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

• Applicant: Professor Dr. Thomas Schmülling, since 3/2007
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2004 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5446458

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.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Professor Dr. Hanjo Hellmann, until 3/2007