The interplay of glycogen metabolism and differentiation provides an insight into the developmental biology of Streptomyces coelicolor

Microbiology ◽  
2005 ◽  
Vol 151 (3) ◽  
pp. 855-861 ◽  
Author(s):  
Marcus Yeo ◽  
Keith Chater
Keyword(s):  
Phase Ii ◽  
Streptomyces Coelicolor ◽  
Aerial Mycelium ◽  
Glycogen Metabolism ◽  
Branching Enzyme ◽  
Obvious Effect ◽  
Substrate Mycelium ◽  
Enzyme Isoforms ◽  
Aerial Hyphae ◽  
Glycogen Deposition

Mycelial colonies of the developmentally complex actinomycete Streptomyces coelicolor growing on solid medium contain glycogen in two distinct locations. Phase I deposits are found in a substrate mycelium region bordering the developing aerial mycelium. Their production involves GlgBI, one of two glycogen branching enzyme isoforms. Phase II deposits occur in the upper regions of aerial hyphae, in long tip cells that are dividing, or have just divided, into unigenomic prespore compartments. Their formation involves a second branching enzyme isoform, GlgBII. To find out if the gene for the second isoform, glgBII, is regulated by any of the well-studied whiA, B, G, H or I genes needed for sporulation septation, glgBI or glgBII was disrupted in a set of whi mutants, and the glycogen phenotypes examined by transmission electron microscopy. In the whiG mutants, deposits were found throughout the aerial mycelium and the adjacent region of the substrate mycelium, but the morphology of all the deposits, i.e. whether they were in the form of granules of branched glycogen or large blobs of unbranched glycan, depended solely on GlgBI. In contrast, the whiA, B, H and I mutations had no obvious effect on the pattern of glycogen deposition, or on the spatial specificity of the branching enzyme isoforms (though phase II glycogen deposits were reduced in size and abundance in the whiA and B mutants, and increased in the whiH mutant). These results indicate that glgBII is regulated (directly or indirectly) by whiG, and not by any of the other whi genes tested, and that the aerial hyphae of a whiG mutant are atypical in being physiologically similar to the substrate hyphae from which they emerge. A new role for aerial hyphae is proposed.

Influences of developmental genes on localized glycogen deposition in colonies of a mycelial prokaryote, Streptomyces coelicolor A3(2): a possible interface between metabolism and morphogenesis

1995 ◽  
Vol 347 (1320) ◽  
pp. 105-121 ◽  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Streptomyces Coelicolor ◽  
Glycogen Synthesis ◽  
Aerial Mycelium ◽  
Thin Sections ◽  
Glycogen Accumulation ◽  
Aerial Hyphae ◽  
Spore Pigment ◽  
Synthesis And Degradation

Two spatially localized phases of glycogen accumulation were detected by electron microscopy after cytological staining of thin sections of Streptomyces coelicolor A3 (2) colonies. In phase I, glycogen granules were present in hyphae in the air—agar interface region of colonies that were undergoing aerial mycelium formation, though absent from aerial hyphae themselves. With one exception (a bldF mutant, which contained abundant glycogen), the absence of aerial mycelium caused by various developmental mutations ( bldA, bldB, bldC, bldD, bldG and bldH mutations) was associated with a virtual absence of detectable glycogen. Mutations that allow aerial hyphae to form but prevent or interfere with the septation needed for spore formation ( whiA,whiB, whiG, whiH and whil mutations) did not impair phase I deposition. In phase II, abundant glycogen granules were present in aerial hyphal tips during intermediate stages of sporulation, but disappeared as spores matured. Phase II glycogen accumulation was observed with bldA, bldC, bldD and bldG mutants grown with mannitol as carbon source — conditions that allowed normal aerial mycelium development and sporulation; but phase I deposition was still at a very low level in these colonies. Glycogen was also deposited in the coiling tips of aerial hyphae of whiA , whiB, whiH and whil mutants, and sporadic clusters of granules were present throughout whiG colonies. Significantly, glycogen was deposited in spore chains that developed ectopically in the normally sporeand glycogen-free substrate mycelium when multiple copies of whiG were present. Overall, the two phases of glycogen synthesis (and degradation) appear to be under separate developmental control rather than being mainly responsive to external growth conditions. Phase II glycogen levels were particularly high in a whiE mutant defective in spore pigment biosynthesis, and particularly low when hyper-pigmentation was induced by additional copies of the whiE genes. Spore pigment may therefore be a major sink for carbon stored as glycogen during sporulation. The possibility is discussed that, in addition to supplying carbon and energy at particular locations, glycogen synthesis and degradation may also play a part in morphogenesis by influencing turgor pressure.

