Suppressor analysis of eepR mutant defects reveals coordinate regulation of secondary metabolites and serralysin biosynthesis by EepR and HexS

Shanks, Robert M. Q.; Stella, Nicholas A.; Lahr, Roni M.; Aston, Marissa A.; Brothers, Kimberly M.; Callaghan, Jake D.; Sigindere, Cihad; Liu, Xinyu

doi:10.1099/mic.0.000422

Cited by 14 publications

(15 citation statements)

References 39 publications

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“…The CRP and HexS transcription factors are potent inhibitors of secondary metabolite biosynthesis in strain PIC3611 and other strains, such that crp and hexS mutants are more highly pigmented than the isogenic wild-type strains (Kalivoda et al 2010; Stella et al 2012; Stella and Shanks 2014; Shanks et al 2017b). It was hypothesized that HexS and CRP were responsible for inhibiting the prodigiosin production at 37°C.…”

Section: Resultsmentioning

confidence: 99%

“…In previous studies, it was determined that the transcription factor genes eepR and pigP were more highly expressed in crp and hexS mutants and that EepR and PigP were positive regulators of pig transcription in S. marcescens and another Serratia species (Fineran et al 2005; Shanks et al 2013; Stella et al 2015; Shanks et al 2017a). A model depicting the interaction between these transcription factors and the pig operon is shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

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Thermoregulation of Prodigiosin Biosynthesis by Serratia marcescens is Controlled at the Transcriptional Level and Requires HexS

Romanowski

Lehner

Martin

et al. 2019

Polish Journal of Microbiology

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Several biotypes of the Gram-negative bacterium Serratia marcescens produce the tri-pyrole pigment and secondary metabolite prodigiosin. The biological activities of this pigment have therapeutic potential. For over half a century it has been known that biosynthesis of prodigiosin is inhibited when bacteria are grown at elevated temperatures, yet the fundamental mechanism underlying this thermoregulation has not been characterized. In this study, chromosomal and plasmid-borne luxCDABE transcriptional reporters revealed reduced transcription of the prodigiosin biosynthetic operon at 37°C compared to 30°C indicating transcriptional control of pigment production. Moreover, induced expression of the prodigiosin biosynthetic operon at 37°C was able to produce pigmented colonies and cultures demonstrating that physiological conditions at 37°C allow prodigiosin production and indicating that post-transcriptional control is not a major contributor to the thermoregulation of prodigiosin pigmentation. Genetic experiments support the model that the HexS transcription factor is a key contributor to thermoregulation of pigmentation, whereas CRP plays a minor role, and a clear role for EepR and PigP was not observed. Together, these data indicate that thermoregulation of prodigiosin production at elevated temperatures is controlled largely, if not exclusively, at the transcriptional level.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Thermoregulation of Prodigiosin Biosynthesis by Serratia marcescens is Controlled at the Transcriptional Level and Requires HexS

Romanowski

Lehner

Martin

et al. 2019

Polish Journal of Microbiology

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“…Simultaneously, many studies have been studied to analyze the metabolic regulatory network of prodigiosin synthesis. Besides the well-studied pig gene cluster, a total of 14 genes, associated with prodigiosin synthesis in S. marcescens , a few other genes that play important roles in prodigiosin synthesis in S. marcescens have also been investigated, including genes copA (Williamson et al, 2006b), crp (Stella and Shanks, 2014), hexS (Stella et al, 2012), rssB (Horng et al, 2010), spnR (Horng et al, 2002), eepR (Shanks et al, 2017), pigP (Shanks et al, 2013), smaI (Coulthurst et al, 2006), gumB (Stella et al, 2018), and rsbR (Lee et al, 2017). In this study, BVG90_02415 ( dacA ) gene encoding D-Ala-D-Ala carboxypeptidase DacA, a negative regulator of prodigiosin production, was screened by constructing the insertion mutant library of Tn 5G transposon.…”

Section: Discussionmentioning

confidence: 99%

“…Finally, the pigC gene encodes the terminal condensing enzyme PigC that condenses MAP and MBC to prodigiosin (Williamson et al, 2006a). In S. marcescens , the synthesis of prodigiosin is also controlled by several transcriptional regulators, including positive regulators EepR (Shanks et al, 2017), PigP (Shanks et al, 2013), SmaI (Coulthurst et al, 2006), GumB (Stella et al, 2018), and RbsR (Lee et al, 2017), and negative regulators CopA (Williamson et al, 2006b), CRP (Stella and Shanks, 2014), HexS (Stella et al, 2012), RssB (Horng et al, 2010), and SpnR (Horng et al, 2002). Among them, HexS, EepR, PigP, and RssB regulators directly bind to the promoter regions of the prodigiosin-associated pig operon, and thus affect the synthesis of prodigiosin.…”

Section: Introductionmentioning

confidence: 99%

Loss of Serine-Type D-Ala-D-Ala Carboxypeptidase DacA Enhances Prodigiosin Production in Serratia marcescens

Pan

Sun

Liu

et al. 2019

Front. Bioeng. Biotechnol.

