Biological Roles of the Prolyl Isomerase, PIN1

脯氨酰异构酶 PIN1 的生物学作用

基本信息

批准号：
7415031
负责人：
ANTHONY R MEANS
金额：
$ 31.03万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-08-06 至 2010-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7415031
关键词：
19p13 19p13.3 Address Alleles Amides Animals Aspergillus nidulans Attention Binding Binding Proteins Binding Sites Biochemistry Biological Biological Assay C-terminal Cell Cycle Cell Cycle Progression Cell Cycle Regulation Cells Cellular biology Chromosomes Complex Consensus Cyclin E Cyclin-Dependent Kinases Development Dominant-Negative Mutation E protein Embryonic Development Enzymes Evaluation Event Family Fibroblasts Fungal Proteins G2/M Transition Genes Genetic Genetic Recombination Genetically Engineered Mouse Genomic Instability Growth Human Hybrids Knockout Mice Loss of Heterozygosity MAP Kinase Gene Malignant Neoplasms Mediating Mitogens Mitosis Mus N-terminal NIMA Nature Null Lymphocytes Object Attachment Oncogenic Peptidylprolyl Isomerase Phenotype Phosphorylation Phosphotransferases Pin1 protein Play Predisposition Process Proline Protein Dephosphorylation Protein Isoforms Protein Kinase Protein Phosphatase 2A Regulatory Subunit PR53 Proteins Rate Reporting Research Research Personnel Role SCF(Fbw7) Ubiquitin Ligase Series Serine Signal Transduction Specificity Specimen Structure of primordial sex cell Substrate Specificity System TP53 gene Testing Threonine Time Tumor Promoters Tumor Suppressor Proteins Xenopus Yeasts c-myc Genes carcinogenesis cell immortalization cell transformation cell type day fascinate fungus genetic regulatory protein human CCNE1 protein interest killings loss of function mouse model novel programs tumor tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): The overarching hypothesis of the proposed research is that loss of function of the Pin1 prolyl isomerase can result in differential susceptibility to tumorigenesis. Pin1 was originally identified as a regulator of a fungal protein kinase required for mitosis and so was suggested to play important roles in cell cycle progression. It is now known that Pin1 functions in both G1 and G2 of the cell cycle and several Pin1 binding proteins that also play important roles in the cell cycle have been identified. Pin1 binds to proteins phosphorylated on pSer/pThr-Pro motifs and isomerization of the prolyl amide bond can cause a conformational change that regulates the abundance of the target protein in the cell either in a positive or negative manner. Pin1 has been implicated to be important in human cancers not only because it is involved in cell cycle regulation but also as several studies have reported either increased levels of Pin1 in human tumor specimens or Loss of Heterozygosity of the portion of chromosome 19p13.3 that contains Pin1. Thus, the question of whether the loss of Pin1 could, depending on the genetic background, either sensitize or protect cells from transformation remains enigmatic. Evaluation of fibroblasts from Pin1 null mice in a pure C57BL6/J genetic background revealed two novel target proteins for Pin1 to be c-Myc, and cyclin E1. Pin1 regulates the degradation of c- Myc. The absence of Pin1 from immortalized mouse fibroblasts increases c-Myc and cyclin E1 levels, results in genomic instability and renders these cells sensitive to Ras-mediated transformation. To extend these remarkably provocative results and address this fascinating conundrum, it is proposed to: 1) evaluate the mechanism of action of Pin1 by using NMR to determine how Pin1 binds to c-Myc and biochemistry/cell biology to evaluate whether Pin1 regulates accumulation of cyclin E1 as it does c-Myc; 2) examine how the loss of function of Pin1 contributes to genomic instability in immortalized mouse fibroblasts; and 3) test the hypothesis that loss of function of Pint can alter the timing of tumorigenesis in a genetically engineered mouse model of cancer wherein spontaneous recombination in whole animals is necessary to activate an oncogenic allele of K-Ras, which in turn leads to tumorigenesis in 100% of the mice by 300 days. We hope that completion of these proposed studies will help to clarify the potential role of Pin1 and/or its target proteins in carcinogenesis.

描述（由申请人提供）：拟议研究的总体假设是 Pin1 脯氨酰异构酶功能丧失可能导致对肿瘤发生的不同易感性。 Pin1 最初被确定为有丝分裂所需的真菌蛋白激酶的调节因子，因此被认为在细胞周期进程中发挥重要作用。现在已知 Pin1 在细胞周期的 G1 和 G2 中均发挥作用，并且已鉴定出几种在细胞周期中也发挥重要作用的 Pin1 结合蛋白。 Pin1 与 pSer/pThr-Pro 基序上磷酸化的蛋白质结合，脯氨酰酰胺键的异构化可引起构象变化，从而以正向或负向方式调节细胞中靶蛋白的丰度。 Pin1 在人类癌症中发挥着重要作用，不仅因为它参与细胞周期调节，还因为一些研究报告了人类肿瘤样本中 Pin1 水平的增加或染色体 19p13.3 部分杂合性的丧失，其中包含引脚 1。因此，根据遗传背景，Pin1 的缺失是否会使细胞变得敏感或保护细胞免受转化，这一问题仍然是个谜。对纯 C57BL6/J 遗传背景下 Pin1 缺失小鼠的成纤维细胞进行评估，发现 Pin1 的两种新靶蛋白是 c-Myc 和细胞周期蛋白 E1。 Pin1 调节 c-Myc 的降解。永生化小鼠成纤维细胞中 Pin1 的缺失会增加 c-Myc 和细胞周期蛋白 E1 水平，导致基因组不稳定，并使这些细胞对 Ras 介导的转化敏感。为了扩展这些引人注目的结果并解决这个令人着迷的难题，建议：1）通过使用 NMR 来评估 Pin1 的作用机制，以确定 Pin1 如何与 c-Myc 结合，并使用生物化学/细胞生物学来评估 Pin1 是否调节细胞周期蛋白 E1 和 c-Myc 一样； 2) 研究 Pin1 功能的丧失如何导致永生化小鼠成纤维细胞的基因组不稳定； 3) 在基因工程小鼠癌症模型中测试 Pint 功能丧失可以改变肿瘤发生时间的假设，其中整个动物中的自发重组对于激活 K-Ras 的致癌等位基因是必要的，这反过来又导致肿瘤发生300 天后 100% 的小鼠出现这种情况。我们希望这些拟议研究的完成将有助于阐明 Pin1 和/或其靶蛋白在致癌作用中的潜在作用。