GlnR-mediated regulation of nitrogen metabolism in the actinomycete Saccharopolyspora erythraea

Yao, Lili; Liao, Chengheng; Huang, Gang; Zhou, Ying; Rigali, Sébastien; Zhang, Buchang; Ye, Bang‐Ce

doi:10.1007/s00253-014-5878-1

Cited by 47 publications

(74 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The MEME/MAST tools (http://meme -suite.org/) and the PREDetector software program were used to identify GlnR and PhoP binding sites in the upstream region of glucosidase-encoding genes in S. erythraea NRRL23338. The training set of sequences used to generate weight matrices and prediction methods has previously been described (34,35,41).…”

Section: Methodsmentioning

confidence: 99%

“…The gene knockout strategy was described in our previous study (34). Briefly, the glnR mutant was generated by protoplast transformation with pUC-glnR (Table 1), replacing the 771 bp of the glnR open reading frame (SACE_7101) with a thiostrepton (tsr) resistance cassette.…”

Section: Methodsmentioning

confidence: 99%

“…However, GlnR has no direct effect on phosphate metabolism (33). Interestingly, we have previously shown that S. erythraea possesses an extensive cross talk mechanism between PhoP and GlnR that is involved in the global coordination of nitrogen and phosphate metabolism (34,35). Recently, we found that GlnR controlled the transport of nonphosphotransferase system carbon sources by directly activating the transcription of most carbohydrate ABC transporter loci in response to nitrogen starvation in actinobacteria (36).…”

mentioning

confidence: 99%

See 2 more Smart Citations

GlnR and PhoP Directly Regulate the Transcription of Genes Encoding Starch-Degrading, Amylolytic Enzymes in Saccharopolyspora erythraea

Liao

Yao

et al. 2016

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

Starch-degrading enzymes hydrolyze starch-and starch-derived oligosaccharides to yield glucose. We investigated the transcriptional regulation of genes encoding starch-degrading enzymes in the industrial actinobacterium Saccharopolyspora erythraea. We observed that most genes encoding amylolytic enzymes (one ␣-amylase, one glucoamylase, and four ␣-glucosidases) were regulated by GlnR and PhoP, which are global regulators of nitrogen and phosphate metabolism, respectively. Electrophoretic mobility shift assays and reverse transcription-PCR (RT-PCR) analyses demonstrated that GlnR and PhoP directly interact with their promoter regions and collaboratively or competitively activate their transcription. Deletion of glnR caused poor growth on starch, maltodextrin, and maltose, whereas overexpression of glnR and phoP increased the total activity of ␣-glucosidase, resulting in enhanced carbohydrate utilization. Additionally, transcript levels of amylolytic genes and total glucosidase activity were induced in response to nitrogen and phosphate limitation. Furthermore, regulatory effects of GlnR and PhoP on starch-degrading enzymes were conserved in Streptomyces coelicolor A3(2). These results demonstrate that GlnR and PhoP are involved in polysaccharide degradation by mediating the interplay among carbon, nitrogen, and phosphate metabolism in response to cellular nutritional states. Our study reveals a novel regulatory mechanism underlying carbohydrate metabolism, and suggests new possibilities for designing genetic engineering approaches to improve the rate of utilization of starch in actinobacteria. IMPORTANCEThe development of efficient strategies for utilization of biomass-derived sugars, such as starch and cellulose, remains a major technical challenge due to the weak activity of associated enzymes. Here, we found that GlnR and PhoP directly regulate the transcription of genes encoding amylolytic enzymes and present insights into the regulatory mechanisms of degradation and utilization of starch in actinobacteria. Two nutrient-sensing regulators may play important roles in creating a direct association between nitrogen/phosphate metabolisms and carbohydrate utilization, as well as modulate the C:N:P balance in response to cellular nutritional states. These findings highlight the interesting possibilities for designing genetic engineering approaches and optimizing the fermentation process to improve the utilization efficiency of sugars in actinobacteria via overexpression of the glnR and phoP genes and nutrient signal stimulation.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

GlnR and PhoP Directly Regulate the Transcription of Genes Encoding Starch-Degrading, Amylolytic Enzymes in Saccharopolyspora erythraea

Liao

Yao

et al. 2016

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

show abstract

“…The GlnR regulon has been determined and includes at least 15 genes that encode proteins (mainly enzymes) involved in nitrogen source uptake and signal sensing (the amtB-glnK-glnD operon), alternative nitrogen source utilization (nirB, nasA, and ureA) and glutamine/glutamate synthesis (glnA, glnII, and gdhA) (6). The role of GlnR has also been investigated in other actinomycetes, including Streptomyces venezuelae (8), Amycolatopsis mediterranei (9), and Saccharopolyspora erythraea (10), among others. For instance, in S. venezuelae, a genome-wide analysis by chromatin immunoprecipitation (ChIP) assay coupled with microarray analysis (ChIP-chip) was performed and revealed the presence of 36 GlnR-binding sites, mainly located upstream of genes involved in nitrogen metabolism (8).…”

mentioning

confidence: 99%

Direct Involvement of the Master Nitrogen Metabolism Regulator GlnR in Antibiotic Biosynthesis in Streptomyces

