MUCIN GENES--COLON CELL DIFFERENTIATION & TRANSFORMATION

这项建议的重点是克隆、物理特征和 编码人类结肠粘蛋白的基因的调控研究。 粘蛋白是复杂的糖缀合物，其构成了主要的 粘液凝胶的糖蛋白成分。 粘蛋白经常与 作为来自多种器官的腺癌的肿瘤相关抗原 和纸巾。 除了确定碳水化合物的决定因素， 粘蛋白，这可能会成为改变肿瘤细胞，这是重要的， 表征粘蛋白多肽的分子结构并评估 它们与转化和分化的关系。 我们的总体目标是从生物化学和遗传学角度剖析 调节编码人粘蛋白肽的基因， 杯状细胞的分化，结肠上皮细胞谱系， 合成并产生粘蛋白。 了解粘蛋白的调节 基因表达将有助于研究是否以及如何 在肿瘤细胞中改变。 为了实现这些目标，我们将 具体地说： 1.克隆编码粘蛋白骨架的cDNA和基因组序列， 连接肽（所提出的粘蛋白肽结构模型将是 如下所述）。 a.确定基因的物理图谱， 核心肽和连接肽是同一基因家族的成员。 B.确定基因的启动子区域。 2.确定所需的顺式作用元件和反式作用因子， 准确和有效地转录粘蛋白基因。 3.确定连接肽和核心肽基因是否协调 杯状细胞在分化过程中受到调节或是否有反应 不同的调节回路

This proposal focuses on the cloning, physical characterization and regulatory studies of genes which encode human colonic mucin. Mucins are complex glycoconjugates which constitute the principal glycoprotein components of mucus gels. Mucins have often been implicated as tumor-associated antigens of adenocarcinoma from a variety of organs and tissues. Besides determining the carbohydrate determinants in mucins, which may become altered in tumor cells, it is important to characterize the molecular structure of mucin polypeptides and evaluate their relationship to transformation and differentiation. Our overall aim is to dissect biochemically and genetically the regulation of genes which encode peptides of human mucin during the differentiation of goblet cells, the colon epithelial cell lineage which synthesizes and produces mucins. Understanding the regulation of mucin gene expression will be instrumental to investigate whether and how this process is altered in tumor cells. Towards these goals we will specifically: 1. Clone cDNA and genomic sequences which encode a mucin backbone and link peptides (the proposed model of mucin peptide structure will be described below). a. determine the physical map of the genes and whether the genes for the core and link peptides are members of the same gene family. b. determine the promoter region of the gene. 2. Identify cis-acting elements and trans-acting factors required for accurate and efficient transcription of the mucin genes. 3. Determine whether the link and core peptide genes are coordinately regulated in goblets cells during differentiation or whether they respond to distinct regulatory circuits.