PHYSIOLOGICAL MECHANISMS OF INTEGRIN AFFINITY MODULATION

整合素亲和力调节的生理机制

• 批准号: 2231641
• 负责人: Timothy E O'Toole
• 金额: $ 18.98万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-08-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2231641
• 关键词: activation product; biological signal transduction; cell adhesion; cell cell interaction; chemical binding; chimeric proteins; conformation; crosslink; cytokine receptors; cytoplasm; extracellular matrix; fibrinogen; gene expression; human tissue; hybrid cells; integrins; interleukin 2; leukocyte adhesion molecules; ligands; platelets; protein structure function; tissue /cell culture; transcription factor; transfection; yeasts

DESCRIPTION (Adapted from investigator's abstract): Blood cells such as platelets, lymphocytes and neutrophils exert their physiological function through adhesive interactions with the extracellular matrix or with other cells. The integrins, a family of transmembrane alpha, beta heterodimers which mediate the adhesion of many of these cell types, are notable for their dynamic regulation. In response to external stimuli, integrins upregulate ligand binding affinity and alter cellular adhesiveness. Preliminary data suggest that integrin "activation" or affinity modulation involves cell- specific signalling through integrin cytoplasmic domains. In this proposal, the PI will elucidate this physiological pathway. First, he will identify alpha and beta subunit cytoplasmic residues which are involved. Using extracellular alphaIIb, beta3 as a reporter group, he will generate variant cytoplasmic domains, transfect these constructs into heterologous cells and analyze their ability to bind antibody or protein ligands. Second, he will examine the effect of overexpression of integrin cytoplasmic domains on physiological activation mechanisms. Chimera consisting of the extracellular and transmembrane regions of the IL-2 receptor joined to specific integrin cytoplasmic domains have been obtained. These constructs will be co-transfected with constitutively active integrins and the inhibitory effect on binding analyzed. Finally, he will attempt to identify hypothetical cytosolic factors which interact with integrin cytoplasmic domains. Novel factors will be isolated and identified in crosslinking studies utilizing the inhibitory chimera identified above, or by regenerating the GAL4 transcription factor in a two hybrid system. Defining the mechanisms of affinity modulation is crucial to understanding the role of integrins in the physiology and pathology of blood cells.

描述（改编自研究者的摘要）：血细胞，例如 血小板、淋巴细胞和中性粒细胞发挥生理功能 通过与细胞外基质或其他物质的粘附相互作用 细胞。整合素，跨膜α、β异二聚体家族 它介导许多这些细胞类型的粘附，以 他们的动态调节。整合素响应外界刺激 上调配体结合亲和力并改变细胞粘附性。 初步数据表明整合素“激活”或亲和力 调节涉及通过整合素进行的细胞特异性信号传导 细胞质结构域。在本提案中，PI 将阐明这一点 生理途径。首先，他将识别α和β亚基 所涉及的细胞质残基。使用细胞外αIIb， beta3作为报告基团，他会产生变异的胞质结构域， 将这些构建体转染到异源细胞中并分析它们 结合抗体或蛋白质配体的能力。其次，他会检查 整合素胞质结构域过表达的影响 生理激活机制。嵌合体由 IL-2 受体的胞外区和跨膜区连接 已经获得了特定的整合素胞质结构域。这些 构建体将与组成型活性整合素共转染 并分析了对结合的抑制作用。最后，他将尝试 识别与整合素相互作用的假设胞质因子 细胞质结构域。新因素将被分离和识别 利用上面确定的抑制性嵌合体的交联研究， 或者通过在两个混合系统中再生 GAL4 转录因子。 定义亲和力调节机制对于 了解整合素在生理学和病理学中的作用 血细胞。