dictyNews Electronic Edition Volume 31, number 8 August 29, 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. Upon publication of your paper, please send strains and plamids to  the Dicty Stock Center. For more information see  http://dictybase.org/StockCenter/Deposit.html. Back issues of dictyNews, the Dicty Reference database and other useful information is available at dictyBase - http://dictybase.org. ========= Abstracts ========= Exploitation of the derivatives of Dictyostelium differentiation-inducing factor-1, which promote glucose consumption in mammalian cells Yuzuru Kubohara*, Haruhisa Kikuchi, Yoshiteru Oshima Institute for Molecular and Cellular Regulation (IMCR), Gunma University, Maebashi 371-8512, Japan (YK), Laboratory of Natural Product Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Japan (HK, YO) Life Sciences, In press Aims: The differentiation-inducing factor-1 (DIF-1) is a signal molecule  that induces stalk cell formation in the cellular slime mold Dictyostelium  discoideum.  DIF-1 has also been shown to possess pharmacological activities,  such as the suppression of tumor cell growth and the promotion of glucose  uptake in non-transformed mammalian cells.  In this study, we tried to develop  compounds that possess weaker anti-tumor activity and stronger glucose  uptake-promoting activity than DIF-1. Main methods: We investigated the in vitro effects of 12 derivatives of DIF-1  on glucose consumption in mouse 3T3-L1 cells and on cell growth in K562  human leukemia cells.  We also examined the effect of a good compound on  the blood glucose concentration in KK-Ay diabetic mice. Key findings: We found that some derivatives at 20 uM promoted glucose  consumption more than twice as fast as the control.  Of the derivatives, a  compound named DIF-1(3M), which has a weaker anti-leukemic effect than  DIF-1, promoted glucose consumption as strongly as DIF-1 in confluent  3T3-L1 cells.  While DIF-1 at 20 uM was inhibitory to the cell growth of  3T3-L1, DIF-1(3M) at 20 uM exhibited no inhibitory effect on the growing  cells.  We also found that DIF-1(3M) injected (10-12.5 mg/kg body weight)  intraperitoneally in mice tended to lower the blood glucose concentration.   Significance: The present results open the possibility for the development  of new agents that possess strong glucose-uptake-promoting activity but  little anti-tumor activity and may have therapeutic potential for the  treatment of diabetes and/or obesity. Submitted by: Yuzuru Kubohara [kubohara@showa.gunma-u.ac.jp] -------------------------------------------------------------------------------- An ELMO-like protein associated with myosinII restricts spurious F-actin events to coordinate phagocytosis and chemotaxis Nilgun Isik, Ph.D.; Joseph A Brzostowski, Ph.D.^; Tian Jin, Ph.D. Chemotaxis Signal Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Twinbrook II Facility, 12331 Parklawn Drive, Rockville, Maryland 20852, USA ^Laboratory of Immunogenetics Light Imaging Facility, National Institute of Allergy and Infectious Diseases, NIH, Twinbrook II Facility, 12331 Parklawn Drive, Rockville, Maryland 20852, USA Developmental Cell, in press Elmo proteins positively regulate actin polymerization during cell migration and phagocytosis through activation of the small G-protein Rac. We identified an Elmo-like protein, ElmoA, in Dictyostelium discoideum that unexpectedly functions as a negative regulator of actin polymerization. Cells lacking ElmoA display an elevated rate of phagocytosis, increased pseudopod formation and excessive F-actin localization within pseudopods. ElmoA associates with cortical actin and myosin II. TIRF microscopic observations of functional ElmoA-GFP reveal that a fraction of ElmoA localizes near the presumptive actin/myosin II cortex and the levels of ElmoA and myosin II negatively correlate with that of polymerizing F-actin. F-actin-regulated dynamic dispersions of ElmoA and myosin II are interdependent. Taken together, our data suggest that ElmoA modulates actin/myosin II at the cortex to prevent excessive F-actin polymerization around the cell periphery, thereby maintaining proper cell shape during phagocytosis and chemotaxis. Submitted by: Joe Brzostowski [brzostowskij@niaid.nih.gov] ============================================================== [End dictyNews, volume 31, number 8]