Stress-response sigma factor σ Η is essential for morphological differentiation of Streptomyces coelicolor A3(2)

2001 ◽  
Vol 177 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Beatrica Sevciková ◽  
Oldrich Benada ◽  
Olga Kofronova ◽  
Jan Kormanec
Keyword(s):  
Stress Response ◽  
Sigma Factor ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation

scholarly journals The Anti-Anti-Sigma Factor BldG Is Involved in Activation of the Stress Response Sigma Factor σH in Streptomyces coelicolor A3(2)

2010 ◽  
Vol 192 (21) ◽  
pp. 5674-5681 ◽  
Author(s):  
Beatrica Sevcikova ◽  
Bronislava Rezuchova ◽  
Dagmar Homerova ◽  
Jan Kormanec
Keyword(s):  
Stress Response ◽  
Osmotic Stress ◽  
Sigma Factor ◽  
Streptomyces Coelicolor ◽  
Direct Interaction ◽  
Morphological Differentiation ◽  
Osmotic Stress Response ◽  
Its Gene ◽  
Two Hybrid

ABSTRACT The alternative stress response sigma factor σH has a role in regulation of the osmotic stress response and in morphological differentiation in Streptomyces coelicolor A3(2). Its gene, sigH, is located in an operon with the gene that encodes its anti-sigma factor UshX (PrsH). However, no gene with similarity to an anti-anti-sigma factor which may have a role in σH activation by a “partner-switching” mechanism is located in the operon. By using a combination of several approaches, including pull-down and bacterial two-hybrid assays and visualization of the complex by native polyacrylamide electrophoresis, we demonstrated a direct interaction between UshX and the pleiotropic sporulation-specific anti-anti-sigma factor BldG. Osmotic induction of transcription of the sigHp2 promoter that is specifically recognized by RNA polymerase containing σH was absent in an S. coelicolor bldG mutant, indicating a role of BldG in σH activation by a partner-switching-like mechanism.

scholarly journals BldG and SCO3548 Interact Antagonistically To Control Key Developmental Processes in Streptomyces coelicolor

2009 ◽  
Vol 191 (8) ◽  
pp. 2541-2550 ◽  
Author(s):  
Archana Parashar ◽  
Kimberley R. Colvin ◽  
Dawn R. D. Bignell ◽  
Brenda K. Leskiw
Keyword(s):  
Sigma Factor ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Affinity Purification ◽  
Regulatory System ◽  
Direct Interaction ◽  
Morphological Differentiation ◽  
Sigma Factors ◽  
Developmental Processes ◽  
Two Hybrid

ABSTRACT The similarity of BldG and the downstream coexpressed protein SCO3548 to anti-anti-sigma and anti-sigma factors, respectively, together with the phenotype of a bldG mutant, suggests that BldG and SCO3548 interact as part of a regulatory system to control both antibiotic production and morphological differentiation in Streptomyces coelicolor. A combination of bacterial two-hybrid, affinity purification, and far-Western analyses demonstrated that there was self-interaction of both BldG and SCO3548, as well as a direct interaction between the two proteins. Furthermore, a genetic complementation experiment demonstrated that SCO3548 antagonizes the function of BldG, similar to other anti-anti-sigma/anti-sigma factor pairs. It is therefore proposed that BldG and SCO3548 form a partner-switching pair that regulates the function of one or more sigma factors in S. coelicolor. The conservation of bldG and sco3548 in other streptomycetes demonstrates that this system is likely a key regulatory switch controlling developmental processes throughout the genus Streptomyces.

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 Cross-Recognition of Promoters by the Nine SigB Homologues Present in Streptomyces coelicolor A3(2)

2021 ◽  
Vol 22 (15) ◽  
pp. 7849
Author(s):  
Beatrica Sevcikova ◽  
Bronislava Rezuchova ◽  
Vladimira Mazurakova ◽  
Dagmar Homerova ◽  
Renata Novakova ◽  
...  
Keyword(s):  
Stress Response ◽  
Osmotic Stress ◽  
Streptomyces Coelicolor ◽  
Dominant Role ◽  
Morphological Differentiation ◽  
Sigma Factors ◽  
Stress Conditions ◽  
Phenotypic Analysis ◽  
Specific Sequence ◽  
Osmotic Stress Response

In contrast to Bacillus subtilis, Streptomyces coelicolor A3(2) contains nine homologues of stress response sigma factor SigB with a major role in differentiation and osmotic stress response. The aim of this study was to further characterize these SigB homologues. We previously established a two-plasmid system to identify promoters recognized by sigma factors and used it to identify promoters recognized by the three SigB homologues, SigF, SigG, and SigH from S. coelicolor A3(2). Here, we used this system to identify 14 promoters recognized by SigB. The promoters were verified in vivo in S. coelicolor A3(2) under osmotic stress conditions in sigB and sigH operon mutants, indicating some cross-recognition of these promoters by these two SigB homologues. This two-plasmid system was used to examine the recognition of all identified SigB-, SigF-, SigG-, and SigH-dependent promoters with all nine SigB homologues. The results confirmed this cross-recognition. Almost all 24 investigated promoters were recognized by two or more SigB homologues and data suggested some distinguishing groups of promoters recognized by these sigma factors. However, analysis of the promoters did not reveal any specific sequence characteristics for these recognition groups. All promoters showed high similarity in the -35 and -10 regions. Immunoblot analysis revealed the presence of SigB under osmotic stress conditions and SigH during morphological differentiation. Together with the phenotypic analysis of sigB and sigH operon mutants in S. coelicolor A3(2), the results suggest a dominant role for SigB in the osmotic stress response and a dual role for SigH in the osmotic stress response and morphological differentiation. These data suggest a complex regulation of the osmotic stress response in relation to morphological differentiation in S. coelicolor A3(2).

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 A Possible Extended Family of Regulators of Sigma Factor Activity in Streptomyces coelicolor

2008 ◽  
Vol 190 (22) ◽  
pp. 7559-7566 ◽  
Author(s):  
Eun Sook Kim ◽  
Ju Yeon Song ◽  
Dae Wi Kim ◽  
Keith F. Chater ◽  
Kye Joon Lee
Keyword(s):  
Protein Interaction ◽  
Sigma Factor ◽  
Extended Family ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Sigma Factors ◽  
Yeast Two Hybrid ◽  
Protein Protein Interaction ◽  
Two Hybrid

ABSTRACT SCO4677 is one of a large number of similar genes in Streptomyces coelicolor that encode proteins with an HATPase_c domain resembling that of anti-sigma factors such as SpoIIAB of Bacillus subtilis. However, SCO4677 is not located close to genes likely to encode a cognate sigma or anti-anti-sigma factor. SCO4677 was found to regulate antibiotic production and morphological differentiation, both of which were significantly enhanced by the deletion of SCO4677. Through protein-protein interaction screening of candidate sigma factor partners using the yeast two-hybrid system, SCO4677 protein was found to interact with the developmentally specific σF, suggesting that it is an antagonistic regulator of σF. Two other proteins, encoded by SCO0781 and SCO0869, were found to interact with the SCO4677 anti-σF during a subsequent global yeast two-hybrid screen, and the SCO0869-SCO4677 protein-protein interaction was confirmed by coimmunoprecipitation. The SCO0781 and SCO0869 proteins resemble well-known anti-anti-sigma factors such as SpoIIAA of B. subtilis. It appears that streptomycetes may possess an extraordinary abundance of anti-sigma factors, some of which may influence diverse processes through interactions with multiple partners: a novel feature for such regulatory proteins.

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