RESUMO
The electron transport chain (ETC) of mitochondria, bacteria, and archaea couples electron flow to proton pumping and is adapted to diverse oxygen environments. Remarkably, in mice, neurological disease due to ETC complex I dysfunction is rescued by hypoxia through unknown mechanisms. Here, we show that hypoxia rescue and hyperoxia sensitivity of complex I deficiency are evolutionarily conserved to C. elegans and are specific to mutants that compromise the electron-conducting matrix arm. We show that hypoxia rescue does not involve the hypoxia-inducible factor pathway or attenuation of reactive oxygen species. To discover the mechanism, we use C. elegans genetic screens to identify suppressor mutations in the complex I accessory subunit NDUFA6/nuo-3 that phenocopy hypoxia rescue. We show that NDUFA6/nuo-3(G60D) or hypoxia directly restores complex I forward activity, with downstream rescue of ETC flux and, in some cases, complex I levels. Additional screens identify residues within the ubiquinone binding pocket as being required for the rescue by NDUFA6/nuo-3(G60D) or hypoxia. This reveals oxygen-sensitive coupling between an accessory subunit and the quinone binding pocket of complex I that can restore forward activity in the same manner as hypoxia.
Assuntos
Caenorhabditis elegans , Complexo I de Transporte de Elétrons , Hipóxia , Animais , Camundongos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Hipóxia/genética , Hipóxia/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Oxigênio/metabolismoRESUMO
Molybdenum- and tungsten-dependent proteins catalyze essential processes in living organisms and biogeochemical cycles. Among these enzymes, members of the dimethyl sulfoxide (DMSO) reductase superfamily are considered the most diverse, facilitating a wide range of chemical transformations that can be categorized as oxygen atom installation, removal, and transfer. Importantly, DMSO reductase enzymes provide high efficiency and excellent selectivity while operating under mild conditions without conventional oxidants such as oxygen or peroxides. Despite the potential utility of these enzymes as biocatalysts, such applications have not been fully explored. In addition, the vast majority of DMSO reductase enzymes still remain uncharacterized. In this review, we describe the reactivities, proposed mechanisms, and potential synthetic applications of selected enzymes in the DMSO reductase superfamily. We also highlight emerging opportunities to discover new chemical activity and current challenges in studying and engineering proteins in the DMSO reductase superfamily.
Assuntos
Proteínas Ferro-Enxofre , Oxirredutases , Proteínas Ferro-Enxofre/genética , Proteínas Ferro-Enxofre/metabolismo , Oxirredutases/metabolismo , Oxigênio/metabolismo , Tungstênio/metabolismoRESUMO
The investigation of water oxidation in photosynthesis has remained a central topic in biochemical research for the last few decades due to the importance of this catalytic process for technological applications. Significant progress has been made following the 2011 report of a high-resolution X-ray crystallographic structure resolving the site of catalysis, a protein-bound Mn4CaOx complex, which passes through ≥5 intermediate states in the water-splitting cycle. Spectroscopic techniques complemented by quantum chemical calculations aided in understanding the electronic structure of the cofactor in all (detectable) states of the enzymatic process. Together with isotope labeling, these techniques also revealed the binding of the two substrate water molecules to the cluster. These results are described in the context of recent progress using X-ray crystallography with free-electron lasers on these intermediates. The data are instrumental for developing a model for the biological water oxidation cycle.
Assuntos
Coenzimas/química , Manganês/química , Oxigênio/química , Complexo de Proteína do Fotossistema II/química , Água/química , Coenzimas/metabolismo , Cristalografia por Raios X , Expressão Gênica , Lasers , Manganês/metabolismo , Modelos Moleculares , Oxirredução , Oxigênio/metabolismo , Fotossíntese/fisiologia , Complexo de Proteína do Fotossistema II/genética , Complexo de Proteína do Fotossistema II/metabolismo , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Teoria Quântica , Termodinâmica , Thermosynechococcus/química , Thermosynechococcus/enzimologia , Água/metabolismoRESUMO
To celebrate the 2019 Nobel Prize in Physiology or Medicine, awarded to William G. Kaelin Jr., Sir Peter J. Ratcliffe, and Gregg L. Semenza for their discoveries of how cells sense and adapt to oxygen availability, we've asked four researchers in the oxygen-sensing field what they see on the horizon after this momentous milestone.
