Glycoprotein Hormone Oligosaccharides

糖蛋白激素低聚糖

基本信息

批准号：
7066007
负责人：
JACQUES U BAENZIGER
金额：
$ 53.11万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1989
资助国家：
美国
起止时间：
1989-09-01 至 2009-06-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The long-term objective of this grant is to understand the biological role of a family of unique carbohydrate structures that terminate with the sequence S04-4-Ga1NAcBeta1,4GIcNAcBeta1,2Manalpha. We have previously demonstrated that the N-linked carbohydrates on the glycoprotein hormones lutropin (LH) and thyrotropin (TSH) from all vertebrate species terminate with this unique sulfated structure. Furthermore, we have shown that these sulfated structures control the circulatory half-life of LH and are essential for the regulation of estrogen production by the hypothalamic-pituitary-gonadal axis. We have now cloned two GalNAc-4-sulfo-transferases, GaINAc-4-ST1 and GaINAc-4-ST2, that transfer sulfate to terminal Beta1,4-linked GaINAc. GaINAc-4-ST 1 is highly expressed in the pituitary and accounts for the presence of terminal GalNAc-4-S04 on the N-linked oligosaccharides of LH and TSH. Additional glycoproteins terminating with Beta1,4-linked GaINAc-4-S04 produced by cells in the brain, kidney, spleen, lymph nodes, ovary, testis, and uterus indicate that these structures will be critical for other biological processes as well. We will: 1) Characterize the expression of GaINAc-4-sulfotransferase in the adult and developing embryo. 2) Generate and characterize GalNAc-4-sulfotransferase deficient mice. 3) define the structure:function relationships of the GalNAc-4-sulfotransferases. And 4) Clone the protein-specific Beta 1,4-GalNAc-transferase and characterize its peptide recognition determinant, using a novel secreted chimeric protein to directly screen for expression of the Beta 1 ,4-GalNAc-transferase following transfection of cells with a cDNA expression library. The conservation of these sulfated structures on the glycoprotein hormones throughout vertebrate evolution, as well as the receptor that recognizes them, attests to their importance. The combination of genetic, biochemical, and structural approaches we will use to study the biological role of these oligosaccharides will advance our understanding of their role in the regulation of estrogen production by the hypothalamic-pituitary-gonadal axis. Alterations in the synthesis of these structures are expected to lead to hormonal imbalances due to altered clearance of LH and TSH. Such alterations may also result in abnormalities in brain development and in the immune response to antigens due to the highly regulated expression of glycoproteins bearing structures terminating with GaINAc-4-S04 in the brain and dendritic cells of the lymph node. Our studies will also reveal the role of these sulfated oligosaccharides in other settings.

描述（由申请人提供）：这项资助的长期目标是了解以序列 S04-4-GalNAcBeta1,4GlcNAcBeta1,2Manalpha 终止的独特碳水化合物结构家族的生物学作用。我们之前已经证明，所有脊椎动物的糖蛋白激素促黄体素 (LH) 和促甲状腺素 (TSH) 上的 N 连接碳水化合物都以这种独特的硫酸化结构终止。此外，我们还发现这些硫酸化结构控制 LH 的循环半衰期，并且对于下丘脑-垂体-性腺轴调节雌激素的产生至关重要。我们现在克隆了两种 GalNAc-4-磺基转移酶 GaINAc-4-ST1 和 GaINAc-4-ST2，它们将硫酸盐转移到末端 Beta1,4 连接的 GaINAc。 GaINAc-4-ST 1 在垂体中高度表达，并解释了 LH 和 TSH 的 N 连接寡糖上末端 GalNAc-4-S04 的存在。脑、肾、脾、淋巴结、卵巢、睾丸和子宫中的细胞产生的以 Beta1,4 连接的 GaINAc-4-S04 结尾的其他糖蛋白表明这些结构对于其他生物过程也至关重要。我们将： 1) 表征成人和发育中胚胎中 GaINAc-4-磺基转移酶的表达。 2) 生成并表征 GalNAc-4-磺基转移酶缺陷小鼠。 3) 定义GalNAc-4-磺基转移酶的结构：功能关系。 4)克隆蛋白质特异性β1，4-GalNAc-转移酶并表征其肽识别决定簇，使用新型分泌嵌合蛋白直接筛选在用cDNA表达文库。在整个脊椎动物进化过程中，这些硫酸化结构在糖蛋白激素上的保守性以及识别它们的受体证明了它们的重要性。我们将结合遗传、生物化学和结构方法来研究这些寡糖的生物学作用，这将加深我们对它们在下丘脑-垂体-性腺轴调节雌激素产生中的作用的理解。由于 LH 和 TSH 清除率的改变，这些结构合成的改变预计会导致激素失衡。由于大脑和淋巴结树突细胞中带有以 GaINAc-4-S04 终止的结构的糖蛋白的表达受到高度调节，这种改变还可能导致大脑发育和对抗原的免疫反应异常。我们的研究还将揭示这些硫酸化寡糖在其他环境中的作用。