RRC ID 6724
Author Anjard C, Loomis WF.
Title Peptide signaling during terminal differentiation of Dictyostelium.
Journal Proc. Natl. Acad. Sci. U.S.A.
Abstract A wide variety of mechanisms have evolved for intercellular communication in metazoans, but some of the signaling molecules were already used in their predecessors. The social amoeba, Dictyostelium discoideum, is known to use peptides to trigger sporulation within fruiting bodies, but their sequences have not been defined. We found that the peptide signal spore differentiation factor 2 (SDF-2) is processed from acyl-CoA binding protein, AcbA. The mammalian homolog of AcbA is processed to diazepam binding inhibitor that binds to the GABA(A) receptor in the brain and to peripheral 1,4 benzodiazepine receptors. Although Dictyostelium has neither GABA(A) nor peripheral-type benzodiazepine receptors, we find that both a diazepam binding inhibitor peptide and diazepam (Valium) can mimic SDF-2 in a Dictyostelium bioassay. Mutants lacking AcbA sporulate well only when developed in chimeras with WT cells. Using a yeast system we show that ligand binding to the SDF-2 receptor histidine kinase, DhkA, inhibits phosphorelay, which can account for its ability to induce rapid sporulation.
Volume 102(21)
Pages 7607-11
Published 2005-5-24
DOI 10.1073/pnas.0501820102
PII 0501820102
PMID 15897458
PMC PMC1140433
MeSH Amino Acid Sequence Animals Biological Assay Carbon Radioisotopes Cloning, Molecular Diazepam / metabolism Diazepam Binding Inhibitor / metabolism* Dictyostelium / metabolism Dictyostelium / physiology* Genetic Vectors Ligands Molecular Sequence Data Mutation / genetics Peptides / metabolism* Protein Kinases / genetics Protein Kinases / metabolism Reproduction / physiology Signal Transduction / physiology* Yeasts
IF 9.504
Times Cited 54
Cellular slime molds G01682