REGULATION OF ACINAR CELL PROLIFERATION

腺泡细胞增殖的调节

• 批准号: 2130190
• 负责人: MICHAEL G HUMPHREYS-BEHER
• 金额: $ 18.55万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-05-01 至 1996-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2130190
• 关键词: Golgi apparatus; RNA splicing; acinar cell; antibody; beta adrenergic agent; biological signal transduction; bulimia nervosa; calmodulin dependent protein kinase; cell adhesion; cell cycle; cell differentiation; cell growth regulation; chloramphenicol acetyltransferase; complementary DNA; enzyme activity; enzyme mechanism; galactosyltransferases; gene expression; genetic library; genetic regulation; genetic regulatory element; genetic transcription; glycoproteins; glycosyltransferase; human tissue; hyperplasia; hypertrophy; isoproterenol; laboratory mouse; laboratory rat; membrane activity; membrane proteins; messenger RNA; molecular cloning; northern blottings; nucleic acid sequence; nutrition related tag; parotid gland; phosphorylation; polymerase chain reaction; protein biosynthesis; recombinant DNA; salivary gland neoplasms; southern blotting; thymidine kinase; tissue /cell culture; transfection; western blottings

Chronic injections of the beta-adrenergic agonist, isoproterenol, produce in addition to cell hypertrophy and hyperplasia, biochemical alterations in protein synthesis in the rat and mouse parotid gland. Among the biochemical changes is an increase in specific activity and topography for an enzyme normally thought of as a Golgi membrane marker enzyme 4beta- galactosyltransferase (Gal Tase). A similar change in enzyme activity and localization is observed with the introduction of dietary and hormonal changes that result in an increased functional gland activity and resulting hyperplasia. The importance of the up-regulation and surface localization of Gal Tase became apparent in experiments in which agents that interact with this enzyme were shown to severely inhibit parotid gland hypertrophy and hyperplasia in vivo or in vitro. A cDNA clone has been isolated which specifically modulates the cell surface appearance of Gal Tase and therefore acinar cell growth. Sequence analysis of a partial cDNA indicated homology to a class of enzymes involved in cell division. The clone designated GTA (Gal Tase activator) is a Ca+2/calmodulin dependent serine protein kinase which is induced in parotid cells in response to isoproterenol. The substrate of the kinase Golgi localized Gal Tase, which upon phosphorylation, is targeted to the plasma membrane. Numerous reports have shown that alteration of cell surface Gal Tase activity might be involved in cell adhesion, differentiation and tumorogenesis. We therefore believe that studies of the regulation of the GTA gene are crucial to understanding growth control of parotid and other tissues regulated by surface Gal Tase. To accomplish this, the GTA cDNA will be used to isolate chromosomal sequences which will be analyzed for organization of regulatory sequences as well as intron and exon structure. The GTA cDNA will allow us to examine at the molecular level, the effects that gene expression and cell surface localization of Gal Tase have on acinar cell growth in vivo and in vitro. The GTA protein will be isolated and biochemically analyzed; using the purified protein for antibody production and immunohistological studies. Finally, we will continue to investigate the sequence of intracellular events involved in the signal transduction from beta-agonist to the nucleus causing expression of GTA, and the action of Gal Tase in the plasma membrane in perpetuating the signal for acinar cell proliferation. These findings will ultimately be used to evaluate the contribution of GTA expression and galactosyltransferase-mediated cell proliferation in human pathologies of the oral cavity, and in particular, disorders of the salivary glands involving tissue hypertrophy and hyperplasia.

β-肾上腺素激动剂的慢性注射异丙肾上腺素产生 除了细胞肥大和增生外，生化改变 大鼠和小鼠腮腺中的蛋白质合成。 在 生化变化是特定活动和地形的增加 通常被认为是高尔基膜标记酶4Beta-的酶 半乳糖基转移酶（GAL Tase）。 酶活性和 通过引入饮食和荷尔蒙观察到本地化 导致功能腺活性增加的变化和结果 增生。 上调和表面定位的重要性 Gal Tase在相互作用的试剂中显而易见 用这种酶显示出严重抑制腮腺肥大 和体内或体外增生。 cDNA克隆已被隔离 特异性调节gal tase的细胞表面外观和 因此，腺泡细胞生长。 部分cDNA的序列分析 指示与一类参与细胞分裂的酶的同源性。 这 克隆指定的GTA（GAL Tase激活剂）是Ca+2/钙调蛋白依赖性 丝氨酸蛋白激酶在腮腺细胞中诱导的响应 异丙肾上腺素。 激酶Golgi局部gal tase的底物， 磷酸化时，靶向质膜。 许多报告 已经表明，细胞表面gal tase活性的改变可能是 参与细胞粘附，分化和肿瘤发生。 因此，我们 认为对GTA基因调节的研究对于 了解对腮腺和其他组织的生长控制 表面gal tase。 为此，GTA cDNA将用于分离 染色体序列将进行分析以进行调节的组织 序列以及内含子和外显子结构。 GTA cDNA将允许我们 在分子水平上检查基因表达和 gal tase的细胞表面定位在体内腺泡细胞生长上 并在体外。 GTA蛋白将被分离并通过生化分析。 使用纯化的蛋白质进行抗体产生和免疫组织学 研究。 最后，我们将继续研究 β-激动剂引起的信号转导的细胞内事件 到引起GTA表达的细胞核，以及GAL Tase在 质膜在永久性的腺泡细胞增殖信号中。 这些发现最终将用于评估GTA的贡献 人类的表达和半乳糖基转移酶介导的细胞增殖 口腔的病理，特别是 涉及组织肥大和增生的唾液腺。