Investigations of Mammalian Aminopropyltransferases

哺乳动物氨丙基转移酶的研究

基本信息

批准号：
7274778
负责人：
ANTHONY E PEGG
金额：
$ 27.69万
依托单位：
PENNSYLVANIA STATE UNIV HERSHEY MED CTR
依托单位国家：
美国
项目类别：
财政年份：
1979
资助国家：
美国
起止时间：
1979-04-01 至 2009-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7274778
关键词：
5&apos -deoxyadenosine Abbreviations AbeAdo Acetyltransferase Active Sites Adenosylmethionine Decarboxylase Anthracenes Autacoids BE-333 Be-3-4-3 Behavior Behavioral Binding Biological Assay Biological Models Breeding CGP 48664 Carmustine Cell physiology Cells Chromosome Deletion Cultured Cells DL-alpha-Difluoromethylornithine Data Defect Diet Diethylhomospermine Drug Design Eating Eflornithine Enzymes Exposure to Family Female Fertility Genes Goals Growth Human Inborn Errors of Metabolism Investigation Ionizing radiation Link Maintenance Mammals Measurement Metabolism Methionine Methods Methyltransferase Mitoguazone Modeling Molecular Mus Mutation N(1),N(11)-bis(ethyl)norspermine N(1)-ethyl-N-(11)-((cycloheptyl)methyl)-4,8-diazaundecane Nature Neoplasms Nitrosourea Compounds ODC1 gene Ornithine Decarboxylase Oxidases Pathway interactions Physiological Play Polyamines Preparation Principal Investigator Procedures Process Production Protein Overexpression Purpose RNA Splicing Reaction Reactive Oxygen Species Recombinants Regulation Role S-Adenosylmethionine S-adenosyl-1,12-diamino-3-thio-9-azadodecane S-adenosyl-3-thio-1,8-diaminooctane SAT gene Site Site-Directed Mutagenesis Snyder-Robinson syndrome Source Spermidine Spermidine Synthase Spermidine/Spermine N1-Acetyltransferase Spermine Spermine Synthase Structure Substrate Specificity Syndrome System Techniques Testing Tetradecanoylphorbol Acetate Tissues Transcriptional Activation Transgenic Mice Up-Regulation Work analog anthracene base design dimethylbenzanthracene follow-up in vivo inhibitor/antagonist male metabolic abnormality assessment methionine adenosyltransferase mutant polyamine oxidase prevent promoter protein expression putrescine N-methyltransferase research study uptake

项目摘要

DESCRIPTION (provided by applicant): Polyamines are ubiquitous cellular components that play many roles in cellular physiology and in normal and neoplastic growth. There is good evidence that the polyamine biosynthetic pathway is a valid target for drug design. The planned experiments focus on studies of the synthesis, function and regulation of spermine levels in mammals. They follow up on several major findings made during the last period of support. These include: determination of the crystal structure of an aminopropyltransferase with an associated multisubstrate analog inhibitor; the finding that a rare X-linked human syndrome (Snyder-Robinson syndrome-SRS) is due to a mutation reducing activity of the spermine synthase gene; our observation that CAG-SpmS transgenic mice that greatly overexpress spermine synthase have only modest alterations in spermine, indicating that compensatory mechanism must prevent its accumulation; the findings that male Gy mice, which have an X-chromosomal deletion in the SpmS gene, have no spermine despite the presence of spermine in their diets; and preliminary results indicating that restoring a source of spermine by breeding female Gy carrier mice with CAG-SpmS mice restores normal growth and fertility to these mice despite the unregulated nature of spermine synthase expression. There are four interrelated specific aims: (1) To understand the mechanism of action and substrate specificity of the aminopropyltransferase enzymes. These studies will use structural data, which allows predictions to be made concerning the aminopropyltransferase reaction and tested by site-directed mutagenesis. They will determine the mechanism of aminopropyl transfer from decarboxylated S-adenosyl-methionine, compare this process to methyl transfer from S-adenosylmethionine and determine the molecular basis of the strikingly exclusive substrate specificities of spermidine and spermine synthases. (2) To understand the regulatory mechanisms in vivo that control spermine levels and the consequences of overproduction or underproduction of spermine. These studies will use CAG-SpmS mice and crosses of them with mice that overexpress other enzymes of polyamine metabolism to evaluate the regulatory factors the control spermine levels and the effects of overriding these factors. (3) To examine the uptake of spermine from exogenous sources and devise procedures to facilitate such uptake and thus restore normal polyamine levels and function in Gy mice and SRS cells. (4) To investigate the regulation of spermine content and the unique function(s) of spermine in cultured cells using cells derived from Gy mice, and SRS cells that have a greatly reduced spermine synthase level due to a mutation in a splice site.

描述（由申请人提供）：多胺是无处不在的细胞成分，它们在细胞生理以及正常和肿瘤生长中起许多作用。有充分的证据表明，多胺生物合成途径是药物设计的有效目标。计划的实验集中于哺乳动物中精子水平的合成，功能和调节的研究。他们跟进了最后一个支持期间的几个重大发现。其中包括：确定与相关的多底物类似物抑制剂的氨基丙基转移酶的晶体结构；罕见的X连锁人类综合征（Snyder-Robinson综合征-SR）的发现是由于精子合酶基因的突变减少了活性。我们的观察到，CAG-SPMS转基因小鼠极大地表达精子合酶的精子仅适度改变，这表明补偿机制必须防止其积累。 SPMS基因中有X染色体缺失的雄性GY小鼠的发现，尽管饮食中存在精子，但在SPMS基因中却没有精子。并且初步结果表明，尽管精子合酶表达的性质不受调节的性质，但通过繁殖具有CAG-SPMS小鼠的雌性GY载体小鼠来恢复精子的正常生长和生育能力。有四个相互关联的特定目的：（1）了解氨基丙基转移酶的作用机理和底物特异性。这些研究将使用结构数据，该数据允许对氨基丙基转移酶反应进行预测，并通过定点诱变进行测试。他们将确定氨基丙基转移从脱羧的S-腺苷甲硫代转移的机制，将该过程与从s-腺苷甲氨酸的甲基转移，并确定精子素和精子合酶的引人注目的排他性底物特异性的分子基础。（2）了解控制精子水平的体内调节机制以及生产过多或生产精子的后果。这些研究将使用CAG-SPM小鼠和它们的杂交与小鼠过表达的小鼠，以过表达多胺代谢的其他酶来评估控制精子水平的调节因素以及这些因素的影响。（3）检查来自外源源的精子的摄取，并设计程序以促进这种摄取，从而恢复GY小鼠和SRS细胞中正常的多胺水平和功能。（4）使用源自GY小鼠的细胞以及由于剪接部位突变引起的精子合酶水平大大降低的SRS细胞，研究精子含量的调节和精子的独特功能。