dictyNews Electronic Edition Volume 33, number 12 November 6, 2009 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 now on twitter: http://twitter.com/dictybase We are very grateful to Jakob for providing yet another update of the Reference Database. Information and download of the Endnote library can be found at http://dictybase.org/reference_database/index.html ========= Abstracts ========= The Galpha4 G protein subunit interacts with the MAP kinase ERK2 using a D-motif that regulates developmental morphogenesis in Dictyostelium Hoai-Nghia Nguyen and Jeffrey A. Hadwiger* Department of Microbiology and Molecular Genetics, Oklahoma State University Developmental Biology, in press G protein Galpha subunits contribute to the specificity of different signal transduction pathways in Dictyostelium discoideum but Ga subunit-effector interactions have not been previously identified. The requirement of the Dictyostelium Galpha4 subunit for MAP kinase (MAPK) activation and the identification of a putative MAPK docking site (D-motif) in this subunit suggested a possible interaction between the Galpha4 subunit and MAPKs. In vivo association of the Galpha4 subunit and ERK2 was demonstrated by pull-down and co-immunoprecipitation assays. Alteration of the D-motif reduced Galpha4 subunit-ERK2 interactions but only slightly altered MAPK activation in response to folate. Expression of the Galpha4 subunit with the altered D-motif in Galpha4- cells allowed for slug formation but not the morphogenesis associated with culmination. Expression of this mutant Galpha4 subunit was sufficient to rescue chemotactic movement to folate. Alteration of the D-motif also reduced the aggregation defect associated with constitutively active Galpha4 subunits. These results suggest Galpha4 subunit-MAPK interactions are necessary for developmental morphogenesis but not for chemotaxis to folate. Submitted by Jeff Hadwiger [jeff.hadwiger@okstate.edu] ============================================================== [End dictyNews, volume 33, number 12]