Toghether with Hanspeter Herzel from the Institute for Theoretical Biology, Humboldt University in Berlin, I worked on the regulation of the mammalian clock controlled genes. This work was part of a project on circadian rhythms funded by the International Research Training Group on Genomics and Systems Biology of Molecular Networks.
Circadian rhythm is the approximately 24-hour cycle of the physiological, chemical, and behavioral processes in our bodies. Though this cycle can be influenced by external factors, such as light and food, the cycle itself is endogenous - each cell of our bodies contains molecular components responsible for the generation of circadian rhythms. The rhythms within a body are organized in a hierarchical manner with the master clock in the hypothalamus. Light received by our eyes entrains the phase of the master clock, that then sends synchronizing signals to the rest of the body.
Core circadian clock genes produce proteins necessary for the generation and regulation of circadian rhythms. These genes are common to most cells throughout the body and regulate their own expression and the expression of clock output genes. Genes that are not a part of the core clock system but oscillate with circadian rhythm are termed clock controlled genes (CCGs).
In this project we investigated the regulatory links between the core clock and the numerous CCGs throughout the body. Our results point to connections between the circadian clock and other functional systems including metabolism, endocrine regulation and pharmacokinetics.

Bozek K, Kielbasa SM, Kramer A, Herzel H. Promoter analysis of mammalian clock controlled genes. Genome Inform. 2007;18:65-74.

Bozek K, Relogio A, Kielbasa SM, Heine M, Dame C, Kramer A, Herzel H. Regulation of clock-controlled genes in mammals. PLoS One. 2009;4(3):e4882. Epub 2009 Mar 16.

Bozek K, Rosahl AL, Gaub S, Lorenzen S, Herzel H. Circadian Transcription in Liver. Biosystems. 2010 Jul 21.