Repression of Antibiotic Production and Sporulation in Streptomyces coelicolor by Overexpression of a TetR Family Transcriptional Regulator
| Autor: | Catherine Esnault, Delin Xu, Nicolas Seghezzi, Marie-Joelle Virolle |
|---|---|
| Přispěvatelé: | Institut de génétique et microbiologie [Orsay] (IGM), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Biologie des Bactéries pathogènes à Gram-positif - Biology of Gram-Positive Pathogens, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), This work was supported by the Université Paris Sud 11, the PRES UniverSud Paris, and the CNRS., Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Transcription
Genetic [SDV]Life Sciences [q-bio] Mutant Gene Expression Applied Microbiology and Biotechnology MESH: Recombinant Proteins chemistry.chemical_compound Gene Knockout Techniques Suppression Genetic Gene Expression Regulation Fungal Transcriptional regulation DNA Fungal Promoter Regions Genetic MESH: Suppression Genetic MESH: Gene Knockout Techniques 2. Zero hunger Genetics Spores Bacterial 0303 health sciences Ecology biology Streptomyces coelicolor Recombinant Proteins Anti-Bacterial Agents [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology MESH: Spores Bacteria MESH: Gene Expression Regulation Fungal Biotechnology Protein Binding MESH: Gene Expression MESH: Streptomyces lividans Genetics and Molecular Biology Actinorhodin 03 medical and health sciences MESH: Anti-Bacterial Agents MESH: Promoter Regions Genetic MESH: Protein Binding TetR Gene 030304 developmental biology 030306 microbiology MESH: Transcription Genetic fungi Wild type MESH: Streptomyces coelicolor biology.organism_classification Methylenomycin Repressor Proteins MESH: DNA Fungal chemistry Streptomyces lividans Food Science |
| Zdroj: | Applied and Environmental Microbiology Applied and Environmental Microbiology, 2010, 76 (23), pp.7741-7753. ⟨10.1128/AEM.00819-10⟩ Applied and Environmental Microbiology, American Society for Microbiology, 2010, 76 (23), pp.7741-7753. ⟨10.1128/AEM.00819-10⟩ |
| ISSN: | 0099-2240 1098-5336 |
| Popis: | The development of the Gram-positive genus Streptomyces is characterized by a complex morphological differentiation process thought to be triggered by conditions of nutritional limitation that often correlate with high cell density (41). This process includes the arising of an aerial mycelium from the vegetative mycelium and then the differentiation of the tips of the aerial hyphae into spores (10, 15). This process is coupled to a metabolic differentiation that correlates with the production of a wide range of pharmaceutically important secondary metabolites, including antibacterial, anticancer, and immunosuppressive drugs (8, 10). The genes responsible for the biosynthesis of these secondary metabolites are clustered in the genome and coordinately regulated by pathway-specific transcriptional regulators (1, 4, 18, 19, 62, 70). The expression of these specific regulators linked to the biosynthetic pathways is directly or indirectly controlled either by positive pleiotropic regulators, such as AfsR2 (69), AfsS (29), AtrA (65), PtpA (67), PkaD (68), and the two-component systems AfsK/AfsR (66) and EcrA1/EcrA2 (39), by negative regulators, including the two-component systems AbsA1/AbsA2 (44), PhoR/PhoP (55), and CutR/CutS (9), or by enzymatic systems, such as Ppk (16). The pleiotropic regulators, thought to sense a variety of extracellular or intracellular signals related to nutriment availability, cell crowding, or energy shortage, are necessary to trigger the necessary metabolic adjustments to adapt to these conditions (27, 43), whereas the ppk gene is thought to act as an ATP-regenerating enzyme (54). Streptomyces coelicolor A3(2) is usually used as the reference strain to study morphological and metabolic differentiation in relation with antibiotic biosynthesis (10, 15). S. coelicolor has long been known to produce four major antibiotics, actinorhodin (ACT) (40), undecylprodigiosin (RED) (13), methylenomycin (MMY) (36), and calcium-dependent antibiotic (CDA) (21), and recently, two novel ones were characterized, CPK, a putative type I polyketide (17, 50), and albaflavenone, a sesquiterpene antibiotic (72). ACT is a secondary metabolite of the polyketide family that is strongly produced by S. coelicolor but only weakly produced by its close relative, Streptomyces lividans. However, S. lividans has the genetic capability to produce this compound since the weak production of ACT could be stimulated by various genetic manipulations that include the overexpression of the pathway-specific activator gene actII-ORF4 (7), the afsR and afsR2 (now afsS) genes (35), the rep gene (42), and the phosphotyrosine protein phosphatase-encoding gene ptpA (67). The inactivation of other genes, such as ppk (11), or mutations in the rpoB gene (25) or in the ribosomal protein S12 (23) are also leading to an enhancement of ACT production, indicating that ACT production was subjected to complex positive and negative controls. Furthermore, the extracellular addition of the signal molecule S-adenosylmethionine (34) or of ATP (38) or the replacement of glucose by glycerol in a minimal medium (35) was also shown to enhance ACT production in S. lividans. However, a systemic understanding of the regulation of antibiotic biosynthesis and in particular of the molecular basis of the very different abilities of S. lividans and S. coelicolor to produce ACT is still lacking. In order to tackle this question, we hypothesized that a major negative regulator of ACT production might be present in S. lividans but absent or nonfunctional in S. coelicolor. In an attempt to get this putative negative regulator, a genomic library of S. lividans DNA was constructed into the high-copy-number replicative plasmid pIJ702 (33) and introduced into S. coelicolor. An unique white transformant (ACT−) was obtained. This phenotype was shown to result from the overexpression of a regulator of the TetR family (equivalent to SCO3201 of S. coelicolor). The consequences of the overexpression and of the deletion of SCO3201 on the metabolic and morphological differentiation processes of S. coelicolor and S. lividans (wild type [wt] and ppk mutant) were assessed. The ability of SCO3201 to negatively regulate its own transcription was demonstrated by both in vitro and in vivo approaches, and the sequence of its operator site located in its own promoter region was determined. Sequences related to the SCO3201 operator site were found in the promoter region of scbA, a gene encoding a butyrolactone-synthesizing enzyme (61). These sequences were shown to be part of the binding site of ScbR, a TetR family regulator, positively controlling scbA expression, as SCO3201 does when overexpressed. |
| Databáze: | OpenAIRE |
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