PhD position in Proteomics and Protein Biochemistry

The WHIRLY proteins belong to a small family of DNA/RNA binding proteins of higher plants. Most plants possess two WHIRLY proteins located in various compartments in the cell. In Arabidopsis three WHIRLY encoding genes exist in the genome. So far, it is known that WHIRLY1 and 3 play redundant functions, and WHIRLY3 can replace mitochondrial WHY2 during development. Nevertheless, the fundamental function of WHIRLY proteins in the cell is known. Their roles in all these diverse processes might be linked to their binding to DNA and RNA. In plastids, WHIRLY1 and 3 have been found to be major components of nucleoids. The WHIRLY proteins have the ability to bind to single-stranded DNA (ssDNA) and act as transcription factors to regulate defense gene expression and organelle DNA copy number. In addition to that WHIRLIES were found to promote accurate repair of DNA double-strand breaks. Analysis of the crystal structure of potato and Arabidopsis Whirly proteins has provided insight into the DNA-binding mechanism of this family of proteins, their mode of action, and possible autoregulation. In fact, WHIRLY proteins form tetramers and 24-mer higher-order structures. Outstandingly, the plastid-nucleus located WHIRLY1 and mitochondria localized WHIRLY2 both play an important role in the regulation of ABA signaling. In addition, it was found that WHIRLY proteins are involved in chloroplast biogenesis and function, maintaining organelle genome stability and repair, disease resistance, drought stress response, senescence, pollen development and prominently retrograde signaling.

Thesis project: The advertised project will build on our recent findings and aims to elucidate mechanisms regulating WHIRLIES functions. To this end, we will investigate ubiquitin-dependent regulation of WHIRLIES function and targeting.This research will allow identification of a novel signaling routes mediated via WHIRLY proteins.