Protein ubiquitination and plant development

高度保守、调控良好的泛素化途径是许多细胞过程的组成部分，是真核生物正常生长发育所必需的。该途径有效地靶向蛋白质被26S蛋白酶体降解，并参与蛋白质的活化、分类和内化。泛素偶联级联的中心是底物结合E3泛素连接酶，它控制着通路的特异性。超过5%的拟南芥基因组致力于蛋白质泛素化/蛋白酶体降解，其中大多数基因编码E3连接酶。越来越多的E3s参与了多种植物生长发育过程，包括光形态发生、自交不亲和和激素信号传导。然而，大多数e3在很大程度上仍然没有特征。本研究的重点是了解蛋白质泛素化在植物发育中的作用，特别关注大而多样的RING （Really Interesting New Gene）型E3连接酶家族的功能。在拟南芥基因组中鉴定的469个RING E3编码基因中，只有少数具有指定的生物学功能。本提案的目标包括环E3连接酶亚群的功能表征和底物蛋白的鉴定。本研究将发现蛋白质泛素化在植物发育中的新作用，为该领域的研究做出重要贡献。从这项工作中获得的知识对生物研究、植物生物技术和农业的其他领域具有潜在的影响。

The highly conserved, well regulated ubiquitination pathway is an integral part of numerous cellular processes and is required for proper growth and development of eukaryotic organisms. The pathway effectively targets protein for degradation by the 26S proteasome and is also involved in protein activation, sorting and internalization. At the center of the ubiquitin conjugation cascade is the substrate binding E3 ubiqutin-ligase enzyme, which governs specificity of the pathway. Over 5% Arabidopsis genome is dedicated to protein ubiquitination/proteasomal degradation, the majority these genes encode for E3 ligases. A growing number of E3s have been implicated in diverse plant growth and developmental processes including photomorphogenesis, self-incompatibility and hormone signaling. However, the majority of E3s remain largely uncharacterized. The proposed research focuses on understanding the role of protein ubiquitination in plant development with particular interest paid to the function of the large and diverse family of RING (Really Interesting New Gene)- type E3 ligases. Of the 469 RING E3 encoding genes identified in the Arabidopsis genome only a handful has assigned biological functions. The objectives of this proposal include the functional characterization and identification of substrate proteins for sub-groups of RING E3 ligases. This research will identify novel roles for protein ubiquitination in plant development and make significant contributions to this area of research. Knowledge acquired from this work has potential implications in other areas of biological research, plant biotechnology and agriculture.