dictyNews Electronic Edition Volume 30, number 15 May 9, 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 ========= Actin: its cumbersome pilgrimage through cellular compartments (Review) Michael Schleicher (1) and Brigitte M. Jockusch (2) (1) Adolf-Butenandt-Institute, Cell Biology and Center for Integrated Protein Science (CIPSM), Ludwig-Maximilians-University, 80336 Munich, Germany (2) Cell Biology Group, Technical University of Braunschweig, Spielmannstr. 7, 38092 Braunschweig, Germany Histochemistry and Cell Biology, in press Open access link: http://www.springerlink.com/content/b165347g01w270g4/ In this article, we follow the history of one of the most abundant, most intensely studied proteins of the eukaryotic cells: actin. We report on hallmarks of its discovery, its structural and functional characterization and localization over time, and point to present daysÂ’ knowledge on its position as a member of a large family. We focus on the rather puzzling number of diverse functions as proposed for actin as a dual compartment protein. Finally, we venture on some speculations as to its origin. Submitted by: Michael Schleicher [schleicher@lrz.uni-muenchen.de] -------------------------------------------------------------------------------- The function of PP2A/B56 in non-metazoan multicellular development. Nam-Sihk Lee, Sudhakar Veeranki, Bohye Kim, and Leung Kim* Dept of Biological Sciences, Florida International University, Miami, FL 33199 * Corresponding author: kiml@fiu.edu Tel) 305-348-7315 Key words: B56, PP2A, GSK3, Dictyostelium development Differentiation, in press DB56, the Dictyostelium B56 homolog, displayed high sequence homology to other eukaryotic B56 subunits of the PP2A and a specific association with the PP2A catalytic subunit. Cells lacking DB56, psrA-, displayed higher PP2A phosphatase activity compared to the wild type, ~ 10 hours of delayed expression of ecmA and ecmB prestalk markers, and inefficient culmination. The prespore marker cotB declined as wild type cells culminate, but no such decline was observed from psrA- cells. Interestingly, psrA- cells exhibited higher GSK3 kinase activity. Furthermore, the expression of the dominant negative GSK3 mutant (K84/85M) in psrA- cells improved both prestalk and prespore expression patterns similarly to wild type cells. However, culmination was not restored in psrA- cells expressing dominant negative GSK3, which suggests that PP2A/DB56 has an extra target during terminal differentiation. This report shows that PP2A/DB56 controls not only metazoan development, but also non-metazoan cell fate decision processes. Submitted by: Leung Kim [kiml@fiu.edu] ============================================================== [End dictyNews, volume 30, number 15]