scholarly journals Prodiginines Postpone the Onset of Sporulation in Streptomyces coelicolor

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 847
Author(s):  
Elodie Tenconi ◽  
Matthew Traxler ◽  
Déborah Tellatin ◽  
Gilles P. van Wezel ◽  
Sébastien Rigali
Keyword(s):  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Mature Spore ◽  
Aerial Mycelium ◽  
Protective Role ◽  
Transcriptional Analysis ◽  
Bioactive Natural Products ◽  
Intracellular Content ◽  
Σ Factor ◽  
Mediated Reduction

Bioactive natural products are typically secreted by the producer strain. Besides that, this allows the targeting of competitors, also filling a protective role, reducing the chance of self-killing. Surprisingly, DNA-degrading and membrane damaging prodiginines (PdGs) are only produced intracellularly, and are required for the onset of the second round of programmed cell death (PCD) in Streptomyces coelicolor. In this work, we investigated the influence of PdGs on the timing of the morphological differentiation of S. coelicolor. The deletion of the transcriptional activator gene redD that activates the red cluster for PdGs or nutrient-mediated reduction of PdG synthesis both resulted in the precocious appearance of mature spore chains. Transcriptional analysis revealed an accelerated expression of key developmental genes in the redD null mutant, including bldN for the developmental σ factor BldN which is essential for aerial mycelium formation. In contrast, PdG overproduction due to the enhanced copy number of redD resulted in a delay or block in sporulation. In addition, confocal fluorescence microscopy revealed that the earliest aerial hyphae do not produce PdGs. This suggests that filaments that eventually differentiate into spore chains and are hence required for survival of the colony, are excluded from the second round of PCD induced by PdGs. We propose that one of the roles of PdGs would be to delay the entrance of S. coelicolor into the dormancy state (sporulation) by inducing the leakage of the intracellular content of dying filaments thereby providing nutrients for the survivors.

scholarly journals Regulation of Sporangium Formation by BldD in the Rare Actinomycete Actinoplanes missouriensis

2017 ◽  
Vol 199 (12) ◽  
Author(s):  
Yoshihiro Mouri ◽  
Kenji Konishi ◽  
Azusa Fujita ◽  
Takeaki Tezuka ◽  
Yasuo Ohnishi
Keyword(s):  
Vegetative Growth ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Transcriptional Regulator ◽  
Saccharopolyspora Erythraea ◽  
Transcriptional Analysis ◽  
Morphological Development ◽  
Sequencing Analysis ◽  
Content Type ◽  
Biological Studies

ABSTRACT The rare actinomycete Actinoplanes missouriensis forms sporangia, including hundreds of flagellated spores that start swimming as zoospores after their release. Under conditions suitable for vegetative growth, zoospores stop swimming and germinate. A comparative proteome analysis between zoospores and germinating cells identified 15 proteins that were produced in larger amounts in germinating cells. They include an orthologue of BldD (herein named AmBldD [BldD of A. missouriensis]), which is a transcriptional regulator involved in morphological development and secondary metabolism in Streptomyces. AmBldD was detected in mycelia during vegetative growth but was barely detected in mycelia during the sporangium-forming phase, in spite of the constant transcription of AmbldD throughout growth. An AmbldD mutant started to form sporangia much earlier than the wild-type strain, and the resulting sporangia were morphologically abnormal. Recombinant AmBldD bound a palindromic sequence, the AmBldD box, located upstream from AmbldD. 3′,5′-Cyclic di-GMP significantly enhanced the in vitro DNA-binding ability of AmBldD. A chromatin immunoprecipitation-sequencing analysis and an in silico search for AmBldD boxes revealed that AmBldD bound 346 genomic loci that contained the 19-bp inverted repeat 5′-NN(G/A)TNACN(C/G)N(G/C)NGTNA(C/T)NN-3′ as the consensus AmBldD-binding sequence. The transcriptional analysis of 27 selected AmBldD target gene candidates indicated that AmBldD should repress 12 of the 27 genes, including bldM, ssgB, whiD, ddbA, and wblA orthologues. These genes are involved in morphological development in Streptomyces coelicolor A3(2). Thus, AmBldD is a global transcriptional regulator that seems to repress the transcription of tens of genes during vegetative growth, some of which are likely to be required for sporangium formation. IMPORTANCE The rare actinomycete Actinoplanes missouriensis undergoes complex morphological differentiation, including sporangium formation. However, almost no molecular biological studies have been conducted on this bacterium. BldD is a key global regulator involved in the morphological development of streptomycetes. BldD orthologues are highly conserved among sporulating actinomycetes, but no BldD orthologues, except one in Saccharopolyspora erythraea, have been studied outside the streptomycetes. Here, it was revealed that the BldD orthologue AmBldD is essential for normal developmental processes in A. missouriensis. The AmBldD regulon seems to be different from the BldD regulon in Streptomyces coelicolor A3(2), but they share four genes that are involved in morphological differentiation in S. coelicolor A3(2).

