通过II类交易激活器进行GTP绑定:在核进口中的作用
J A Harton1, D E Cressman, K C Chin
1Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599, USA.
概括
二级交换活化剂 (CIITA) 结合关三酸盐 (GTP),这是其在人类白细胞抗原-D (HLA-D) 基因激活中的关键作用. 这种GTP绑定有助于CIITA.
科学领域:
- 分子生物学分子生物学
- 免疫遗传学 免疫遗传学
- 转录条例 转录条例 转录条例
背景情况:
- 二级交互活化剂 (CIITA) 是人类白细胞抗原-D (HLA-D) 基因的关键联合活化剂.
- CIITA具有类似于关三酸盐 (GTP) 结合蛋白质的图案.
研究的目的:
- 为了研究CIITA的GTP结合能力.
- 确定CIITA的GTP结合基因在转录激活和核导入中的功能意义.
主要方法:
- CIITA假定GTP结合基因的局部定向突变发生.
- 关三酸盐 (GTP) 的结合测定.
- 转录活动测定.
- 对CIITA核进口的分析.
主要成果:
- CIITA直接与瓜诺辛三酸盐 (GTP) 相结合.
- 在GTP结合基因的突变损害了GTP结合和事务激活.
- 用相似的Ras序列替换可以挽救CIITA的功能.
- GTP结合与CIITA核进口相关,而增强的GTPase活性会降低转录功能.
结论:
- CIITA使用GTP结合用于其核进口,这种机制与正规的GTP结合蛋白不同.
- 结合GTP对于CIITA在调节人类白细胞抗原-D (HLA-D) 基因表达中的作用至关重要.
相关概念视频
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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...
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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...


