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. ========= Abstracts ========= 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] -------------------------------------------------------------------------------- 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] ============================================================== [End dictyNews, volume 31, number 20]