Science's STKE: cAMP Signaling Pathways

Science's STKE Web site has published two Connection Maps. One pertaining to the events associated with the chemotaxis response in early aggregation (http://stke.sciencemag.org/cgi/cm/stkecm;CMP_7918) and the other with the G protein-independent signaling that occurs through the cAR1 receptor (http://stke.sciencemag.org/cgi/cm/stkecm;CMP_11471). A ViewPoint published in the June 6, 2003 issue of Science accompanies the two Connection Maps. In addition, animators at Science helped design a movie depicting the signaling events that occur in response to cAMP (http://stke.sciencemag.org/cgi/content/full/sigtrans;CMP_7918/DC1). To view the Connection Maps, all that is required is free registration either to Science Online or to the STKE. To access the Viewpoint, you must either be a AAAS member, have an individual subscription to STKE, or be accessing STKE through an institutional site license. Please see http://www.sciencemag.org/subscriptions/accessinfo-stke.dtl for more information.

The pathways were based on an intense review of the literature. However, since we are far from perfect, we might have overseen/oversimplified some aspects. We encourage the Dictyostelium community to access the pathways and forward any comments to either of us. We have access to the database and intend to continuously update it. We hope that this will add to the many tools the community possesses and that it will become a central arena for discussion about signaling pathways.

Alan Kimmel and Carole Parent

Signal transduction events leading to the spatial and temporal regulation of chemotaxis. A simplifed model depicting the major effectors (in blue) activated by cAMP receptors. Receptor stimulation ultimately gives rise to actin polymerization at the front for propulsion, myosin II assembly at the sides to suppress lateral pseudopod formation, and myosin II assembly also at the rear for retraction. The molecular details leading to the regulation of PTEN, PI3K, GC, and AC by Gßy are still being elucidated. Ras appears to be directly required for the activation of PI3K, although its role in PI3K localization is not known. Green arrows, enzyme activation; blue arrows, membrane localization; red arrows, product relation; dashed arrow, complex regulations that have yet to be fully established. (Image, provided by S. Shu and E. Korn) Myosin heavy chain (MHC) and actin fiament distribution in polarized cells. Cells expressing MHC fused with green fluorescent protein (GFP) were fully differentiated, fixed, and stained with tetramethyl rhodamine isothiocyanate (TRITC)-phalloidin. The MHC-GFP posterior signal appears in green, and the actin filaments in red. Bar, 10 µm.

Reprinted with permission from AR Kimmel and CA Parent, Science 300:1525-1527 (6 Jun 2003). Copyright © 2003 American Association for the Advancement of Science [http://www.sciencemag.org].