dictyNews Electronic Edition Volume 41, number 14 July 3, 2015 Please submit abstracts of your papers as soon as they have been accepted for publication 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. Follow dictyBase on twitter: http://twitter.com/dictybase ========= Abstracts ========= Proteomic profiling of the extracellular matrix (slime sheath) of Dictyostelium discoideum Robert J. Huber 1 and Danton H. O’Day 2,3 1 Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA 2 Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada 3 Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada PROTEOMICS, in press Dictyostelium discoideum has historically served as a model system for cell and developmental biology, but recently it has gained increasing attention as a model for the study of human diseases. The extracellular matrix (ECM) of this eukaryotic microbe serves multiple essential functions during development. It not only provides structural integrity to the moving multicellular pseudoplasmodium, or slug, it also provides components that regulate cell motility and differentiation. An LC/MS/MS analysis of slug ECM revealed the presence of a large number of proteins in two wild-type strains, NC4 and WS380B. GO annotation identified a large number of proteins involved in some form of binding (e.g., protein, polysaccharide, cellulose, carbohydrate, ATP, cAMP, ion, lipid, vitamin), as well as proteins that modulate metabolic processes, cell movement, and multicellular development. In addition, this proteomic analysis identified numerous expected (e.g., EcmA, EcmD, discoidin I, discoidin II), as well as unexpected (e.g., ribosomal and nuclear proteins) components. These topics are discussed in terms of the structure and function of the ECM during the development of this model amoebozoan and their relevance to ongoing biomedical research. Submitted by Robert Huber [rhuber@mgh.harvard.edu] ---------------------------------------------------------------------- Chemotaxis of a model organism: progress with Dictyostelium John M.E. Nichols1,2, Douwe Veltman1 and Robert R. Kay1 1. MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom 2. MRC Laboratory of Molecular cell Biology, University College London, Gower St, London WC1E 6BT Current Opinion in Cell Biology, in press Model organisms have been key to understanding many core biological processes. Dictyostelium amoebae have the attributes required to perform this role for chemotaxis, and by providing an evolutionary distant reference point to mammalian cells, they allow the central features of chemotaxis to be discerned. Here we highlight progress with Dictyostelium in understanding: pseudopod and bleb driven movement; the role of the actin cytoskeleton; chemotactic signal processing, including how cells adapt to background stimulation, and the controversial role of PIP3. Macropinocytosis and the axenic mutations are raised as potential confounding factors, while the identification of new players through proteomics holds great promise. Submitted by Robert Kay[rrk@mrc-lmb.cam.ac.uk] ============================================================== [End dictyNews, volume 41, number 14]