Regulatoriske nettverk og biologisk rolle for det mulige DCAF proteinet WDR55 i planters reproduksjon

This project seek to identify and elucidate the role of novel regulators in plant development. Our current knowledge is mainly focused on different levels of transcriptionally based regulation, including the various roles of chromatin and the distribution of hormone gradients. However, the action of regulatory proteins are also regulated by proteolysis, and a major route is through the UBIQUITIN-26S proteasome (UPS)-dependent pathway. More than 5% of the Arabidopsis proteome consists of components of the UPS pathway, and with growing evidence of proteolytic and nonproteolytic roles of ubiquitylation, this regulation system thus rivals the role of transcription as the foremost regulatory mechanism. The WDxR motif containing protein, WDR55 has been identified by its requirement in seed development and plant reproduction. WDR55 interacts with DDB1A and is therefore a potential substrate receptor for a DDB1-CUL4-based E3 ubiquitin ligase complex. In this project we will elucidate the biological role of WDR55 by mutant studies and in biochemical and genome-wide approaches identify targets as well as components of the complex through which WDR55 acts. Additionally, we will investigate the evolutionary role of WDR55 in eukaryotes through a bioinformatics approach, and finally, test the translational value of Arabidopsis gained knowledge into the crop model rice. We expect the project to deliver major novel insights inthe role of proteolytic or non-proteolytic regulation throughout eukaryotes.