September 17, 2013

Series of prizes for postdocs at IST Austria

Prestigious awards highlight excellence of junior scientists

The postdocs at Institute of Science and Technology Austria (IST Austria) are as varied as the questions they pursue in their work, the approaches they take and the countries they come from. But one of the things that unite them is that they have performed excellent research before coming to IST Austria, in the process of their PhD thesis and during previous postdoc positions. This is shown again by prizes that postdocs at IST Austria received recently for their doctoral work and publications from their thesis research.

Mechanics of cell contacts: Mateusz Sikora received a prize for the best PhD diploma in 2012 by the Institute of Physics of the Polish Academy of Sciences, as well as a long-term fellowship grant by the European Molecular Biology Organization (EMBO) to support the next two years of his research as a postdoc in the lab of Prof. Carl-Philipp Heisenberg at IST Austria. Mateusz’ thesis in theoretical physics focused on theoretical models of the unfolding and stretching of proteins. Mateusz joined Carl-Philipp Heisenberg’s developmental biology group in the spring of 2013, where he combines his theoretical background with experimental techniques to understand questions on the mechanics at work in cell-cell junctions. Mateusz will use experiments to build a model of contacts between cells, and apply this model to predict the behavior of such cell-cell contacts. In a feedback loop, his experimental results will then be used to refine his model, which attempts to explain cell-cell contacts at a whole range of levels, from single proteins to cells and on to the whole embryo.

Evolution’s stand-stills: Marjon de Vos published her project completed during her PhD studies at FOM Institute AMOLF , Amsterdam, on evolutionary dynamics in PLoS Genetics in June. Marjon used the bacterium Escherichia coli to study genetic stand-stills in evolution. Under natural selection, an organism will generally evolve traits that provide it with an advantage. If, however, one step in the evolution towards this advantageous trait is actually unfavorable, evolution will come to a “stand-still”. Marjon studied how molecular signals can help overcome such a stand-still by adding a compound that changes the function of the bacterial Lac repressor. Comparing the mutations occurring in E. coli grown in environments with or without the added compound, Marjon showed that the mutations arising depend on the presence of the compound. Marjon’s research proved that environmental constraints can control which routes evolution can take.

Marjon de Vos is now pursuing postdoctoral research in the group of Prof. Tobias Bollenbach and applies the concept of constraints and optimality to ecological systems by studying interactions between bacteria. The two model systems she uses are the gut bacteria of infants and bacteria found in urinary tract infections. In both systems, the many bacteria present form complex communities. These bacteria strongly influence each other, affecting growth rates and even survival in the presence of antibiotics. Marjon de Vos will study these biotic interactions to better understand how such ecological influences affect bacterial survival.

Digging up protein fossils: In his PhD thesis, Alvaro Ingles Prieta developed a method that digs up fossil protein structures to reveal how they have evolved; his work was published in Structure on August 8. The physical structure of proteins is important for their function and differs greatly between proteins. However, little is known about how these structures evolve. So far, only the structures of proteins in their present form have been compared in order to gain insights into protein evolution. This approach is similar to comparing only living birds to understand bird evolution rather than looking at the fossil record. Alvaro and his colleagues reconstructed the basic amino acid sequence of so-called thioredoxin proteins of Precambrian bacteria, archaea and eukaryotes, living four billion years ago. They then produced these proteins in the lab and analyzed their X-ray crystal structure. Looking at the “molecular fossils” they built, the researchers found that the structures of present day thioredoxins are remarkably similar to that of ancient thioredoxins. This suggests that protein structures remain constant over long time periods, and change – and thus evolve – in short spurts. Alvaro is now a postdoctoral researcher in the lab of Prof. Harald Janovjak, where he uses optogenetics to study the signal cascade from a protein family called FDFR1 receptors, which are over-activated in some forms of cancer.

Controlling genes: Anna Staron received one of three thesis awards by the VAAM, the Association of General and Applied Microbiology in Germany. During her PhD, Anna studied bacterial sigma factors, which regulate if a gene is activated. Anna focused on a subgroup, the extracytoplasmic function (ECF) sigma factors, which are able to regulate genes only in response to a stimulus. When the stimulus is absent, ECF sigma factors are kept inactive by so-called antisigma factors. Anna analyzed how antisigma factors exert their control, using genome analysis to classify the mechanisms of control. Anna is now a postdoc in the group of Prof. Calin Guet where she studies the transcription of DNA into mRNA in bacteria, in particular how the termination of transcription is controlled. Anna focuses on transcriptional read-through in bacteria. Transcriptional read-through occurs when transcription is not terminated at the end of one gene, resulting in two neighboring genes being transcribed into one RNA molecule. Anna investigates how transcriptional read-through affects gene regulation.

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