HUMAN MYELOID CHEMOTACTIC RECEPTOR: STRUCTURE-FUNCTION

白细胞样多肽受体识别细菌的一种产物 新陈代谢和调节白细胞对微生物入侵的反应。这个 长期目标是确定这种反应的生化途径。 这项提议将重点放在通过甲酰肽进行的信号转导上。 受体。磷脂酶C的激活似乎是最早的 受体占有率的可测量的生化后果。甘油二酯 和三磷酸肌醇；前者激活蛋白质 激酶C，后者从细胞内储存中释放钙离子。我们有 建立了一种新的测定二酰甘油绝对水平的方法 生物样本。本试验将用于甘油二酯的测定 甲酰肽等刺激后白细胞的水平 激动剂。脂肪酸组成、亚细胞定位和代谢 甘油二酯的含量将会被测定。甘油二酯在血管紧张素系统中的作用 将探索受体脱敏作用。将开发一种检测方法，用于 膜上甲酰肽刺激的甘油二酯产量的测定 并将研究GTP结合蛋白在这一过程中的作用。 合成的二辛酰甘油会导致脱粒和氧化爆发， 而十二烷基甘油只会导致脱粒。我们将对这些进行比较 与C激酶转位和[32P]磷酸蛋白有关的化合物 在完整的白细胞中引起的变化。这可能允许区分 参与每种反应的磷蛋白。甲酰肽受体 将通过既定的技术进行提纯，提纯产品 与亲和标记法鉴定的受体进行比较。这项建议 是否与健康有关，因为白细胞功能缺陷会导致复发 感染。许多其他细胞表面受体利用二酰甘油作为一种 第二信使，所以从这些研究中获得的信息将具有广泛的 在肿瘤转化、创面愈合和组织化学中的应用 血管疾病。

The leukocyte form peptide receptor recognizes a product of bacterial metabolism and mediates leukocyte responses to microbial invasion. The long term objective is to define the biochemical pathway of this response. This proposal will focus on signal transduction via the formyl peptide receptor. Activation of phospholipase C appears to be the earliest measurable biochemical consequence of receptor occupancy. Diacylglycerol and inositol trisphosphate are generated; the former activates protein kinase C, the latter releases Ca2+ from intracellular stores. We have developed a novel assay to measure absolute levels of diacylglycerol in biological samples. This assay will be used to measure diacylglycerol levels in leukocytes after stimulation with formyl peptides and other agonists. The fatty acid composition, subcellular location and metabolism of the diacylglycerols will be determined. The role of diacylglycerol in receptor desensitization will be explored. An assay will be developed for measuring formyl peptide-stimulated diacylglycerol production in membranes and the role of a GTP binding protein in this process will be investigated. Synthetic dioctanoylglycerol causes both degranulation and oxidative burst, while didecanoylglycerol causes only degranulation. We will compare these compounds with regard to C kinase translocation and [32P] phosphoprotein changes induced in intact leukocytes. This may allow distinction between phosphoproteins involved in each response. The formyl peptide receptor will be purified by established techniques and the purified product compared with the receptor identified by affinity labeling. The proposal is health related because defects in leukocyte function result in recurrent infections. Many other cell surface receptors utilize diacylglycerol as a second messenger, so information obtained from these studies will have wide application to mechanisms of neoplastic transformation, wound healing and vascular disease.