Department of Molecular, Cellular and Developmental Biology, Faculty of Arts and Sciences, Yale University, New Haven, CT 06511, USA.
Faculté des Sciences et Techniques, Nantes Université, CNRS, US2B, UMR 6286, 44000 Nantes, France.
Int J Mol Sci. 2023 Jan 5;24(2):1051. doi: 10.3390/ijms24021051.
The nucleosome is composed of histones and DNA. Prior to their deposition on chromatin, histones are shielded by specialized and diverse proteins known as histone chaperones. They escort histones during their entire cellular life and ensure their proper incorporation in chromatin. is a Mycetozoan, a clade located at the crown of the eukaryotic tree. We previously found that histones, which are highly conserved between plants and animals, are also highly conserved in . However, histone chaperones differ significantly between animal and plant kingdoms, and this thus probed us to further study the conservation of histone chaperones in and their evolution relative to animal and plants. Most of the known histone chaperones and their functional domains are conserved as well as key residues required for histone and chaperone interactions. is divergent from yeast, plants and animals, but PpHIRA, PpCABIN1 and PpSPT6 are similar in structure to plant orthologues. PpFACT is closely related to the yeast complex, and the genome encodes the animal-specific APFL chaperone. Furthermore, we performed RNA sequencing to monitor chaperone expression during the cell cycle and uncovered two distinct patterns during S-phase. In summary, our study demonstrates the conserved role of histone chaperones in handling histones in an early-branching eukaryote.
核小体由组蛋白和 DNA 组成。在组蛋白沉积到染色质上之前，它们被称为组蛋白伴侣的专门且多样化的蛋白质所屏蔽。它们在细胞的整个生命周期中护送组蛋白，并确保它们在染色质中正确掺入。 是一种粘菌，位于真核生物树的顶端。我们之前发现，组蛋白在动植物之间高度保守，在 中也高度保守。然而，组蛋白伴侣在动物和植物王国之间存在显著差异，这促使我们进一步研究 中的组蛋白伴侣的保守性及其与动物和植物的进化关系。大多数已知的组蛋白伴侣及其功能结构域以及组蛋白和伴侣相互作用所需的关键残基都得到了保守。 与酵母、植物和动物不同，但 PpHIRA、PpCABIN1 和 PpSPT6 的结构与植物同源物相似。PpFACT 与酵母复合物密切相关， 基因组编码动物特异性的 APFL 伴侣。此外，我们进行了 RNA 测序以监测细胞周期中伴侣蛋白的表达，并在 S 期发现了两种不同的模式。总之，我们的研究表明组蛋白伴侣在处理早期分支真核生物中的组蛋白方面发挥着保守作用。
