関連する実験動画
Updated: Dec 9, 2025

10:37
Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
9.5K
cGASの緊密な核結合と不活性化の分子基礎
Baoyu Zhao1, Pengbiao Xu1, Chesley M Rowlett2
1Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA.
Nature
|September 10, 2020
まとめ
サイクルGMP- AMP合成酵素 (cGAS) は核細胞に結合し,そのDNA感知活性を抑制する. この相互作用は,核の局所化はcGASを不活性状態に保ち,先天的な免疫シグナリングに影響を及ぼすことを説明します.
科学分野:
- 免疫学
- 分子生物学
- 構造生物学
背景:
- 病原体由来核酸は 生まれつきの免疫反応を引き起こします
- サイクルGMP- AMP合成酵素 (cGAS) は,STING- TBK1- IRF3経路によるタイプIインターフェロン誘導に不可欠なDNAセンサーである.
- 最近の発見は,cGASが核に局所し,その活動は核結合によって抑制されていることを示しています.
研究 の 目的:
- 核結合によるcGAS無活性化に伴う分子メカニズムを調査する.
- 核相とcGASの相互作用の構造的基礎を決定する.
主な方法:
- クリオ電子顕微鏡 (cryo-EM) で,マウスのcGASがヒトのヌクレオソームに結合する構造を決定する.
- cGAS結合親和性と触媒活性を評価する生化学的測定法
- 信号効果を研究するために変異したcGASを用いた細胞測定法.
主要な成果:
- cGASは,高 (ナノモラー) アフィニティでニュクレオソームに結合する.
- 核細胞結合は,DNA結合を阻害することによって,cGASの触媒活性を強力に抑制する.
- 構造分析により,cGASはヒストンH2A/H2B酸性パッチに結合し,不活性な形状を維持することが明らかになった.
- 核細胞結合を阻害する突然変異は,細胞内のcGAS活性を再生する.
結論:
- 核細胞結合は,核内のcGASを無効化する重要なメカニズムである.
- この相互作用は自己DNAによる異常な免疫活性化を防ぐ.
- cGAS- 核群の相互作用を理解することで,先天的な免疫調節と潜在的な治療目標の洞察が得られます.
関連する概念動画
Activation and Inactivation of G Proteins
9.7K
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high...
9.7K
Actin Filament Depolymerization
3.6K
Actin filaments (F-actin) are composed of actin subunits. The dissociation of actin monomers can occur from either end of F-actin. The rate of dissociation is faster from the minus-end or the pointed end, where the actin subunits exist with a bound ADP, together known as ADP-actin. The depolymerization of F-actin is aided by proteins, including the actin-depolymerizing factor (ADF) and cofilin family of proteins, gelsolin, and glia maturation factor (GMF).
In F-actin, the ADF/cofilin proteins...
In F-actin, the ADF/cofilin proteins...
3.6K
GTPases and their Regulation
9.5K
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins,...
Large G-proteins,...
9.5K
GTPases and their Regulation
2.7K
2.7K
Anaphase Promoting Complex
3.2K
The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
3.2K
Catenins
2.9K
Catenins are characterized by multiple binding domains and dynamic structures that allow them to function as linker proteins in cell junction complexes. All catenins, except α-catenin, contain a characteristic protein sequence called the armadillo repeat and are therefore also called armadillo proteins.
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the...
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the...
2.9K

