Institut für Chemie - Biochemie
Thielallee 63, 14195 Berlin, Germany
Phone +49-30-8385 6425
Fax +49-30-8385 3753
eMail: hotto@chemie.fu-berlin.de
Keywords: Cell Nucleus, Nuclear Envelope, Phosphorylation, Protein
Kinase, Protein Phosphatase, Signal Transduction
Research Interests
Cellular Biochemistry: Phosphorylation-dependent Protein Interactions
at the Nuclear Envelope. The nuclear envelope separates the cell nucleus
from the cytoplasm and the endoplasmic reticulum. It consists of two membranes
that are continuous with each other and with the membrane of the endoplasmic
reticulum. The inner nuclear membrane is attached to and stabilized by
the lamina, a very stable meshwork of intermediary filaments. This inner
membrane may be involved in signal transduction processes in the nucleus.
Up to now, only few proteins are known that specifically reside in this
membrane. Most of those proteins seem to be involved in the spatial and
functional organization of the cell nucleus.
Aims of our research are the identification of novel proteins of the
inner nuclear membrane by protein
chemical means and mass spectrometric analysis, their functional characterization,
and the description of interactions with other macromolecules in the nucleus.
In particular, we are interested in phosphorylation-dependent interactions
of such proteins.
We use the integral inner nuclear membrane protein LAP 2 beta (lamina-associated
polypeptide 2 beta) as a model protein of this membrane. We are analyzing
its phosphorylation status, in particular during interphase of the cell
cycle. We screen nuclear fractions for binding partners of LAP 2 beta and
characterize its interactions by using a combination of cell biochemical
and molecular biological methods (recombinant protein expression, cell
culture using fibroblast and neuroblastoma cell lines).