Assuntos
Pesquisa Biomédica/tendências , Hipóxia/metabolismo , Oxigênio/metabolismo , Distinções e Prêmios , Pesquisa Biomédica/história , História do Século XX , Humanos , Prêmio Nobel , PesquisadoresRESUMO
Acute physical activity leads to several changes in metabolic, cardiovascular, and immune pathways. Although studies have examined selected changes in these pathways, the system-wide molecular response to an acute bout of exercise has not been fully characterized. We performed longitudinal multi-omic profiling of plasma and peripheral blood mononuclear cells including metabolome, lipidome, immunome, proteome, and transcriptome from 36 well-characterized volunteers, before and after a controlled bout of symptom-limited exercise. Time-series analysis revealed thousands of molecular changes and an orchestrated choreography of biological processes involving energy metabolism, oxidative stress, inflammation, tissue repair, and growth factor response, as well as regulatory pathways. Most of these processes were dampened and some were reversed in insulin-resistant participants. Finally, we discovered biological pathways involved in cardiopulmonary exercise response and developed prediction models revealing potential resting blood-based biomarkers of peak oxygen consumption.
Assuntos
Metabolismo Energético/fisiologia , Exercício Físico/fisiologia , Idoso , Biomarcadores/metabolismo , Feminino , Humanos , Insulina/metabolismo , Resistência à Insulina , Leucócitos Mononucleares/metabolismo , Estudos Longitudinais , Masculino , Metaboloma , Pessoa de Meia-Idade , Oxigênio/metabolismo , Consumo de Oxigênio , Proteoma , TranscriptomaRESUMO
Human cells are able to sense and adapt to variations in oxygen levels. Historically, much research in this field has focused on hypoxia-inducible factor (HIF) signaling and reactive oxygen species (ROS). Here, we perform genome-wide CRISPR growth screens at 21%, 5%, and 1% oxygen to systematically identify gene knockouts with relative fitness defects in high oxygen (213 genes) or low oxygen (109 genes), most without known connection to HIF or ROS. Knockouts of many mitochondrial pathways thought to be essential, including complex I and enzymes in Fe-S biosynthesis, grow relatively well at low oxygen and thus are buffered by hypoxia. In contrast, in certain cell types, knockout of lipid biosynthetic and peroxisomal genes causes fitness defects only in low oxygen. Our resource nominates genetic diseases whose severity may be modulated by oxygen and links hundreds of genes to oxygen homeostasis.
Assuntos
Metabolismo dos Lipídeos/genética , Mitocôndrias/genética , Oxigênio/metabolismo , Transcriptoma/genética , Hipóxia Celular , Testes Genéticos/métodos , Estudo de Associação Genômica Ampla/métodos , Células HEK293 , Humanos , Hipóxia/metabolismo , Células K562 , Metabolismo dos Lipídeos/fisiologia , Lipídeos/genética , Lipídeos/fisiologia , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/fisiologiaRESUMO
Aerobic life is possible because the molecular structure of oxygen (O2) makes direct reaction with most organic materials at ambient temperatures an exceptionally slow process. Of course, these reactions are inherently very favorable, and they occur rapidly with the release of a great deal of energy at high temperature. Nature has been able to tap this sequestered reservoir of energy with great spatial and temporal selectivity at ambient temperatures through the evolution of oxidase and oxygenase enzymes. One mechanism used by these enzymes for O2 activation has been studied in detail for the soluble form of the enzyme methane monooxygenase. These studies have revealed the step-by-step process of O2 activation and insertion into the ultimately stable C-H bond of methane. Additionally, an elegant regulatory mechanism has been defined that enlists size selection and quantum tunneling to allow methane oxidation to occur specifically in the presence of more easily oxidized substrates.
Assuntos
Bactérias/enzimologia , Metano/metabolismo , Oxigênio/metabolismo , Oxigenases/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Cristalografia , Cinética , Methylococcus capsulatus/enzimologia , Methylosinus trichosporium/enzimologia , Oxigenases/química , Conformação ProteicaRESUMO
Microbial populations can maximize fitness in dynamic environments through bet hedging, a process wherein a subpopulation assumes a phenotype not optimally adapted to the present environment but well adapted to an environment likely to be encountered. Here, we show that oxygen induces fluctuating expression of the trimethylamine oxide (TMAO) respiratory system of Escherichia coli, diversifying the cell population and enabling a bet-hedging strategy that permits growth following oxygen loss. This regulation by oxygen affects the variance in gene expression but leaves the mean unchanged. We show that the oxygen-sensitive transcription factor IscR is the key regulator of variability. Oxygen causes IscR to repress expression of a TMAO-responsive signaling system, allowing stochastic effects to have a strong effect on the output of the system and resulting in heterogeneous expression of the TMAO reduction machinery. This work reveals a mechanism through which cells regulate molecular noise to enhance fitness.
