title: DIF-1 regulates Dictyostelium basal disc differentiation by inducing the nuclear accumulation of a bZIP transcription factor.
abstract: Exposure of monolayer Dictyostelium cells to the signalling polyketide DIF-1 causes DimB, a bZIPtranscription factor, to accumulate in the nucleus where it induces prestalk gene expression. Here we analyse DimB signalling during normal development. In slugs DimB is specifically nuclear enriched in the pstB cells; a cluster of vital dye-staining cells located on the ventral surface of the posterior, prespore region. PstB cells move at culmination, to form the lower cup and the outer basal disc of the fruiting body, and DimB retains a high nuclear concentration in both these tissues. In a dimB null (dimB-) strain there are very few pstB or lower cup cells, as detected by neutral red staining, and it is known that the outer basal disc is absent or much reduced. In the dimB- strain ecmB, a marker of pstB differentiation, is not DIF inducible. Furthermore, ChIP analysis shows that DimB binds to the ecmB promoter in DIF-induced cells. These results suggest that the differentiation of pstB cells is caused by a high perceived level of DIF-1 signalling, leading to nuclear localization of DimB and direct activation of cell type-specific gene expression.
authors: College of Life Sciences, Welcome Trust Building, University of Dundee, Dow St., Dundee, UK.
authors: Yoko
authors: Y
authors: Yamada
authors: Beatriz
authors: B
authors: Nuñez-Corcuera
authors: Jeffrey G
authors: JG
authors: Williams
mesh_terms: D000818:Animals; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D004023:Dictyostelium / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006588:Hexanones / Q000494:pharmacology*; D018613:Microscopy, Confocal; D009068:Movement / Q000502:physiology; D009154:Mutation; D011485:Protein Binding; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D016326:Extracellular Matrix Proteins; D006588:Hexanones; D015800:Protozoan Proteins; C069214:ecmB protein, Dictyostelium; C053433:1-((3,5-dichloro)-2,6-dihydroxy-4-methoxyphenyl)-1-hexanone; D049452:Green Fluorescent Proteins