RRC ID 29073
Author Zhukovskaya NV, Fukuzawa M, Yamada Y, Araki T, Williams JG.
Title The Dictyostelium bZIP transcription factor DimB regulates prestalk-specific gene expression.
Journal Development
Abstract The ecmA gene is specifically expressed in prestalk cells and its transcription is induced by the chlorinated hexaphenone DIF-1. We have purified a novel bZIP transcription factor, DimB, by affinity chromatography on two spatially separated ecmA promoter fragments. Mutagenesis of the cap-site proximal DimB-binding site (the -510 site) greatly decreases ecmA expression in the pstO cells, which comprise the rear half of the prestalk zone, and also in the Anterior-Like Cells, which lie scattered throughout the prespore region. However, DimB is not essential for normal expression of the ecmA gene, instead it spatially limits its expression; ecmA is relatively highly expressed in the subset of prestalk cells that coats the prestalk zone, but in slugs of a DimB-null strain, ecmA is highly expressed throughout the prestalk zone. Because the -510 site is required for correct ecmA expression, we posit a separate activator protein that competes with DimB for binding to the -510 site. DimB rapidly accumulates in the nucleus when cells are exposed to DIF-1, and ChIP analysis shows that, in the presence of extracellular cAMP, DIF-1 causes DimB to associate with the ecmA promoter in vivo. Thus, DIF-1 regulates DimB activity to generate a gradient of ecmA expression in the prestalk zone of the slug.
Volume 133(3)
Pages 439-48
Published 2006-2-1
DOI 10.1242/dev.02190
PII dev.02190
PMID 16396914
MeSH Amino Acid Sequence Animals Basic-Leucine Zipper Transcription Factors / genetics Basic-Leucine Zipper Transcription Factors / metabolism* Binding Sites Cell Differentiation Cell Nucleus / metabolism Cyclic AMP / metabolism Dictyostelium / cytology Dictyostelium / genetics Dictyostelium / metabolism* Extracellular Matrix Proteins / genetics Extracellular Matrix Proteins / metabolism* Gene Expression Regulation* Hexanones / metabolism Molecular Sequence Data Morphogenesis / physiology Point Mutation Promoter Regions, Genetic Protozoan Proteins / genetics Protozoan Proteins / metabolism* Sequence Alignment
IF 5.611
Times Cited 48
Cellular slime molds S90379