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

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).

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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

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

Journal of Bacteriology ◽

10.1128/jb.00828-10 ◽

2010 ◽

Vol 192 (21) ◽

pp. 5674-5681 ◽

Cited By ~ 19

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.

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Specialized osmotic stress response systems involve multiple SigB-like sigma factors in Streptomyces coelicolor

Molecular Microbiology ◽

10.1046/j.1365-2958.2003.03302.x ◽

2003 ◽

Vol 47 (3) ◽

pp. 699-714 ◽

Cited By ~ 58

Author(s):

Patrick H. Viollier ◽

Gabriella H. Kelemen ◽

Glenn E. Dale ◽

Kien T. Nguyen ◽

Mark J. Buttner ◽

...

Keyword(s):

Stress Response ◽

Osmotic Stress ◽

Streptomyces Coelicolor ◽

Sigma Factors ◽

Osmotic Stress Response ◽

Response Systems

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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.

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