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Press Release
Molecules of worldwide repute - The
role of nitric oxide synthase in slime moulds
Vienna (FWF) - In 1992, it was awarded the title "Molecule of the
Year". In 1998 three scientists received the Nobel Prize for their
work on this molecule, which had already gained worldwide repute. And
today, Georg Golderer from the Institute of Medical Chemistry and Biochemistry
at Innsbruck University can report further groundbreaking findings. We
are talking about nitric oxide (NO), a molecule performing a wide range
of essential functions in animal organisms. Golderer and his team, sponsored
by the Austrian Science Fund, have now detected this enzyme also in a
single-celled non-animal organism, the slime mould Physarum polycephalum,
and determined its biological role.
The slime mould can be cultured under laboratory conditions and represents
a well established cell-biological model. It is thus ideally suited for
the investigations pursued by Golderer, who followed two goals in his
project. "Nitric oxide is a small gaseous molecule influencing many
signal pathways within the cell. In animal organisms, for instance, it
acts as a neurotransmitter, is involved in the regulation of the blood
pressure and plays a diverse role in the immune response. While NO synthase
activity was known to exist in non-animal organisms, it was, however,
not accessible by any sequence data. Our first aim was therefore to identify
NO synthase activity in the slime mould and to characterise the enzyme",
says Golderer. "We were able to clean and clone the enzyme from the
organism and thus characterise the first non-animal NO synthase".
Starring role in cell differentiation
Golderer also achieved his second aim, which was to shed new light on
the biological function of NO synthase within the slime mould organism.
"Upon entering a stage of hunger or desiccation, the slime mould
is able to form spores and thus reproduce in time before its death. This
process is called differentiation. We found out that a large amount of
NO is produced during the hunger phase preceding differentiation",
explains Golderer. The enzyme plays an essential part in controlling spore
formation. It acts as a signal molecule triggering a whole series of reactions
and finally controls the formation of fruiting bodies (spores). This reveals
a new role of the NO signal pathway: the control in cell differentiation.
Regulatory details
The details of this process are not yet known, but Golderer intends to
provide new findings in the coming years. "We now know the central
significance of NO synthase in the slime mould. This is a fundamental
progress. But we would also like to find out, for instance, with what
proteins the molecule interacts, what reactions it triggers where in detail
and what functions it performs", Golderer concludes. In this way,
Golderer hopes to gain a better understanding of as yet unknown cellular
control concepts of general biological relevance. The chemist considers
this issue an important area of work for fundamental research.
Dr. Georg Golderer
University of Innsbruck, Institute of Medical Chemistry and Biochemistry
Tel.: +43 512 5073532
E-mail: georg.golderer@uibk.ac.at
Distributed by:
CLOOS + PARTNER, Public Relations Agency
Tel: ++43 1 710 85 99
August 29th, 2001
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