Negative transcriptional regulation in the Caulobacter flagellar hierarchy.
- 1 September 1989
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 86 (17), 6656-6660
- https://doi.org/10.1073/pnas.86.17.6656
Abstract
The Caulobacter crescentus flagellum is formed at a specific time in the cell cycle and its assembly requires the ordered expression of a large number of genes. These genes are controlled in a positive trans-acting hierarchy that reflects the order of assembly of the flagellum. Using plasmids carrying transcriptional fusions of either a neo or a lux reporter gene to the promoters of three flagellar genes representing different ranks in the hierarchy (the hook operon, a basal body gene flbN, and the flaO gene), we have measured the level of chimeric gene expression in 13 flagellar mutant backgrounds. Mutants in the hook operon or in basal body genes caused overproduction of both hook operon and basal body gene chimeric mRNAs, suggesting that negative regulation is superimposed on the positive trans-acting control for these early events in the flagellar hierarchy. Mutants in the structural genes and in genes involved in flagellar assembly had no effect on flaO expression, placing the flaO gene near the top of the hierarchy. However, flaO expression appears to be under negative control by two regulatory genes flaS and flaW. Negative control, as a response to the completion of specific steps in the assembly process, may be an important mechanism used by the cell to turn off flagellar gene expression once the gene product is no longer needed.This publication has 37 references indexed in Scilit:
- A set of positively regulated flagellar gene promoters in Caulobacter crescentus with sequence homology to the nif gene promoters of Klebsiella pneumoniaeJournal of Molecular Biology, 1987
- Identification of a gene cluster involved in flagellar basal body biogenesis in Caulobacter crescentusJournal of Molecular Biology, 1987
- Cascade regulation of Caulobacter flagellar and chemotaxis genesJournal of Molecular Biology, 1987
- Characterization of the proteins of the Caulobacter crescentus flagellar filament. Peptide analysis and filament organization.Journal of Biological Chemistry, 1982
- Sequential polymerization of flagellin A and flagellin B into Caulobacter flagellaJournal of Molecular Biology, 1981
- Three-dimensional reconstruction of the flagellar hook from Caulobacter crescentusJournal of Molecular Biology, 1981
- Regulation of periodic protein synthesis in the cell cycle: Control of initiation and termination of flagellar gene expressionCell, 1981
- Broad host range DNA cloning system for gram-negative bacteria: construction of a gene bank of Rhizobium meliloti.Proceedings of the National Academy of Sciences, 1980
- Temporal control of the cell cycle in Caulobacter crescentus: Roles of DNA chain elongation and completionJournal of Molecular Biology, 1980
- Generation of asymmetry during development. Segregation of type-specific proteins in Caulobacter.The Journal of cell biology, 1979