Young Investigator Group "Biochemistry of plant RecQ helicases"

The DNA, the genetic information of the organisms, is always subjected to damaging factors. But the stability of the genome is important for the survival of the cell and the maintenance of species. Therefore efficient repair pathways evolved during evolution, which are based on a network of specialized proteins.

One kind of proteins that play an important role in the maintenance of genomic stability are the RecQ helicases. Humans for example, possess five different RecQ helicases. A defect in three of them is linked to severe genetic diseases - to Bloom's, Werner, and Rothmund Thomson syndrome, respectively. While the overall symptomes differ in the different diseases, they are all charcterized by genomic instability. This genomic instability leads to the development of cancers. As the diseases arise by the defect of one single gene, and as they are different from each other, the different human RecQ helicases must have specialized functions.

In the model plant Arabidopsis thaliana (mouse-ear cress, thale cress) even seven different RecQ helicases have been identified. On the next subpage it is shown what this young investigator group in trying to find out about those RecQ helicases.

Junior research group of Dr. Daniela Kobbe

The impact of the important enzyme family of RecQ helicases was introduced with a focus on human health on the subpage RecQ helicases. On this page, you will find how the junior research group "Biochemistry of RecQ helicases" is going to find out about the tasks of the RecQ helicases of the model plant Arabidopsis thaliana.

In vivo data, such as those of  the Puchta group at KIT show, that also the plant RecQ helicases play a significant role in DNA repair and recombination. As in humans, the different plant RecQ helicases are functionally specialized.

In order to find out a function of a protein the results from several analytic methods have to be combined.

The RecQ helicases are proteins that "work" with DNA, they unwind atypic, aberrant, DNA structures. Using biochemical methods one can analyze what an enzyme is doing with a defined atypic DNA structure.
This way you will be able to set up a hypothesis about a function or you will sustain a hypothesis that came up using different methods. In the figure you can see, that AtRECQ2 processes a so called Holliday junction into splayed arm products. This suggests that AtRECQ2 plays a role in recombination.
 
If you compare the properties of the RecQ helicases of different species you might be able to conclude about functional similarity (homology). Alternatively you might postulate species specific functions for a given RecQ helicase.

We are analyzing the RecQ helicases of the model plant Arabidopsis thaliana biochemically. The results contribute to a better understanding of the RecQ helicases in general, which is relevant in face of the different human genetic diseases linked with RecQ helicases. Additionally we find out about the properties of the plant RecQ helicases, which is important for green biotechnology as the influence DNA recombination.

This Young Investigator Group is supported by the Karlsruhe Institute of Technology (KIT) in the framework of the concept of the future of the excellence initiative of the DFG.