酸序列表明它们定义了新的细胞骨架蛋白类别，不同于关节蛋白和表质溶素蛋白。我们还将讨论近期关于这些皮层蛋白组装调控的体内和体外研究。这将包括有关卵裂过程中表质蛋白下调、其在细胞周期中的拓扑调控以及表质C蛋白体外组装和结合研究结果的信息。
