ATP-dependent chromatin remodelers
are enzymes which use the energy from ATP hydrolysis to alter
the chromatin structure. Thus, they play a key role in the
transcriptional control of many important cellular processes
such as proliferation,senescence and differentiation.The
first part of this study focused on CHD5, a novel chromatin
remodeling enzyme. To gain further insight into its
expression profile and biological function, polyclonal
peptide antisera were, together with a commercially available
antiserum, successfully established for use in western blot,
immunoprecipitation and immunofluorescence staining.
ATP-dependent chromatin remodelers are expressed by very
different patterns ranging from ubiquitous expression to an
expression restricted to specific cell populations. So far,
CHD5 expression was thought to be restricted to
neural-related tissues. Here, it was shown for the first time
that CHD5 expression is not restricted to neural tissues but
additionally expressed in rodent testes. Furthermore, several
cell lines were tested for CHD5 expression on transcript and
protein level. CHD5 expression was not detected in any of the
tested neuroblastoma and glioblastoma cell lines. In
neuroblastoma cell lines this was expected due to the
suggested function as tumor suppressor. Furthermore, a
primary astrocyte culture was established. No CHD5 could be
detected in protein lysates from astrocytes but was found in
those from murine neural stem cells. This suggests that CHD5
expression in brain is restricted to neural stem cells and
probably also to neurons. In the second part of this thesis,
the impact of the chromatin remodelers CHD4 and BRG1 on a
TNFα-induced inflammatory response was investigated. BRG1 and
CHD4 expression was disrupted by a siRNA-mediated knockdown
in HEK293 cells. After stimulations with TNFα for one to four
hours, gene induction of typical inflammatory NF-κB target
genes was determined by RT-qPCR. BRG1 and CHD4 were both
required for the efficient induction of all tested target
genes exclusively after one hour but not after four hours of
TNFα treatment. Expression of the housekeeping gene ß-actin
was unaffected. Surprisingly, although CHD4 is mainly known
to be involved in transcriptional repression, a requiremen...