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Serratia marcescens, a gram-negative bacterium, found in a wide range of ecological niches can produce several high-value products, including prodigiosin, althiomycin, and serratamolide. Among them, prodigiosin has attracted attention due to its immunosuppressive, antimicrobial, and anticancer properties. However, the regulatory mechanisms behind prodigiosin synthesis in Serratia marcescens remains limited. Here, a transposon mutant library was constructed to identify the genes related to prodigiosin synthesis, and BVG90_02415 gene encoding a peptidoglycan synthesizing enzyme D-Ala-D-Ala carboxypeptidase DacA was found to negatively regulates prodigiosin synthesis. Quantitative measurements revealed that disruption of dacA increased prodigiosin production 1.46-fold that of the wild-type strain JNB5-1 in fermentation medium. By comparing differences in cell growth, pigA gene expression level, cell morphology, membrane permeability, and intracellular prodigiosin concentration between wild-type strain JNB5-1 and dacA mutant SK4-72, results revealed that the mechanism for hyper-producing of prodigiosin by the dacA mutant was probably that dacA disruption enhanced prodigiosin leakage, which in turn alleviated feedback inhibition of prodigiosin and increased expression of pig gene cluster. Collectively, this work provides a novel insight into regulatory mechanisms of prodigiosin synthesis and uncovers new roles of DacA protein in regulating cell growth, cell morphology, and membrane permeability in Serratia marcescens. Finally, this study offers a new strategy for improving production of high-value compounds in Serratia marcescens.

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“…Previous studies on the metabolic regulation network of prodigiosin biosynthesis in S. marcescens have revealed that pigABCDEFGHIJKLMN genes were involved in the biosynthetic pathway of prodigiosin synthesis ( Supplementary Figure S1 ) ( 1 ). Also, it is reported that prodigiosin biosynthesis in S. marcescens was widely regulated by a number of transcription factors including positive regulators EepR ( 6 ), PigP ( 7 ), GumB ( 8 ) and RbsR ( 9 ), and negative regulators MetR ( 10 ), SpnR ( 11 ), CopA ( 12 ), CRP ( 13 ), HexS ( 14 ), RssB ( 15 ), RcsB ( 16 , 17 ) and SmaR ( 18 ).…”

Section: Introductionmentioning

confidence: 99%

PsrA is a novel regulator contributes to antibiotic synthesis, bacterial virulence, cell motility and extracellular polysaccharides production in Serratia marcescens

Pan

You

Osire

et al. 2021

Nucleic Acids Research

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Serratia marcescens is a Gram-negative bacterium of the Enterobacteriaceae family that can produce numbers of biologically active secondary metabolites. However, our understanding of the regulatory mechanisms behind secondary metabolites biosynthesis in S. marcescens remains limited. In this study, we identified an uncharacterized LysR family transcriptional regulator, encoding gene BVG90_12635, here we named psrA, that positively controlled prodigiosin synthesis in S. marcescens. This phenotype corresponded to PsrA positive control of transcriptional of the prodigiosin-associated pig operon by directly binding to a regulatory binding site (RBS) and an activating binding site (ABS) in the promoter region of the pig operon. We demonstrated that L-proline is an effector for the PsrA, which enhances the binding affinity of PsrA to its target promoters. Using transcriptomics and further experiments, we show that PsrA indirectly regulates pleiotropic phenotypes, including serrawettin W1 biosynthesis, extracellular polysaccharide production, biofilm formation, swarming motility and T6SS-mediated antibacterial activity in S. marcescens. Collectively, this study proposes that PsrA is a novel regulator that contributes to antibiotic synthesis, bacterial virulence, cell motility and extracellular polysaccharides production in S. marcescens and provides important clues for future studies exploring the function of the PsrA and PsrA-like proteins which are widely present in many other bacteria.

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Suppressor analysis of eepR mutant defects reveals coordinate regulation of secondary metabolites and serralysin biosynthesis by EepR and HexS

Cited by 14 publications

References 39 publications

Thermoregulation of Prodigiosin Biosynthesis by Serratia marcescens is Controlled at the Transcriptional Level and Requires HexS

Thermoregulation of Prodigiosin Biosynthesis by Serratia marcescens is Controlled at the Transcriptional Level and Requires HexS

Loss of Serine-Type D-Ala-D-Ala Carboxypeptidase DacA Enhances Prodigiosin Production in Serratia marcescens

PsrA is a novel regulator contributes to antibiotic synthesis, bacterial virulence, cell motility and extracellular polysaccharides production in Serratia marcescens

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