関連する実験動画
Updated: Jul 7, 2026

10:37
Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
クラスIIのトランザクティバータによるGTPの拘束:核輸入における役割
J A Harton1, D E Cressman, K C Chin
1Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599, USA.
まとめ
クラスIIトランザクティベーター (CIITA) はグアナシン三リン酸 (GTP) を結合し,これはヒト白血球抗原D (HLA-D) 遺伝子の活性化におけるその役割に不可欠な機能である. このGTPの拘束はCIITAを容易にする.
科学分野:
- 分子生物学は分子生物学である.
- 免疫遺伝学 免疫遺伝学とは
- トランスクリプションに関する規則
背景:
- クラスIIトランザクティベーター (CIITA) は,ヒト白血球抗原D (HLA-D) 遺伝子の重要な共同活性化剤である.
- CIITAは,グアノシン三酸塩 (GTP) 結合タンパク質に似たモチーフを持っています.
研究 の 目的:
- CIITAのGTP結合能力を調査する.
- CIITAのGTP結合モチーフのトランスクリプション活性化と核インポートにおける機能的重要性を決定する.
主な方法:
- CIITAの推定GTP結合モチーフのサイト指向型変異.
- グアノシントリホスファート (GTP) の結合測定法.
- トランスクリプション活動の測定.
- CIITAの核輸入に関する分析.
主要な成果:
- CIITAは,グアノシントリホスファート (GTP) を直接結合する.
- GTP結合モチーフの変異は,GTP結合とトランザクティベーションの両方を損なう.
- アナログの Ras 配列に置き換えることで,CIITA 機能が救われます.
- GTP結合はCIITA核インポートと相関し,GTP酵素の活性が増加すると転写機能が低下する.
結論:
- CIITAは,核インポートのためにGTP結合を利用しており,これは,正規のGTP結合タンパク質とは異なるメカニズムである.
- GTP結合は,ヒト白血球抗原D (HLA-D) 遺伝子発現を調節するCIITAの役割に不可欠です.
関連する概念動画
G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
GTPases and their Regulation
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, also known...
Large G-proteins, also known...
Nuclear Localization Signals and Import
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G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
GTPases and their Regulation
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, also known...
Large G-proteins, also known...
Activation and Inactivation of G Proteins
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 affinity and are together...

