瑞士伯尔尼大学Peter Meister团队近期取得重要工作进展，他们研究提出，凝缩蛋白 I 折叠秀丽隐杆线虫基因组。相关研究成果2024年7月22日在线发表于《自然—遗传学》杂志上。

据介绍，染色体结构维持（SMC）复合物（黏连蛋白和凝缩蛋白）对细胞分裂过程中的染色体分离和压缩至关重要。在间期，哺乳动物的黏连蛋白还将基因组折叠成环和结构域。

研究人员表明，在秀丽隐杆线虫（一种具有全中心染色体的物种）中，凝缩蛋白 I是主要的长程环挤压器。凝缩蛋白 I及其X特异性变体凝缩蛋白I^DC的缺失导致全基因组失活、染色体混合和X特异性拓扑相关结构域的消失，同时加强了精细尺度的表观基因组区室。

此外，凝缩蛋白I/I^DC失活导致X连锁基因的上调，并揭示了聚集在一起的核体，这些核体是凝缩蛋白I^DC的X靶向负载复合物的结合位点。因此，秀丽隐杆线虫凝缩蛋白I/I^DC独特地组织了全中心间期染色体，类似于哺乳动物中的黏连蛋白，并调节X染色体基因的表达。

附：英文原文

Title: Condensin I folds the Caenorhabditis elegans genome

Author: Das, Moushumi, Semple, Jennifer I., Haemmerli, Anja, Volodkina, Valeriia, Scotton, Janik, Gitchev, Todor, Annan, Ahrmad, Campos, Julie, Statzer, Cyril, Dakhovnik, Alexander, Ewald, Collin Y., Mozziconacci, Julien, Meister, Peter

Issue&Volume: 2024-07-22

Abstract: The structural maintenance of chromosome (SMC) complexes—cohesin and condensins—are crucial for chromosome separation and compaction during cell division. During the interphase, mammalian cohesins additionally fold the genome into loops and domains. Here we show that, in Caenorhabditis elegans, a species with holocentric chromosomes, condensin I is the primary, long-range loop extruder. The loss of condensin I and its X-specific variant, condensin IDC, leads to genome-wide decompaction, chromosome mixing and disappearance of X-specific topologically associating domains, while reinforcing fine-scale epigenomic compartments. In addition, condensin I/IDC inactivation led to the upregulation of X-linked genes and unveiled nuclear bodies grouping together binding sites for the X-targeting loading complex of condensin IDC. C. elegans condensin I/IDC thus uniquely organizes holocentric interphase chromosomes, akin to cohesin in mammals, as well as regulates X-chromosome gene expression.

DOI: 10.1038/s41588-024-01832-5

Source: https://www.nature.com/articles/s41588-024-01832-5