Compositional Analysis of the Arabidopsis 26S Proteasome

描述（由申请人提供）：本研究的目的是以拟南芥为模型，揭示多细胞真核生物26S蛋白酶体的分子组成和功能。生物体依靠蛋白质降解来实现各种基本功能，包括维持游离氨基酸库、去除受损蛋白质和控制调节蛋白质丰度。这种分解的主要机器是26S蛋白酶体，一种依赖atp的2-MDa蛋白水解复合物。本项目的具体目的是确定拟南芥天然26S蛋白酶体的组成，揭示各种亚基的功能，并确定植物是否通过各种同种异构体的选择性配对来优先组装该复合物的特定亚型。对26S蛋白酶体的更完整的表征将导致对蛋白质如何选择性降解的更深入的理解，这可能会找到控制蛋白质在体内分解的新方法。鉴于Ub和26S蛋白酶体在真核生物生理和发育的几乎所有方面的重要性，这项工作应该对医学和农业都有实际的好处，包括由泛素/26S蛋白酶体系统缺陷引起的各种疾病。

DESCRIPTION (provided by applicant): The goal of this research is to reveal the molecular composition and functions of the 26S proteasome in a multicellular eukaryote, using Arabidopsis thaliana as the model. Organisms rely on protein degradation for a variety of essential functions, including the maintenance of free amino acid pools, the removal of damaged proteins, and the control of regulatory protein abundance. The major machine for this breakdown is the 26S proteasome, an ATP-dependent 2-MDa proteolytic complex. The specific aim of this project is to define the composition of the native 26S proteasome from Arabidopsis, reveal the functions of various subunits, and determine whether the plant preferentially assembles specific subtypes of the complex through selective pairing of various isoforms. A more complete characterization of the 26S proteasome will lead to a deeper understanding of how proteins are selectively degraded which may potentially identify new ways to control protein breakdown in vivo. Given the importance of Ub and the 26S proteasome to almost all facets of eukaryotic physiology and development, this work should have practical benefits to both medicine and agriculture, including various disease caused by defects in the Ubiquitin/26S proteasome system.