Research
NAC transcription factors: the p53 network of plants
NAC proteins are a plant-specific family of transcription factors involved in different aspects of the DNA damage response, development, and stress response. Plants contain over one hundred such proteins that consist of a DNA binding domain combined with large intrinsically disordered regions in its C-terminal halve. Most NAC transcription factors have specific functions but one NAC protein, called SOG1, seems to have a more general function similar to mammalian p53. We wish to understand how SOG1 can differentially regulated hundreds of genes, identify and understand the underlying mechanisms of its assumed transcription activation domain, identify its protein interactors, and find out the role of liquid-liquid phase separation in its cellular functioning.
Improving crop yields via aluminum tolerance
SOG1 mutants exhibit increased tolerance against aluminum-containing acidic soils and some components that increase Al3+ tolerance act indirectly on SOG1 by inhibiting the CK2 kinase. Thus, knowledge of the SOG1 interaction network may lead to the development of crops with higher yields and increased tolerance for Al3+-poisoned or phosphate-limited soils. In this respect, also other cellular targets are considered such as phosphoenol pyruvate carboxylase that is involved in the citric acid cycle, carbon fixation by CAM and C4 plants and amino acid biosynthesis.
Intrinsic disorder in prokaryotes: toxin-antitoxin modules
Toxin-antitoxin (TA) modules are small operons encoding an inhibitor of general bacterial physiology (the toxin) and a matching regulator (the antitoxin) that controls the activity in the context of bacterial stress response. Toxins target basic physiology such translation, transcription or cell wall synthesis. The domain of antitoxins that is responsible for toxin neutralization is often intrinsically disordered and functions via folding upon binding. This IPD nature often allows for a specific rejuvenation mechanism to reactivate toxin-arrested cells. In addition, the antitoxin IDP domain collaborates with its folded DNA binding domain to regulate TA expression in often complicated and non-trivial ways.
Molecular basis of fuzzy recognition
Macromolecular interactions are traditionally regarded as lock-and-key or induced fit events. Recent studies nevertheless show that many interactions between two proteins or between protein and DNA can be considered "fuzzy": One or more of the interacting partners does not adopt a unique conformation, but remains partially or even completely disordered. High affinity and specificity can be reached by systems that apparently do not use specific one-to-one contacts. The underlying mechanisms from these phenomena, which are typically driven by entropy rather than enthalpy, are poorly understood and theoretical models that can explain them are largely lacking.