Rim-kinases in fungal secondary metabolism and pathogenicity

Molds play a variety of ecological roles on our planet, especially in natural nutrient cycles and as pathogens of plants and animals. Of particular interest is their ability to produce a wide variety of small, bioactive molecules. One example of a very useful molecule is the antibiotic penicillin, which has saved millions of lives to date. But there are also dangerous molecules, such as toxins produced by molds, that can contaminate our food and thereby threaten consumer health. So the final goal must be to precisely understand the molecular and cellular programs in those fungi and thus develop natural solutions against fungal infections. Our previous research has shown that epigenetic processes regulate toxin production, but also a specific kinase - a regulatory protein that can chemically modify other proteins in its environment - plays a decisive role. In a previously unknown way, it is able to transmit a starvation signal in the cell, which ultimately leads to a complete change in the cellular metabolism and thereby activates the genetic machinery for toxin formation. In this project, we are now addressing the question of exactly how the starvation signal is processed by the fungal cell so that mycotoxins are formed. For this, we are using as experimental systems a conventional mold that is present ubiquitously in nature and buildings (Aspergillus) and a fungus that is considered one of the most important pathogens in crop plants worldwide (Fusarium). The entire genetic response of both fungi at the RNA level and at the protein level will be analyzed molecularly, biochemically and bioinformatically during different stages of their life cycles. In addition, those proteins whose function is regulated by the kinase should be identified. In this way, the signaling pathway from nutrient deficiency from the cell surface to the genetic activation of toxin production in two different molds should be elucidated as completely as possible. Ultimately, the results of this research could close a gap in the fundamental understanding of cellular processes during toxin production in mold fungi. This knowledge can then be used to develop new control strategies to ward off plant diseases and prevent biological contamination of food.