Post-transcriptional Control of Immunoglobulin Expression

9507513 Peterson调节免疫球蛋白（IG）重链的转录终止和RNA加工（基因将在B细胞发育期间进行检查。这项研究的长期目标是更好地了解这些事件的一般机制，以及确定B细胞成熟过程中发生的发育调节变化的基础。α前体RNA形成β和β mRNA的受调节的替代加工不需要任何IG基因特异性序列。相反，该基因的重要特征是它包含竞争剪接和切割多聚腺苷酸化反应的信号。因此，在B细胞成熟过程中，参与这两个过程的一般因子的量或活性必须改变。通过分析与浆细胞相比，在B细胞中缺少多聚腺苷酸位点的情况下进行的可变剪接选择，将确定剪接是否在B细胞成熟期间受到调节。将检查将模拟体内基因特征的体外剪接/聚腺苷酸化系统。成功地建立一个体外系统来研究（调节）将为许多未来的实验提供基础。将检查已知的一般RNA加工调节剂在B细胞和浆细胞中的表达以鉴定潜在介导调节的因子;将通过在B细胞和/或浆细胞中的过表达来进一步研究其表达与加工变化相关的任何因子。这些实验结合在一起，将提供一个更完整的图片的加工调节，并应开始，以确定反式作用的RNA加工组件，在B细胞成熟过程中改变。为了研究转录终止及其调控，将通过核连续实验分析稳定引入浆细胞和B细胞系中的完整和修饰的基因的转录，以鉴定其终止区域。设计基因修饰以确定两个聚腺苷酸位点、聚腺苷酸位点强度和终止区内的下游序列对整个终止过程的贡献。本研究通过比较单个细胞类型中的正常基因和修饰基因，将提供有关终止的一般过程的信息，并通过比较B细胞和浆细胞中的修饰基因，将检查该过程中调控变化的基础。 %在B细胞发育过程中检查免疫球蛋白（IG）重链（基因）的受调控转录终止和RNA加工。这项研究的长期目标是更好地了解这些事件的一般机制，以及确定B细胞成熟过程中发生的发育调节变化的基础。 ***

9507513 Peterson Regulated transcriptional termination and RNA processing of the immunoglobulin (Ig) heavy chain ( gene will be examined during B cell development. The long-term goal of this research is to better understand the general mechanisms governing these events as well as to determine the basis for the developmentally regulated changes that occur during B cell maturation. The regulated alternative processing of a ( precursor RNA to form (s and (m mRNA does not require any Ig gene-specific sequences. Instead, the important feature of this gene is that it contains signals for competing splice and cleavage-polyadenylation reactions. Thus, the amount or activity of a general factor(s) involved in these two processes must be altered during B cell maturation. It will be determined whether splicing is regulated during B cell maturation by analyzing alternative splice choices made in the absence of a poly(A) site in B cells as compared to plasma cells. An in vitro splicing/polyadenylation system that will mimic in vivo ( gene characteristics will be examined. Successfully establishing an in vitro system to study ( regulation would provide the basis for many future experiments. The expression of the known general RNA processing regulators in B cells and plasma cells will be examined to identify factors that potentially mediate the regulation; any whose expression correlates with ( processing changes will be studied further by over-expression in B cells and/or plasma cells. These experiments, taken together, will provide a more complete picture of ( processing regulation and should begin to identify the trans-acting RNA processing components that are altered during B cell maturation. To investigate transcriptional termination and its regulation, the transcription of intact and modified ( genes, stably introduced into plasma cell and B cell lines, will be analyzed by nuclear run-on experiments to identify their termination regions. Gene modifications will be designed to determine the contributio n that the two ( poly(A) sites, the poly(A) site strength, and the downstream sequences within the termination region make to the overall termination process. This study, by comparing normal and modified genes in a single cell type will provide information about the general process of termination and, by comparing the modified genes in both B cells and plasma cells, will examine the basis for regulatory changes in this process. %%% Regulated transcriptional termination and RNA processing of the immunoglobulin (Ig) heavy chain ( gene will be examined during B cell development. The long-term goal of this research is to better understand the general mechanisms governing these events as well as to determine the basis for the developmentally regulated changes that occur during B cell maturation. ***