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Streptomyces natalensis programmed cell death and morphological differentiation are dependent on oxidative stress.

Beites T, Oliveira P, Rioseras B, Pires SD, Oliveira R, Tamagnini P, Moradas-Ferreira P, Manteca Á, Mendes MV - Sci Rep (2015)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus

Transcription analysis by RT-PCR of genes associated with the development program in S. natalensis wild-type, ΔkatA1 and ΔcatR strains.The used pair of primers and annealing temperatures are presented in Supplementary Table S2. The amplicons are the result of 30 PCR cycles. Transcription profiles are representative of three independent experiments.
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f2: Transcription analysis by RT-PCR of genes associated with the development program in S. natalensis wild-type, ΔkatA1 and ΔcatR strains.The used pair of primers and annealing temperatures are presented in Supplementary Table S2. The amplicons are the result of 30 PCR cycles. Transcription profiles are representative of three independent experiments.

Mentions: To further characterize the morphological impairment phenotype displayed by the mutant strains in solid medium we examined the transcription of genes associated with the onset of aerial mycelium (bldD, bldH and bldN) and formation of the aerial hyphae hydrophobic coat (ramS, ramC, chpC, and rdlA) at 24 h (vegetative growth), 48 h and 72 h (formation of aerial mycelium) (Fig. 2). No major differences were observed for bldD expression under the conditions tested. However, ΔkatA1 strain displayed a progressive decrease of bldH transcript levels in contrast with the wild-type and ΔcatR strains that presented a constitutive expression. Interestingly, the transcription of ramC and ramS was down-regulated in both mutant strains when compared to the wild-type, pointing out to a deficient SapB production, particularly in ΔkatA1 strain. In addition, the poor correlation between the transcription of bldH and ram genes, especially in ΔcatR strain, suggests the presence of additional players in the regulation of SapB biosynthesis in S. natalensis.


Streptomyces natalensis programmed cell death and morphological differentiation are dependent on oxidative stress.

Beites T, Oliveira P, Rioseras B, Pires SD, Oliveira R, Tamagnini P, Moradas-Ferreira P, Manteca Á, Mendes MV - Sci Rep (2015)

Transcription analysis by RT-PCR of genes associated with the development program in S. natalensis wild-type, ΔkatA1 and ΔcatR strains.The used pair of primers and annealing temperatures are presented in Supplementary Table S2. The amplicons are the result of 30 PCR cycles. Transcription profiles are representative of three independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4530454&req=5

f2: Transcription analysis by RT-PCR of genes associated with the development program in S. natalensis wild-type, ΔkatA1 and ΔcatR strains.The used pair of primers and annealing temperatures are presented in Supplementary Table S2. The amplicons are the result of 30 PCR cycles. Transcription profiles are representative of three independent experiments.
Mentions: To further characterize the morphological impairment phenotype displayed by the mutant strains in solid medium we examined the transcription of genes associated with the onset of aerial mycelium (bldD, bldH and bldN) and formation of the aerial hyphae hydrophobic coat (ramS, ramC, chpC, and rdlA) at 24 h (vegetative growth), 48 h and 72 h (formation of aerial mycelium) (Fig. 2). No major differences were observed for bldD expression under the conditions tested. However, ΔkatA1 strain displayed a progressive decrease of bldH transcript levels in contrast with the wild-type and ΔcatR strains that presented a constitutive expression. Interestingly, the transcription of ramC and ramS was down-regulated in both mutant strains when compared to the wild-type, pointing out to a deficient SapB production, particularly in ΔkatA1 strain. In addition, the poor correlation between the transcription of bldH and ram genes, especially in ΔcatR strain, suggests the presence of additional players in the regulation of SapB biosynthesis in S. natalensis.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus