Abstracts (poster) - Wissenschaft Online

Christine Vogler, Tanja Waldmann, Lora Braun, Mirek Dundr, Robert Schneider
The tale of a tail - Histone H2A and its C-terminal tail
In the eukaryotic nucleus the DNA is organized in the form of chromatin. The basic unit
of chromatin is the nucleosome consisting of 146 bp of DNA wrapped around an octamer
of the four core histones H2A, H2B, H3 and H4. The histone proteins are not only
important for the compaction of chromatin but also play an important role in the
regulation of DNA-dependent processes such as transcription and repair.
Posttranslational modifications of the flexible tails of the histones are one way to achieve
this regulation. H2A is the only core histone that not only has an N-terminal tail but
additionally contains a flexible C-terminal tail. This tail is thought to be located at the
entry and exit site of the nucleosomal DNA. Almost nothing is known about the role of
this tail in chromatin structure and function nor about proteins interacting with it. We
were able to show that this tail is important for nucleosome stability in vitro and in vivo
and that its deletion significantly increases nucleosome mobility. Furthermore, we found
that expression of C-terminally truncated H2A influences cell proliferation and cell cycle
progression in vivo. This is the first demonstration of a biological function for the H2A Cterminus.
contact:
Christine Vogler
MPI for Immunobiology
Vogler@immunbio.mpg.de
Stuebeweg 51
79108 Freiburg (Germany)