scholarly journals The Level of AdpA Directly Affects Expression of Developmental Genes in Streptomyces coelicolor

2011 ◽  
Vol 193 (22) ◽  
pp. 6358-6365 ◽  
Author(s):  
Marcin Wolański ◽  
Rafał Donczew ◽  
Agnieszka Kois-Ostrowska ◽  
Paweł Masiewicz ◽  
Dagmara Jakimowicz ◽  
...  
Keyword(s):  
Early Stage ◽  
Response Regulator ◽  
Streptomyces Coelicolor ◽  
Streptomyces Griseus ◽  
Morphological Differentiation ◽  
Aerial Mycelium ◽  
Content Type ◽  
Protein Functions

AdpA is a key regulator of morphological differentiation inStreptomyces. In contrast toStreptomyces griseus, relatively little is known about AdpA protein functions inStreptomyces coelicolor. Here, we report for the first time the translation accumulation profile of theS. coelicoloradpA(adpASc) gene; the level ofS. coelicolorAdpA (AdpASc) increased, reaching a maximum in the early stage of aerial mycelium formation (after 36 h), and remained relatively stable for the next several hours (48 to 60 h), and then the signal intensity decreased considerably. AdpAScspecifically binds theadpAScpromoter regionin vitroandin vivo, suggesting that its expression is autoregulated; surprisingly, in contrast toS. griseus, the protein presumably acts as a transcriptional activator. We also demonstrate a direct influence of AdpAScon the expression of several genes whose products play key roles in the differentiation ofS. coelicolor: STI, a protease inhibitor; RamR, an atypical response regulator that itself activates expression of the genes for a small modified peptide that is required for aerial growth; and ClpP1, an ATP-dependent protease. The diverse influence of AdpAScprotein on the expression of the analyzed genes presumably results mainly from different affinities of AdpAScprotein to individual promoters.

Extracellular Complementation and the Identification of Additional Genes Involved in Aerial Mycelium Formation in Streptomyces coelicolor

Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 569-584
Author(s):  
Justin R Nodwell ◽  
Melody Yang ◽  
David Kuo ◽  
Richard Losick
Keyword(s):  
Genetic Control ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Aerial Mycelium ◽  
The Other ◽  
Sporulation Medium ◽  
Aerial Hyphae ◽  
Mutant Strains ◽  
Colony Surface ◽  
Complementation Groups

Abstract Morphogenesis in the bacterium Streptomyces coelicolor involves the formation of a lawn of hair-like aerial hyphae on the colony surface that stands up in the air and differentiates into chains of spores. bld mutants are defective in the formation of this aerial mycelium and grow as smooth, hairless colonies. When certain pairs of bld mutants are grown close to one another on rich sporulation medium, they exhibit extracellular complementation such that one mutant restores aerial mycelium formation to the other. The extracellular complementation relationships of most of the previously isolated bld mutants placed them in a hierarchy of extracellular complementation groups. We have screened for further bld mutants with precautions intended to maximize the discovery of additional genes. Most of the 50 newly isolated mutant strains occupy one of three of the previously described positions in the hierarchy, behaving like bldK, bldC, or bldD mutants. We show that the mutations in some of the strains that behave like bldK are bldK alleles but that others fall in a cluster at a position on the chromosome distinct from that of any known bld gene. We name this locus bldL. By introducing cloned genes into the strains that exhibit bldC or bldD-like extracellular complementation phenotypes, we show that most of these strains are likely to contain mutations in genes other than bldC or bldD. These results indicate that the genetic control of aerial mycelium formation is more complex than previously recognized and support the idea that a high proportion of bld genes are directly or indirectly involved in the production of substances that are exchanged between cells during morphological differentiation.

