title: Pleiotropic effect of a null mutation in the cvn1 conservon of Streptomyces coelicolor A3(2).
abstract: The conservon (cvn) of Streptomyces species encodes a putative membrane-associated signaling complex resembling the eukaryotic G-protein-coupled receptor (GPCR) system. The cvn is widely distributed in the genomes of Actinobacteria, indicating that it plays an important role in this group of bacterial species; however, the exact role of this regulatory system is hitherto poorly understood. In the present study, we generated null mutants for all 13 copies of the cvn operon distributed in the genome of Streptomyces coelicolor A3(2) and observed that the aerial mycelium formation and antibiotic production in a cvn1 mutant were markedly impaired. The cvn1 mutant formed aerial mycelium and produced actinorhodin and undecylprodigiosin at remarkably low levels on solid medium containing 1-2% glucose and at high levels on medium containing 6-10% glucose. The same phenotype as this was observed with a cvnA1 mutant. Transcriptional analyses revealed that the expression of sigU encoding a vegetative sigma factor was upregulated in the cvn1 mutant. Overexpression of rsuA encoding the σ(SigU) antagonist restored aerial mycelium formation and pigment production in the cvn1 mutant, suggesting that the developmental defect in the cvn1 mutant is based on the high expression level of sigU.
authors.affiliation: Life Science Research Center, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa 252-0880, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Takano
authors.forename: Kazuki
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Beppu
authors.forename: Kenji
authors.initials: K
authors.lastname: Ueda
mesh_terms: D000880:Anthraquinones / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D058685:Genetic Pleiotropy; D016680:Genome, Bacterial / Q000235:genetics; D005947:Glucose / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D025282:Mycelium / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D009876:Operon; D010641:Phenotype; D011353:Prodigiosin / Q000031:analogs & derivatives / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D048372:Streptomyces coelicolor / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D000095622:Benzoisochromanequinones
chemical_list: D000880:Anthraquinones; D001426:Bacterial Proteins; D005947:Glucose; D011353:Prodigiosin; C047347:undecylprodigiosin; C013390:actinorhodin; D000095622:Benzoisochromanequinones