Activation of an Endoribonuclease by Non-intein Protein Splicing

蛋白质的序列可以从指定它的RNA的序列中预测出来。换句话说，嵌入在RNA分子中的代码与作为模板的RNA活动产生的蛋白质之间通常存在对应关系。一种叫做RB47的蛋白质没有遵循这种模式，是这个项目的主要焦点。具体来说，RB47是根据其RNA模板合成的，但随后蛋白质的内部部分被移除，两侧的两个部分被拼接成一个更小的蛋白质。这种蛋白质剪接反应在自然界中是已知的，但通常是自发的。就RB47而言，需要特定的细胞因子来剪切它。目前的研究主要围绕这种剪接的机制展开，尚无明显的先例。RB47的第二个方面是，该蛋白的初始版本是酶惰性的，但剪接的版本具有RNA切割活性。因此，蛋白质剪接激活了这种酶。这提示剪接也具有调节功能。该项目有三个具体目标：首先，确定RNA切割活性所需的蛋白质内部信号；第二，发现进行剪接反应的分子装置；第三，利用基因实验来识别RB47的生物学作用。虽然RB47是一种来自莱茵衣藻叶绿体的蛋白质，但研究的机制可能存在于许多生物中。更广泛的影响。这个项目有可能产生广泛的生物影响，也将被用作培训机会。主要的新颖之处在于，所研究的蛋白质剪接形式是新描述的，因此提出了一种以前未被认识的蛋白质多样性产生机制。因此，这项研究可能会刺激或促进对更大规模的蛋白质剪接的探索，即在其他生物体中。如果这种类型的蛋白质剪接得到广泛应用，将对分析当前RNA和蛋白质序列的大型数据集产生重要影响，这反过来又会影响对不断增长的基因组信息洪流的分析。该项目将通过在主办机构（博伊斯·汤普森研究所）开展的实习项目，培训高中和本科阶段的学生，包括来自代表性不足群体的学生。该项目有良好的多样化参与记录，并通过强有力的管理确保广泛接触植物科学，以及与职业相关的指导和观点。该项目将制作一份视频出版物，介绍该项目使用的一项关键生化技术；之前的视频被广泛观看，并帮助了许多实验室的研究人员。博伊斯·汤普森研究所不仅为下一代科学家，也为高中教师提供了强大的培训环境。此外，它将投入资源来支持各种外展计划的规划发展。这些项目为博伊斯汤普森研究所的博士后提供了许多机会，包括那些在这个项目中接受培训的博士后，他们可以直接参与外展工作，从而丰富他们的职业道路。

The sequence of a protein can be predicted from that of the RNA which specifies it. In other words, there is usually a correspondence between the code embedded in an RNA molecule, and the protein resulting from the activity of that RNA as a template. A protein called RB47 fails to follow this paradigm and is the main focus of this project. Specifically, RB47 is synthesized according to its RNA template, but then an internal portion of the protein is removed, with the two flanking portions being combined into a spliced, smaller protein. Such protein splicing reactions are known in nature, but are normally spontaneous. In the case of RB47, specific cellular factors are required to splice it. The research is focused around the mechanism of this splicing, which has no obvious precedent. A second aspect of RB47 is that the initial version of the protein is enzymatically inert, but the spliced version harbors an RNA cleavage activity. Thus, protein splicing activates this enzyme. This hints that the splicing has a regulatory function as well. The project has three specific goals: first, to define the signals within the protein itself that are required for RNA cleavage activity; second, to discover the molecular apparatus that carries out the splicing reaction; and third, to use genetic experiments to discern the biological role of RB47. Although RB47 is a protein from the chloroplast of the green alga Chlamydomonas reinhardtii, the mechanism under study may well occur in many organisms.Broader impacts. This project has potential for broad biological impacts, and will also be used as a training opportunity. The major novelty is that the form of protein splicing under study is newly described, and therefore suggests a previously unrecognized mechanism for creating diversity in proteins. This research may therefore stimulate or facilitate exploration of protein splicing on a larger scale, i.e. in other organisms. If this type of protein splicing is widespread, there will be important implications for analyzing the current large datasets of RNA and protein sequences, which in turn impinges on the analysis of the ever-growing deluge of genomic information. The project will train students at the high school and undergraduate levels, including those from underrepresented groups, through an internship program run at the host institution (Boyce Thompson Institute). This program has a strong record of diverse participation, and ensures through strong management a broad exposure to plant science, as well as career-related guidance and perspective. The project will create a video publication on a key biochemical technique employed in this project; a prior video was widely viewed and has assisted re-searchers in many laboratories. Boyce Thompson Institute has committed resources to a robust training environment not only for the next generation of scientists, but also for high school teachers. In addition, it will commit resources to support programmatic development for a variety of outreach programs. These programs provide numerous opportunities for postdoctoral fellows at Boyce Thompson Institute, including those to be trained in this project, to participate directly in outreach efforts and thus enrich their career paths.