scholarly journals Secreted-Protein Response to σU Activity in Streptomyces coelicolor

2007 ◽  
Vol 190 (3) ◽  
pp. 894-904 ◽  
Author(s):  
Nadria D. Gordon ◽  
Geri L. Ottaviano ◽  
Sarah E. Connell ◽  
Gregory V. Tobkin ◽  
Crystal H. Son ◽  
...  
Keyword(s):  
Sigma Factor ◽  
Fluorescent Protein ◽  
Cell Envelope ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Aerial Mycelium ◽  
Secreted Proteins ◽  
Wild Type ◽  
Extracellular Proteome ◽  
Peptide Mass

ABSTRACT The filamentous bacterium Streptomyces coelicolor forms an aerial mycelium as a prerequisite to sporulation, which occurs in the aerial hyphae. Uncontrolled activity of the extracytoplasmic function sigma factor σU blocks the process of aerial mycelium formation in this organism. Using a green fluorescent protein transcriptional reporter, we have demonstrated that sigU transcription is autoregulated. We have defined a σU-dependent promoter sequence and used this to identify 22 likely σU regulon members in the S. coelicolor genome. Since many of these genes encode probable secreted proteins, we characterized the extracellular proteome of a mutant with high σU activity caused by disruption of rsuA, the presumed cognate anti-sigma factor of σU. This mutant secreted a much greater quantity and diversity of proteins than the wild-type strain. Peptide mass fingerprinting was used to identify 79 proteins from the rsuA mutant culture supernatant. The most abundant species, SCO2217, SCO0930, and SCO2207, corresponded to secreted proteins or lipoproteins of unknown functions whose genes are in the proposed σU regulon. Several unique proteases were also detected in the extracellular proteome of the mutant, and the levels of the protease inhibitor SCO0762 were much reduced compared to those of the wild type. Consequently, extracellular protease activity was elevated about fourfold in the rsuA mutant. The functions of the proteins secreted as a result of σU activity may be important for combating cell envelope stress and modulating morphological differentiation in S. coelicolor.

scholarly journals Identification of a Gene Negatively Affecting Antibiotic Production and Morphological Differentiation in Streptomyces coelicolor A3(2)

2006 ◽  
Vol 188 (24) ◽  
pp. 8368-8375 ◽  
Author(s):  
Wencheng Li ◽  
Xin Ying ◽  
Yuzheng Guo ◽  
Zhen Yu ◽  
Xiufen Zhou ◽  
...  
Keyword(s):  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Regulatory Gene ◽  
Morphological Differentiation ◽  
Aerial Mycelium ◽  
Protein Domain ◽  
Chromosomal Dna ◽  
Reading Frame ◽  
Directed Mutation ◽  
In The Wild

ABSTRACT SC7A1 is a cosmid with an insert of chromosomal DNA from Streptomyces coelicolor A3(2). Its insertion into the chromosome of S. coelicolor strains caused a duplication of a segment of ca. 40 kb and delayed actinorhodin antibiotic production and sporulation, implying that SC7A1 carried a gene negatively affecting these processes. The subcloning of SC7A1 insert DNA resulted in the identification of the open reading frame SCO5582 as nsdA, a gene n egatively affecting S treptomyces d ifferentiation. The disruption of chromosomal nsdA caused the overproduction of spores and of three of four known S. coelicolor antibiotics of quite different chemical types. In at least one case (that of actinorhodin), this was correlated with premature expression of a pathway-specific regulatory gene (actII-orf4), implying that nsdA in the wild-type strain indirectly repressed the expression of the actinorhodin biosynthesis cluster. nsdA expression was up-regulated upon aerial mycelium initiation and was strongest in the aerial mycelium. NsdA has DUF921, a Streptomyces protein domain of unknown function and a conserved SXR site. A site-directed mutation (S458A) in this site in NsdA abolished its function. Blast searching showed that NsdA homologues are present in some Streptomyces genomes. Outside of streptomycetes, NsdA-like proteins have been found in several actinomycetes. The disruption of the nsdA-like gene SCO4114 had no obvious phenotypic effects on S. coelicolor. The nsdA orthologue SAV2652 in S. avermitilis could complement the S. coelicolor nsdA-null mutant phenotype.

