THE PROTEIN-CONDUCTING CHANNEL

蛋白质传导通道

• 批准号: 8172034
• 负责人: JAMES C GUMBART
• 金额: $ 5.02万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8172034
• 关键词: Archaea; Back; Bacteria; Be++ element; Behavior; Beryllium; Cell membrane; Cells; Complex; Computer Retrieval of Information on Scientific Projects Database; Endoplasmic Reticulum; Eukaryota; Feeds; Funding; Grant; Institution; Insulin; Left; Life; Membrane; Membrane Proteins; Methanococcus; Prions; Proteins; Research; Research Personnel; Resolution; Resources; Ribosomes; Role; Source; Structure; United States National Institutes of Health; base; dimer; in vivo; monomer; polypeptide; protein complex

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The protein-conducting channel, more specifically known as the translocon (http://www.ks.uiuc.edu/Research/translocon/) or Sec complex, is an evolutionarily ancient protein complex that helps proteins cross or integrate into membranes (depending on whether they are soluble or membrane proteins). Present in all branches of life, the Sec complex is found in the cytoplasmic membrane in bacteria and archaea and in the membrane of the endoplasmic reticulum in eukaryotes. A passive channel, the Sec complex partners with other proteins that drive translocation of an unfolded polypeptide through the channel. In co-translational translocation, a common mode of translocation, this partner is the ribosome which feeds the nascent protein through the channel as it is synthesized. As a key step in protein targeting, translocation can be a deciding factor in the fate of proteins and even the cell as a whole. For example, poor recognition of the prion protein (PrP) leads to its abnormal aggregation and ultimately to lethal levels in the cell [1]. However, being able to enhance recognition and passage across the membrane could increase yields for artificially created proteins such as insulin [2]. In 2004, the Resource's collaborator, Tom Rapoport, released the first high resolution structure of the translocon. Obtained from Methanococcus jannaschii, this heterotrimeric membrane protein complex was resolved to 3.5 Angstroms. Based on this structure, specific details of translocation began to emerge. Observed structural elements were proposed to have specific functions, such as a constrictive pore ring and a plug blocking the exit of the channel. It was also proposed that a singular monomer within a dimeric or tetrameric complex serves as the active channel, leaving the role of oligomerization in question. Two dimeric forms of the channel with different functional behavior have been proposed (a 'back-to-back' and a 'front-to-front' dimer) although which is the in vivo state is unknown.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 蛋白质传导通道，更特别地称为Clressocon（http://www.ks.uiuc.edu/research/research/translocon/） 或SEC复合物，是一种进化上古老的蛋白质复合物，可帮助蛋白质交叉或整合到膜中 （取决于它们是可溶性还是膜蛋白）。 SEC建筑群都存在于生命的所有分支中 细菌和古细菌中的细胞质膜以及真核生物中内质网的膜。 一个 被动渠道，SEC复合伙伴与其他蛋白质的合作伙伴 频道。在共译（一种常见的易位方式）中，该伴侣是核糖体的核糖体 通过合成的通道，新生的蛋白质通过通道。作为蛋白质靶向的关键步骤，易位可以是 决定蛋白质甚至整个细胞的命运因素。例如，对prion蛋白（PRP）的识别不佳 导致其异常聚集，并最终导致细胞中的致命水平[1]。 但是，能够增强认可 并通过膜穿过可以增加人为产生的蛋白质（例如胰岛素）的产量[2]。在2004年 资源的合作者汤姆·拉波波特（Tom Rapoport）发布了Cranslocon的第一个高分辨率结构。从 Jannaschii的甲甲球菌，将这种异三聚体蛋白质复合物解析为3.5埃。基于此 结构，易位的具体细节开始出现。提出观察到的结构元素具有特定 功能，例如收缩的孔环和插头阻塞通道的出口。还提出了一个单数 二聚体或四聚体络合物内的单体充当活性通道，留下了寡聚的作用 问题。已经提出了具有不同功能行为的通道的二合一形式（“背对背”和一个 “前到前”二聚体）尽管这是体内状态的未知。