FUNCTION OF A GALACTOSE-BINDING RECEPTOR IN REPRODUCTION

描述(改编自申请人的摘要)：修改后的建议书 请求为评估分子的研究提供五年的支持 大鼠睾丸半乳糖受体(RTG-r)的结构和功能。 对rtg-r蛋白和信使核糖核酸的研究表明，该受体与 大鼠肝脏凝集素2/3(RHL-2/3) 肝脏中的生物素辅蛋白受体。肝脏受体是 负责在死亡后清除循环中的糖蛋白 唾液酸残留物被去除。提出了五个具体目标。1) 测定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， 基因分离、测序和信使核糖核酸分析。此外，a 将制备单特异性、亲和力纯化的抗体以对抗纯化的 Rtg-r.2)确定rtg-r的磷酸化部位和机制。 3)研究rtg-r在胎儿细胞-细胞识别中的作用 在睾丸和精子发生过程中。这些实验将评估这一角色 RtG-r在生精细胞与支持细胞特异性结合中的表达 介导胎儿生殖细胞在半乳糖上的潜在迁移 渐变。4)确定支持细胞中的RTG-r是否占据 优先表面区，负责受体介导的 特定配体的内吞作用。5)确定RHL-1(大鼠 肝脏凝集素)通过将功能DNA导入rtg-r而影响rtg-r的功能 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.