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dictyNews Volume 31 Number 20
dictyNews
Electronic Edition
Volume 31, number 20
December 26, 2008
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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Autophagic or necrotic cell death triggered by distinct motifs of the
differentiation factor DIF-1.
MF Luciani, Y Kubohara, H Kikuchi, Y Oshima and P Golstein
Cell Death and Differentiation, doi: 10.1038/cdd.2008.177, in press
Autophagic or necrotic cell death (ACD and NCD, respectively), studied in
the model organism Dictyostelium which offers unique advantages, require
triggering by the same differentiation-inducing factor DIF-1. To initiate
these two types of cell death, does DIF-1 act through only one or through
two distinct recognition structures ? Such distinct structures may
recognize distinct motifs of DIF-1. To test this albeit indirectly, DIF-1
was modified at one or two of several positions, and the corresponding
derivatives were tested for their ability to induce ACD or NCD. The results
strongly indicated that distinct biochemical motifs of DIF-1 were required
to trigger ACD or NCD, and that these motifs were separately recognized
at the onset of ACD or NCD. In addition, both ACD and NCD were induced
more efficiently by DIF-1 than by either its precursors or its immediate
catabolite. These results showed an unexpected relation between a
differentiation factor, the cellular structures that recognize it, the cell
death types it can trigger, and the metabolic state of the cell. The latter
seems to guide the choice of the signaling pathway to cell death, which
in turn imposes the cell death type and the recognition pattern of the
differentiation factor.
Submitted by: Pierre Golstein [golstein@ciml.univ-mrs.fr]
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Autophagic cell death: analysis in Dictyostelium
Corinne Giusti, Emilie Tresse, Marie-Françoise Luciani, Pierre Golstein
BBA - Molecular Cell Research, doi:10.1016/j.bbamcr.2008.12.005, in press
Autophagic cell death (ACD) can be operationally described as cell death
with an autophagic component. While most molecular bases of this autophagic
component are known, in ACD the mechanism of cell death proper is not well
defined, in particular because in animal cells there is poor experimental
distinction between what triggers autophagy and what triggers ACD. Perhaps
as a consequence, it is often thought that in animal cells a little autophagy
is protective while a lot is destructive and leads to ACD, thus that the
shift from autophagy to ACD is quantitative. The aim of this article is to
review current knowledge on ACD in Dictyostelium, a very favorable model,
with emphasis on (1) the qualitative, not quantitative nature of the shift
from autophagy to ACD, in contrast to the above, and (2) random or targeted
mutations of in particular the following genes: iplA (IP3R), TalB (talinB),
DcsA (cellulose synthase), GbfA, ugpB, glcS (glycogen synthase) and atg1.
These mutations allowed the genetic dissection of ACD features, dissociating
in particular vacuolisation from cell death.
Submitted by: Pierre Golstein [golstein@ciml.univ-mrs.fr]
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[End dictyNews, volume 31, number 20]
