当前位置:科学网首页 > 小柯机器人 >详情
体外和活细胞研究表明浓缩染色质在中尺度上表现为固体
作者:小柯机器人 发布时间:2020/12/16 15:40:42

加拿大艾伯塔大学Michael J. Hendzel和美国科罗拉多州立大学Jeffrey C. Hansen研究小组合作发现,在体外和活细胞中浓缩染色质表现为固体状。该研究成果在线发表在2020年12月15日的《细胞》。

在本研究中,研究人员揭示了体外和体内浓缩染色质的物理状态。体外研究表明,在广泛溶液条件下,核小体序列的自缔合会产生超分子聚集物,在这种情况下染色质收缩并呈固体状。通过测量活细胞中DNA的迁移率,研究人员证明了浓缩染色质在体内同样也呈现固体态。然而,典型异染色质蛋白则呈现液体态并聚集在固体样染色质结构周围。

重要的是,即使在染色质纤维之间产生有限相互作用的条件下,常染色质和异染色质仍具有类似的固体状态。该研究结果表明,浓缩染色质以固态存在,其可以抵抗外力并产生弹性凝胶,这提供了支持染色质结合蛋白液-液相分离的基础。

研究人员表示,细胞核DNA与组蛋白结合形成染色质对于真核生物基因组的时间和空间调控至关重要。

附:英文原文

Title: Condensed Chromatin Behaves like a Solid on the Mesoscale In Vitro and in Living Cells

Author: Hilmar Strickfaden, Thomas O. Tolsma, Ajit Sharma, D. Alan Underhill, Jeffrey C. Hansen, Michael J. Hendzel

Issue&Volume: 2020-12-15

Abstract: The association of nuclear DNA with histones to form chromatin is essential for temporaland spatial control of eukaryotic genomes. In this study, we examined the physicalstate of condensed chromatin in vitro and in vivo. Our in vitro studies demonstrate that self-association of nucleosomal arrays under a wide rangeof solution conditions produces supramolecular condensates in which the chromatinis physically constrained and solid-like. By measuring DNA mobility in living cells,we show that condensed chromatin also exhibits solid-like behavior in vivo. Representative heterochromatin proteins, however, display liquid-like behavior andcoalesce around the solid chromatin scaffold. Importantly, euchromatin and heterochromatinshow solid-like behavior even under conditions that produce limited interactions betweenchromatin fibers. Our results reveal that condensed chromatin exists in a solid-likestate whose properties resist external forces and create an elastic gel and providesa scaffold that supports liquid-liquid phase separation of chromatin binding proteins.

DOI: 10.1016/j.cell.2020.11.027

Source: https://www.cell.com/cell/fulltext/S0092-8674(20)31544-0

期刊信息
Cell:《细胞》,创刊于1974年。隶属于细胞出版社,最新IF:36.216
官方网址:https://www.cell.com/