VCS and TDT reveal Developmental Roles for mRNA Decapping

植物叶片是进行光合作用的主要器官，在全球碳平衡和农业生产力中发挥着重要作用。然而，这种植物是如何制造叶子的，人们仍然知之甚少。两种突变体，称为静脉曲张（vcs）和三叉戟（tdt），不能产生正常的叶片，因此识别出正常叶片发育所需功能的基因。这些基因编码脱帽复合体的成分，这是mRNA衰变所必需的。脱帽酶去除mRNA的5‘核苷酸（帽），暴露出作为XRN4外核糖核酸酶底物的5’端。vc和tdt突变体所显示的发育缺陷表明，这种mRNA衰变途径是正常发育所必需的。这项工作的目的是了解mRNA脱帽的发育作用，特别是在叶片发育的背景下。遗传、分子和细胞生物学方法将用于研究在发育中的作用，并确定在这一途径中起作用的其他分子。由于拟南芥脱盖复合物与人类的脱盖复合物非常相似，而人类和拟南芥脱盖复合物都与酵母不同，因此该遗传系统有望提供对RNA衰变途径的深入了解，这将与植物和动物系统具有广泛的科学相关性。开展这项研究将为一名博士后研究员、一名研究生和几名本科生提供跨学科培训。将通过面向服务不足群体的外展努力招聘本科工作人员。

Leslie E. SieburthIOB-0642118VCS and TDT reveal Developmental Roles for mRNA Decapping Plant leaves are the major organs that carry out photosynthesis, and so they provide essential roles in global carbon balance and agricultural productivity. How the plant makes leaves, however, is still poorly understood. Two mutants, called varicose (vcs) and trident (tdt), are unable to produce normal leaves, and thus identify genes whose function is required for normal leaf development. These genes encode components of the decapping complex, which is required for mRNA decay. Decapping enzymes remove the 5'-most nucleotide of an mRNA (the cap), exposing a 5' end that is a substrate for the XRN4 exoribonuclease. The developmental defects shown by vcs and tdt mutants indicate that this mRNA decay pathway is required for normal development. The goal of this work is to understand the developmental roles of mRNA decapping, especially in the context of leaf development. Genetic, molecular, and cell-biological approaches will be used to investigate roles in development and to identify additional molecules functioning in this pathway. Because the Arabidopsis decapping complex is very similar to that of humans, while both the human and Arabidopsis decapping complexes differ from yeast, this genetic system is expected to provide insight into RNA decay pathways that will have broad scientific relevance to both plant and animal systems. Carrying out this research will provide interdisciplinary training to a postdoctoral researcher, a graduate student, and several undergraduates. Undergraduate workers will be recruited through out-reach efforts focusing on underserved groups.