Assuntos
Escherichia coli/metabolismo , Transdução de Sinais , Aerobiose , Anaerobiose , Sequência de Bases , Sítios de Ligação , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Metilaminas/metabolismo , Metilaminas/farmacologia , Oxigênio/metabolismo , Proteínas Periplásmicas/química , Proteínas Periplásmicas/genética , Proteínas Periplásmicas/metabolismo , Fosfotransferases/química , Fosfotransferases/genética , Fosfotransferases/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Regulação para CimaRESUMO
Molecular oxygen (O2) sustains intracellular bioenergetics and is consumed by numerous biochemical reactions, making it essential for most species on Earth. Accordingly, decreased oxygen concentration (hypoxia) is a major stressor that generally subverts life of aerobic species and is a prominent feature of pathological states encountered in bacterial infection, inflammation, wounds, cardiovascular defects and cancer. Therefore, key adaptive mechanisms to cope with hypoxia have evolved in mammals. Systemically, these adaptations include increased ventilation, cardiac output, blood vessel growth and circulating red blood cell numbers. On a cellular level, ATP-consuming reactions are suppressed, and metabolism is altered until oxygen homeostasis is restored. A critical question is how mammalian cells sense oxygen levels to coordinate diverse biological outputs during hypoxia. The best-studied mechanism of response to hypoxia involves hypoxia inducible factors (HIFs), which are stabilized by low oxygen availability and control the expression of a multitude of genes, including those involved in cell survival, angiogenesis, glycolysis and invasion/metastasis. Importantly, changes in oxygen can also be sensed via other stress pathways as well as changes in metabolite levels and the generation of reactive oxygen species by mitochondria. Collectively, this leads to cellular adaptations of protein synthesis, energy metabolism, mitochondrial respiration, lipid and carbon metabolism as well as nutrient acquisition. These mechanisms are integral inputs into fine-tuning the responses to hypoxic stress.
Assuntos
Hipóxia Celular/genética , Metabolismo Energético/genética , Estresse Oxidativo/genética , Oxigênio/metabolismo , Trifosfato de Adenosina/metabolismo , Humanos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/genéticaRESUMO
The 2016 Albert Lasker Basic Medical Research Award is being awarded to Gregg Semenza, William Kaelin, and Peter Ratcliffe for discovery of the pathway by which human and animal cells sense and adapt to changes in oxygen availability-an essential requirement for survival. Bill and Peter joined Cell editor João Monteiro in an informal conversation about science, medicine, designing experiments, and training the next generation.
Assuntos
Distinções e Prêmios , Hipóxia Celular , Oxigênio/metabolismo , Animais , HumanosRESUMO
This year's Lasker Basic Medical Research Award is shared by William Kaelin, Peter Ratcliffe, and Gregg Semenza for discovery of the pathway by which animal cells sense and adapt to changes in oxygen availability, which plays an essential role in adaptation to a wide variety of physiologic and pathologic conditions.