scholarly journals Modulation of Actinorhodin Biosynthesis in Streptomyces lividans by Glucose Repression of afsR2 Gene Transcription

2001 ◽  
Vol 183 (7) ◽  
pp. 2198-2203 ◽  
Author(s):  
Eung-Soo Kim ◽  
Hee-Jeon Hong ◽  
Cha-Yong Choi ◽  
Stanley N. Cohen
Keyword(s):  
Carbon Source ◽  
Glucose Repression ◽  
Streptomyces Coelicolor ◽  
Bacterial Species ◽  
Morphological Differentiation ◽  
Aerial Mycelium ◽  
Biosynthetic Gene Cluster ◽  
Streptomyces Lividans ◽  
Deep Blue ◽  
Solid Media

ABSTRACT While the biosynthetic gene cluster encoding the pigmented antibiotic actinorhodin (ACT) is present in the two closely related bacterial species, Streptomyces lividans andStreptomyces coelicolor, it normally is expressed only inS. coelicolor—generating the deep-blue colonies responsible for the S. coelicolor name. However, multiple copies of the two regulatory genes, afsR andafsR2, activate ACT production in S. lividans, indicating that this streptomycete encodes a functional ACT biosynthetic pathway. Here we report that the occurrence of ACT biosynthesis in S. lividans is determined conditionally by the carbon source used for culture. We found that the growth ofS. lividans on solid media containing glucose prevents ACT production in this species by repressing the synthesis ofafsR2 mRNA; a shift to glycerol as the sole carbon source dramatically relieved this repression, leading to extensive ACT synthesis and obliterating this phenotypic distinction between S. lividans and S. coelicolor. Transcription from theafsR2 promoter during growth in glycerol was dependent onafsR gene function and was developmentally regulated, occurring specifically at the time of aerial mycelium formation and coinciding temporally with the onset of ACT production. In liquid media, where morphological differentiation does not occur, ACT production in the absence of glucose increased as S. lividans cells entered stationary phase, but unlike ACT biosynthesis on solid media, occurred by a mechanism that did not require either afsR or afsR2. Our results identify parallel medium-dependent pathways that regulate ACT biosynthesis in S. lividans and further demonstrate that the production of this antibiotic in S. lividans grown on agar can be modulated by carbon source through the regulation ofafsR2 mRNA synthesis.

scholarly journals Purification of an Extracellular Signaling Molecule Involved in Production of Aerial Mycelium by Streptomyces coelicolor

1998 ◽  
Vol 180 (5) ◽  
pp. 1334-1337 ◽  
Author(s):  
Justin R. Nodwell ◽  
Richard Losick
Keyword(s):  
Conditioned Medium ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Aerial Mycelium ◽  
Signaling Molecule ◽  
Extracellular Signaling ◽  
Import System

ABSTRACT We have extensively purified a factor from conditioned medium that restores aerial mycelium formation to a mutant of Streptomyces coelicolor that is defective in morphological differentiation. Response to this factor is shown to depend on the presence of the BldK oligopeptide import system. We suggest that this substance acts at the first step in a putative cascade of developmental regulatory signals.

scholarly journals Novel Genes That Influence Development in Streptomyces coelicolor

2004 ◽  
Vol 186 (11) ◽  
pp. 3570-3577 ◽  
Author(s):  
Amy M. Gehring ◽  
Stephanie T. Wang ◽  
Daniel B. Kearns ◽  
Narie Yoo Storer ◽  
Richard Losick
Keyword(s):  
Soil Bacteria ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Aerial Mycelium ◽  
Colony Growth ◽  
Methionine Synthase ◽  
Regulatory Proteins ◽  
Methionine Biosynthesis ◽  
Acyl Coenzyme A

ABSTRACT Filamentous soil bacteria of the genus Streptomyces carry out complex developmental cycles that result in sporulation and production of numerous secondary metabolites with pharmaceutically important activities. To further characterize the molecular basis of these developmental events, we screened for mutants of Streptomyces coelicolor that exhibit aberrant morphological differentiation and/or secondary metabolite production. On the basis of this screening analysis and the subsequent complementation analysis of the mutants obtained we assigned developmental roles to a gene involved in methionine biosynthesis (metH) and two previously uncharacterized genes (SCO6938 and SCO2525) and we reidentified two previously described developmental genes (bldA and bldM). In contrast to most previously studied genes involved in development, the genes newly identified in the present study all appear to encode biosynthetic enzymes instead of regulatory proteins. The MetH methionine synthase appears to be required for conversion of aerial hyphae into chains of spores, SCO6938 is a probable acyl coenzyme A dehydrogenase that contributes to the proper timing of aerial mycelium formation and antibiotic production, and SCO2525 is a putative methyltransferase that influences various aspects of colony growth and development.

