The Aux/IAA and ARF Gene Families in Auxin Signaling

生长素信号转导中的 Aux/IAA 和 ARF 基因家族

• 批准号: 6761782
• 负责人: Athanasios Theologis
• 金额: $ 15.75万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-04-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6761782
• 关键词: Arabidopsis; DNA binding protein; SDS polyacrylamide gel electrophoresis; binding sites; biological signal transduction; chimeric proteins; functional /structural genomics; gene expression; gene mutation; genetic regulation; genetic screening; genetically modified plants; hormone regulation /control mechanism; immunoprecipitation; indoleacetate; microarray technology; molecular cloning; nucleic acid sequence; phytohormones; plant genetics; plant growth /development; polymerase chain reaction; protein structure function; transcription factor

DESCRIPTION (provided by applicant): The plant hormone auxin, typified by indole-3-acetic acid (IAA), regulates various aspects of plant growth and development such as cell division, vascular differentiation, lateral root formation, apical dominance, morphogenesis, oncogenesis, tropisms, and is generally considered to be responsible for regulating plant cell growth. Despite the importance of auxin in plant development, the primary molecular mechanism of auxin action is poorly understood. Experimental evidence accumulated during the past 10 years indicates that the hormone acts rapidly (3-5 min) at the transcriptional level regulating expression of a variety of genes such as Aux/IAAs, SAURs, and GHs. Early auxin-induced Aux/IAA gene expression is mediated in part by the interaction of Aux/IAA proteins with the ARFs (auxin responsive factors). This interaction is regulated by auxin-mediated proteolytic degradation of Aux/IAA proteins. The Aux/IAA proteins are transcription factors that interact with the ARFs and together control a large number of genes involved in a large spectrum of developmental processes regulated by auxin. The specific aims of the proposal are:1. To characterize null mutations for most of the Aux/IAA and ARF gene family members and construct higher order mutations for elucidating the biological function of these proteins. The null mutations will be used for RNA profiling to determine the downstream genes that are regulated by some of the Aux/IAA and ARF gene family members, and for biochemical studies.2. To determine the DNA binding specificities of some ARF gene family members, define the DNA binding domains of ARF1 and ARF6 using a yeast molecular genetic screen, and determine their genomic binding sites with microarray technology.3. To molecularly characterize the recently cloned age1 mutation, a negative regulator of early Aux/IAA gene expression. AGE1 is a homolog of the yeast RAD3 and human XPD/ERCC2 protein, which is a component of the TFIIH transcription factor that participates in nucleotide excision repair (NER) and basal transcription. To clone and characterize the age2 mutation, another negative regulator of the auxin signaling pathway.The elucidation of the primary mechanisrn of auxin action is of paramount importance in Plant Science.

描述(申请人提供)：植物激素生长素，以吲哚-3-乙酸(IAA)为代表，调节植物生长和发育的各个方面，如细胞分裂、维管分化、侧根形成、顶端优势、形态发生、肿瘤发生、向阳作用，通常被认为对植物细胞生长起调节作用。尽管生长素在植物发育中很重要，但生长素作用的主要分子机制却知之甚少。过去10年积累的实验证据表明，这种激素在转录水平上作用迅速(3-5分钟)，调节多种基因的表达，如AUX/IAA、SAUR和GHS。早期生长素诱导的AUX/IAA基因表达部分是通过AUX/IAA蛋白与生长素反应因子(ARF)的相互作用来调节的。这种相互作用受生长素介导的AUX/IAA蛋白降解的调节。AUX/IAA蛋白是与ARF相互作用的转录因子，共同控制生长素调控的一系列发育过程中的大量基因。本研究的具体目的是：1.鉴定AUX/IAA和ARF基因家族中大多数成员的零突变，并构建高阶突变，以阐明这些蛋白的生物学功能。零突变将用于RNA分析，以确定受一些AUX/IAA和ARF基因家族成员调控的下游基因，并用于生化研究。确定部分ARF基因家族成员的DNA结合特异性，利用酵母分子遗传学筛选确定ARF1和ARF6的DNA结合域，并利用基因芯片技术确定其基因组结合部位。最近克隆的AGE1突变是早期AUX/IAA基因表达的负调控因子。AGE 1是酵母RAD3和人类XPD/ERCC2蛋白的同源物，后者是参与核苷酸切除修复(NER)和碱基转录的TFIIH转录因子的组成部分。为了克隆和鉴定生长素信号通路的另一个负调控基因AGE2突变，阐明生长素的主要作用机制在植物科学中具有极其重要的意义。