UBIQUITINATION LENS PROLIFERATION/DIFFERENTIATION

描述(摘自申请者摘要)：在形成和成长过程中 晶状体细胞必须执行增殖、有丝分裂退出和 差异化。在大多数细胞中，为了从增殖期进展到 不同的表型，许多调节和结构蛋白(如p57) 通过泛素(Ub)蛋白分解途径去除。Ub的功能 蛋白分解途径在所有真核细胞中都被发现，并与 细胞调控的几乎方方面面，包括细胞周期进程 以及分化、胁迫反应、DNA修复、信号转导、基因 原癌基因、细胞重构、抗原的调控 呈现，并去除受损的蛋白质。我们已经演示了 晶状体细胞中功能Ub通路的存在和收集的初步数据 这与Ub调节从有丝分裂到有丝分裂的过程是一致的 分化的表型。然而，Ub通路在调节细胞周期中的作用。 晶状体中的细胞周期和分化一直只是三个研究的焦点 目前还没有针对Ub依赖途径的特定底物 在整个晶状体细胞系统中被识别。根据我们最初的出版物， 初步数据和来自其他细胞类型的数据，我们假设Ub 蛋白分解途径，特别是泛素结合酶Ubc2、3和4， 以允许晶状体细胞从增殖剂转变为 分化的细胞类型。我们将使用晶状体外植体和 在活体内。我们的长期目标是确定和展示 Ub蛋白分解途径的组成部分，包括底物，调节 晶状体细胞的增殖和分化。调查人员有经验 这项研究所需的所有技术。此外, 他们将有1)博拉斯和泽伦卡医生的指导来治疗晶状体感染 腺病毒的细胞，以及2)显性负性结构的贡献 在所有可用的UBC和UBC基因敲除小鼠中，Pagano博士和Wing博士。自.以来 目前关于Ub途径功能的文献有限，仅限于 哺乳动物系统，这项工作将会引起所有哺乳动物学者的兴趣 发展与差异化。泰勒博士的团队是一个主要的贡献者 有关Ub通路在细胞应激反应中的作用的文献。

DESCRIPTION (Adapted from applicant's abstract): During formation and growth lens cells must execute a program of proliferation, mitotic withdrawal and differentiation. In most cells, in order to progress from proliferative to differentiated phenotypes, many regulatory and structural proteins (i.e. p57) are removed via the ubiquitin (Ub) proteolytic pathway. Function of the Ub proteolytic pathway is found in all eucaryotic cells and is implicated in virtually every facet of cellular regulation, including cell cycle progression and differentiation, the stress response, DNA repair, signal transduction, gene regulation, control of protooncogenes, cellular remodeling, antigen presentation, and removal of damaged proteins. We have demonstrated the presence of a functional Ub pathway in lens cells and gathered preliminary data which is consistent with the Ub pathway regulating progress from a mitotic to a differentiated phenotype. However, the role of the Ub pathway in regulation of cell cycle and differentiation in lens has been the focus of only three publications, and no specific substrate for the Ub dependent pathway has been identified in a whole lens cell system. Based on our initial publications, preliminary data and data from other cell types, we hypothesize that the Ub proteolytic pathway, particularly ubiquitin conjugating enzymes Ubc2,3,and 4, are required to allow transition of lens cells from a proliferative to a differentiated cell type. We will test this hypothesis using lens explants and in vivo. Our long-term goals are to identify and demonstrate the function of components of the Ub proteolytic pathway, including substrates, which regulate lens cell proliferation and differentiation. The investigators have experience in all of the techniques which are required for this research. In addition, they will have 1) the guidance of Drs. Borras and Zelenka for infection of lens cells with adenovirus, and 2) the contributions of dominant negative constructs of all available Ubc and Ubc knockout mice from Drs. Pagano and Wing. Since there is only a limited literature regarding functions of the Ub pathway in mammalian systems, this work will be of interest to all scholars of mammalian development and differentiation. Dr. Taylor's group is a major contributor to the literature regarding Ub pathway functions in response to cellular stress.