RESUMO
Exercise exerts a wide range of beneficial effects for healthy physiology1. However, the mechanisms regulating an individual's motivation to engage in physical activity remain incompletely understood. An important factor stimulating the engagement in both competitive and recreational exercise is the motivating pleasure derived from prolonged physical activity, which is triggered by exercise-induced neurochemical changes in the brain. Here, we report on the discovery of a gut-brain connection in mice that enhances exercise performance by augmenting dopamine signalling during physical activity. We find that microbiome-dependent production of endocannabinoid metabolites in the gut stimulates the activity of TRPV1-expressing sensory neurons and thereby elevates dopamine levels in the ventral striatum during exercise. Stimulation of this pathway improves running performance, whereas microbiome depletion, peripheral endocannabinoid receptor inhibition, ablation of spinal afferent neurons or dopamine blockade abrogate exercise capacity. These findings indicate that the rewarding properties of exercise are influenced by gut-derived interoceptive circuits and provide a microbiome-dependent explanation for interindividual variability in exercise performance. Our study also suggests that interoceptomimetic molecules that stimulate the transmission of gut-derived signals to the brain may enhance the motivation for exercise.
Assuntos
Eixo Encéfalo-Intestino , Dopamina , Exercício Físico , Microbioma Gastrointestinal , Motivação , Corrida , Animais , Camundongos , Encéfalo/citologia , Encéfalo/metabolismo , Dopamina/metabolismo , Endocanabinoides/antagonistas & inibidores , Endocanabinoides/metabolismo , Células Receptoras Sensoriais/metabolismo , Eixo Encéfalo-Intestino/fisiologia , Microbioma Gastrointestinal/fisiologia , Exercício Físico/fisiologia , Exercício Físico/psicologia , Condicionamento Físico Animal/fisiologia , Condicionamento Físico Animal/psicologia , Modelos Animais , Humanos , Estriado Ventral/citologia , Estriado Ventral/metabolismo , Corrida/fisiologia , Corrida/psicologia , Recompensa , IndividualidadeRESUMO
Biomacromolecules are known to feature complex three-dimensional shapes that are essential for their function. Among natural products, ambiguous molecular shapes are a rare phenomenon. The hexapeptide tryptorubin A can adopt one of two unusual atropisomeric configurations. Initially hypothesized to be a non-ribosomal peptide, we show that tryptorubin A is the first characterized member of a new family of ribosomally synthesized and posttranslationally modified peptides (RiPPs) that we named atropopeptides. The sole modifying enzyme encoded in the gene cluster, a cytochrome P450 monooxygenase, is responsible for the atropospecific formation of one carbon-carbon and two carbon-nitrogen bonds. The characterization of two additional atropopeptide biosynthetic pathways revealed a two-step maturation process. Atropopeptides promote pro-angiogenic cell functions as indicated by an increase in endothelial cell proliferation and undirected migration. Our study expands the biochemical space of RiPP-modifying enzymes and paves the way towards the chemoenzymatic utilization of atropopeptide-modifying P450s.
Assuntos
Produtos Biológicos , Ribossomos , Produtos Biológicos/química , Carbono/metabolismo , Oxigenases de Função Mista/metabolismo , Família Multigênica , Nitrogênio/metabolismo , Peptídeos/química , Processamento de Proteína Pós-Traducional , Ribossomos/metabolismoRESUMO
Bisphenol A (BPA) is one of the most common toxic endocrine disruptors in the environment. A fast, efficient and environmental-friendly method for BPA detoxification is urgently needed. In this study, we show that the enzymatic transformation of BPA into a non-estrogenic BPA sulfate can be performed by the aryl sulfotransferase (ASTB) from Desulfitobacterium hafniense. We developed and compared two Escherichia coli ASTB cell-surface displaying systems using the outer membrane porin F (OprF) and the lipoprotein outer membrane A (Lpp-OmpA) as carriers. The surface localization of both fusion proteins was confirmed by Western blot and flow cytometry analysis as well as the enzymatic activity assay of the outer membrane fractions. Unfortunately, Lpp-OmpA-ASTB cells had an adverse effect on cell growth. In contrast, the OprF-ASTB cell biocatalyst was stable, expressing 70% of enzyme activity for 7 days. It also efficiently sulfated 90% of 5 mM BPA (1 mg/mL) in wastewater within 6 h.
