Dataset Information

Coordinate Regulation of Antimycin and Candicidin Biosynthesis.

ABSTRACT: Streptomyces species produce an incredible array of high-value specialty chemicals and medicinal therapeutics. A single species typically harbors ~30 biosynthetic pathways, but only a few them are expressed in the laboratory; thus, poor understanding of how natural-product biosynthesis is regulated is a major bottleneck in drug discovery. Antimycins are a large family of anticancer compounds widely produced by Streptomyces species, and their regulation is atypical compared to that of most other natural products. Here we demonstrate that antimycin production by Streptomyces albus S4 is regulated by FscRI, a PAS-LuxR family cluster-situated regulator of the polyene antifungal agent candicidin. We report that heterologous production of antimycins by Streptomyces coelicolor is dependent on FscRI and show that FscRI activates the transcription of key biosynthetic genes. We also demonstrate through chromatin immunoprecipitation sequencing that FscRI regulation is direct, and we provide evidence that this regulation strategy is conserved and unique to short-form antimycin gene clusters. Our study provides direct in vivo evidence of the cross-regulation of disparate biosynthetic gene clusters specifying unrelated natural products and expands the paradigmatic understanding of the regulation of secondary metabolism. IMPORTANCE Natural products produced by members of the phylum Actinobacteria underpin many industrially and medically important compounds; however, the majority of the ~30 biosynthetic pathways harbored by an average species are not expressed in the laboratory. Understanding the diversity of regulatory strategies controlling the expression of these pathways is therefore critical if their biosynthetic potential is to be explored for new drug leads. Our findings reveal that the candicidin cluster-situated regulator FscRI coordinately controls the biosynthesis of both candicidin and antimycin, which is the first observation of cross-regulation of disparate biosynthetic gene clusters specifying unrelated natural products. We anticipate that this will emerge as a major strategy by which members of the phylum Actinobacteria coordinately produce natural products, which will advance our understanding of how the expression of secondary metabolism is controlled and will aid the pursuit of "silent" biosynthetic pathway activation.

SUBMITTER: McLean TC

PROVIDER: S-EPMC5143413 | biostudies-literature | 2016 Nov-Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Coordinate Regulation of Antimycin and Candicidin Biosynthesis.

McLean Thomas C TC Hoskisson Paul A PA Seipke Ryan F RF

mSphere 20161101 6

<i>Streptomyces</i> species produce an incredible array of high-value specialty chemicals and medicinal therapeutics. A single species typically harbors ~30 biosynthetic pathways, but only a few them are expressed in the laboratory; thus, poor understanding of how natural-product biosynthesis is regulated is a major bottleneck in drug discovery. Antimycins are a large family of anticancer compounds widely produced by <i>Streptomyces</i> species, and their regulation is atypical compared to that ...[more]

PMID: 27981234

Similar Datasets

Project description:The survival of any microbe relies on its ability to respond to environmental change. Use of extracytoplasmic function (ECF) RNA polymerase sigma (σ) factors is a major strategy enabling dynamic responses to extracellular signals. Streptomyces species harbor a large number of ECF σ factors, nearly all of which are uncharacterized, but those that have been characterized generally regulate genes required for morphological differentiation and/or response to environmental stress, except for σAntA, which regulates starter-unit biosynthesis in the production of antimycin, an anticancer compound. Unlike a canonical ECF σ factor, whose activity is regulated by a cognate anti-σ factor, σAntA is an orphan, raising intriguing questions about how its activity may be controlled. Here, we reconstituted in vitro ClpXP proteolysis of σAntA but not of a variant lacking a C-terminal di-alanine motif. Furthermore, we show that the abundance of σAntAin vivo was enhanced by removal of the ClpXP recognition sequence and that levels of the protein rose when cellular ClpXP protease activity was abolished. These data establish direct proteolysis as an alternative and, thus far, unique control strategy for an ECF RNA polymerase σ factor and expands the paradigmatic understanding of microbial signal transduction regulation.IMPORTANCE Natural products produced by Streptomyces species underpin many industrially and medically important compounds. However, the majority of the ∼30 biosynthetic pathways harbored by an average species are not expressed in the laboratory. This unrevealed biochemical diversity is believed to comprise an untapped resource for natural product drug discovery. Major roadblocks preventing the exploitation of unexpressed biosynthetic pathways are a lack of insight into their regulation and limited technology for activating their expression. Our findings reveal that the abundance of σAntA, which is the cluster-situated regulator of antimycin biosynthesis, is controlled by the ClpXP protease. These data link proteolysis to the regulation of natural product biosynthesis for the first time to our knowledge, and we anticipate that this will emerge as a major strategy by which actinobacteria regulate production of their natural products. Further study of this process will advance understanding of how expression of secondary metabolism is controlled and will aid pursuit of activating unexpressed biosynthetic pathways.

Project description:Secondary metabolites play a key role in coordinating ecology and defense strategies of plants. Diversity of these metabolites arise by conjugation of core structures with diverse chemical moieties, such as sugars in glycosylation. Active pools of phytohormones, including those involved in plant stress response are also regulated by glycosylation. While, much is known about the enzymes involved in glycosylation, we know little about their regulation or coordination with other processes. We characterized the flavonoid pathway transcription factor, TRANSPARENT TESTA 8 (TT8) in Arabidopsis thaliana, using an integrative omics strategy. This approach provides a systems level understanding of the cellular machinery that is used to generate metabolite diversity by glycosylation. Metabolomics analysis of TT8 loss-of-function and inducible overexpression lines showed that TT8 coordinates glycosylation of not only flavonoids, but also nucleotides, thus, implicating TT8 in regulating pools of activated nucleotide sugars. Transcriptome and promoter network analyses revealed that TT8 regulome included sugar transporters, proteins involved in sugar binding and sequestration, and a number of carbohydrate active enzymes. Importantly, TT8 affects stress response, along with brassinosteroid and jasmonic acid biosynthesis, by directly binding to the promoters of key genes of these processes. This combined effect on metabolites glycosylation and stress hormones by TT8 inducible overexpression led to significant increase in tolerance towards multiple abiotic and biotic stresses. Conversely, loss of TT8 leads to increased sensitivity to these stresses. Thus, the transcription factor TT8 is an integrator of secondary metabolism and stress response. These findings provide novel approaches to improve broad-spectrum stress tolerance. Gene expression analysis for 6-day old Arabidopsis thaliana seedling were performed for TT8 loss-of-function line, tt8-3 (in Ws background), and its wild type background control, Ws. Two independent biological replicates for each line were hybridized onto two slides of Agilent SurePrint G2 Agilent Arabidopsis V4 (4x44K), with each slide having two technical replicates for each line. Contributors: Amit Rai, Shivshankar Umashankar, Megha, Lim Boon Kiat, Johanan Aow Shao Bing, Sanjay Swarup.

Dataset Information

Coordinate Regulation of Antimycin and Candicidin Biosynthesis.

Publications

Coordinate Regulation of Antimycin and Candicidin Biosynthesis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets