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Workshop Week Symposium

With talks by Dr. Benedict Tan (Pharmaceutical Chemistry, University of Marburg), Prof. Kai Thormann (Microbiology, University of Gießen), Dr. Patricia Bedrunka (SYNMIKRO, PI of GRK 2937's Project 9, University of Marburg) and Prof. Haike Antelmann (Microbiology, University of Berlin).

Veranstaltungsdaten

The annual Workshop Week of GRK 2937 will be concluded with a half-day symposium. We are looking forward to welcoming the four guest speakers and a large active audience in the SYNMIKRO Lecture Hall and foyer. Attendance is free and without registration. Click here for the directions to the Centre for Synthetic Microbiology, SYNMIKRO.

13:00     Welcome

 13:05     Prof. Kai Thormann, Gießen
Phage Tales – Entering a New World

The Thormann Lab is part of the Institute for Microbiology and Molecular Biology at the Justus-Liebig-Universität Gießen and is located at Interdisziplinäres Forschungszentrum (iFZ), a Research Centre for Biosystems, Land Use and Nutrition. The Lab is also part of SYNMIKRO.
A great benefit of being PI is the freedom of science and the opportunity to move into new fields of research at any time. Being inspired by a chance finding a long while ago, my group started to move into the amazing world of bacterial phages and trying to combine the present lab’s knowledge with phage biology. Phages are the most abundant biological entity on Earth, and science has just started to realize the wealth of novel protein functions and fascinating biology underlying the billions of years of phage-host interactions that await their discovery.
About 5 years ago, we started to isolate new phages for our model species Shewanella, and to characterize the new isolates. Here I will present the latest findings starring Shewanella phages LambdaSo, Thanatos, Xenos and Dolos. I will show the functions of novel phage effectors, how big a gap of knowledge can be, and I will describe the discovery of a tiny but mighty phage pirate.

 14:05     Dr. Patricia Bedrunka, Marburg
New insights into the regulatory networks of Bacillus subtilis controlling biofilm formation and cell motility

Biofilms are multicellular microbial communities found to be associated to almost every existing natural and artificial surface or interface. The highly differentiated community members are embedded in an extracellular matrix (ECM) of their own synthesis, which enables the generation of spatially organized three-dimensional (3-D) structures. In B. subtilis, biofilm formation requires the expression of the eps and tapA-sipW-tasA operons to synthesize ECM components. Expression of both operons is inhibited by the DNA-binding protein and master regulator of biofilm formation SinR. Transcriptional activation of the corresponding genes is thought to be controlled in parallel by two central regulatory proteins RemA and RemB. We will present the structure of the RemA homologue from Geobacillus thermodenitrificans, showing a unique octameric ring with the potential to form a 16-meric superstructure in vitro. These results, together with further biochemical and in vivo characterization of B. subtilis RemA, suggests that the protein can wrap DNA around its ring-like structure through a LytTR-related domain. AlphaFold models predict RemB shares a nearly identical fold to RemA. We will provide new insights on the relationship between RemA and RemB, adding another central regulatory layer of biofilm formation in B. subtilis.
Another key aspect to biofilm formation is the regulation of cell motility. When transitioning to the biofilm state motile bacteria must first become sessile. A key regulator of the bacterial motility-to-biofilm transition is the small cytoplasmic signaling molecule c-di-GMP. In B. subtilis, c-di-GMP-bound MotI directly inhibits similarly to other YcgR-type proteins motility through its interaction with the flagellar motor component MotA to disturb motor-rotor interactions of the flagellar apparatus. In order to terminate the signaling cascade, c-di-GMP is degraded in two-steps, linearization into pGpG by PdeH and subsequent cleavage to two GMPs mediated by the oligoribonuclease NrnA. In this context, we will present a putative alternative degradation mechanism.

15:05     Coffee break

 15:25     Dr. Benedict Tan, Marburg
The regulation of mitochondrial transcription by non-coding RNAs

The human mitochondrial genome (mtDNA) is a 16.6 kb circular, double-stranded, polyploid molecule that replicates independently of the cell cycle and is maintained by an assortment of proteins predominantly of bacterial and viral lineage. Of the ~90 proteins involved in mitochondrial ATP synthesis via oxidative phosphorylation, 13 proteins are exclusively encoded by mtDNA, and their dysregulated expression is linked to a wide spectrum of mitochondriopathies. In humans, these manifest as incurable diseases prominently affecting energy-demanding tissues such as the brain, heart, and eyes. 
The expression of mitochondrial genes is tailored to match the energy demands of different tissue types. However, our understanding of how this process is regulated at a fundamental and mechanistic level remains naïve. In my talk, I will discuss two closely related non-coding transcripts that are involved in the mechanistic coupling between transcription and mtDNA replication, as well as directly regulating the activity of the mitochondrial RNA polymerase.

16:25     Prof. Haike Antelmann, Berlin
Adaptation mechanisms of Staphylococcus aureus towards oxidants and novel antimicrobials

My research is focused on the defense mechanisms against oxidative and electrophile stress in Gram-positive pathogens, such as Staphylococcus aureus. Using redox proteomics, we discovered novel thiol-switches, which control cellular metabolism, virulence and detoxification of reactive species. We characterized the mechanisms of novel redox-sensing regulators, such as the HOCl/HOSCN-sensing HypR repressor and the quinone-sensing MhqR and QsrR repressors, which confer resistance against (pseudo)hypohalous acids (HOCl, HOSCN), electrophiles and redox-active antimicrobials. Overall, our research aims to elucidate the mechanisms and functions of redox-controlled proteins that enable the survival and adaptation of S. aureus during colonization and infection of the host.

17:25   Scientific exchange and standing snack