Structure and Function of hnRNP Proteins

hnRNP 蛋白的结构和功能

• 批准号: 9514179
• 负责人: Kenneth Williams
• 金额: $ 30万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-06-01 至 2000-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9514179&HistoricalAwards=false
• 关键词: Structure; Function; hnRNP; Proteins

9514179 Williams Heterogeneous nuclear RNAs (hnRNA) are found in the nucleus in complexes with more than 20 hnRNP proteins. A1 hnRNP is unusual in that it appears to have several functions in addition to its structural role in hnRNP fiber formation. A1 interacts with intermediate filaments; modulates alternative 5'-splicing; can recognize a high affinity RNA target sequence that is similar to splice site consensus sequences; and facilitates annealing of complementary nucleic acids. The latter "activity" is controlled by phosphorylation of a critical serine residue in A1. A1 hnRNP also contains two conserved RNA binding domains at its NH2 terminus, and has an RGG repeat which may be a significant RNA binding domain. In these studies, the yeast two hybrid system will be used to identify other proteins that interact with A1 in vivo. Circular dichroism, fluorescence spectroscopy, and nuclear magnetic resonance will be used to probe the structure and nucleic acid binding properties of the RGG motif, and to locate sites of methylation within the domain. The methylase that carries out the posttranslational modification of the RGG will be cloned and analyzed. The results of these studies will significantly increase our understanding of a multi-functional hnRNP protein that plays a key role in pre-mRNA biogenesis. %%% Although all of the information contained within a cell is encoded in its DNA, most of the actual functions of cells and the organs and systems that they make up are carried out by proteins that are in turn composed of varying sequences of amino acids. Since proteins are made in the cytoplasm of the cell while the DNA that encodes them is in the nucleus, a molecule called messenger RNA (mRNA), structurally related to DNA, serves to transport the "message" for protein synthesis from the nucleus to the cytoplasm. In general, there is a unique mRNA for each protein. This project is directed at understanding how a particular class of nuclear proteins (hnRNP proteins) that are cri tical for the formation and transport of mRNA carry out their functions. In particular, how hnRNP proteins bind to mRNA and to other proteins will be investigated so that this critical step in gene expression will be better understood. ***

9514179威廉姆斯异源核RNA（hnRNA）在细胞核中与20多种hnRNP蛋白质形成复合物。 A1 hnRNP是不寻常的，因为它似乎有几个功能，除了它的结构作用hnRNP纤维的形成。 A1与中间丝相互作用;调节选择性5 '-剪接;可以识别与剪接位点共有序列相似的高亲和力RNA靶序列;并促进互补核酸的退火。 后者的“活性”是由A1中一个关键丝氨酸残基的磷酸化控制的。 A1 hnRNP在其NH 2末端还含有两个保守的RNA结合结构域，并且具有可能是重要的RNA结合结构域的RGG重复。 在这些研究中，酵母双杂交系统将被用来确定其他蛋白质与A1在体内相互作用。 圆二色谱，荧光光谱，和核磁共振将用于探测RGG基序的结构和核酸结合特性，并定位甲基化的网站内的域。 将克隆并分析进行RGG翻译后修饰的甲基化酶。 这些研究的结果将显着增加我们的多功能hnRNP蛋白质，发挥了关键作用的前mRNA的生物合成的理解。 虽然细胞内包含的所有信息都编码在其DNA中，但细胞及其组成的器官和系统的大多数实际功能都是由蛋白质执行的，而蛋白质又由不同的氨基酸序列组成。由于蛋白质是在细胞的细胞质中产生的，而编码它们的DNA是在细胞核中，一种称为信使RNA（mRNA）的分子，在结构上与DNA相关，用于将蛋白质合成的“信息”从细胞核运输到细胞质。 一般来说，每种蛋白质都有一个独特的mRNA。 该项目旨在了解一类特殊的核蛋白（hnRNP蛋白）是如何对mRNA的形成和转运起关键作用的。 特别是，hnRNP蛋白如何结合到mRNA和其他蛋白质将进行研究，以便更好地了解基因表达中的这一关键步骤。 ***