DOMINANT NEGATIVE MUTANTS OF C-IUN AND THEIR BIOLOGIC ACTIVITIES

Ap-1转录复合体是基因转录的重要调控因子 表情 很明显，这种复合物介导了 许多基因，也在一定程度上介导了这类基因的生物学效应。 肿瘤促进剂佛波醇酯 由于cJun是其中的主要组成部分， 复杂，我们已经着手分离和表征显性阴性 试图阻断c-jun依赖性过程的c-jun突变体 包括肿瘤促进和/或细胞转化。 已经构建了几种突变体，包括： 1)在氨基酸之间具有缺失的反式激活缺陷突变体 cJun 2-122， 2)三种DNA结合突变体，包括一种在 在位置265处缺失，在位置269-272处缺失，并且一个具有插入 在位置265处的3个氨基酸， 第三章 缺少亮氨酸拉链的二聚化依赖突变体。 这些突变体的特征在于它们结合DNA的能力， 二聚化。 此外，还分析了它们的反式激活 和转变。 反式激活和DNA结合突变体出现 具有显著的抑制c-jun活性的能力。 这些突变体现在是探索和阻断c-jun依赖性的理想药物 途径。 我们知道反式激活突变体有能力抑制 佛波酯诱导的肿瘤促进和c-jun细胞转化。 我们与科尔本、拉普和鲍登博士合作， 这些突变体在不同的细胞系统中， 转型

The Ap-1 transcriptional complex is an important regulator of gene expression. It is clear that this complex mediates the expression of many genes and also mediates in part the biologic effects of the class of tumor promoters, phorbol esters. Since cJun is a major component of this complex, we have undertaken to isolate and characterize dominant-negative mutants of c-jun in an attempt to block c-jun dependent processes including tumor promotion and/or cellular transformation. Several mutants have been constructed including: 1) a transactivation deficient mutant with deletion between amino acid 2-122 of cJun, 2)three DNA binding mutants including one with a point mutation at position 265, a deletion at positions 269-272, and one with an insertion of 3 amino acids at position 265, 3) a dimerization dependent mutant missing the Leucine zipper. These mutants have been characterized for their ability to bind DNA and to dimerize. In addition, they have been analyzed for transactivation and transformation. The transactivation and DNA binding mutants appear to have significant ability to inhibit c-jun activity. These mutants are now ideal agents to explore and block c-jun dependent pathways. We know the transactivation mutant has the ability to inhibit phorbol ester induced tumor promotion and c-jun cellular transformation. In collaboration with Drs. Colburn, Rapp, and Bowden, we are testing these mutants in different cells systems in an attempt to block cellular transformation.