Zhu

Zheng

et al. 2016

Journal of Biological Chemistry

View full text Add to dashboard Cite

Edited by Joel GottesfeldGlnR, an OmpR-like orphan two-component system response regulator, is a master regulator of nitrogen metabolism in the genus Streptomyces. In this work, evidence that GlnR is also directly involved in the regulation of antibiotic biosynthesis is provided. In the model strain Streptomyces coelicolor M145, an in-frame deletion of glnR resulted in markedly increased actinorhodin (ACT) production but reduced undecylprodigiosin (RED) biosynthesis when exposed to R2YE culture medium. Transcriptional analysis coupled with DNA binding studies revealed that GlnR represses ACT but activates RED production directly via the pathway-specific activator genes actII-ORF4 and redZ, respectively. The precise GlnR-binding sites upstream of these two target genes were defined. In addition, the direct involvement of GlnR in antibiotic biosynthesis was further identified in Streptomyces avermitilis, which produces the important anthelmintic agent avermectin. We found that S. avermitilis GlnR (GlnRsav) could stimulate avermectin but repress oligomycin production directly through the respective pathway-specific activator genes, aveR and olmRI/RII. To the best of our knowledge, this report describes the first experimental evidence demonstrating that GlnR regulates antibiotic biosynthesis directly through pathway-specific regulators in Streptomyces. Our results suggest that GlnR-mediated regulation of antibiotic biosynthesis is likely to be universal in streptomycetes. These findings also indicate that GlnR is not only a master nitrogen regulator but also an important controller of secondary metabolism, which may help to balance nitrogen metabolism and antibiotic biosynthesis in streptomycetes.

show abstract

“…S2; ref. 23), and GlnR has been shown to regulate their expression (24). We found that two GS enzymes, GSI-β GlnA1 and GSII GlnA4, were directly acetylated in vitro after incubation with AcuA and AcCoA; AcuA did not acetylate GlnA2 or GlnA3 ( Fig.…”

Section: Resultsmentioning

confidence: 70%

Sirtuin-dependent reversible lysine acetylation of glutamine synthetases reveals an autofeedback loop in nitrogen metabolism

You

Yin

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

In cells of all domains of life, reversible lysine acetylation modulates the function of proteins involved in central cellular processes such as metabolism. In this study, we demonstrate that the nitrogen regulator GlnR of the actinomycete Saccharopolyspora erythraea directly regulates transcription of the acuA gene (SACE_5148), which encodes a Gcn5-type lysine acetyltransferase. We found that AcuA acetylates two glutamine synthetases (GlnA1 and GlnA4) and that this lysine acetylation inactivated GlnA4 (GSII) but had no significant effect on GlnA1 (GSI-β) activity under the conditions tested. Instead, acetylation of GlnA1 led to a gain-of-function that modulated its interaction with the GlnR regulator and enhanced GlnR–DNA binding. It was observed that this regulatory function of acetylated GSI-β enzymes is highly conserved across actinomycetes. In turn, GlnR controls the catalytic and regulatory activities (intracellular acetylation levels) of glutamine synthetases at the transcriptional and posttranslational levels, indicating an autofeedback loop that regulates nitrogen metabolism in response to environmental change. Thus, this GlnR-mediated acetylation pathway provides a signaling cascade that acts from nutrient sensing to acetylation of proteins to feedback regulation. This work presents significant new insights at the molecular level into the mechanisms underlying the regulation of protein acetylation and nitrogen metabolism in actinomycetes.

show abstract

GlnR-mediated regulation of nitrogen metabolism in the actinomycete Saccharopolyspora erythraea

Cited by 47 publications

References 22 publications

GlnR and PhoP Directly Regulate the Transcription of Genes Encoding Starch-Degrading, Amylolytic Enzymes in Saccharopolyspora erythraea

GlnR and PhoP Directly Regulate the Transcription of Genes Encoding Starch-Degrading, Amylolytic Enzymes in Saccharopolyspora erythraea

Direct Involvement of the Master Nitrogen Metabolism Regulator GlnR in Antibiotic Biosynthesis in Streptomyces

Sirtuin-dependent reversible lysine acetylation of glutamine synthetases reveals an autofeedback loop in nitrogen metabolism

Contact Info

Product

Resources

About