GLYCOPROTEIN HORMONE OLIGOSACCHARIDES

糖蛋白激素低聚糖

基本信息

批准号：
7577091
负责人：
JACQUES U BAENZIGER
金额：
$ 60.98万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-07-27 至 2011-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7577091
关键词：
Ablation Accounting Alzheimer&apos s Disease Amino Acid Sequence Amino Acids Area Bacteriophages Binding Biochemical Genetics Biological Biological Assay Blood Brain Carbohydrates Complex Computer-Assisted Image Analysis Development Estrogens Family Family member Fertility Gene Expression Genetic Glycoproteins Grant Half-Life Hormonal Hormone Receptor Hormones In Vitro Inorganic Sulfates Kidney Kinetics Libraries Link Location Luteinizing Hormone Malignant Neoplasms Malignant neoplasm of prostate Mannose Mediating Mus N-Acetylgalactosaminyltransferases Oligosaccharides Pattern Peptides Pituitary Gland Predisposition Production Progesterone Property Protein Region Proteins Regulation Reproduction Reproductive Behavior Reproductive Biology Role Salivary Glands Sexual Development Sialic Acids Sialyltransferases Specificity Structure Structure-Activity Relationship System Testosterone Thyroid Function Tests Thyrotropin Time Tissues Transferase Unspecified or Sulfate Ion Sulfates Ursidae Family Welding carbohydrate structure family structure glycosylation hormone regulation hypothalamic pituitary gonadal axis in vivo insight malignant breast neoplasm member novel protein aminoacid sequence protein structure receptor sugar sulfotransferase tool

项目摘要

The long-term objective of this grant is to define the biological significance of a family of unique N-linked carbohydrate structures that contain the sequence GalNAc􀁅1,4GlcNAc􀁅1,2Man􀁄-, rather than the sequence Gal􀁅1,4GlcNAc􀁅1,2Man􀁄- that is found on many glycoproteins. The 􀁅1,4-N-acetylgalactosaminyltransferases (􀁅GTs) that add GalNAc to this structure are protein-selective, recognizing specific amino acid sequences in the distinctive set of glycoproteins that become modified. When present in the substrate protein, the recognition sequences can increase the catalytic efficiency of GalNAc transfer to a carbohydrate acceptor 500 fold. The terminal GalNAc can remain unmodified or be substituted with SO4 to form terminal SO4-4-GalNAc or with Sialic acid (Sia) to form Sia􀁄2,6GalNAc. We have shown that glycoproteins such as luteinizing hormone (LH) that bear SO4-4-GalNAc are removed from the blood by the Mannose/GalNAc-4- SO4-receptor while those bearing either GalNAc or Sia􀁄2,6GalNAc are removed by the asialoglycoproteinreceptor. Using genetic strategies to alter the structure of the carbohydrates on LH, we have demonstrated that the precise structures of the carbohydrates determine the LH concentration in the blood and the amount of estrogen and testosterone that are produced. As a result sexual development and reproductive behavior are altered. We will characterize the recognition determinant in glycoprotein substrates that is utilized by the 􀁅GTs via a novel new assay system that allows us to determine the efficiency of GalNAc addition both in vivo and in vitro. We will also examine how different domains or regions of the protein-selective 􀁅GTs contribute to the selective addition of GalNAc to LH and other glycoproteins. Members of the family of GalNAc containing structures that we have characterized on LH and other pituitary glycoproteins are also found on glycoproteins produced in the brain, kidney, salivary glands, and other tissues. We will further define the impact of genetic ablation of the GalNAc-4-sulfotransferases on LH function as well as on kidney and brain functions. We will also define regulation of the expression of the transferases that mediate the synthesis of this family of structures. Their expression may change over the course of the hormonal cycle and at specific times during sexual development such as when sexual maturity is attained. We have clearly shown that changing the structures of the carbohydrates on LH has a significant impact on its in vivo function. We have demonstrated that the pattern of glycosylation is modulated in vivo. This is one of the first instances in which modulation of carbohydrate structures has been shown to have an impact in vivo. Defining precisely how this is regulated is critical for understanding reproductive biology and for understanding the role of glycosylation in modulating the properties of a wide range of glycoproteins such as hormones, receptors, and matrix components.

这项资助的长期目标是定义一个独特的 N 连锁家族的生物学意义包含序列 GalNAcр1,4GlcNAcр1,2Manр- 的碳水化合物结构，而不是序列 Galр1,4GlcNAcр1,2Manр- 存在于许多糖蛋白上 р1,4-N-乙酰半乳糖胺基转移酶。将 GalNAc 添加到该结构的 GT（GT）具有蛋白质选择性，可识别特定氨基酸当存在于底物中时，一组独特的糖蛋白中的序列被修饰。蛋白质，识别序列可以提高 GalNAc 转移到碳水化合物的催化效率受体500倍，末端GalNAc可以保持未修饰或被SO4取代以形成末端。 SO4-4-GalNAc或与唾液酸(Sia)形成Sia☆2,6GalNAc等糖蛋白。含有 SO4-4-GalNAc 的黄体生成素 (LH) 通过甘露糖/GalNAc-4-从血液中去除 SO4 受体，而那些带有 GalNAc 或 Siaр2,6GalNAc 的受体则被脱唾液酸糖蛋白受体去除。我们已经证明，利用遗传策略来改变 LH 上碳水化合物的结构碳水化合物的精确结构决定了血液中 LH 的浓度和含量性发育和生殖行为产生的雌激素和睾酮。我们将描述糖蛋白底物中的识别决定簇。 GT 通过一种新颖的检测系统，使我们能够确定 GalNAc 添加的效率我们还将研究蛋白质选择性 GT 的不同结构域或区域。有助于将 GalNAc 选择性添加到 LH 和其他糖蛋白家族成员中。我们在 LH 和其他垂体糖蛋白上表征的含有 GalNAc 的结构也是在大脑、肾脏、唾液腺和其他组织中产生的糖蛋白中发现了这一点，我们将进一步进行研究。定义 GalNAc-4-磺基转移酶基因消除对 LH 功能以及肾脏的影响我们还将定义介导转移酶表达的调节。该结构家族的合成可能会随着激素周期的变化而变化。以及在性发育过程中的特定时间，例如达到性成熟时。结果表明，改变 LH 上碳水化合物的结构对其体内的作用具有显着影响我们已经证明糖基化的模式在体内受到调节。碳水化合物结构的调节已被证明对体内产生影响的首次实例。准确定义其调控方式对于理解生殖生物学和了解糖基化在调节多种糖蛋白特性中的作用，例如激素、受体和基质成分。