Response regulator heterodimer formation controls a key stage in Streptomyces development
| Autor: | Matthew J. Bush, Mahmoud M. Al-Bassam, Mark J. Buttner, Govind Chandra, Maureen J. Bibb |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Cancer Research
lcsh:QH426-470 Hyphae Gene Expression Sigma Factor DNA-binding protein Streptomyces Biochemistry Microbiology Bacterial Proteins Cell Signaling Sigma factor DNA-binding proteins Genetics Gene Regulation Promoter Regions Genetic Molecular Biology Gene Genetics (clinical) Ecology Evolution Behavior and Systematics Regulation of gene expression Spores Bacterial biology Biology and life sciences Mechanisms of Signal Transduction Proteins Promoter Gene Expression Regulation Bacterial Cell Biology biology.organism_classification Regulatory Proteins Response regulator lcsh:Genetics Regulon Transcriptional Signaling Protein Multimerization Transcription Activators Signal Transduction Research Article Transcription Factors |
| Zdroj: | PLoS Genetics PLoS Genetics, Vol 10, Iss 8, p e1004554 (2014) |
| ISSN: | 1553-7404 |
| Popis: | The orphan, atypical response regulators BldM and WhiI each play critical roles in Streptomyces differentiation. BldM is required for the formation of aerial hyphae, and WhiI is required for the differentiation of these reproductive structures into mature spores. To gain insight into BldM function, we defined the genome-wide BldM regulon using ChIP-Seq and transcriptional profiling. BldM target genes clustered into two groups based on their whi gene dependency. Expression of Group I genes depended on bldM but was independent of all the whi genes, and biochemical experiments showed that Group I promoters were controlled by a BldM homodimer. In contrast, Group II genes were expressed later than Group I genes and their expression depended not only on bldM but also on whiI and whiG (encoding the sigma factor that activates whiI). Additional ChIP-Seq analysis showed that BldM Group II genes were also direct targets of WhiI and that in vivo binding of WhiI to these promoters depended on BldM and vice versa. We go on to demonstrate that BldM and WhiI form a functional heterodimer that controls Group II promoters, serving to integrate signals from two distinct developmental pathways. The BldM-WhiI system thus exemplifies the potential of response regulator heterodimer formation as a mechanism to expand the signaling capabilities of bacterial cells. Author Summary Two-component signal transduction systems are a primary means of regulating gene expression in bacteria. Recognizing the diversity of mechanisms associated with these systems is therefore critical to understanding the full signaling potential of bacterial cells. We have analyzed the behavior of two orphan, atypical response regulators that play key roles in controlling morphological differentiation in the filamentous bacteria Streptomyces-BldM and WhiI. We demonstrate that BldM activates its Group I target promoters as a homodimer, but that it subsequently activates its Group II target promoters by forming a functional heterodimer with WhiI. BldM-WhiI heterodimer formation thus represents an unusual mechanism for the coactivation of target genes and the integration of regulatory signals at promoters, enhancing the known repertoire of signaling capabilities associated with two-component systems. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|