Assuntos
Arilsulfotransferase/metabolismo , Compostos Benzidrílicos/metabolismo , Desulfitobacterium/enzimologia , Disruptores Endócrinos/metabolismo , Fenóis/metabolismo , Poluentes Químicos da Água/metabolismo , Compostos Benzidrílicos/isolamento & purificação , Biotransformação , Disruptores Endócrinos/isolamento & purificação , Escherichia coli/enzimologia , Fenóis/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodosRESUMO
The Sinorhizobium meliloti chpA promoter is highly induced in the presence of the pesticide chlorpyrifos (CPF) through the action of the transcriptional activator, ChpR. A whole-cell biosensor for the detection of CPF was developed and is composed of an Escherichia coli strain carrying a chpR expression vector and a chpA promoter-atsBA transcriptional fusion plasmid encoding sulfatase (atsA) and formylglycine generating enzyme (atsB) from Klebsiella sp. The sulfatase is posttranslationally activated by formylglycine generating enzyme (FGE) and then converts 4-methylumbelliferyl sulfate (4-MUS) to the fluorescent product, 4-methyllumbelliferone (4-MU). This biosensor system exhibited a linear response range from 25 to 500 nM CPF.
Assuntos
Técnicas Biossensoriais/métodos , Clorpirifos/análise , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Praguicidas/análise , Sinorhizobium meliloti/genética , Proteínas de Bactérias/genética , Clorpirifos/metabolismo , Klebsiella/genética , Praguicidas/metabolismo , Plasmídeos/genética , Regiões Promotoras Genéticas/efeitos dos fármacosRESUMO
Complex peptide natural products exhibit diverse biological functions and a wide range of physico-chemical properties. As a result, many peptides have entered the clinics for various applications. Two main routes for the biosynthesis of complex peptides have evolved in nature: ribosomally synthesized and post-translationally modified peptide (RiPP) biosynthetic pathways and non-ribosomal peptide synthetases (NRPSs). Insights into both bioorthogonal peptide biosynthetic strategies led to the establishment of universal principles for each of the two routes. These universal rules can be leveraged for the targeted identification of novel peptide biosynthetic blueprints in genome sequences and used for the rational engineering of biosynthetic pathways to produce non-natural peptides. In this review, we contrast the key principles of both biosynthetic routes and compare the different biochemical strategies to install the most frequently encountered peptide modifications. In addition, the influence of the fundamentally different biosynthetic principles on past, current and future engineering approaches is illustrated. Despite the different biosynthetic principles of both peptide biosynthetic routes, the arsenal of characterized peptide modifications encountered in RiPP and NRPS systems is largely overlapping. The continuous expansion of the biocatalytic toolbox of peptide modifying enzymes for both routes paves the way towards the production of complex tailor-made peptides and opens up the possibility to produce NRPS-derived peptides using the ribosomal route and vice versa.
RESUMO
Morphotype switches frequently occur in Actinobacteria and are often associated with disparate natural product production. Here, we report on differences in the secondary metabolomes of two morphotypes of a Streptomyces species, including the discovery of a novel antimicrobial glycosylated macrolide, which we named termidomycin A. While exhibiting an unusual 46-member polyene backbone, termidomycin A (1) shares structural features with the clinically important antifungal agents amphotericin B and nystatin A1. Genomic analyses revealed a biosynthetic gene cluster encoding for a putative giant type I polyketide synthase (PKS), whose domain structure allowed us to propose the relative configuration of the 46-member macrolide. The architecture of the biosynthetic gene cluster was different in both morphotypes, thus leading to diversification of the product spectrum. Given the high frequency of genomic rearrangements in Streptomycetes, the metabolic analysis of distinct morphotypes as exemplified in this study is a promising approach for the discovery of bioactive natural products and pathways of diversification.
Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Macrolídeos/farmacologia , Streptomyces/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antifúngicos/química , Antifúngicos/isolamento & purificação , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Genômica , Macrolídeos/química , Macrolídeos/isolamento & purificação , Metabolômica , Testes de Sensibilidade Microbiana , Família Multigênica , Policetídeo Sintases/genética , Policetídeo Sintases/metabolismo , Streptomyces/genética , Streptomyces/metabolismoRESUMO
Proteus sp. SW1 was found to produce an extracellular solvent tolerant lipase. The gene, lipA, encoding a bacterial lipase, was cloned from total Proteus sp. SW1 DNA. lipA was predicted to encode a 287 amino acid protein of 31.2 kDa belonging to the Group I proteobacterial lipases. Purified His-tagged LipA exhibited optimal activity at pH 10.0 and 55°C. It was highly stable in organic solvents retaining 112% of its activity in 100% isopropanol after 24 h, and exhibited more than 200% of its initial activity upon exposure to 60% acetone, ethanol, and hexane for 18 h. Biodiesel synthesis reactions, using a single step addition of 13% an acyl acceptor ethanol, showed that LipA was highly effective at converting palm oil into biodiesel.