Functions of FACT in Breaking the Nucleosome and Maintaining Its Integrity at the Single-Nucleosome Level
Ping Chen, Liping Dong, Mingli Hu, Yi-Zhou Wang, Xue Xiao, Zhongliang Zhao, Jie Yan, Peng-Ye Wang, Danny Reinberg, Ming Li, Wei Li, Guohong Li
Abstract
The human FACT (facilitates chromatin transcription) complex, composed of two subunits SPT16 (Suppressor of Ty 16) and SSRP1 (Structure-specific recognition protein-1), plays essential roles in nucleosome remodeling. However, the molecular mechanism of FACT reorganizing the nucleosome still remains elusive. In this study, we demonstrate that FACT displays dual functions in destabilizing the nucleosome and maintaining the original histones and nucleosome integrity at the single-nucleosome level. We found that the subunit SSRP1 is responsible for maintenance of nucleosome integrity by holding the H3/H4 tetramer on DNA and promoting the deposition of the H2A/H2B dimer onto the nucleosome. In contrast, the large subunit SPT16 destabilizes the nucleosome structure by displacing the H2A/H2B dimers. Our findings provide mechanistic insights by which the two subunits of FACT coordinate with each other to fulfill its functions and suggest that FACT may play essential roles in preserving the original histones with epigenetic identity during transcription or DNA replication.
附件下载：
Functions of FACT in Breaking the Nucleosome and Maintaining Its Integrity at the Single-Nucleosome Level, Mol Cell, 19 July 2018
Molecular Cell, 19 July 2018，DOI: https://doi.org/10.1016/j.molcel.2018.06.020
Functions of FACT in Breaking the Nucleosome and Maintaining Its Integrity at the Single-Nucleosome Level
Ping Chen, Liping Dong, Mingli Hu, Yi-Zhou Wang, Xue Xiao, Zhongliang Zhao, Jie Yan, Peng-Ye Wang, Danny Reinberg, Ming Li, Wei Li, Guohong Li
Abstract
The human FACT (facilitates chromatin transcription) complex, composed of two subunits SPT16 (Suppressor of Ty 16) and SSRP1 (Structure-specific recognition protein-1), plays essential roles in nucleosome remodeling. However, the molecular mechanism of FACT reorganizing the nucleosome still remains elusive. In this study, we demonstrate that FACT displays dual functions in destabilizing the nucleosome and maintaining the original histones and nucleosome integrity at the single-nucleosome level. We found that the subunit SSRP1 is responsible for maintenance of nucleosome integrity by holding the H3/H4 tetramer on DNA and promoting the deposition of the H2A/H2B dimer onto the nucleosome. In contrast, the large subunit SPT16 destabilizes the nucleosome structure by displacing the H2A/H2B dimers. Our findings provide mechanistic insights by which the two subunits of FACT coordinate with each other to fulfill its functions and suggest that FACT may play essential roles in preserving the original histones with epigenetic identity during transcription or DNA replication.
文章链接：https://www.cell.com/molecular-cell/fulltext/S1097-2765(18)30465-9
相关报道：http://www.ibp.cas.cn/kyjz/zxdt/201807/t20180723_5046493.html
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