Assuntos
Adaptação Fisiológica , Distinções e Prêmios , Pesquisa Biomédica , Hipóxia Celular , Oxigênio/metabolismo , Anaerobiose , Animais , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismoRESUMO
Aerobic organisms survive low oxygen (O2) through activation of diverse molecular, metabolic, and physiological responses. In most plants, root water permeability (in other words, hydraulic conductivity, Lpr) is downregulated under O2 deficiency. Here, we used a quantitative genetics approach in Arabidopsis to clone Hydraulic Conductivity of Root 1 (HCR1), a Raf-like MAPKKK that negatively controls Lpr. HCR1 accumulates and is functional under combined O2 limitation and potassium (K(+)) sufficiency. HCR1 regulates Lpr and hypoxia responsive genes, through the control of RAP2.12, a key transcriptional regulator of the core anaerobic response. A substantial variation of HCR1 in regulating Lpr is observed at the Arabidopsis species level. Thus, by combinatorially integrating two soil signals, K(+) and O2 availability, HCR1 modulates the resilience of plants to multiple flooding scenarios.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Oxigênio/metabolismo , Raízes de Plantas/metabolismo , Potássio/metabolismo , Água/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA , Regulação da Expressão Gênica de Plantas , MAP Quinase Quinase Quinases/genética , Permeabilidade , Fatores de Transcrição/genéticaRESUMO
Cancer cells must evade immune responses at distant sites to establish metastases. The lung is a frequent site for metastasis. We hypothesized that lung-specific immunoregulatory mechanisms create an immunologically permissive environment for tumor colonization. We found that T-cell-intrinsic expression of the oxygen-sensing prolyl-hydroxylase (PHD) proteins is required to maintain local tolerance against innocuous antigens in the lung but powerfully licenses colonization by circulating tumor cells. PHD proteins limit pulmonary type helper (Th)-1 responses, promote CD4(+)-regulatory T (Treg) cell induction, and restrain CD8(+) T cell effector function. Tumor colonization is accompanied by PHD-protein-dependent induction of pulmonary Treg cells and suppression of IFN-γ-dependent tumor clearance. T-cell-intrinsic deletion or pharmacological inhibition of PHD proteins limits tumor colonization of the lung and improves the efficacy of adoptive cell transfer immunotherapy. Collectively, PHD proteins function in T cells to coordinate distinct immunoregulatory programs within the lung that are permissive to cancer metastasis. PAPERCLIP.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/secundário , Pulmão/imunologia , Oxigênio/metabolismo , Prolil Hidroxilases/metabolismo , Linfócitos T Reguladores/imunologia , Transferência Adotiva , Animais , Linfócitos T CD8-Positivos/enzimologia , Glicólise/imunologia , Interferon gama/imunologia , Pulmão/patologia , Neoplasias Pulmonares/terapia , Ativação Linfocitária , Camundongos , Camundongos Knockout , Metástase Neoplásica , Neuropilina-1/metabolismo , Prolil Hidroxilases/genética , Linfócitos T Reguladores/enzimologia , Células Th1/enzimologia , Células Th1/imunologiaRESUMO
Oxygen is toxic across all three domains of life. Yet, the underlying molecular mechanisms remain largely unknown. Here, we systematically investigate the major cellular pathways affected by excess molecular oxygen. We find that hyperoxia destabilizes a specific subset of Fe-S cluster (ISC)-containing proteins, resulting in impaired diphthamide synthesis, purine metabolism, nucleotide excision repair, and electron transport chain (ETC) function. Our findings translate to primary human lung cells and a mouse model of pulmonary oxygen toxicity. We demonstrate that the ETC is the most vulnerable to damage, resulting in decreased mitochondrial oxygen consumption. This leads to further tissue hyperoxia and cyclic damage of the additional ISC-containing pathways. In support of this model, primary ETC dysfunction in the Ndufs4 KO mouse model causes lung tissue hyperoxia and dramatically increases sensitivity to hyperoxia-mediated ISC damage. This work has important implications for hyperoxia pathologies, including bronchopulmonary dysplasia, ischemia-reperfusion injury, aging, and mitochondrial disorders.
Assuntos
Hiperóxia , Doenças Mitocondriais , Animais , Humanos , Camundongos , Complexo I de Transporte de Elétrons/metabolismo , Hiperóxia/metabolismo , Hiperóxia/patologia , Pulmão/metabolismo , Mitocôndrias/metabolismo , Doenças Mitocondriais/metabolismo , Oxigênio/metabolismoRESUMO
Oxygenic photosynthesis is the principal converter of sunlight into chemical energy on Earth. Cyanobacteria and plants provide the oxygen, food, fuel, fibers, and platform chemicals for life on Earth. The conversion of solar energy into chemical energy is catalyzed by two multisubunit membrane protein complexes, photosystem I (PSI) and photosystem II (PSII). Light is absorbed by the pigment cofactors, and excitation energy is transferred among the antennae pigments and converted into chemical energy at very high efficiency. Oxygenic photosynthesis has existed for more than three billion years, during which its molecular machinery was perfected to minimize wasteful reactions. Light excitation transfer and singlet trapping won over fluorescence, radiation-less decay, and triplet formation. Photosynthetic reaction centers operate in organisms ranging from bacteria to higher plants. They are all evolutionarily linked. The crystal structure determination of photosynthetic protein complexes sheds light on the various partial reactions and explains how they are protected against wasteful pathways and why their function is robust. This review discusses the efficiency of photosynthetic solar energy conversion.
