PLANT TRANSCRIPTION FACTORS AND RNA POLYMERASES

控制基因表达的机制主要是 对了解所有生物体的生长和发育都很重要。 基因表达在转录和转录后水平受到控制 程度. 理解真核生物的转录调控机制 是这里提出的研究的长期目标，具体 目的是（a）确定哪些特定的转录因子 与真核细胞核RNA聚合酶相互作用， 转录以及调节转录（B），以确定 这些过程在真核生物中的进化保守性，以及（c） 确定RNA聚合酶亚基在细胞中所起的功能作用。 转录过程。 主要重点将放在确定 哪些转录因子可以取代类似的转录因子 在不同物种的转录系统中， 这些因素是物种特有的。 RNA聚合酶似乎显示了物种- 特异性，特别是关于它们的一些较小的亚基， 可能是RNA最大亚基的羧基末端结构域 聚合酶II。 这可能是物种特异性显示， RNA聚合酶在物种特异性转录中具有对应物 与RNA聚合酶直接或间接相互作用的因子。 这一假设将通过试图补充一个 从人细胞中纯化转录因子形成的转录系统 来自远亲物种（即，植物）。 此外该 RNA聚合酶与特定转录因子的相互作用 将使用RNA聚合酶亲和力测试不同物种 层析和RNA聚合酶结合测定。 的第一步 确定一些小RNA聚合酶所起的假定作用 亚基，基因将被分离和测序。 这种方法有 提供了大量关于RNA结构域大亚基的信息， 核苷酸结合结构域）与前体RNA的最大亚基 聚合酶。 此外，这些基因的分离将提供 研究RNA聚合酶基因调控的特异性探针 表情

Mechanisms underlying the control of gene expression are of central importance in understanding growth and development in all organisms. Gene expression is controlled at transcriptional and posttranscriptional levels. Understanding transcription regulatory mechanisms in eukayrotes is the long range objective of the research proposed here, and specific objectives are (a) to determine what specific transcription factors interact with eukaryotic nuclear RNA polymerases to facilitate accurate transcription as well as modulate transcription (b) to determine the evolutionary conservation of these processes in eukaryotes, and (c) to determine the functional roles played by RNA polymerase subunits in the transcription process. Major emphasis will be placed on determining which transcription factors can replace analogous transcription factors in transcription systems from different species and which transcription factors are species-specific. RNA polymerases appear to show species- specificity especially in regard to some of their smaller subunits and possibly a carboxyl terminal domain in the largest subunit of RNA polymerase II. It is likely that the species-specificity displayed by RNA polymerases has a counterpart in species-specific transcription factors that interact directly or indirectly with the RNA polymerases. This hypothesis will be tested by attempting to complement a transcription system form human cells with transcription factors purified from a distantly related species (i.e., plants). In addition, the interaction of RNA polymerases with specific transcription factors from divergent species will be tested using RNA polymerase affinity chromatography and RNA polymerase binding assays. As a first step in determining the putative roles played by some of the small RNA polymerase subunits, genes will be isolated and sequenced. This approach has provided a wealth of information on the large subunits of RNA domains, nucleotide binding domains) to the largest subunits of Prokaryotic RNA polymerase. In addition, the isolation of these genes will provide specific probes for studying the regulation of RNA polymerase gene expression.