Ruprecht-Karls-Universität Heidelberg

Ilka Bischofs
ZMBH Project Group Leader

Im Neuenheimer Feld 267
69120 Heidelberg, Germany
Tel.: +49-6221 54 51365
Fax: +49-6221 54 51487

Bacterial Signaling Networks

Research in the Bischofs-lab focuses on the experimental and theoretical analysis of bacterial signaling networks. These circuits are used by bacteria to sense and respond to their environment but also to interact with each other. Our broad aim is to understand the relationship between the function and design of these networks which evolved in a world subject to both biological and physical constraints.

Our model system is the gram-positive bacterium Bacillus subtilis. Bacillus shows an exquisite variety of adaptive behaviors to environmental stress and differentiates into special cell phenotypes. Differentiation is under control of interlinked signaling networks. The fairly detailed prior knowledge about the networks, in particular the sporulation phosphorelay, allows us to ask “higher-order” questions about network organization in relationship to facilitating complex tasks such as cell communication or the generation of phenotypic diversity. Answering those experimentally requires novel (still “low-throughput”) techniques to measure signaling activity both across the population and at the single cell level. We particularly employ biophysical approaches based on fluorescence microscopy. In addition, the extensive prior and our own experimental studies provide sufficient information to develop and further refine computational models to help us guide future experiments and to abstract our findings.

Please also note our web pages at BioQuant


Selected publications

H. Babel and I.B. Bischofs. Molecular and Cellular Factors Control Signal Transduction via Switchable Allosteric Modulator Proteins (SAMPs). BMC Systems Biology 10:35, 2016

D. Wolf, V. Rippa, J.C. Mobarec, P.Sauer, L. Adlung, P. Kolb & I. B. Bischofs. The quorum sensing regulator ComA from Bacillus subtilis activates transcription using topologically distinct DNA motifs. Nucleic Acids Research 44 (5), 2160-2172, 2016.

S. Pande, S. Shitut, L. Freund, M. Westermann, F. Bertels, C. Colesie, I.B. Bischofs, C. Kost. Metabolic cross-feeding via intercellular nanotubes among bacteria Nature Communications 6: 6238, 2015

B. Drees, M. Reiger, K. Jung, I.B. Bischofs. A Modular View of the Diversity of Cell-Density-Encoding Schemes in Bacterial Quorum-Sensing Systems Biophysical Journal 107, 266-277, 2014

S. Trauth, I.B. Bischofs. Ectopic Integration Vectors for Generating Fluorescent Promoter Fusions in Bacillus subtilis with Minimal Dark Noise PLoS One 9(5) e98360, 2014

I.B. Bischofs, J. Hug, A. Liu, D.M. Wolf and A.P. Arkin. Complexity in bacterial cell-cell communication: Quorum signal integration and subpopulation signaling in the B. subtilis phosphorelay Proc. Nat. Acad. USA, 106 (16), 6459-6464, 2009

I.B. Bischofs, F. Klein, D.Lehnert, M. Bastmeyer, U.S. Schwarz. Filamentous network mechanics and active contractility determine cell and tissue shape Biophysical Journal 95 (7), 3488-3496, 2008

I.B. Bischofs, U.S. Schwarz. Cell organization in soft media due to active mechanosensing Proc. Nat. Acad. USA 100 (16), 9274-9279, 2003


Snapshot of a sporulating micro-colony showing a large degree of phenotypic heterogeneity. Cells that activate the sporulation pathway are expressing CFP (blue) driven from a sporulation promoter PspoIIA while cells that delay sporulation express YFP (yellow) from the PrapA promoter. This promoter drives not only the expression a regulatory protein (RapA) but also the transcription of an extracellular signaling peptide (PhrA) that is implied to serve bacterial communication. The bright spots denote maturing endo-spores.