Limiting Amounts of Centrosome Material Set Centrosome Size in C. elegans Embryos
Limiting Amounts of Centrosome Material Set Centrosome Size in C. elegans Embryos
复制标题
DOI：
10.1016/j.cub.2011.06.002
复制
发表时间：
2011-08-09
期刊：
影响因子：
9.2
通讯作者：
Hyman, Anthony A.
中科院分区：
文献类型：
--
作者：
Decker, Markus;Jaensch, Steffen;Hyman, Anthony A.
背景：细胞设定细胞内结构大小的方式是一个重要但很大程度上尚未解决的问题[1]。早期胚胎分裂在这方面提出了特殊问题。体细胞中常见的许多检查点在这些分裂中缺失，其特点是细胞大小快速减小和细胞周期短[2]。因此，胚胎细胞必须拥有简单而强大的机制，使其许多细胞内结构的大小能够随着细胞大小的变化而快速缩放。结果：在这里，我们研究了一种结构（中心体）在秀丽隐杆线虫早期胚胎分裂过程中缩放大小的机制。我们表明中心体大小与细胞大小直接相关并且与谱系无关。两项研究结果表明，母体提供的中心体蛋白质的总量可能会限制中心体的大小。首先，发育胚胎中任意时刻形成的所有中心体的总体积是恒定的。其次，任何一个细胞中中心体的总体积与中心体数量无关。通过增加细胞中中心体蛋白的数量，我们提供了证据，证明限制中心体大小的一个成分是保守的中心粒周围材料蛋白 SPD-2 [3]，我们证明它与 polo 样激酶 1 [3, 4] 结合并将其靶向中心体。结论：我们提出了一种限制成分假说，其中细胞的体积通过限制中心体成分的总量来设定中心体大小。这个想法可能是在发育过程中设定细胞内细胞器大小的通用机制。
Background: The ways in which cells set the size of intracellular structures is an important but largely unsolved problem [1]. Early embryonic divisions pose special problems in this regard. Many checkpoints common in somatic cells are missing from these divisions, which are characterized by rapid reductions in cell size and short cell cycles [2]. Embryonic cells must therefore possess simple and robust mechanisms that allow the size of many of their intracellular structures to rapidly scale with cell size.Results: Here, we study the mechanism by which one structure, the centrosome, scales in size during the early embryonic divisions of C. elegans. We show that centrosome size is directly related to cell size and is independent of lineage. Two findings suggest that the total amount of maternally supplied centrosome proteins could limit centrosome size. First, the combined volume of all centrosomes formed at any one time in the developing embryo is constant. Second, the total volume of centrosomes in any one cell is independent of centrosome number. By increasing the amount of centrosome proteins in the cell, we provide evidence that one component that limits centrosome size is the conserved pericentriolar material protein SPD-2 [3], which we show binds to and targets polo-like kinase 1 [3, 4] to centrosomes.Conclusions: We propose a limiting component hypothesis, in which the volume of the cell sets centrosome size by limiting the total amount of centrosome components. This idea could be a general mechanism for setting the size of intracellular organelles during development.