GAP JUNCTION

间隙连接

• 批准号: 8361077
• 负责人: GINA E SOSINSKY
• 金额: $ 1.23万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8361077
• 关键词: Actin-Binding Protein; Amino Acids; Area; Back; C-terminal; Cadherins; Cell membrane; Cells; Connexin 43; Connexins; Cytoplasmic Tail; Disease; Electron Microscopy; Electrons; Extracellular Domain; Functional disorder; Funding; Gap Junctions; Grant; Image; Ligand Binding Domain; Methods; Movement; National Center for Research Resources; Phosphotransferases; Play; Principal Investigator; Protein Family; Research; Research Infrastructure; Resolution; Resources; Roentgen Rays; Role; Source; Structure; Tertiary Protein Structure; Transmembrane Domain; Tubulin; United States National Institutes of Health; congenital cataract; cost; flexibility; gap junction channel; human GJB2 protein; lens; macromolecule; member; mutant; particle; reconstruction

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Gap junctions are plasma membrane specializations found at cell-cell appositional areas. They contain tens to thousands of channels that allow the movement of molecules of 1 kDa or less between neighboring cells. Gap junction channels are built from members of the connexin (Cx) protein family, ranging in size from ~23 kDa to ~62 kDa, although the most studied connexins are Cx26 (26 kDa), Cx32 (32 kDa) and Cx43 (43 kDa). A gap junction channel consists of two connexin hexamers (hemichannels), one from each of the interacting cells, stacked back-to-back. Single particle reconstruction is being used to synthesize a more complete view of the tertiary structure of Connexin50 (Cx50) hemichannels. Cx50 gap junctions play important roles in the lens and dysfunction or mistrafficking of Cx50 mutants results in congenital cataracts. Structural studies of gap junction channels using electron or X-ray crystallographic methods have obtained atomic or near atomic resolution structures for Cx26 and a C-terminal truncated Cx43. The rigid transmembrane and extracellular domains are resolved, but the flexible cytoplasmic loop and C-terminus have not been adequately visualized either due to disorder or truncation. In connexins larger than ~40 kDa, these cytoplasmic domains, particularly the C- terminus, often contain as many amino acids as the N-terminus, transmembrane and extracellular domains combined. These cytoplasmic domains contain important kinase regulatory domains and binding sites for PDZ domain proteins (e.g. ZO-1), tubulin, debrin (an actin-binding protein) and possibly cadherins or ¿-catenin. Therefore, the crystallographic structures are missing important parts of the structure. We have made advances in imaging Cx50 pannexons using vitrified cryo-EM methods and reconstruction with single particles methods.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供 该子项目的主要支持。 并且子项目的首席研究员可能是由其他来源提供的， 包括其他 NIH 来源的子项目可能列出的总成本。 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 间隙连接是在细胞与细胞并置区域发现的质膜特化。 它们包含数十到数千个通道，允许 1 的分子运动 相邻细胞之间的间隙连接通道由 kDa 或更少的成员构建。 连接蛋白 (Cx) 蛋白家族，大小范围从 ~23 kDa 到 ~62 kDa，尽管 研究最多的连接蛋白是 Cx26 (26 kDa)、Cx32 (32 kDa) 和 Cx43 (43 kDa)。 连接通道由两个连接蛋白六聚体（半通道）组成，每个连接蛋白六聚体各一个 相互作用的细胞，背对背堆叠的单粒子重建被用来。 合成 Connexin50 (Cx50) 三级结构的更完整视图 Cx50 间隙连接在晶状体和功能障碍中发挥重要作用。 Cx50 突变体的错误贩运导致先天性白内障的间隙结构研究。 使用电子或X射线晶体学方法的结通道已经获得了原子 或 Cx26 的近原子分辨率结构和 C 端截短的 Cx43。 跨膜和细胞外结构域已被解析，但灵活的细胞质环 由于无序或截断，C 末端尚未充分可视化。 在大于 ~40 kDa 的连接蛋白中，这些细胞质结构域，特别是 C- 末端，通常含有与 N 末端一样多的氨基酸，跨膜和 这些细胞质结构域包含重要的激酶。 PDZ 结构域蛋白（例如 ZO-1）、微管蛋白、德布林的调节结构域和结合位点 （肌动蛋白结合蛋白）和可能的钙粘蛋白或 ¿ -连环蛋白。 晶体结构缺少结构的重要部分。 使用玻璃化冷冻电镜方法和重建对 Cx50 pannexons 进行成像的进展 用单粒子方法。