トルションストレスは,活性遺伝子のDNAase I感受性を促進する

B Villeponteau, M Lundell, H Martinson

Cell

|December 1, 1984

まとめ

鶏の赤血球におけるトポイソメラーゼIIの阻害は,活性ベータ・グロービン遺伝子のDNAアゼI感受性を逆転させ,DNAスーパーコーリングが活性クロマチンの構造を維持することを示唆しています.

科学分野:

分子生物学は分子生物学である.
エピジェネティクスエピジェネティクス
クロマチンの構造クロマチンの構造

背景:

活性遺伝子は,DNAase I消化に対する感受性が高いユニークな染色体構造を示します.
この感受性は,遺伝子のアクセシビリティと調節に極めて重要です.

研究の目的:

DNAスーパーコイルとトポイソメラーゼIIが,活性遺伝子のDNAアゼI感受性を維持する役割を調査する.
トポイソメラーゼIIを阻害すると,活性遺伝子構成がin vivoで変化するかどうかを判断する.

主な方法:

鶏の赤血球は,トポイソメラーゼII阻害剤であるノボビオシンで治療した.
DNAase I 感受性アッセイは,治療細胞と対照細胞で行われました.
In vitro実験では,DNAの分裂を誘導するために,スタフィロコックスの核酵素を用いた.

主要な成果:

ノボビオシン治療は,活性β-グロービン遺伝子の好ましいDNAase I感受性をin vivoで迅速に逆転させました.
制御実験では,トポイソメラーゼII抑制が,この形状の変化の原因であることを確認した.
実験室での部分的なDNA分裂は,DNAase I感受性の逆転を模倣した.

結論:

トポイソメラーゼIIによって促進される継続的なDNAスーパーコーリングは,活性クロマチンの開いたDNAアゼI感受性構造を維持するために不可欠です.
超螺旋的な張力がない場合,活性クロマチンは,より敏感な状態に戻ります.

さらに関連する動画

07:11

Laser Micro-Irradiation to Study DNA Recruitment During S Phase

Published on: April 16, 2021

06:48

CD Spectroscopy to Study DNA-Protein Interactions

Published on: February 10, 2022

関連する概念動画

01:02

The DNA Replication Fork

An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in...

02:02

DNA Topoisomerases

Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...

02:25

Overview of DNA Repair

In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage.
Chemically...

02:10

Translesion DNA Polymerases

Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...

02:36

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...

02:36

DNA Damage Can Stall the Cell Cycle

関連する実験動画