Molecular Control of Flower Development

拟南芥花的发育是由一个进化保守的基因网络控制的，该基因网络控制着花的分生组织身份、花器官发育和配子体发生的建立和维持。然而，对于这些基因如何在细胞和分子水平上共同发挥作用，人们知之甚少。aptala2 （AP2）基因在拟南芥花发育中起着重要的调控作用，其部分机制是通过调控另一个花同源基因AGAMOUS （AG）的时空表达模式实现的。AP2蛋白是目前已知的一个重要的植物DNA结合蛋白新家族中的第一个，包括erebp、AINTEGUMENTA和TINY。本项目的实验目的是通过分析AP2在体外的DNA结合活性，了解AP2如何在分子水平上控制AG基因的表达，并鉴定在花发育过程中可能与AP2物理相互作用并共同起作用的蛋白。具体目标包括：(1)鉴定体外AP2 DNA结合活性所需的AP2多肽序列，(2)鉴定体内AP2功能所需的AP2多肽序列，(3)确定AP2基因活性是如何在翻译后水平调控的，(4)确定体内AP2是与自身形成多聚体还是与其他含AP2结构域的蛋白形成多聚体。(5)利用凝胶过滤色谱法鉴定与AP2形成稳定物理相互作用的蛋白。AP2功能的阐明将最终为在分子水平上调控植物生长发育提供新的思路。

OKAMURO 9604507 Arabidopsis flower development is governed by an evolutionarily conserved network of genes that control the establishment and maintenance of flower meristem identity, floral organ development, and gametogenesis. However, little is known about how these genes function together at the cell and molecular levels. The APETALA2 (AP2) gene plays a central role in controlling flower development in Arabidopsis, in part, by controlling the temporal and spatial expression pattern of another floral homeotic gene AGAMOUS (AG). The AP2 protein represents the first of what is now known to be an important new family of plant DNA binding proteins including EREBPs, AINTEGUMENTA, and TINY. The goal of the experiments in this project is to understand how AP2 controls AG gene expression at the molecular level by analyzing its DNA binding activity in vitro and to identify proteins that may physically interact with and function together with AP2 during flower development. Specific goals include: (1) identifying sequences within the AP2 polypeptide that are required for AP2 DNA binding activity in vitro, (2) identifying sequences within the AP2 polypeptide that are required for AP2 function in viva, (3) determining how AP2 gene activity is regulated at the posttranslational level, (4) determining whether AP2 forms multimers with itself or with other AP2 domain containing proteins in viva, and (5) identifying proteins that form stable physical interactions with AP2 using gel filtration chromatography. The elucidation of AP2 function will ultimately provide new insight into the control of plant growth and development at the molecular level.