小柯机器人

德国马克斯·普朗克分子细胞生物学与遗传学研究所Stephan W. Grill等研究人员合作发现，一种凝结的动态不稳定性协调肌动球蛋白皮质激活。2022年8月17日，《自然》杂志在线发表了这项成果。

研究人员发现，在秀丽隐杆线虫的卵母细胞中，肌动球蛋白皮质激活是由成千上万富含F-肌动蛋白、N-WASP和ARP2/3复合物的短寿命蛋白凝结物的出现来支持的，它们形成了一种活跃的微乳液。对单个皮质凝结物动态的相图分析显示，凝结物最初生长，然后过渡到分解，最后完全溶解。研究人员发现，与通过扩散的凝结物生长相反，皮质凝结物的生长动力学是由化学驱动的。

值得注意的是，相关的化学反应服从于质量作用动力学，它同时控制着成分和大小。研究人员认为，由此产生的凝结物动态不稳定性抑制了活性微乳液的粗粒化，确保反应动力学不受凝结物大小的影响，并防止在形成第一个皮质肌动球蛋白网状结构期间失控的F-肌动蛋白成核。

据悉，发育开始时的一个关键事件是在卵细胞向胚胎过渡期间激活收缩性肌动蛋白皮质。

附：英文原文

Title: A condensate dynamic instability orchestrates actomyosin cortex activation

Author: Yan, Victoria Tianjing, Narayanan, Arjun, Wiegand, Tina, Jlicher, Frank, Grill, Stephan W.

Issue&Volume: 2022-08-17

Abstract: A key event at the onset of development is the activation of a contractile actomyosin cortex during the oocyte-to-embryo transition1,2,3. Here we report on the discovery that, in Caenorhabditis elegans oocytes, actomyosin cortex activation is supported by the emergence of thousands of short-lived protein condensates rich in F-actin, N-WASP and the ARP2/3 complex4,5,6,7,8 that form an active micro-emulsion. A phase portrait analysis of the dynamics of individual cortical condensates reveals that condensates initially grow and then transition to disassembly before dissolving completely. We find that, in contrast to condensate growth through diffusion9, the growth dynamics of cortical condensates are chemically driven. Notably, the associated chemical reactions obey mass action kinetics that govern both composition and size. We suggest that the resultant condensate dynamic instability10 suppresses coarsening of the active micro-emulsion11, ensures reaction kinetics that are independent of condensate size and prevents runaway F-actin nucleation during the formation of the first cortical actin meshwork.

DOI: 10.1038/s41586-022-05084-3

Source: https://www.nature.com/articles/s41586-022-05084-3

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html