Molecular Basis For Functional Diversity Of PSGL-1

PSGL-1 功能多样性的分子基础

• 批准号: 6520152
• 负责人: KAREN R SNAPP
• 金额: $ 3.55万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6520152
• 关键词: Ehrlichia; bacteria infection mechanism; cell adhesion; cell cell interaction; cell line; cytoplasm; cytoskeletal proteins; cytoskeleton; flow cytometry; genetically modified animals; glycoproteins; inflammation; intermolecular interaction; laboratory mouse; leukocyte activation /transformation; ligands; molecular site; platelets; posttranslational modifications; protein sequence; protein structure function; receptor; selectins; site directed mutagenesis; vascular endothelium; western blottings

DESCRIPTION (applicant's description): The regulation of leukocyte recruitment into inflammatory sites occurs at the level of leukocyte recognition of endothelium. This crucial event is mediated by interactions between the selectin family of adhesion molecules and their leukocyte and endothelial expressed ligands. This proposal is directed at understanding the cellular and molecular basis of adhesion mediated by P-selectin Glycoprotein Ligand-1 (PSGL-l). This adhesion molecule is expressed on all classes of leukocytes and mediates adhesion primarily to endothelial or platelet P-selectin, but also mediates interactions with leukocyte L-selectin. Thus, PSGL- 1 is essential for leukocyte recognition of other leukocytes, platelets, and endothelium, and plays a major role in the recruitment of leukocytes to endothelium and amplification of the inflammatory response. Many features of the PSGL-1 ectodomain required for these interactions have been described, and we have recently shown that interactions between the PSGL-l cytoplasmic domain and the actin cytoskeleton via the linker protein moesin, are essential for binding to P-selectin. PSGL- 1 also serves as the entry receptor for the pathogen responsible for Human Granulocytic Ehrlichiosis (HGE). HOE is a recently described tick-borne infection of humans which infects and proliferates within circulating neutrophils. HGE bacterium bind to an area of PSGL-1 identical to or overlapping the P-selectin binding region, but it is not known what features of this binding site are required for bacterial binding and subsequent entry. In this proposal, we hope to further understand the structural requirements of PSGL-1 interactions with P-selectin and HGE by: 1) identifying residues within the cytoplasmic domain of PSGL- 1 responsible for cytoskeletal attachment and cell adhesion; 2) determining the functional importance of interactions between moesin and the cytoplasmic domain of PSGL- 1; and 3) defining the biochemical features of PSGL-1 required for HOE bacterium binding and entry. These studies should greatly enhance our understanding of the essential components of PSGL- 1 required for interactions with both selectins and an intracellular parasite. The combined information gained from exploring these specific alms will add significantly to our understanding of how PSGL- 1 functions, and should identify new clinical targets for intervention in acute and chronic inflammatory disorders, prevention and/or treatment of HGE, and treatment of other diseases involving the immune system.

描述(申请人描述)：白细胞募集的调节 进入炎症部位发生在白细胞识别的水平上 内皮细胞。这一关键事件是由 黏附分子选择素家族及其白细胞和内皮细胞 表达的配体。这项建议旨在了解细胞和 P-选择素糖蛋白配体-1介导黏附的分子基础 (PSGL-L)这种黏附分子在所有类别的白细胞上都有表达， 主要介导与内皮或血小板P-选择素的黏附，但也 介导与白细胞L-选择素的相互作用。因此，PSGL-1对于 白细胞对其他白细胞、血小板和内皮的识别，以及 在白细胞募集到内皮细胞和 炎症反应的放大。PSGL-1的许多功能 已经描述了这些交互所需的外域，我们已经 最近的研究表明，PSGL-L胞质结构域与细胞周期蛋白的相互作用 肌动蛋白细胞骨架通过连接蛋白moesin，是与 P-选择素。PSGL-1也是病原体的进入受体 负责人类粒细胞性埃立克体病(HGE)。HOE是最近才出现的 描述了扁虱传播的人类感染，感染并在 循环中的中性粒细胞。HGE细菌与PSGL-1区域结合 或重叠P-选择素结合区，但尚不清楚有哪些功能 细菌结合和随后进入所需的结合位点数。 在这份提案中，我们希望进一步了解 PSGL-1与P-选择素和HGE的相互作用：1)识别 PSGL-1的胞质结构域负责细胞骨架的附着和 细胞黏附；2)确定相互作用的功能重要性 Moesin和PSGL-1的细胞质结构域；以及3)定义生化 细菌结合和进入所需的PSGL-1特性。这些研究 应该会大大提高我们对PSGL-1的基本组成部分的了解 与选择素和细胞内寄生虫相互作用所必需的。 从探索这些特定施舍中获得的综合信息将添加 对我们理解PSGL-1是如何工作的，以及应该 确定急慢性疾病干预的新临床靶点 炎症性疾病，预防和/或治疗HGE，以及治疗 其他涉及免疫系统的疾病。