Heterochromatin dynamics revealed by single nucleosome imaging

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H04746
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Molecular biology
• Research Institution: National Institute of Genetics
• Principal Investigator: Maeshima Kazuhiro 国立遺伝学研究所, 遺伝メカニズム研究系, 教授 (00392118)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: クロマチン動態 / 染色体 / ヌクレオソーム / 1分子イメージング

Outline of Final Research Achievements

How is two meters of genome DNA three-dimensionally organized in the cell as chromatin? For this ten years, we have revealed that chromatin has a dynamic and highly variable configuration like a fluid, rather than a static regular structure like a crystal. If chromatin is fluid-like, what is the organization of heterochromatin, which is assumed to be more condensed, silenced and inactive? We hypothesized that local chromatin dynamics are suppressed in heterochromatin regions, causing a limited access to the regions. We investigated the nucleosome motion in heterochromatin by single nucleosome imaging and fluorescent nucleotide labeling, and proved our hypothesis. We suggested that heterochromatin, whose nucleosomes are crosslinked by some specific chromatin proteins, has lower local mobility and causes lower accessibility of the genome regions, contributing to their silencing.

Free Research Field

分子生物学

Academic Significance and Societal Importance of the Research Achievements

個々のヌクレオソームの動きは、クロマチンへのアクセシビリティの制御とも直結し、遺伝子発現調節、DNA 複製、染色体構築のような関連領域に大きなインパクトを与える。その学術的意義は大きい。また、ヒトゲノム情報は私たちの健康や生命に深く関わっている。本研究課題の成果は、「私たちの生命に関わる細胞内のゲノム情報がどのように整理され、アクセスされ、読み出されるのか？」という疑問の解決に直結するものであり、その社会的意義は大きい。