相关实验视频
Updated: Aug 2, 2026

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Measuring Peptide Translocation into Large Unilamellar Vesicles
Published on: January 27, 2012
通过与抗原处理相关的载体变异的转位
M T Heemels1, T N Schumacher, K Wonigeit
1Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
概括
与抗原处理 (TAP) 相关的载体会影响为主要基因相容性复合体 (MHC) I类呈现的选择. 在老鼠中,不同的TAP等位基因会导致不同的谱,影响免疫反应.
科学领域:
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
背景情况:
- 主体自身相容性复合体 (MHC) 类I分子呈现来自细胞内蛋白质T细胞的.
- 与抗原处理 (TAP) 相关的转运器对于将从细胞质转移到MHC I类载荷的内分泌网膜光层至关重要.
- 已知 TAP 功能表现出结合特异性,影响 MHC I 类分子所呈现的类谱.
研究的目的:
- 调查与抗原处理 (TAP) 基相关的不同载体在形成主要组织相容性复合体 (MHC) I 类分子所呈现的类谱中的作用.
- 确定观察到的积差异是否归因于TAP等位基因或其他遗传因素.
- 为了阐明不同TAP变体的转位特异性.
主要方法:
- 对Sprague-Dawley (SHR) 和易斯大鼠的肝脏显微体中的积分析,这些大鼠分别具有明显的TAP等位基因 (cim(b) 和cim(a).
- 利用MHC先天性老鼠来区分MHC位点与其他遗传差异的影响.
- 通过cim (a) 和cim (b) TAP复合物的转位的比较分析.
主要成果:
- SHR和易斯大鼠表达不同的TAP等位基因,在他们的肝脏显微体中积累了不同的基因组.
- 观察到的积差异被映射到MHC位置,独立于表达的特定I类产品.
- 两种cim (a) 和cim (b) TAP复合体都有效地转移了具有疏水性碳酸末端的;然而,转移具有碳酸末端His,Lys或Arg的是特定于cim (a) 基因组的.
结论:
- 与抗原处理 (TAP) 相关的载体的结特异性直接限制了可用于主要基因相容性复合体 (MHC) I 类呈现的池.
- TAP等位基因的遗传变异对MHC I类分子所呈现的类谱的多样性作出了重大贡献.
- 了解TAP的特异性对于理解免疫监测和设计有效的免疫疗法至关重要.
相关概念视频
Translocation of Proteins into the Mitochondria
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Energy to Drive Translocation
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generally, polypeptides are unfolded by two distinct...
Protein Transport into the Inner Mitochondrial Membrane
Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Cotranslational Protein Translocation
Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Post-translational Translocation of Proteins to the RER
A sizable fraction of proteins destined for ER are first synthesized in the cell cytosol and then transported across the ER membrane–a process called post-translational translocation. Similar to cotranslationally translocated proteins, these proteins also use the Sec translocon complex to enter the ER lumen.
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
Protein Translocation Machinery on the ER Membrane
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent peptides into the ER lumen and their insertion into the ER membrane.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the translocon complex.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the translocon complex.

