Functional Characterization of the Arabidopsis thaliana BTB/POZ-MATH domain protein family

进化保守的BTB/POZ和数学基序可以在昆虫、鱼类、哺乳动物和植物等各种生物中找到。含有这两个基序的蛋白质已被证明参与转录调控和减数分裂过程。此外，最近的发现揭示了BTB/POZ-MATH-蛋白与含有E3泛素连接酶的Cullin之间的联系，这些连接酶活跃在泛素蛋白酶体途径中。拟南芥基因组编码6种BTB/POZ-MATH蛋白，它们都与哺乳动物和线虫的斑点型POZ蛋白相关。到目前为止，人们对该家族在植物中的功能和生物学作用一无所知。我们已经克隆了三个具有代表性的成员，并且可以展示ALL与AtCUL3蛋白的相互作用以及它们之间的同源和异源二聚体。交互依赖于BTB-域，不需要数学主题。因此，在该项目中，将详细分析所有六个BTB/POZ-MATH基因的详细表达模式、亚细胞蛋白定位和零突变的表型。该项目将识别新的相互作用蛋白，验证该家族与泛素蛋白酶体途径的功能联系，并将每个单独的BTB/POZ-MATH蛋白置于其活跃的调控网络中。

The evolutionary conserved BTB/POZ and MATH-motifs can be found in various organisms ranging from insects, fish, mammals and plants. Proteins containing both motifs have been demonstrated to participate in transcriptional regulation and meiotic processes. In addition, recent findings revealed the connection between BTB/POZ-MATH-proteins and Cullin containing E3 ubiquitin ligases that are active in the ubiquitin proteasome pathway. The Arabidopsis genome encodes for six BTB/POZ-MATH proteins all related to speckle-type POZ proteins from mammals and C. elegans. So far nothing is known about the function and biological roles of this family in plants. We have cloned three representative members and can demonstrate interaction of all with AtCUL3 proteins as well as homo- and heterodimerization with each other. Interactions depend on the BTB-domain and do not require the MATH-motif. Thus, within the project detailed expression patterns of all six BTB/POZ-MATH genes, subcellular protein localization and phenotypes of null mutants will be analyzed in detail. The project will identify new interacting proteins, verify functional connections of the family to the ubiquitin proteasome pathway, and place each individual BTB/POZ-MATH protein into the regulatory networks in which it is active.