STSM2 Report Melanie Binkert

The impact of UVR8 chromatin association on UV-B signaling

Melanie Binkert visited Prof. Gareth Jenkins in the UK (12 days in August 2011).


UVR8 dimers perceive UV-B radiation, monomerize and initiate UV-B responses in Arabidopsis (Rizzini et al. 2011). Chromatin immunoprecipitation (ChIP) experiments performed by Dr. Catherine Cloix at the University of Glasgow (laboratory of Prof. Gareth Jenkins) revealed UVR8 binding to the promoter regions of several UV-B-induced genes, including the HY5 promoter (Brown et al. 2005, Cloix and Jenkins 2008). UVR8 chromatin association seems to be independent of UV-B and via histone H2B (Cloix and Jenkins 2008).


In the frame of my PhD work I am addressing the impact of UVR8 chromatin association on UV-B signaling. The purpose of the STSM in Gareth Jenkins’s lab was to guide me through a successful UVR8 ChIP experiment and to troubleshoot possible technical problems. Specificity issues raised during this work will need to be addressed in further collaboration: it remains to be determined whether the present model of UVR8 chromatin association to specific genes remains valid (and, if yes, how this specificity is generated, considering that UVR8 is a histone binding protein rather than a DNA binding protein), or whether UVR8 has a broader function at the chromatin level than presently anticipated. In the latter case the mechanism that results in UV-B activation of specific UV-B-responsive genes remains to be identified.

Through the STSM the foundation to answer these important and fundamental questions in a collaborative effort in frame of the COST Action UV4Growth was laid down.

As minor differences in experimental procedures can be revealed only on site, the STSM was required to equalize the technical procedures performed in the two laboratories. This will further allow to compare the results and to resolve problems, making future re-investigation of UVR8 chromatin association in both laboratories possible.

Being exposed to a different research environment allowed me to acquire new handling techniques and discuss problems and the research topic intensively. In addition to the important contribution to my research skills, experience and scientific career, the visit in Gareth Jenkins’s laboratory intensified communication and common research spirit. Thus the STSM strengthened the invaluable knowledge exchange in the UV-B signaling field leading to improved collaboration.