ALTERED RNA COMPARTMENTATION IN CARCINOGENESIS

这项提议继续对改变的RNA进行调查 与癌症发生的早期阶段相关的区隔。在……里面 在之前的授权期内，两项基本的调查工作是 被追捕。首先，涉及到假定的核支架(NS)NTPase 在RNA运输中，这里称为p46，被确定为N-末端 第二，出现在细胞质中的RNA序列 经致癌物治疗后的RNA被发现由一个 B2序列的亚家族。这个B2亚家族对应于一个 人类Alu序列的一个亚家族，它被活跃地转录和 参与了人类的逆转位突变。B2转录本 显示改变的隔室是170-360个新台币PolIII“感觉” 转录本，而改变的区隔发生在 大鼠肝脏内清晰可见的病灶。我们的基本假设是 B2(类Alu)转录本的区隔是一种起始事件， 它使细胞永生，并使它们容易受到后续 促进/进步的改变。有人建议更改B2 结构/功能异常导致的分区 通过改变p46的表达而产生。两个独立的目标， 它们可能是相互关联的，它们将确定：1. 改装后的功能重要性 B2转录本的区划。实验将会 定义：a)B2转录本的转录后改变 与它们改变的间隔有关；B)B2的调制 成绩单水平将使用新的策略来完成，以及 对细胞生长、分化和生长的影响 将调查永生/转变；c)是否 B2区隔改变与基因组不稳定有关 和逆转位，使用三种不同的方法。2)角色 高血压早期NS-NTPase升高的意义 致癌。NS-NTPase活性在脑损伤中的重要性 RNA运输已经记录在案，我们已经确定了 推测NTPase是Lamins A/C的N-末端(P46)。生产 P46的表达似乎是由一种核多催化剂完成的。 蛋白酶，它去除核定位信号(NLS)。 我们已经通过插入表位标签创建了修改的p46结构 和NLS插入线圈L和2之间的连接区。这一构建 将被测试ATPase/激酶的活性，并在细胞培养中 对：A)核结构；B)NS NTPase和RNA封端；C)的影响 细胞的生长、分化和永生化/转化；以及 D)B2区划。

This proposal continues investigations into altered RNA compartmentation associated with early stages of carcinogenesis. In the preceding grant period, two basic lines of investigation were pursued. First, the putative nuclear scaffold (NS) NTPase involved in RNA transport, here termed p46, was identified as the N-terminus of lamins A/C. Second, RNA sequences which appear in cytoplasmic RNA following carcinogen treatment were found to consist of a subfamily of B2 sequences. This B2 subfamily corresponds to a subfamily of human Alu sequences, which is actively transcribed and involved in retrotranspositional human mutations. B2 transcripts showing altered compartmentation are 170-360 nt pol III "sense" transcripts, and the altered compartmentation occurs in welldelineated foci in rat liver. Our basic hypothesis is that altered compartmentation of B2 (Alu-like) transcripts is an initiation event, which immortalizes cells and predisposes them to subsequent promotional/progressional alterations. It is proposed thataltered B2 compartmentation results from structural/functional abnormalities produced by altered expression of p46. Two independent objectives, which are likely to be interrelated, are to determine: 1. THE FUNCTIONAL IMPORTANCE OF ALTERED COMPARTMENTATION OF B2 TRANSCRIPTS. Bxperiments will define: A) Posttranscriptional alterations in B2 transcripts which relate to their altered compartmentation; B) Modulation of B2 transcript levels will be accomplished using novel strategies, and effects on cell growth, differentiation and immortalization/transformation will be investigated; C) Whether altered B2 compartmentation is associated with genomic instability and retrotransposition, using 3 distinct approaches. 2) THE ROLE OF ELEVATED NS NTPase IN EARLY STAGES OF CARCINOGENESIS. The importance of NS NTPase activity in RNA transport has been documented, and we have identified the putative NTPase as the N-terminus of lamins A/C (p46). Production of p46 appears to be accomplished by a nuclear multicatalytic proteinase,, which removes the nuclear localization signal (NLS). We have created a modified p46 construct by inserting an epitope tag and NLS into the linker region between coils l and 2. This construct will be tested for ATPase/kinase activities, and in cell culture for effects on: A) nuclear structure; B) NS NTPase & RNA capping; C) cell growth, differentiation, and immortalization/transformation; and D) B2 compartmentation.