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 DevA, a GntR-Like Transcriptional Regulator Required for Development in Streptomyces coelicolor

2006 ◽  
Vol 188 (14) ◽  
pp. 5014-5023 ◽  
Author(s):  
Paul A. Hoskisson ◽  
Sebastien Rigali ◽  
Kay Fowler ◽  
Kim C. Findlay ◽  
Mark J. Buttner
Keyword(s):  
Fluorescent Protein ◽  
Streptomyces Coelicolor ◽  
Aerial Mycelium ◽  
Developmental Cycle ◽  
Wild Type ◽  
Mobility Shift ◽  
S1 Nuclease ◽  
Aerial Hyphae ◽  
In The Wild

ABSTRACT The gram-positive filamentous bacterium Streptomyces coelicolor has a complex developmental cycle with three distinct phases: growth of the substrate mycelium, development of reproductive structures called aerial hyphae, and differentiation of these aerial filaments into long chains of exospores. During a transposon mutagenesis screen, we identified a novel gene (devA) required for proper development. The devA mutant produced only rare aerial hyphae, and those that were produced developed aberrant spore chains that were much shorter than wild-type chains and had misplaced septa. devA encodes a member of the GntR superfamily, a class of transcriptional regulators that typically respond to metabolite effector molecules. devA forms an operon with the downstream gene devB, which encodes a putative hydrolase that is also required for aerial mycelium formation on R5 medium. S1 nuclease protection analysis showed that transcription from the single devA promoter was temporally associated with vegetative growth, and enhanced green fluorescent protein transcriptional fusions showed that transcription was spatially confined to the substrate hyphae in the wild type. In contrast, devAB transcript levels were dramatically upregulated in a devA mutant and the devA promoter was also active in aerial hyphae and spores in this background, suggesting that DevA might negatively regulate its own production. This suggestion was confirmed by gel mobility shift assays that showed that DevA binds its own promoter region in vitro.

scholarly journals Replisome Localization in Vegetative and Aerial Hyphae of Streptomyces coelicolor

2006 ◽  
Vol 188 (20) ◽  
pp. 7311-7316 ◽  
Author(s):  
Beata Ruban-Ośmiałowska ◽  
Dagmara Jakimowicz ◽  
Aleksandra Smulczyk-Krawczyszyn ◽  
Keith F. Chater ◽  
Jolanta Zakrzewska-Czerwińska
Keyword(s):  
Green Fluorescent Protein ◽  
Enhanced Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Streptomyces Coelicolor ◽  
Aerial Mycelium ◽  
Vegetative Mycelium ◽  
Single Compartment ◽  
Aerial Hyphae ◽  
Green Fluorescent ◽  
Replication Activity

ABSTRACT Using a functional fusion of DnaN to enhanced green fluorescent protein, we examined the subcellular localization of the replisome machinery in the vegetative mycelium and aerial mycelium of the multinucleoid organism Streptomyces coelicolor. Chromosome replication took place in many compartments of both types of hypha, with the apical compartments of the aerial mycelium exhibiting the highest replication activity. Within a single compartment, the number of “current” ongoing DNA replications was lower than the expected chromosome number, and the appearance of fluorescent foci was often heterogeneous, indicating that this process is asynchronous within compartments and that only selected chromosomes undergo replication.

scholarly journals Dimerization of the RamC Morphogenetic Protein of Streptomyces coelicolor

2004 ◽  
Vol 186 (5) ◽  
pp. 1330-1336 ◽  
Author(s):  
Michael E. Hudson ◽  
Justin R. Nodwell
Keyword(s):  
Protein Kinase ◽  
Streptomyces Coelicolor ◽  
Kinase Domain ◽  
Terminal Protein ◽  
Amino Terminal ◽  
Morphogenetic Protein ◽  
Aerial Hyphae ◽  
Multiple Copies ◽  
Defective Allele

ABSTRACT RamC is required for the formation of spore-forming cells called aerial hyphae by the bacterium Streptomyces coelicolor. This protein is membrane associated and has an amino-terminal protein kinase-like domain, but little is known about its mechanism of action. In this study we found that the presence of multiple copies of a defective allele of ramC inhibits morphogenesis in S. coelicolor, consistent with either titration of a target or formation of inactive RamC multimers. We identified a domain in RamC that is C terminal to the putative kinase domain and forms a dimer with a Kd of ∼0.1 μM. These data suggest that RamC acts as a dimer in vivo.

scholarly journals GLC3 and GHA1 of Saccharomyces cerevisiae are allelic and encode the glycogen branching enzyme.

1992 ◽  
Vol 12 (1) ◽  
pp. 22-29 ◽  
Author(s):  
D W Rowen ◽  
M Meinke ◽  
D C LaPorte
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glycogen Metabolism ◽  
Striking Difference ◽  
Branching Enzyme ◽  
Yeast Saccharomyces Cerevisiae ◽  
Storage Carbohydrate ◽  
Functional Product ◽  
Cloned Gene ◽  
Transposon Insertions ◽  
Glycogen Branching Enzyme

In the yeast Saccharomyces cerevisiae, glycogen serves as a major storage carbohydrate. In a previous study, mutants with altered glycogen metabolism were isolated on the basis of the altered iodine-staining properties of colonies. We found that when glycogen produced by strains carrying the glc-1p (previously called gha1-1) mutation is stained with iodine, the absorption spectrum resembles that of starch rather than that of glycogen, suggesting that this mutation might reduce the level of branching in the glycogen particles. Indeed, glycogen branching activity was undetectable in extracts from a glc3-1p strain but was elevated in strains which expressed GLC3 from a high-copy-number plasmid. These observations suggest that GLC3 encodes the glycogen branching enzyme. In contrast to glc3-1p, the glc3-4 mutation greatly reduces the ability of yeast to accumulate glycogen. These mutations appear to be allelic despite the striking difference in the phenotypes which they produce. The GLC3 clone complemented both glc3-1p and glc3-4. Deletions and transposon insertions in this clone had parallel effects on its ability to complement glc3-1p and glc3-4. Finally, a fragment of the cloned gene was able to direct the repair of both glc3-1p and glc3-4. Disruption of GLC3 yielded the glycogen-deficient phenotype, indicating that glycogen deficiency is the null phenotype. The glc3-1p allele appears to encode a partially functional product, since it is dominant over glc3-4 but recessive to GLC3. These observations suggest that the ability to introduce branches into glycogen greatly increases the ability of the cell to accumulate that polysaccharide. Northern (RNA) blot analysis identified a single mRNA of 2,300 nucleotides that increased in abundance ca. 20-fold as the culture approached stationary phase. It thus appears that the expression of GLC3 is regulated, probably at the level of transcription.

scholarly journals An Unusual Response Regulator Influences Sporulation at Early and Late Stages in Streptomyces coelicolor

2007 ◽  
Vol 189 (7) ◽  
pp. 2873-2885 ◽  
Author(s):  
Yuqing Tian ◽  
Kay Fowler ◽  
Kim Findlay ◽  
Huarong Tan ◽  
Keith F. Chater
Keyword(s):  
Streptomyces Coelicolor ◽  
Point Mutations ◽  
Aerial Mycelium ◽  
Site Directed Mutagenesis ◽  
Null Mutant ◽  
Wild Type ◽  
New Variant ◽  
In The Wild ◽  
Pcr Targeting ◽  
Spore Maturation

ABSTRACT WhiI, a regulator required for efficient sporulation septation in the aerial mycelium of Streptomyces coelicolor, resembles response regulators of bacterial two-component systems but lacks some conserved features of typical phosphorylation pockets. Four amino acids of the abnormal “phosphorylation pocket” were changed by site-directed mutagenesis. Unlike whiI null mutations, these point mutations did not interfere with sporulation septation but had various effects on spore maturation. Transcriptome analysis was used to compare gene expression in the wild-type strain, a D27A mutant (pale gray spores), a D69E mutant (wild-type spores), and a null mutant (white aerial mycelium, no spores) (a new variant of PCR targeting was used to introduce the point mutations into the chromosomal copy of whiI). The results revealed 45 genes that were affected by the deletion of whiI. Many of these showed increased expression in the wild type at the time when aerial growth and development were taking place. About half of them showed reduced expression in the null mutant, and about half showed increased expression. Some, but not all, of these 45 genes were also affected by the D27A mutation, and a few were affected by the D69E mutation. The results were consistent with a model in which WhiI acts differently at sequential stages of development. Consideration of the functions of whiI-influenced genes provides some insights into the physiology of aerial hyphae. Mutation of seven whiI-influenced genes revealed that three of them play roles in spore maturation.

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