HIRA is critical for a nucleosome assembly pathway independent of DNA synthesis
HIRA is critical for a nucleosome assembly pathway independent of DNA synthesis
复制标题
DOI：
10.1016/s1097-2765(02)00526-9
复制
发表时间：
2002-05-01
期刊：
影响因子：
16
通讯作者：
Almouzni, G
中科院分区：
文献类型：
--
作者：
Ray-Gallet, D;Quivy, JP;Almouzni, G
哺乳动物HIRA基因编码一种组蛋白相互作用蛋白，其在非洲爪蟾中的同源物在这里被表征。在体外，重组非洲爪蟾HIRA结合纯化的核心组蛋白并促进其沉积到质粒DNA上。在非洲爪蟾早期胚胎的可溶性母体池中发现了与体细胞核结构密切相关的HIRA蛋白。以其染色质组装效率而闻名的爪蟾卵提取物对HIRA具有特异性免疫缺失。尽管与DNA合成相关的核小体形成仍然有效，但这些耗尽的提取物在非复制DNA上组装核小体的能力严重受损。此外，通过重新引入HIRA和（H3-H4）(2)四聚体，这一缺陷在很大程度上得到了纠正。因此，我们描绘了依赖于HIRA的核小体组装途径。
The mammalian HIRA gene encodes a histone-interacting protein whose homolog in Xenopus laevis is characterized here. In vitro, recombinant Xenopus HIRA bound purified core histones and promoted their deposition onto plasmid DNA. The Xenopus HIRA protein, tightly associated with nuclear structures in somatic cells, was found in a soluble maternal pool in early embryos. Xenopus egg extracts, known for their chromatin assembly efficiency, were specifically immunodepleted for HIRA. These depleted extracts were severely impaired in their ability to assemble nucleosomes on nonreplicated DNA, although nucleosome formation associated with DNA synthesis remained efficient. Furthermore, this defect was largely corrected by reintroduction of HIRA along with (H3-H4)(2) tetramers. We thus delineate a nucleosome assembly pathway that depends on HIRA.