FUNCTION OF A GALACTOSE-BINDING RECEPTOR IN REPRODUCTION

描述（改编自申请人摘要）：本修订提案 要求五年的支持，以评估分子 大鼠睾丸半乳糖受体（RTG-r）的结构和功能。 RTG-r蛋白和mRNA的研究表明，该受体与 大鼠肝凝集素2/3（RHL-2/3）， 去唾液酸糖蛋白受体。 肝脏受体是 负责清除终末后循环中的糖蛋白 除去唾液酸残基。 提出了五个具体目标。 第一章 确定RTG-r的生化和分子结构，包括N- 肽片段的末端氨基酸序列，碳水化合物分析， cDNA分离和测序以及mRNA分析。 另外还有按 单特异性的、亲和纯化的抗体将针对纯化的抗体制备。 RTG-r. 2)确定RTG-r的磷酸化位点和机制。 3)RTG-r在胎儿细胞间识别中的作用研究 睾丸和精子发生过程中。 这些实验将评估 RTG-r在生精细胞和支持细胞之间的特异性结合中的作用， 半乳糖介导胎儿生殖细胞的潜在迁移 梯度。 4)确定支持细胞中的RTG-r是否占据 优先表面结构域，负责受体介导的 特异性配体的内吞作用。 5)确定RHL-1（主要大鼠） 肝凝集素）通过将功能性DNA引入RTG-r中来影响RTG-r功能。 支持细胞和生精细胞。

DESCRIPTION (Adapted from the applicant's abstract): This revised proposal requests five years of support for studies assessing the molecular structure and function of the rat testis galactosyl receptor (RTG-r). Studies of RTG-r protein and mRNA suggest that this receptor is related to the rat hepatic lectin 2/3 (RHL-2/3), the minor species of asiologylcoprotein receptor in the liver. The hepatic receptors are responsible for clearing glycoproteins from the circulation after terminal sialic acid residues are removed. Five specific aims are presented. 1) Determine the biochemical and molecular structure of RTG-r, including N- terminus amino acid sequence of peptide fragments, carbohydrate analyses, cDNA isolation and sequencing, and mRNA analysis. In addition, a monospecific, affinity-purified antibody will be prepared against purified RTG-r. 2) Determine the site and mechanism of phosphoylationn of RTG-r. 3) Study the functional role of RTG-r in cell-cell recognition in fetal testis and during spermatogenesis. These experiments will assess the role of RTG-r in specific binding between spermatogenic and Sertoli cells and in mediating the potential migration of fetal germ cells on galactose gradients. 4) Determine whether RTG-r in Sertoli cells occupies a preferential surface domain and is responsible for the receptor-mediated endocytosis of specific ligands. 5) Determine whether RHL-1 (major rat hepatic lectin) affects RTG-r function by introducing functional DNA into Sertoli and spermatogenic cells.