Within eukaryotic cells the environment for all genomic processes is chromatin. This structural highly dynamic
polymeric molecule is composed of DNA and mainly histone proteins. Chromatin can be further divided into
transcriptional active euchromatin or transcriptional inert heterochromatin. Post-translational modifications (PTM)
of histones appear as key regulators of chromatin function thereby epitomizing the biochemical basis for epigenetic
phenomena. One way how PTMs impact chromatin biology is via the recruitment of modification dependent
"effector" proteins which further relay the modification to a particular biologic effect.
Methylation of histone H3 at lysine 9 (H3K9) is considered one of the hallmarks of heterochromatin. One novel
factor that was demonstrated recently to recognize this modification via a chromodomain is CDYL, indicating a
possible function in organization of heterochromatin. This factor was shown to possess transcriptional repressor
activity, probably via transient interaction with a repressor complex; however the function of CDYL in chromatin
biology is not yet characterized.
In this project I will analyze the role of CDYL in chromatin biology via biochemical, biophysical and cell biology
approaches. To this end I will determine the subcellular localization of CDYL via fluorescence-microscopy and the
chromatin related localization via genome wide mapping approaches. I will accurately analyze thermodynamic
parameters of CDYL binding to chromatin and effects of this association on chromatin structure in vivo and in
vitro. Further I will investigate consequences of CDYL binding on transcriptional regulation in vivo. To get a
comprehensive understanding of CDYL direct and indirect functions in chromatin organization I will identify and
characterize CDYL associated proteins as well as RNAs. The impact of these factors on CDYL chromatin-
functions will be addressed via biochemical and biophysical methods.
I expect the dataset generated from the suggested experiments to significantly expand our knowledge how CDYL
may participate in heterochromatin formation.