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研究揭示有丝分裂过程中线粒体均等分离的机制
2021-03-07 21:30

美国宾夕法尼亚大学Erika L. F. Holzbaur研究团队取得一项新突破。他们的研究发现肌动蛋白网络和彗星尾巴在有丝分裂过程中参与线粒体网络的组装。该研究于2021年3月3日发表于国际学术期刊《自然》杂志。

研究人员发现了在有丝分裂过程中与线粒体组织和遗传相关的独特但互补的多个肌动蛋白组装体。首先,研究人员发现了在有丝分裂细胞质中由皮下肌动蛋白组装成的致密网络。该网络支撑内质网并组织三维线粒体定位,以确保胞质分裂时线粒体可以均等分离。

其次,研究确定在有丝分裂期间,肌动蛋白丝在线粒体表面形成可逆地组装动态波。具有动态波的线粒体包裹在肌动蛋白网中,肌动蛋白网可自发地破坏其对称性,从而形成细长的彗星尾巴。线粒体彗星尾巴会促进随机定向运动的爆发,从而改变母细胞中线粒体的位置,使子细胞之间健康和受损线粒体的遗传随机化。因此,肌动蛋白细胞骨架介导的平行机制确保了对称分裂细胞中线粒体的均等和随机遗传。

据介绍,对称细胞分裂需要在子细胞之间均匀分配遗传信息和细胞基质。尽管众所周知调控基因组分离的机制,但对确保子细胞之间细胞器分离的机制仍知之甚少。

附:英文原文

Title: Actin cables and comet tails organize mitochondrial networks in mitosis

Author: Andrew S. Moore, Stephen M. Coscia, Cory L. Simpson, Fabian E. Ortega, Eric C. Wait, John M. Heddleston, Jeffrey J. Nirschl, Christopher J. Obara, Pedro Guedes-Dias, C. Alexander Boecker, Teng-Leong Chew, Julie A. Theriot, Jennifer Lippincott-Schwartz, Erika L. F. Holzbaur

Issue&Volume: 2021-03-03

Abstract: Symmetric cell division requires the even partitioning of genetic information and cytoplasmic contents between daughter cells. Whereas the mechanisms coordinating the segregation of the genome are well known, the processes that ensure organelle segregation between daughter cells remain less well understood1. Here we identify multiple actin assemblies with distinct but complementary roles in mitochondrial organization and inheritance in mitosis. First, we find a dense meshwork of subcortical actin cables assembled throughout the mitotic cytoplasm. This network scaffolds the endoplasmic reticulum and organizes three-dimensional mitochondrial positioning to ensure the equal segregation of mitochondrial mass at cytokinesis. Second, we identify a dynamic wave of actin filaments reversibly assembling on the surface of mitochondria during mitosis. Mitochondria sampled by this wave are enveloped within actin clouds that can spontaneously break symmetry to form elongated comet tails. Mitochondrial comet tails promote randomly directed bursts of movement that shuffle mitochondrial position within the mother cell to randomize inheritance of healthy and damaged mitochondria between daughter cells. Thus, parallel mechanisms mediated by the actin cytoskeleton ensure both equal and random inheritance of mitochondria in symmetrically dividing cells. During mitosis, complementary actin-based mechanisms ensure equal and random distributions of mitochondria among daughter cells following symmetrical cell division.

DOI: 10.1038/s41586-021-03309-5

Source: https://www.nature.com/articles/s41586-021-03309-5

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:43.07
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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