Catez Frédéric, Lim Jae-Hwan, Hock Robert, Postnikov Yuri V, Bustin Michael
Protein Section, Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Biochem Cell Biol. 2003 Jun;81(3):113-22. doi: 10.1139/o03-040.
Recent studies indicate that most nuclear proteins, including histone H1 and HMG are highly mobile and their interaction with chromatin is transient. These findings suggest that the structure of chromatin is dynamic and the protein composition at any particular chromatin site is not fixed. Here we discuss how the dynamic behavior of the nucleosome binding HMGN proteins affects the structure and function of chromatin. The high intranuclear mobility of HMGN insures adequate supply of protein throughout the nucleus and serves to target these proteins to their binding sites. Transient interactions of the proteins with nucleosomes destabilize the higher order chromatin, enhance the access to nucleosomal DNA, and impart flexibility to the chromatin fiber. While roaming the nucleus, the HMGN proteins encounter binding partners and form metastable multiprotein complexes, which modulate their chromatin interactions. Studies with HMGN proteins underscore the important role of protein dynamics in chromatin function.
最近的研究表明，包括组蛋白H1和高迁移率族蛋白（HMG）在内的大多数核蛋白具有高度的流动性，并且它们与染色质的相互作用是短暂的。这些发现表明染色质的结构是动态的，任何特定染色质位点的蛋白质组成都不是固定的。在这里，我们讨论结合核小体的HMGN蛋白的动态行为如何影响染色质的结构和功能。HMGN在细胞核内的高迁移率确保了蛋白质在整个细胞核中的充足供应，并有助于将这些蛋白质靶向其结合位点。这些蛋白质与核小体的短暂相互作用会破坏高阶染色质的稳定性，增加对核小体DNA的可及性，并赋予染色质纤维柔韧性。在细胞核中移动时，HMGN蛋白会遇到结合伙伴并形成亚稳态的多蛋白复合物，这些复合物会调节它们与染色质的相互作用。对HMGN蛋白的研究强调了蛋白质动力学在染色质功能中的重要作用。
