SPLICE VARIANTS OF THE HA RECEPTOR FOR ENDOCYTOSIS

描述(由申请人提供)： 透明质酸是一种动态的大分子糖胺多聚糖，在细胞外基质、细胞信号、器官发育、伤口愈合和细胞运动中发挥重要作用。人透明质酸(HA)内吞受体(HARE/STAB2)是由69个外显子组成的180227个碱基基因编码的。这种1型受体是唯一已知的通过网状蛋白介导的内吞作用结合和内化HA和硫酸软骨素(CS)的HA受体。由于基因中外显子的数量，我们假设通过基因拼接产生了编码功能不同的hHARE变体的多个mRNA物种。该项目的主要目标是识别和表征Hare/Stab2剪接变异体，并确定它们对GAG稳态的潜在影响。该项目分为3个具体目标：1)继续从人体组织中筛选剪接变异体的cDNA库；2)在细胞培养和结合实验中评估稳定表达的Hare剪接变异体的GAG结合活性；3)确定哪些剪接变异体在成人发育和未发育的人体组织中表达。HARE异构体的重要意义在于有可能创造一个受体家族，结合/内化一系列不同的GAG。

DESCRIPTION (provided by applicant): Hyaluronic acid is a large dynamic glycosaminoglycan (GAG), which plays an important role in the extracellular matrix, cell signalling, organ development, wound healing and cell motility. The human hyaluronic acid (HA) receptor for endocytosis (HARE/Stab2) is encoded by a 180227 bp gene consisting of 69 exons. This type 1 receptor is the only known HA receptor to bind and internalize HA and Chondroitin Sulfates (CS) though clathrin-mediated endocytosis. Due to the number of exons in the gene, we hypothesize that multiple mRNA species encoding functionally distinct hHARE variants arise through gene splicing. The primary goals of this project are to identify and characterize HARE/Stab2 splice variants and determine their potential impact on GAG homeostasis. The project is divided into 3 specific aims which are; 1) to continue screening cDNA pools from human tissues for splice variants, 2) to assess GAG binding activity of stably expressed HARE splice variants in cell culture and binding assays, and 3) determine what splice variants are expressed in adult developed and undeveloped human tissues. The significance of HARE isoforms is the potential to create a family of receptors that bind/internalize a host of different GAGs.