Marshall W F, Rosenbaum J L
Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA.
J Cell Biol. 2001 Oct 29;155(3):405-14. doi: 10.1083/jcb.200106141.
A central question in cell biology is how cells determine the size of their organelles. Flagellar length control is a convenient system for studying organelle size regulation. Mechanistic models proposed for flagellar length regulation have been constrained by the assumption that flagella are static structures once they are assembled. However, recent work has shown that flagella are dynamic and are constantly turning over. We have determined that this turnover occurs at the flagellar tips, and that the assembly portion of the turnover is mediated by intraflagellar transport (IFT). Blocking IFT inhibits the incorporation of tubulin at the flagellar tips and causes the flagella to resorb. These results lead to a simple steady-state model for flagellar length regulation by which a balance of assembly and disassembly can effectively regulate flagellar length.
细胞生物学中的一个核心问题是细胞如何确定其细胞器的大小。鞭毛长度控制是研究细胞器大小调节的一个便捷系统。针对鞭毛长度调节提出的机制模型一直受到这样一种假设的限制，即鞭毛一旦组装完成就是静态结构。然而，最近的研究表明鞭毛是动态的，并且在不断更新。我们已经确定这种更新发生在鞭毛尖端，并且更新的组装部分是由鞭毛内运输（IFT）介导的。阻断IFT会抑制微管蛋白在鞭毛尖端的掺入并导致鞭毛吸收。这些结果导致了一个简单的鞭毛长度调节稳态模型，通过组装和拆卸的平衡可以有效地调节鞭毛长度。