scholarly journals RNA Polymerase Sigma Factor That Blocks Morphological Differentiation by Streptomyces coelicolor

2001 ◽  
Vol 183 (20) ◽  
pp. 5991-5996 ◽  
Author(s):  
Amy M. Gehring ◽  
Narie J. Yoo ◽  
Richard Losick
Keyword(s):  
Rna Polymerase ◽  
Sigma Factor ◽  
Insertional Mutagenesis ◽  
Early Stage ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Aerial Mycelium ◽  
Growth Defect ◽  
Insertion Mutant

ABSTRACT The filamentous bacterium Streptomyces coelicolorundergoes a complicated process of morphological differentiation that begins with the formation of an aerial mycelium and culminates in sporulation. Genes required for the initiation of aerial mycelium formation have been termed bld (bald), describing the smooth, undifferentiated colonies of mutant strains. By using an insertional mutagenesis protocol that relies on in vitro transposition, we have isolated a bld mutant harboring an insertion in a previously uncharacterized gene, SCE59.12c, renamed here rsuA. The insertion mutant exhibited no measurable growth defect but failed to produce an aerial mycelium and showed a significant delay in the production of the polyketide antibiotic actinorhodin. The rsuA gene encodes an apparent anti-sigma factor and is located immediately downstream ofSCE59.13c, renamed here sigU, whose product is inferred to be a member of the extracytoplasmic function subfamily of RNA polymerase sigma factors. The absence ofrsuA in a strain that contained sigUcaused a block in development, and the overexpression ofsigU in an otherwise wild-type strain caused a delay in aerial mycelium formation. However, a strain in which bothrsuA and sigU had been deleted was able to undergo morphological differentiation normally. We conclude that thersuA-encoded anti-sigma factor is responsible for antagonizing the function of the sigma factor encoded bysigU. We also conclude that thesigU-encoded sigma factor is not normally required for development but that its uncontrolled activity obstructs morphological differentiation at an early stage.

scholarly journals The Streptomyces coelicolor Developmental Transcription Factor σBldN Is Synthesized as a Proprotein

2003 ◽  
Vol 185 (7) ◽  
pp. 2338-2345 ◽  
Author(s):  
Maureen J. Bibb ◽  
Mark J. Buttner
Keyword(s):  
Time Course ◽  
Streptomyces Coelicolor ◽  
Aerial Mycelium ◽  
Immunoblot Analysis ◽  
Proteolytic Processing ◽  
Site Directed Mutagenesis ◽  
Start Codon ◽  
Genes Encoding ◽  
Σ Factor ◽  
Early Production

ABSTRACT bldN is one of a set of genes required for the formation of specialized, spore-bearing aerial hyphae during differentiation in the mycelial bacterium Streptomyces coelicolor. Previous analysis (M. J. Bibb et al., J. Bacteriol. 182:4606-4616, 2000) showed that bldN encodes a member of the extracytoplasmic function subfamily of RNA polymerase σ factors and that translation from the most strongly predicted start codon (GTG1) would give rise to a σ factor having an unusual N-terminal extension of ca. 86 residues. Here, by using a combination of site-directed mutagenesis and immunoblot analysis, we provide evidence that all bldN translation arises from initiation at GTG1 and that the primary translation product is a proprotein (pro-σBldN) that is proteolytically processed to a mature species (σBldN) by removal of most of the unusual N-terminal extension. A time course taken during differentiation of the wild type on solid medium showed early production of pro-σBldN and the subsequent appearance of mature σBldN, which was concomitant with aerial mycelium formation and the disappearance of pro-σBldN. Two genes encoding members of a family of metalloproteases that are involved in the regulated proteolytic processing of transcription factors in other organisms were identified in the S. coelicolor genome, but their disruption did not affect differentiation or pro-σBldN processing.

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