Disease relevance of SCO2083

• We show that the cell division gene ftsQ of Streptomyces coelicolor A3(2) is dispensable for growth and viability but is needed during development for the efficient conversion of aerial filaments into spores [1].
• Our experiments paint a picture of a novel protein family that acts through timing and localization of the activity of penicillin-binding proteins and autolysins, thus controlling important steps during the initiation and the completion of sporulation in actinomycetes [2].
• With a vector derived from the temperate bacteriophage phi C31, a 5.6-kilobase fragment of wildtype DNA was cloned which restored sporulation to five independent bldA mutants when lysogenized with the recombinant phage [3].
• WhiA, a protein of unknown function conserved among gram-positive bacteria, is essential for sporulation in Streptomyces coelicolor A3(2) [4].
• In this study, we have analyzed an ORF from Corynebacterium glutamicum, which codes for a homologue of the Streptomyces coelicolor WhiB-family of proteins known to be involved in sporulation [5].

High impact information on SCO2083

• The sporulation mutant harbored an insertion in one of three adjacent genes that are apparently unique to Streptomyces but are each represented by at least 20 paralogs at dispersed locations in the chromosome [6].
• Using DNA microarrays to globally identify S. coelicolor genes whose transcription was affected by ramR mutation or overexpression, we discovered a ramR-activated locus of contiguous cotranscribed developmental genes that modulate both aerial hyphae formation and sporulation [7].
• While SsgA and SsgB are essential for sporulation-specific cell division in Streptomyces coelicolor, SsgC-G are responsible for correct DNA segregation/condensation (SsgC), spore wall synthesis (SsgD), autolytic spore separation (SsgE, SsgF) or exact septum localization (SsgG) [2].
• Remarkably, SapB and SapT, and the fungal hydrophobin SC3 were shown to restore to a SapB-deficient S. coelicolor mutant the capacity to undergo complete morphogenesis, such that the extracellular addition of protein resulted in sporulation [8].
• In contrast, sporulation septation was almost completely abolished, resulting in a phenotype reminiscent of whiH and ftsZdelta2p mutants [9].

Chemical compound and disease context of SCO2083

• The optically active form of tritium-labeled A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone), a pleiotropic autoregulator responsible for streptomycin production, streptomycin resistance, and sporulation in Streptomyces griseus, was chemically synthesized [10].
• Disruption of the orthologous gene in Streptomyces coelicolor indicates that whereas CrgA is not essential for sporulation in this species, during growth on glucose-containing media, it influences the timing of the onset of reproductive growth, with precocious erection of aerial hyphae and antibiotic production by the mutant [11].
• The AIB factor produced by the tested microorganisms on an agar media allows for germination, growth, and sporulation of the testing Streptomyces coelicolor on an agar medium containing 20 mmol/L acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, and 2-methylbutyrate [12].

Biological context of SCO2083

• This upregulation required all the six early regulatory sporulation genes that were tested: whiA, B, G, H, I and J [13].
• The results suggest that cytokinesis may be developmentally controlled at the level of Z-ring assembly during sporulation of S. coelicolor A3(2) [9].
• No significant alterations were observed when the gene dosage of ftsQ was increased [14].
• Consistent with this idea, introduction of cprA on a low-copy-number plasmid into the parental strain led to overproduction of these secondary metabolites and accelerated the timing of sporulation [15].
• Morphological changes leading to aerial mycelium formation and sporulation in the mycelial bacterium Streptomyces coelicolor rely on establishing distinct patterns of gene expression in separate regions of the colony. sigmaH was identified previously as one of three paralogous sigma factors associated with stress responses in S. coelicolor [16].

Anatomical context of SCO2083

• The suppressor mutations were genetically mapped to regions of the chromosome, distinct from each other and the division and cell wall cluster containing ftsQ [17].

Associations of SCO2083 with chemical compounds

• Together with the observation that VB-C had almost no biological activity on the restoration of streptomycin production or sporulation in an A-factor-deficient mutant of S. griseus, these results indicated that the binding protein had a strict ligand specificity [10].
• These strains were unaffected in growth and sporulation, demonstrating that the histidine-tagged RNA polymerase was competent to carry out all essential in-vivo functions [18].
• Although DeltabldC mutants produced the tripyrrole antibiotic undecylprodigiosin, transcripts of the pathway-specific activator gene (redD) were reduced to almost undetectable levels after 48 h in the bldC mutant, in contrast to the bldC+ parent strain in which redD transcription continued during aerial mycelium formation and sporulation [19].

Regulatory relationships of SCO2083

• Over-expression of ftsZ in S. coelicolor M145 inhibited aerial mycelium formation and blocked sporulation [14].

Other interactions of SCO2083

• Cell division gene ftsQ is required for efficient sporulation but not growth and viability in Streptomyces coelicolor A3(2) [1].
• We show here that developmental control of ftsZ transcription is required for sporulation in Streptomyces coelicolor A3(2) [13].
• Expression from parABp(2) depended absolutely on two sporulation regulatory genes, whiA and whiB, and partially on two others, whiH and whiI, all four of which are needed for sporulation septation [20].
• A DNA fragment which induced aerial mycelium formation and sporulation in an A-factor-deficient mutant strain, S. griseus HH1, was cloned from this strain on a high-copy-number plasmid [21].
• Sporulation of a subset of Sg bald mutants, which produce no aerial mycelium or spores, was restored in the presence of bldA from Sc or Sg [22].

Analytical, diagnostic and therapeutic context of SCO2083

• 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 [23].
• Analysis of ssgB mutant hyphae by electron microscopy and by confocal fluorescence microscopy showed that it was defective in the initiation of sporulation, as no sporulation septa could be identified, and DNA segregation had not yet been initiated in the mutant [24].
• Sequence analysis has revealed an ORF exhibiting high similarity to sporulation transcription factors WhiB and WhiD [25].

References