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

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.

Download Full-text

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

Journal of Bacteriology ◽

10.1128/jb.01695-08 ◽

2009 ◽

Vol 191 (8) ◽

pp. 2541-2550 ◽

Cited By ~ 13

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.

Download Full-text

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

International Journal of Molecular Sciences ◽

10.3390/ijms22157849 ◽

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).

Download Full-text

NMR and LC-MS-Based Metabolomics to Study Osmotic Stress in Lignan-Deficient Flax

Molecules ◽

10.3390/molecules26030767 ◽

2021 ◽

Vol 26 (3) ◽

pp. 767

Author(s):

Kamar Hamade ◽

Ophélie Fliniaux ◽

Jean-Xavier Fontaine ◽

Roland Molinié ◽

Elvis Otogo Nnang ◽

...

Keyword(s):

Stress Response ◽

Osmotic Stress ◽

Biosynthetic Pathway ◽

Potential Role ◽

Plant Secondary Metabolites ◽

Wild Type ◽

Osmotic Stress Response ◽

Transgenic Flax ◽

Insight Into

Lignans, phenolic plant secondary metabolites, are derived from the phenylpropanoid biosynthetic pathway. Although, being investigated for their health benefits in terms of antioxidant, antitumor, anti-inflammatory and antiviral properties, the role of these molecules in plants remains incompletely elucidated; a potential role in stress response mechanisms has been, however, proposed. In this study, a non-targeted metabolomic analysis of the roots, stems, and leaves of wild-type and PLR1-RNAi transgenic flax, devoid of (+) secoisolariciresinol diglucoside ((+) SDG)—the main flaxseed lignan, was performed using 1H-NMR and LC-MS, in order to obtain further insight into the involvement of lignan in the response of plant to osmotic stress. Results showed that wild-type and lignan-deficient flax plants have different metabolic responses after being exposed to osmotic stress conditions, but they both showed the capacity to induce an adaptive response to osmotic stress. These findings suggest the indirect involvement of lignans in osmotic stress response.

Download Full-text

Nitric Oxide and the Neuroendocrine Control of the Osmotic Stress Response in Teleosts

International Journal of Molecular Sciences ◽

10.3390/ijms20030489 ◽

2019 ◽

Vol 20 (3) ◽

pp. 489 ◽

Cited By ~ 3

Author(s):

Carla Cioni ◽

Elisa Angiulli ◽

Mattia Toni

Keyword(s):

Nitric Oxide ◽

Stress Response ◽

Osmotic Stress ◽

No Synthase ◽

Hormone Release ◽

Neurosecretory Neurons ◽

Osmotic Stress Response ◽

Osmotic Challenge ◽

Osmotic Stimuli

The involvement of nitric oxide (NO) in the modulation of teleost osmoresponsive circuits is suggested by the facts that NO synthase enzymes are expressed in the neurosecretory systems and may be regulated by osmotic stimuli. The present paper is an overview on the research suggesting a role for NO in the central modulation of hormone release in the hypothalamo-neurohypophysial and the caudal neurosecretory systems of teleosts during the osmotic stress response. Active NOS enzymes are constitutively expressed by the magnocellular and parvocellular hypophysiotropic neurons and the caudal neurosecretory neurons of teleosts. Moreover, their expression may be regulated in response to the osmotic challenge. Available data suggests that the regulatory role of NO appeared early during vertebrate phylogeny and the neuroendocrine modulation by NO is conservative. Nonetheless, NO seems to have opposite effects in fish compared to mammals. Indeed, NO exerts excitatory effects on the electrical activity of the caudal neurosecretory neurons, influencing the amount of peptides released from the urophysis, while it inhibits hormone release from the magnocellular neurons in mammals.

Download Full-text

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

Archives of Microbiology ◽

10.1007/s00203-001-0367-1 ◽

2001 ◽

Vol 177 (1) ◽

pp. 98-106 ◽

Cited By ~ 41

Author(s):

Beatrica Sevciková ◽

Oldrich Benada ◽

Olga Kofronova ◽

Jan Kormanec

Keyword(s):

Stress Response ◽

Sigma Factor ◽

Streptomyces Coelicolor ◽

Morphological Differentiation

Download Full-text

Faculty Opinions recommendation of Specialized osmotic stress response systems involve multiple SigB-like sigma factors in Streptomyces coelicolor.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1011959.183615 ◽

2003 ◽

Author(s):

Regine Hengge

Keyword(s):

Stress Response ◽

Osmotic Stress ◽

Streptomyces Coelicolor ◽

Sigma Factors ◽

Osmotic Stress Response ◽

Response Systems

Download Full-text

Regulation of σB by an Anti- and an Anti-Anti-Sigma Factor in Streptomyces coelicolor in Response to Osmotic Stress

Journal of Bacteriology ◽

10.1128/jb.186.24.8490-8498.2004 ◽

2004 ◽

Vol 186 (24) ◽

pp. 8490-8498 ◽

Cited By ~ 37

Author(s):

Eun-Jin Lee ◽

You-Hee Cho ◽

Hyo-Sub Kim ◽

Bo-Eun Ahn ◽

Jung-Hye Roe

Keyword(s):

Osmotic Stress ◽

Sigma Factor ◽

Target Genes ◽

Sequence Similarity ◽

Streptomyces Coelicolor ◽

Dependent Manner ◽

Its Gene ◽

Genes Encoding

ABSTRACT σB, a homolog of stress-responsive σB of Bacillus subtilis, controls both osmoprotection and differentiation in Streptomyces coelicolor A3 (2). Its gene is preceded by rsbA and rsbB genes encoding homologs of an anti-sigma factor, RsbW, and its antagonist, RsbV, of B. subtilis, respectively. Purified RsbA bound to σB and prevented σB-directed transcription from the sigBp1 promoter in vitro. An rsbA-null mutant exhibited contrasting behavior to the sigB mutant, with elevated sigBp1 transcription, no actinorhodin production, and precocious aerial mycelial formation, reflecting enhanced activity of σB in vivo. Despite sequence similarity to RsbV, RsbB lacks the conserved phosphorylatable serine residue and its gene disruption produced no distinct phenotype. RsbV (SCO7325) from a putative six-gene operon (rsbV-rsbR-rsbS-rsbT-rsbU1-rsbU) was strongly induced by osmotic stress in a σB-dependent manner. It antagonized the inhibitory action of RsbA on σB-directed transcription and was phosphorylated by RsbA in vitro. These results support the hypothesis that the rapid induction of σB target genes by osmotic stress results from modulation of σB activity by the kinase-anti-sigma factor RsbA and its phosphorylatable antagonist RsbV, which function by a partner-switching mechanism. Amplified induction could result from a rapid increase in the synthesis of both σB and its inhibitor antagonist.

Download Full-text

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

Journal of Bacteriology ◽

10.1128/jb.00470-08 ◽

2008 ◽

Vol 190 (22) ◽

pp. 7559-7566 ◽

Cited By ~ 25

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.

Download Full-text