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：
7232416
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/7232416
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脯氨酰异构酶的功能丧失会导致对肿瘤发生的敏感性差异。 PIN1最初被确定为有丝分裂所需的真菌蛋白激酶的调节剂，因此建议在细胞周期进程中起重要作用。现在知道，PIN1在细胞周期的G1和G2中的功能以及几种在细胞周期中也起着重要作用的PIN1结合蛋白。 PIN1与在PSER/PTHR-PRO基序上磷酸化的蛋白质结合，而Prolyl酰胺键的异构化可能会导致构象变化，以阳性或负方式调节细胞中靶蛋白的丰度。 PIN1在人类癌症中的重要意义不仅是因为它参与了细胞周期调节，而且由于一些研究报道了人类肿瘤标本中PIN1的水平升高或含有PIN1的19p13.3染色体部分的杂合性丧失。因此，在遗传背景下，PIN1丢失是否可能存在敏感或保护细胞免受转化的问题。对纯C57BL6/J遗传背景中PIN1 NULL小鼠的成纤维细胞的评估显示，PIN1为C-MYC和Cyclin E1的两个新型靶蛋白。 PIN1调节C- MYC的降解。永生小鼠成纤维细胞中不存在PIN1会增加C-MYC和细胞周期蛋白E1水平，从而导致基因组不稳定性，并使这些细胞对RAS介导的转化敏感。为了扩展这些引人入胜的结果并解决这个令人着迷的难题，提议：1）通过使用NMR使用NMR来确定PIN1如何与C-MYC和生物化学/细胞生物学结合来评估PIN1的作用机理，以评估PIN1是否调节Cyclin E1的积累是否像C-Myc一样调节Cyclin E1的积累； 2）检查PIN1的功能丧失如何导致永生小鼠成纤维细胞中的基因组不稳定性； 3）检验以下假设：在癌症的遗传工程小鼠模型中可以改变肿瘤发生的时机，其中必须在整个动物中自发重组以激活K-RAS的致癌等位基因，从而导致小鼠100％的小鼠肿瘤发生。我们希望这些提出的研究的完成将有助于阐明PIN1和/或其靶蛋白在癌变中的潜在作用。