Harvard Medical School, Boston, Massachusetts 02115, USA; email:
Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA.
Annu Rev Cell Dev Biol. 2021 Oct 6;37:23-41. doi: 10.1146/annurev-cellbio-120319-025356. Epub 2021 Jun 29.
The purpose of this review is to explore self-organizing mechanisms that pattern microtubules (MTs) and spatially organize animal cell cytoplasm, inspired by recent experiments in frog egg extract. We start by reviewing conceptual distinctions between self-organizing and templating mechanisms for subcellular organization. We then discuss self-organizing mechanisms that generate radial MT arrays and cell centers in the absence of centrosomes. These include autocatalytic MT nucleation, transport of minus ends, and nucleation from organelles such as melanosomes and Golgi vesicles that are also dynein cargoes. We then discuss mechanisms that partition the cytoplasm in syncytia, in which multiple nuclei share a common cytoplasm, starting with cytokinesis, when all metazoan cells are transiently syncytial. The cytoplasm of frog eggs is partitioned prior to cytokinesis by two self-organizing modules, protein regulator of cytokinesis 1 (PRC1)-kinesin family member 4A (KIF4A) and chromosome passenger complex (CPC)-KIF20A. Similar modules may partition longer-lasting syncytia, such as early embryos. We end by discussing shared mechanisms and principles for the MT-based self-organization of cellular units.
本文旨在探讨受近期蛙卵提取物实验启发的微管（MT）形态发生和动物细胞质空间组织的自组织机制。我们首先回顾了亚细胞组织中自组织和模板机制之间的概念区别。然后，我们讨论了在没有中心体的情况下生成径向 MT 阵列和细胞中心的自组织机制。这些机制包括 MT 自催化核形成、负端运输以及从黑素体和高尔基体小泡等细胞器进行核形成，这些细胞器也是动力蛋白的货物。然后，我们讨论了在细胞质中进行分区的机制，在细胞质中，多个核共享一个共同的细胞质，首先是胞质分裂，所有后生动物细胞都是短暂的合胞体。在胞质分裂之前，蛙卵的细胞质通过两个自组织模块进行分区，即胞质分裂蛋白调节剂 1（PRC1）-驱动蛋白家族成员 4A（KIF4A）和染色体乘客复合物（CPC）-驱动蛋白 20A（KIF20A）。类似的模块可能会将更长时间的合胞体（如早期胚胎）分隔开。最后，我们讨论了基于 MT 的细胞单位自组织的共享机制和原则。
