Ubiquitination Lens Proliferation/Differentiation

泛素化透镜增殖/分化

• 批准号: 6875442
• 负责人: ALLEN TAYLOR
• 金额: $ 36.79万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6875442
• 关键词: acid aminoacid ligase; cataract; cell cycle; cell differentiation; cell proliferation; cyclin dependent kinase; enzyme activity; enzyme mechanism; genetically modified animals; green fluorescent proteins; growth /development; immunocytochemistry; immunoprecipitation; in situ hybridization; infant animal; laboratory mouse; laboratory rat; lens; northern blottings; phosphorylation; protein isoforms; proteolysis; tissue /cell culture; ubiquitin; western blottings

DESCRIPTION (provided by applicant): Lens formation requires a chronologically and spatially executed program of cell division and proliferation, as well as exit from the cell cycle and differentiation into lens fibers. These processes are controlled in most cell types by the timely degradation of cell cycle regulators by Ubiquitin Proteasome Pathways (UPPs). Aberrations, in these processes frequently result in microphthalmia or cataract. Yet there are few published papers that address either the lens cell cycle or its control by- UPPs. During the ongoing grant, we demonstrated that Ub and Ubc3 (a Ub ligase) are required for proliferation and differentiation. However, regulation of the cell cycle by-these moieties occurs at the G2/M transition and not, as predicted, at G1/S. We now seek to determine if the same controls are observed in vivo by directing expression of mutant Ub to the epithelial and differentiating lens cells in transgenic animals. Our recent data beget two new overall hypotheses: 1) proteolysis involving Ub and Ubc3 is required for proliferation, differentiation, and lens formation in vivo; 2) a UPP which involves an undescribed Ubc3-E3 interaction is involved in control of G2/M events in lens. These overall hypotheses are separated into 4 specific aims, to test the hypotheses that: an active UPP is required for proliferation, differentiation and lens formation in vivo; ubiquitination is required for the lens cell cycle, particularly in G2/M; lens Ubc3 cooperates with an E3, which we will identify, to control the G2/M transition; and control of the cell: cycle at G2/M requires ubiquitination of the APC regulators in a Ubc3-dependent process. These studies will address a major objective of the NEI lens and cataract program: to characterize controls of lens cell division and differentiation, and their roles in formation of secondary cataract. The long-term objective is to prolong function of 1) the natural lens by gaining a better understanding of processes involved in control of lens cell proliferation and differentiation, as well as in lens formation, and 2) implanted lenses by limiting secondary cataract due to overgrowth. Our recent papers show that these results will also lead to a better understanding of corneal wound healing and retina responses to stress. This information, and our novel "reagents", will also find use in new ways to limit secondary cataract, prolong function of glaucoma medication, limit cancer and in fighting other proliferative maladies. We are joined in this effort by excellent collaborators, each of whom is a leader in his field.

描述（由申请人提供）：晶状体的形成需要按时间顺序和空间顺序执行细胞分裂和增殖程序，以及退出细胞周期和分化成晶状体纤维。在大多数细胞类型中，这些过程是通过泛素蛋白酶体途径 (UPP) 及时降解细胞周期调节因子来控制的。 这些过程中的像差经常导致小眼球或白内障。然而，很少有发表的论文涉及晶状体细胞周期或其 UPP 控制。在正在进行的资助期间，我们证明了 Ub 和 Ubc3（一种 Ub 连接酶）是增殖和分化所必需的。然而，这些部分对细胞周期的调节发生在 G2/M 期，而不是如预测的那样发生在 G1/S 期。 现在，我们试图通过将突变体 Ub 的表达导向转基因动物的上皮细胞和分化的晶状体细胞来确定是否在体内观察到相同的对照。我们最近的数据产生了两个新的总体假设：1）涉及 Ub 和 Ubc3 的蛋白水解是体内增殖、分化和晶状体形成所必需的； 2)涉及未描述的Ubc3-E3相互作用的UPP参与晶状体中G2/M事件的控制。这些总体假设分为 4 个具体目标，以检验以下假设： 体内增殖、分化和晶状体形成需要活性 UPP；晶状体细胞周期需要泛素化，特别是在 G2/M 期；镜头 Ubc3 与我们将要识别的 E3 配合，控制 G2/M 过渡；和细胞控制：G2/M 周期需要 Ubc3 依赖性过程中 APC 调节因子的泛素化。这些研究将解决 NEI 晶状体和白内障计划的一个主要目标：表征晶状体细胞分裂和分化的控制及其在继发性白内障形成中的作用。长期目标是通过更好地了解晶状体细胞增殖和分化以及晶状体形成的控制过程来延长天然晶状体的功能，以及 2) 通过限制过度生长导致的继发性白内障来延长植入晶状体的功能。我们最近的论文表明，这些结果还将有助于更好地了解角膜伤口愈合和视网膜对压力的反应。这些信息以及我们的新型“试剂”还将以新的方式发挥作用，以限制继发性白内障、延长青光眼药物的作用、限制癌症以及对抗其他增殖性疾病。我们与优秀的合作者一起努力，他们每个人都是各自领域的领导者。