REGULATION OF VARIANT HUMAN HISTONE MRNAS

人类组蛋白 MRNAS 变异体的调控

• 批准号: 6233239
• 负责人: DAVID G COLLART
• 金额: $ 6.95万
• 依托单位: CLARK ATLANTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-02-28 至 2003-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6233239
• 关键词: 3T3 cells; RNA splicing; autoradiography; biological signal transduction; carcinogenesis; cell cycle; cell differentiation; cell growth regulation; gene expression; gene mutation; histones; human genetic material tag; messenger RNA; molecular cloning; northern blottings; nucleic acid sequence; polymerase chain reaction; posttranscriptional RNA processing; regulatory gene; southern blotting; tissue /cell culture

We have isolated a variant human H2B core (GL105) histone gene and a variant Hl linker (CI110) histone cDNA. The H2B histone gene expresses alternative mRNAs regulated differentially during the HeLa cell cycle.. The H2B gene encodes both a 500 nt replication-dependent mRNA and a 2300 NT HHC89 constitutively expressed mRNA. The 3' end of the cell cycle regulated mRNA terminates immediately following the region of hyphenated dyad symmetry typical of most histone mRNAs, whereas the constitutively expressed HHC289 mRNA has a 1798 nt non-translated trailer that contains the same region of hyphenated dyad symmetry but is polyadenylated. Our results demonstrate that replication-dependent and constitutively expressed histone mRNAs can be encoded by the same gene and indicate that alternative 3' end processing is a major level of regulation by which cells can modulate the synthesis of variant histone proteins during the cell cycle and at the onset of differentiation. When Northern blot analysis was carried out we observed the 2300 nt expression of a second variant H2B gene. The H1 histone gene, like the H2B variant, contains a 3' region of hyphenated dyad symmetry and a polyaddenylation sequence. The regulation of this gene is now under investigation. The long-range objective of these studies is to understand the cellular mechanisms and signals, that modulate the expression and processing of RNA transcripts from the variant histone genes under different biological conditions. These studies will address the extent to which the expression of variant histone genes is modulated by the growth state of the cell. We will also examine the role specific nucleotide sequences play in the regulation and alternative processing of variant human histone mRNAs. The post-transcriptional regulation of variant human histone genes will be analyzed during changes in the proliferative state of the cell. These results will provide additional insight into eukaryotic gene expression growth regulation, differentiation, and carcinogenesis.

我们已经分离了一个变体的人H2b核（GL105）组蛋白基因和一个变体HL接头（CI110）组蛋白cDNA。 H2B组蛋白基因在HELA细胞周期中表达了差异调节的替代mRNA。H2B基因编码500 NT复制依赖性mRNA和2300 NT HHC89组成表达的mRNA。在大多数组蛋白mRNA的连字符二元对称区域之后，细胞周期调节的mRNA的3'末端终止，而组成型表达的HHC289 mRNA具有1798 nt非翻译拖车，其中包含连字符二氧对称的同一区域，但是多丙酰化的。我们的结果表明，可以通过相同的基因对复制依赖性和组成型表达的组蛋白mRNA进行编码，并表明替代3'末端加工是细胞在细胞周期和差异化开始时细胞可以调节变异组蛋白蛋白的合成的主要调节水平。进行北印迹分析时，我们观察到第二种变体H2B基因的2300 nt表达。 H1组蛋白基因与H2b变体一样，包含连甲化的二元对称性的3'区域和聚胆料序列。该基因的调节现在正在研究中。这些研究的远程目标是了解细胞机制和信号，以调节不同生物学条件下变体组蛋白基因的RNA转录本的表达和处理。这些研究将解决因细胞的生长状态调节变异组蛋白基因的表达程度。我们还将检查特异性核苷酸序列在变异的人组蛋白mRNA的调节和替代处理中起的作用。在细胞的增殖状态变化期间，将分析变异人组蛋白基因的转录后调节。这些结果将提供对真核基因表达生长调节，分化和致癌作用的更多见解。