Histone mRNA Regulation in Development

描述（由申请人提供）：动物复制依赖性组蛋白 mRNA 是唯一缺乏多聚腺苷酸尾部而是在保守茎环中的真核 mRNA。相比之下，组蛋白变体的 mRNA，例如H3.3 和 H2.v 由聚腺苷酸化 mRNA 编码。所有五种组蛋白的基因都聚集在后生动物基因组中，组蛋白基因表达所需的因子位于组蛋白基因附近。我们将使用果蝇作为模型系统确定体内复制依赖性组蛋白 mRNA 协调表达的要求，特别是组蛋白基因座体在组蛋白 mRNA 代谢中的作用。我们将使用生化和遗传学方法来确定 1. 有效生产正确加工的组蛋白 mRNA 所需的 HLB 成分 FLASH 和 NPAT 的结构要求，2. 组蛋白基因座中指定在组蛋白位点处形成 HLB 的序列，以及 3. 组蛋白裂解因子（包含多聚腺苷酸化因子 Symplekin、CPSF73 和 CPSF100）的组成，以及其作用Symplekin 在体外和体内的组蛋白前体 mRNA 加工中得到阐明。

DESCRIPTION (provided by applicant): Animal replication-dependent histone mRNAs are the only eukaryotic mRNAs that lack a polyA tail ending instead in a conserved stemloop. In contrast mRNAs for histone variants, e.g. H3.3 and H2.v, are encoded by polyadenylated mRNAs. The genes for all five histone proteins are clustered in metazoan genomes, and factors required for histone gene expression are localized near the histone genes. We will determine the requirements for the coordinate expression of the replication-dependent histone mRNAs in vivo using Drosophila as a model system, and in particular the role of the Histone Locus Body in histone mRNA metabolism. We will use both biochemical and genetic approaches to determine 1. The structural requirements in the HLB components FLASH and NPAT required for efficient production of properly processed histone mRNA, 2. The sequences in the histone gene locus that specifies the formation of the HLB at the histone locus and 3. The composition of the histone cleavage factor, which contains polyadenylation factors Symplekin, CPSF73 and CPSF100, will be determined and the role of Symplekin in histone pre-mRNA processing in vitro and in vivo elucidated.