dictyNews Electronic Edition Volume 35, number 15 Nov 26, 2010 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. Follow dictyBase on twitter: http://twitter.com/dictybase ========= Abstracts ========= Dictyostelium dynamin B modulates cytoskeletal structures and membranous organelles Amrita Rai, Heike Noethe, Nikolay Tzvetkov, Elena Korenbaum, Dietmar J. Manstein Institut fuer Biophysikalische Chemie, OE 4350, Medizinische Hochschule Hannover, Carl-Neuberg-Straße 1, 30623 Hannover, Germany Cellular and Molecular Life Sciences, in press Dictyostelium discoideum cells produce five dynamin family proteins. Here, we show that dynamin B is the only member of this group of proteins that is initially produced as a preprotein and requires processing by mitochondrial proteases for formation of the mature protein. Our results show that dynamin B-depletion affects many aspects of cell motility, cell-cell and cell-surface adhesion, resistance to osmotic shock, and fatty acid metabolism. The mature form of dynamin B mediates a wide range and unique combination of functions. Dynamin B affects events at the plasma membrane, peroxisomes, the contractile vacuole system, components of the actin-based cytoskeleton, and cell adhesion sites. The modulating effect of dynamin B on the activity of the contractile vacuole system is unique for the Dictyostelium system. Other functions displayed by dynamin B are commonly associated with either classical or dynamin-related proteins. Submitted by Dietmar Manstein [manstein.dietmar@mh-hannover.de] -------------------------------------------------------------------------------- Domain architecture of the DRpp29 protein and its interaction with the RNA subunit of Dictyostelium discoideum RNase P Vassiliki Stamatopoulou1, Chrisavgi Toumpeki1, Andreas Tzakos2, Anastassios Vourekas1, and Denis Drainas1 1Department of Biochemistry, School of Medicine, University of Patras, Greece. 2Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, Greece Biochemistry in press Dictyostelium discoideum nuclear RNase P is a ribonucleoprotein complex that displays similarities with its counterparts from higher eukaryotes such as the human enzyme, but at the same time it retains distinctive characteristics. In the present study, we report the molecular cloning and interaction details of DRpp29 and RNase P RNA, two subunits of the RNase P holoenzyme from Dictyostelium discoideum. Electrophoretic mobility shift assays exhibited that DRpp29 binds specifically to the RNase P RNA subunit, a feature that was further confirmed by the molecular modeling of the DRpp29 structure. Moreover, deletion mutants of DRpp29 were constructed in order to investigate the domains of DRpp29 that contribute to and/or are responsible for the direct interaction with the D. discoideum RNase P RNA. A eukaryotic specific, lysine and arginine rich region was revealed, which seems to facilitate the interaction between these two subunits. Furthermore, we tested the ability of wild type and mutant DRpp29 to form active RNase P enzymatic particles with the E. coli’s RNase P RNA. Submitted by Denis Drainas [Drainas@med.upatras.gr] ============================================================== [End dictyNews, volume 35, number 14]