Cell News 02/2017
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MEETING REPORT
As in the previous years, the annual Joint Meeting "Signal
Transduction – Receptors, Mediators and Genes" took place in
Weimar (November 9 to 11, 2016) whereby this special meeting
celebrated its 20
th
anniversary. The conference was organized by
the Signal Transduction Society (STS) together with signaling
study groups of the German Societies for Cell Biology (DGZ),
for Biochemistry and Molecular Biology (GBM), for Immunology
(DGfI), and for Pharmacology (DGP). Other financial and scientif-
ic contributors were the Netherlands Societies for Biochemistry
and Molecular Biology (NVBMB) and the SFB 854 “Molecular
Organisation of Cellular Communication in the Immune System”
(B. Schraven, Magdeburg). The meeting organisation was per-
formed by the STS council together with the chairpersons of the
study groups and members of the STS Advisory Board.
The special focus of the 2016 meeting ‘Cells and Molecules in
Motion’ was coordinated by the GBM study group Signal Trans-
duction with a number of exciting keynote lectures.
Jan Faix (Hannover) opened this year’s Joint Meeting by his
keynote talk about actin-based cell migration and associated
molecular mechanisms within the special subtopic “Cells in
Motion”. In various fluorescence microscopic videos Prof. Faix
impressively demonstrated different forms of cellular movement
including a slower mesenchymal mode of migration which is
exhibited by fibroblasts or mesenchymal stroma/stem cells
by strong substrate adherence, prominent stress fibers and
extended formation of protruding lamellipodia/ruffles at the
leading edge. Alternatively, a faster amoeboid-like cell migration
is utilized e.g. by immune cells and characterized by weaker
adhesion, absence of stress-fibers and formation of action-rich
pseudopods in the cellular fronts paralleled by myosin II-driven
contractility in the rears. These actomyosin-dependent dynamics
were followed during the next keynote talk by Robert Grosse
(Marburg) with respect to the migratory and invasive potential
of cancer cells liberated from the primary tumor and subsequent
trans-endothelial migration. Prof. Grosse further focused on
entosis, a process of cell in cell invasion as a form of membrane
blebbing-associated amoeboid migration of the invading cell.
Entosis-promoting signals involve certain LPA-Rs (Lysophos-
phatidic acid receptors), e.g. LPA-R2 coupled with Rho-GTPases
activation and formin-mediated actin dynamics to subsequently
form non-apoptotic plasma membrane blebbing.
Following further mechanisms of cellular movement, Francesca
Odoardi (Göttingen) presented a neurodegenerative multiple
sclerosis model of experimental autoimmune encephalomyelitis
(EAE) to investigate how T cells become brain-associated. In the
workshop “Immune Cell Signaling”, Prof. Odoardi also dis-
cussed potential checkpoints for T cell infiltration of the central
nervous system and appropriate addressing of T cell to different
compartments of the brain.
Within the special subtopic on “Molecules in Motion”, Robert
Tampé (Frankfurt) and Irmgard Sinning (Heidelberg) focused
on intracellular peptide and protein shuttling to the plasma
membrane. After proteasomal degradation of protein products
to small peptides from virally-transformed cells or cancer cells
during immune surveillance, Prof. Tampé discussed the local-
ization of these peptides in the ER lumen associated with MHC
class I molecules and their subsequent transfer to the plasma
membrane to allow further recognition by the immune system.
Prof. Sinning introduced the preparation of moving proteins
to the plasma membrane and proper unfolding by presenting
mechanisms of the SRP (signal recognition particle) cycle. The
SRP requires a N-terminal signal sequence for a RNA-protein
complex formation with subsequent processing and further
remodeling for translocation to appropriate cellular compart-
ments.
Guanylate-binding proteins (GBPs) including GTPases can be
induced in macrophages by γ-interferon signaling in part via
JAK2 and possess homo- and hetero-multimerization proper-
ties which was extensively discussed by Klaus Pfeffer (Düssel-
dorf) within the special subtopic “Organelles in Motion”. Prof.
Pfeffer demonstrated the reversible oligomerization of GMPs in
vesicle-like structures to form large supramolecular complex-
es comprising up to several thousand GMP monomers which
can exhibit anti-microbial activity by targeting pathogens in
vacuoles and therefore can be considered as effector molecules
of host immunity.
Meeting report of the DGZ study group
‘Signal Transduction’ and its participation in the 20
th
anniversary Joint Meeting "Signal Transduction –
Receptors, Mediators and Genes"
Klaudia Giehl, Detlef Neumann, Ottmar Janssen, Katharina Hieke-Kubatzky and Ralf Hass
