INTERCELLULAR COMMUNICATION IN THE EYE LENS

眼晶状体中的细胞间通讯

• 批准号: 2872388
• 负责人: Jean X Jiang
• 金额: $ 9.89万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-02-01 至 2003-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2872388
• 关键词: Xenopus oocyte; active sites; cell line; chick embryo; cytoplasm; gap junctions; in situ hybridization; lens; macrophage inflammatory proteins; membrane channels; phosphorylation; posttranslational modifications; protein kinase; protein structure function; tissue /cell culture

DESCRIPTION (Adapted from applicant's abstract): A recent study shows that mice deficient in the lens gap junction protein connexin 46 (Cx46) develop cataracts, indicating the direct role of gap junction-mediated communication in maintaining lens transparency. Gap junctions are clusters of transmembrane channels that connect the cytoplasm of adjacent cells. These channels permit small metabolites, ions and second messengers to pass from cell to cell. Lens fiber cells within the interior of the vertebrate eye lens have nether a blood supply nor organelles. Thus, lens survival and homeostasis are uniquely dependent on intercellular communication via gap junctions with epithelial cells at the lens surface. The chick lens is chosen as an experimental system as it provides many advantages compared with other species. Three connexins are known to participate in the formation of lens gap junction channels: Cx43 in lens epithelial cells, Cx45.6 and Cx56 mainly in lens fibers. Lens fiber proteins, which survive the whole life span of animals, are susceptible to post-translational phosphorylation. Phosphorylation of lens connexins may have functional implications in the regulation of lens gap junction channels. Moreover, evidence from other species has shown that phosphorylation of connexins is related to gap junction channel assembly and gating. The first goal of this proposal is to determine the functional role of connexin phosphorylation in the lens which includes: identifying phosphorylation sites, studying functional roles of connexin phosphorylation, and determining the relevant kinases involved. The second objective involves experiments to determine the signals for the correct targeting by different lens connexins and the formation of heteromeric connexins. The final objective involves the characterization of relationships between lens connexins and MIP and the function of MIP in lens gap junctions. The proposed experiments will be performed in established systems, including intact embryonic chicken lenses, primary lens cultures, connexin-deficient cell lines and Xenopus oocytes, In addition, a novel retroviral assay system, newly developed by the applicant, will be employed in which exogenous connexins will be introduced into the embryonic chick lens in situ in order to define the roles of lens gap junctions in lens physiology and pathology.

描述（根据申请人的摘要改编）：最近的一项研究表明 缺乏透镜间隙连接蛋白连接蛋白46（CX46）的小鼠发展 白内障，表明间隙连接介导的通信的直接作用 保持晶状体透明度。 间隙连接是 跨膜通道连接相邻细胞的细胞质。 这些 频道允许小型代谢物，离子和第二使者从 细胞到细胞。 脊椎动物眼内部内的透镜纤维细胞 镜头的血液供应和细胞器。 因此，镜头生存和 稳态独特地依赖于通过间隙的细胞间通信 透镜表面上上皮细胞的连接。 小鸡镜是 选择作为实验系统，因为它提供了许多优势 与其他物种。 已知三种连接素参与 透镜间隙连接通道的形成：晶状体上皮细胞中的CX43， CX45.6和CX56主要在镜头纤维中。 镜头纤维蛋白，生存 动物的整个寿命，容易受到翻译后的影响 磷酸化。 晶状体连接素的磷酸化可能具有功能性 镜头间隙连接通道调节的含义。 而且， 来自其他物种的证据表明，连接蛋白的磷酸化是 与间隙连接通道组件和门控有关。 这个目标的第一个目标 提案是确定连接蛋白磷酸化的功能作用 镜头包括：识别磷酸化位点，研究 连接磷酸化的功能作用，并确定相关 激酶涉及。 第二个目标涉及实验以确定 不同镜头连接素和正确靶向的信号 杂体连接素的形成。 最终目标涉及 透镜连接素与MIP与MIP之间的关系的表征 MIP在镜头间隙连接中的功能。 提出的实验将是 在已建立的系统中执行，包括完整的胚胎鸡肉镜头， 原代晶状体培养物，连接蛋白缺陷细胞系和爪蟾卵母细胞中 此外，是一种新型的逆转录病毒测定系统，由申请人新开发 将使用将外源连接素引入 原位胚胎鸡镜头以定义透镜间隙的作用 晶状体生理和病理的连接。