STRUCTURE AND MOLECULAR BIOLOGY OF THE PROTEIN S GENE

蛋白S是调节止血的关键组分。 蛋白S 作为活化蛋白C的辅因子，蛋白C是一种负责 血液凝固途径中两种蛋白质成分的降解。 因此，蛋白S通过蛋白C的作用下调 血液凝固的过程 功能性蛋白质缺乏的个体 S，无论是由于遗传或环境获得的原因， 发生血栓性疾病的风险更高。 症状通常 与蛋白S缺乏相关的包括血栓性静脉炎，深静脉炎， 血栓和肺栓塞 目前，遗传基础 蛋白S缺乏症及其与血栓形成的关系尚不清楚。 拟议研究的长期目标是了解 蛋白S缺乏和血栓形成的遗传基础。 这将是 部分通过拟议的研究完成，旨在提供 更好地了解正常和异常的蛋白S基因， 蛋白S产品的功能特性。 具体目标和 实现这些目标的方法包括： 表达的蛋白S基因（PS-α）的内含子A、C和I，使用PCR 通过基因组Southern杂交进行扩增和确认; B.） 通过DNA测序和Southern作图克隆和表征 来自遗传性蛋白S缺陷个体的PS-α基因; c） 定点诱变和哺乳动物细胞表达研究， 处理与下列人员的作用有关的结构/职能关系： 蛋白S的N-糖基化。与去糖基化的比较研究 还将进行血浆衍生的蛋白S;和d）分离和 血浆常规生化方法表征 降低蛋白S和C4 b结合之间相互作用的组分 蛋白 这些研究的结果将导致更好的 了解蛋白质S的结构和功能;并可能 最终导致改进的诊断和治疗方法， 患有蛋白S缺乏症并导致血栓性疾病。

Protein S is a key component for the regulation of hemostasis. Protein S serves as a cofactor for activated Protein C, an enzyme responsible for the degradation of two protein elements of the blood coagulation pathway. Consequently, Protein S through the action of Protein C down-regulates the blood clotting process. Individuals deficient in functional Protein S, either because of genetic or environmentally-acquired reasons, are at a higher risk of experiencing thrombotic disorders. Symptoms commonly associated with Protein S deficiency include thrombophlebitis, deep vein thrombosis, and pulmonary emboli. At the present time the genetic basis of Protein S deficiency and its relationship to thrombosis are unknown. The long-term objective of the proposed research is to understand the genetic basis of Protein S deficiency and thrombosis. This will be accomplished, in part, through the proposed studies, designed to provide a better understanding of the normal and abnormal Protein S genes and the functional properties of the Protein S products. Specific aims and methods for achieving these goals include: a) characterization of gaps in introns A, C and I of the expressed Protein S gene (PS-alpha), using PCR amplification and confirmation by genomic Southern hybridization; b.) cloning and characterization by DNA sequencing and Southern mapping of the PS-alpha gene from genetically Protein S deficient individuals; c) site-directed mutagenesis and mammalian cell expression studies to address structure/function relationships relating to the role(s) of N-glycosylation for Protein S. Comparative studies with deglycosylated plasma-derived Protein S will also be performed; and d) isolation and characterization with conventional biochemical methods of a plasma component that reduces the interaction between Protein S and C4b-binding protein. The results of these studies will lead to a better understanding of the structure and function of Protein S; and may eventually lead to improved methods of diagnosis and therapy for patients having Protein S deficiency and resulting thrombotic disorders.