Biology of Stress Responses

Biological stress responses are a priority research focus in modern biology and there is an urgent need to understand how cells and organisms respond to environmental, physiological, and pathological stresses.

The cellular stress response is evolutionarily conserved in all living organisms and it dictates whether the organism adapts, survives, or, if injured beyond repair, undergoes death. Thus, the study of stress responses has broad biological applications in microorganisms, plants, animals, and humans in health and in disease.

Ongoing research efforts in the department address such questions in all kingdoms of life, from bacteria (Simon lab) and archaea (Pfeifer lab) to yeast (Bertl lab), and from plants (Kaldenhoff lab, Thiel lab) to animals (Cardoso lab, Löbrich lab). We make use of a variety of experimental approaches combined with computational methods (Hamacher lab). To further establish the field as a research focus, the department has recently created a faculty position in synthetic neurosensory systems (Laube lab). We have active ongoing collaborations with other departments (Drossel lab, Durante lab, Dencher lab).

In the last years, we have established with the GSI Helmholtz center a competence center on Radiation Biology and a new graduate college was launched in 2011.

Bertl Laboratory

Plants in natural environments are being exposed to increasing amounts of salinity, which has detrimental effects by greatly reducing root development, growth and biomass production. Since the baker’s yeast, Saccharomyces cerevisiae, resembles plant cells in terms of cellular compartmentalization, harboring a large acidic vacuole and a similarly equipped machinery for transmembrane transport of ions and small molecules, we are using yeast as a model to studying ion transport processes (ion channels, co-transporter and ion pumps) and their role in salt stress, salt tolerance and osmoregulation.

Cardoso Laboratory

Mammalian cells are constantly exposed to endogenous and exogenous genotoxic challenges. We are investigating how cells respond to such stress situations and manage to precisely maintain and propagate their (epi)genome at every cell cycle. On the one hand, we study the regulatory networks and interactions between the DNA replication and repair machinery. On the other hand, we focus on how epigenetic regulation provides a way to modulate cellular responses to genotoxic stress.

Hamacher Laboratory

We develop computational, multi-scale methods to understand and design biomolecular systems and their respective interactions. These methods and models allow us to a) understand evolution of stress response systems and b) design in silico molecules to interfere with e.g. repair mechanisms for radio-sensitization of tumor cells.

Kaldenhoff Laboratory

Unlike animals, plants cannot escape from sudden unfavorable changes in the environment. Therefore, they have developed effective mechanisms to cope with e.g. high radiation, water deficiency, temporal increase of heat or parasitic attacks. We are studying these responses by analyzing molecular changes and their consequences on plant physiology respectively ecophysiology.

Laube Laboratory

Ionotropic glutamate receptors are key players in the physiology and pathophysiology of central neurons during development and the maintenance of cognitive functions in the brain. Inappropriate activation induces developmental malformations, neuronal loss in acute trauma as well as certain neurodegenerative diseases. It is becoming apparent that oxidative and nitrosative stress mediated by both hyper- and hypoactivity of glutamate receptors plays an important role in promoting neuronal death or survival. Current research projects attempt to understand the function of glutamate receptors in the effect of ionizing radiation as a stress factor on neuronal development. On the other hand, we focus on how glutamatergic signaling interferes with brain tumor proliferation and metastasis.

Löbrich Laboratory

Ionizing radiation is an important stress factor, which is encountered by human beings in the environment and in clinical settings. Medical procedures involving ionizing radiation, such as advanced radio therapeutic and radio diagnostic routines, have substantially increased our standard of living but uncertainties in risk estimates represent a barrier for further applications. Research in our laboratory is devoted to investigate basic molecular and cellular mechanisms in response to ionizing irradiation.

Pfeifer Laboratory

We investigate stress responses in halophilic Archaea at the level of gene expression and structure formation using the formation of gas vesicles as model system. The synthesis of these proteinaceous particles is influenced by temperature, salt, UV light, anaerobiosis and nutrition. We are interested to unravel the signal transduction pathways.

Electron micrograph of a W. succinogenes cell and substrate conversions catalysed by respiratory enzymes involved in nitrate ammonification, nitrous oxide and sulfite respiration as well as in nitric oxide and hydroxylamine detoxification. Dehydrogenases (yellow) and reductases (red) are connected via the menaquinone/menaquinol pool and contribute to the generation of a proton motive force (pmf) that drives ATP synthesis. Hyd, Hydrogenase; Fdh, Formate dehydrogenase; Mcc, cytochrome c sulfite reductase; Nap, periplasmic nitrate reductase; Nrf, cytochrome c nitrite reductase; Nos, nitrous oxide reductase.

Simon Laboratory

Toxic and/or reactive nitrogen species like nitrite, hydroxylamine and nitric oxide and its congeners exert anti-microbial nitrosative stress. This project deals with nitrosative stress defence mechanisms in bacteria and comprises (I) sensing of reactive nitrogen species, (II) signal transduction pathways and (III) characterization of cellular stress protection networks.

Thiel Laboratory

Research in the Thiel lab focuses from a biophysical point of view on structure/ function correlates of ion channels. These proteins play central roles in many stress situations; their activity can be the cause of stress but also a way to avoid it. Current research projects attempt to understand the function of K+ channels in the regulation of the cell cycle under the special influence of ionizing radiation. In another line of research we examine the functional role of ion channels from viruses. Insight into the structure of these proteins should help us to understand the contribution of these channels to viral infections.

Botanical Garden

The Botanical Garden (ca. 8.000 taxa, 4.5 ha outdoors; 1200 m² under glass) offers space, facilities, and expertise for experiments under various conditions. A glasshouse with a fine-tuned regulation in small-sized cabins is available.

Associated Departments

Norbert A. Dencher

Department of Chemistry, TU Darmstadt

  • Influence of radiation and ROS on cells and mitochondrial physiology

Barbara Drossel

Department of Physics, TU Darmstadt

  • Modeling of Biological Networks

Marco Durante

Department of Physics, TU Darmstadt and GSI

  • Radiation Biology