Qa-2分子是比普通I类分子更严格的受体
O Rötzschke1, K Falk, S Stevanović
1Max-Planck-Institut für Biologie, Abteilung Immungenetik, Tübingen, Germany.
Nature
|February 18, 1993
概括
不传统的老鼠Qa-2分子,其功能以前尚不清楚,已被证实是受体. 它们表现出严格的连接物特异性,类似于传统的I类分子,为T细胞监测提供.
科学领域:
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 第I类主要基因相容性复合体 (MHC) 分子向T细胞呈现,以进行免疫监测.
- 非传统的I类MHC分子,如小鼠Qa-2,具有不清楚的功能,尽管它们可以与T细胞相互作用.
- 虽然结构上与传统的MHC I类相似,但Qa-2的呈现作用尚未得到证实.
研究的目的:
- 为了研究非传统的小鼠I类分子,Qa-2.的天然联体.
- 确定Qa-2是否作为受体功能,并描述其连接体特异性.
- 为了比较Qa-2的结特性与传统的I类MHC分子.
主要方法:
- 从Qa-2分子中分离出来的自然配体的池测序.
- 分析的长度,位,和氨基酸占用在配体池内的氨基酸.
主要成果:
- Qa-2分子作为受体起作用,结合主要9个氨基酸长度的.
- 体特异性的特点是特定的位和疏水性末,类似于传统的MHC I类.
- 与其他I类分子相比,Qa-2表现出明显更严格的配体特异性,在九个位中的四个位置的占用量有限.
结论:
- 该研究证实Qa-2是一种结分子,扩大了非传统MHC I类分子的已知功能.
- Qa-2的严格的特异性表明它在免疫识别中发挥着专门的作用,与传统的MHC I类不同.
- 这些发现为通过非传统的MHC分子介导的免疫监测的分子机制提供了洞察力.
相关概念视频
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.
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.
G Protein-coupled Receptors
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
Transducer Mechanism: G Protein–Coupled Receptors
G Protein–Coupled Receptors (GPCRs) are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to various stimuli. GPCRs regulate critical physiological pathways and are excellent drug targets for treating diseases such as diabetes, cancer, obesity, depression, or Alzheimer's. Nearly 35% of approved drugs implement their therapeutic effects by selectively interacting with specific GPCRs.
GPCRs are also called heptahelical, 7TM, or...
GPCRs are also called heptahelical, 7TM, or...
Transducer Mechanism: Enzyme-Linked Receptors
Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
Major types that are helpful drug targets include:
The Two-State Receptor Model
The two-state receptor model explains a drug's interaction with receptors, such as G protein-coupled receptors and ligand-gated ion channels, to induce or inhibit a biological response. When no natural ligands are present, a receptor exists in an equilibrium of inactive (Ri) and active (Ra) conformations. The inactive form does not produce a response, while the active form generates a basal effect known as constitutive activity.
The binding affinity of a drug determines its interaction with one...
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