Molecular Control of Flower Development

OKAMURO 9604507拟南芥的花发育是由一个进化上保守的基因网络控制的，这些基因网络控制着花分生组织特征的建立和维持、花器官的发育和配子发生。然而，人们对这些基因如何在细胞和分子水平上共同发挥作用知之甚少。APETALA2(AP2)基因通过控制另一个花同源异源基因AGAMOUS(AG)的时空表达模式，在控制拟南芥花发育过程中发挥重要作用。AP2蛋白代表了目前已知的一个重要的新的植物DNA结合蛋白家族的第一个，包括EREBPs，AINTEGUMENTA和TINTY。本实验的目的是通过分析AP2在体外的DNA结合活性，了解AP2如何在分子水平上调控AG基因的表达，并寻找在花发育过程中可能与AP2物理相互作用并与其一起发挥作用的蛋白质。具体目标包括：(1)鉴定AP2多肽中体外DNA结合活性所需的序列，(2)鉴定AP2多肽内在活体中发挥AP2功能所需的序列，(3)确定AP2基因活性在翻译后水平上是如何调节的，(4)确定AP2是否与自身或与体内包含AP2结构域的其他蛋白质形成多聚体，以及(5)使用凝胶过滤层析确定与AP2形成稳定物理相互作用的蛋白质。AP2功能的阐明最终将为在分子水平上调控植物的生长发育提供新的视角。

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.