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dictyNews Volume 42 Number 15
dictyNews
Electronic Edition
Volume 42, number 15
June 10, 2016
Please submit abstracts of your papers as soon as they have been
accepted for publication by sending them to dicty@northwestern.edu
or by using the form at
http://dictybase.org/db/cgi-bin/dictyBase/abstract_submit.
Back issues of dictyNews, the Dicty Reference database and other
useful information is available at dictyBase - http://dictybase.org.
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=========
Abstracts
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Actin organization in cells responding to a perforated surface,
revealed by live-imaging and cryo-electron tomography
Marion Jasnin, Mary Ecke, Wolfgang Baumeister, Günther Gerisch
Structure-Cell, in press
In a three-dimensional environment, motile cells accommodate
their protruding and retracting activities to geometrical cues.
Dictyostelium cells migrating on a perforated film explored
its holes by forming actin rings around their border and
extending protrusions through the free space. The response
was initiated when an actin wave passed a hole, and the rings
persisted only in the PIP3-rich territories surrounded by a
wave. To reconstruct actin structures from cryo-electron
tomograms, actin rings were identified by cryo-correlative
light and electron microscopy, and thin wedges of relevant
regions were obtained by cryo-focused ion beam milling.
Retracting stages were distinguished from protruding ones by
the accumulation of myosin-II. Early actin rings consisted of
filaments pointing upright from the membrane, entangled with
a meshwork of filaments close to the membrane. Branches
identified at later stages suggested that formin-based
nucleation of filaments was followed by Arp2/3-mediated
network stabilization, which prevented buckling of the
force-generating filaments.
submitted by: Günther Gerisch [gerisch@biochem.mpg.de]
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[End dictyNews, volume 42, number 15]
