In times of plenty, the uni-cellular slime mold Dictyostelium discoideum leads a solitary life munching on bacteria littering the forest floor. But these simple creatures can perform heroic developmental acts: when the bacterial food supply dries up, Dictyostelium amebas band together with their neighbors and form a multi-cellular tower designed to save the children.
In a forthcoming study in Nature Chemical Biology, investigators at the Salk Institute for Biological Studies and the Medical Research Council of Molecular Biology (MRC) in Cambridge, England, use traditional and computer-based methods to show how Dictyostelium synthesizes the chemical signal called DIF-1, short for Differentiation Inducing Factor, required for this developmental transformation.
The collaboration, explains co-senior author Joe Noel, Ph.D, a Howard Hughes Medical Institute investigator at Salk, "shows the power of a combined approach involving bioinformatics, enzymology, structural biology and genetics to get at the heart of why organisms exploit natural chemicals to survive and prosper in challenging ecosystems."
When slime molds starve, they collectively form a multicellular slug-like creature that locomotes en masse to a warm spot. There, in response to the DIF-1 signal, slugs literally stand up and their cells metamorphose into either a column of stalk cells or next-generation spore cells, which perch atop the column waiting for food supplies to be restored.
Noel and Michael Austin, Ph.D., a postdoctoral fellow in Noel's lab and co-lead author of the study, have an ongoing interest in the biosynthesis of diverse plant and microbial polyketides by enzymes known as type III PKSs. Plants make polyketide natural products such as flavonoids and stilbenes for use as sunscreens, antibiotics, flower pigments, and anti-oxidants. Explains Austin, "Plant polyketides are also increasingly recognized to have significant benefits in the human diet as heal
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Contact: Gina Kirchweger
kirchweger@salk.edu
858-453-4100 x1340
Salk Institute
13-Aug-2006