title: Streptomyces natalensis programmed cell death and morphological differentiation are dependent on oxidative stress.
abstract: Streptomyces are aerobic Gram-positive bacteria characterized by a complex life cycle that includes hyphae differentiation and spore formation. Morphological differentiation is triggered by stressful conditions and takes place in a pro-oxidant environment, which sets the basis for an involvement of the oxidative stress response in this cellular process. Characterization of the phenotypic traits of Streptomyces natalensis ΔkatA1 (mono-functional catalase) and ΔcatR (Fur-like repressor of katA1 expression) strains in solid medium revealed that both mutants had an impaired morphological development process. The sub-lethal oxidative stress caused by the absence of KatA1 resulted in the formation of a highly proliferative and undifferentiated vegetative mycelium, whereas de-repression of CatR regulon, from which KatA1 is the only known representative, resulted in the formation of scarce aerial mycelium. Both mutant strains had the transcription of genes associated with aerial mycelium formation and biosynthesis of the hyphae hydrophobic layer down-regulated. The first round of the programmed cell death (PCD) was inhibited in both strains which caused the prevalence of the transient primary mycelium (MI) over secondary mycelium (MII). Our data shows that the first round of PCD and morphological differentiation in S. natalensis is dependent on oxidative stress in the right amount at the right time.
authors.affiliation: 1] i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal [2] IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
authors.forename: Tiago
authors.initials: T
authors.lastname: Beites
authors.affiliation: 1] i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal [2] IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Oliveira
authors.affiliation: rea de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Rioseras
authors.affiliation: 1] i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal [2] IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal [3] ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal.
authors.forename: Sílvia D S
authors.initials: SD
authors.lastname: Pires
authors.affiliation: 1] i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal [2] IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
authors.forename: Rute
authors.initials: R
authors.lastname: Oliveira
authors.affiliation: 1] i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal [2] IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal [3] Faculdade de Ciências, Departamento de Biologia, Universidade do Porto, Porto, Portugal.
authors.forename: Paula
authors.initials: P
authors.lastname: Tamagnini
authors.affiliation: 1] i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal [2] IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal [3] ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Moradas-Ferreira
authors.affiliation: rea de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Manteca
authors.affiliation: 1] i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal [2] IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
authors.forename: Marta V
authors.initials: MV
authors.lastname: Mendes
mesh_terms: D017209:Apoptosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D015180:Electrophoresis, Gel, Two-Dimensional; D016680:Genome, Bacterial; D059014:High-Throughput Nucleotide Sequencing; D050296:Microbial Viability; D018613:Microscopy, Confocal; D025282:Mycelium / Q000378:metabolism; D018384:Oxidative Stress / Q000235:genetics; D016133:Polymerase Chain Reaction; D020543:Proteome / Q000032:analysis; D013171:Spores, Bacterial; D013302:Streptomyces / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D020543:Proteome; D014157:Transcription Factors; C086843:CatR protein, bacteria; D002374:Catalase