Assuntos
Oxigênio/metabolismo , Complexo de Proteínas do Centro de Reação Fotossintética/química , Proteínas de Bactérias/metabolismo , Cianobactérias/metabolismo , Tomografia com Microscopia Eletrônica , Complexo de Proteínas do Centro de Reação Fotossintética/ultraestrutura , Proteínas de Plantas/metabolismo , Plantas/metabolismoRESUMO
Molecular oxygen (O2) is a key substrate for mitochondrial ATP production and numerous intracellular biochemical reactions. The maintenance of O2 homeostasis is therefore essential for the survival of most species. During O2 deprivation, mammalian cells rely on multiple adaptations mediated by the hypoxia-inducible factors (HIFs), mTOR, autophagy, and the ER stress response. This SnapShot will summarize recent reports expanding our current understanding of HIF-dependent adaptations to low O2 levels.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/química , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Oxigênio/metabolismo , Animais , Humanos , Modelos Moleculares , Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
Hematopoietic stem cells (HSCs) reside in hypoxic niches within bone marrow and cord blood. Yet, essentially all HSC studies have been performed with cells isolated and processed in non-physiologic ambient air. By collecting and manipulating bone marrow and cord blood in native conditions of hypoxia, we demonstrate that brief exposure to ambient oxygen decreases recovery of long-term repopulating HSCs and increases progenitor cells, a phenomenon we term extraphysiologic oxygen shock/stress (EPHOSS). Thus, true numbers of HSCs in the bone marrow and cord blood are routinely underestimated. We linked ROS production and induction of the mitochondrial permeability transition pore (MPTP) via cyclophilin D and p53 as mechanisms of EPHOSS. The MPTP inhibitor cyclosporin A protects mouse bone marrow and human cord blood HSCs from EPHOSS during collection in air, resulting in increased recovery of transplantable HSCs. Mitigating EPHOSS during cell collection and processing by pharmacological means may be clinically advantageous for transplantation.
Assuntos
Medula Óssea , Sangue Fetal/citologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Peptidil-Prolil Isomerase F , Ciclofilinas/metabolismo , Feminino , Transplante de Células-Tronco Hematopoéticas/instrumentação , Células-Tronco Hematopoéticas/citologia , Humanos , Hipóxia , Camundongos , Camundongos Endogâmicos C57BL , Oxigênio/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
Organisms must be able to respond to low oxygen in a number of homeostatic and pathological contexts. Regulation of hypoxic responses via the hypoxia-inducible factor (HIF) is well established, but evidence indicates that other, HIF-independent mechanisms are also involved. Here, we report a hypoxic response that depends on the accumulation of lactate, a metabolite whose production increases in hypoxic conditions. We find that the NDRG3 protein is degraded in a PHD2/VHL-dependent manner in normoxia but is protected from destruction by binding to lactate that accumulates under hypoxia. The stabilized NDRG3 protein binds c-Raf to mediate hypoxia-induced activation of Raf-ERK pathway, promoting angiogenesis and cell growth. Inhibiting cellular lactate production abolishes the NDRG3-mediated hypoxia responses. Our study, therefore, elucidates the molecular basis for lactate-induced hypoxia signaling, which can be exploited for the development of therapies targeting hypoxia-induced diseases.
Assuntos
Hipóxia/metabolismo , Ácido Láctico/metabolismo , Hipóxia Celular , Linhagem Celular , Regulação da Expressão Gênica , Humanos , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Sistema de Sinalização das MAP Quinases , Neovascularização Patológica/metabolismo , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/metabolismo , Oxigênio/metabolismo , Ligação Proteica , Quinases raf/metabolismoRESUMO
Stem cells reside in specialized microenvironments known as niches. During Drosophila development, glial cells provide a niche that sustains the proliferation of neural stem cells (neuroblasts) during starvation. We now find that the glial cell niche also preserves neuroblast proliferation under conditions of hypoxia and oxidative stress. Lipid droplets that form in niche glia during oxidative stress limit the levels of reactive oxygen species (ROS) and inhibit the oxidation of polyunsaturated fatty acids (PUFAs). These droplets protect glia and also neuroblasts from peroxidation chain reactions that can damage many types of macromolecules. The underlying antioxidant mechanism involves diverting PUFAs, including diet-derived linoleic acid, away from membranes to the core of lipid droplets, where they are less vulnerable to peroxidation. This study reveals an antioxidant role for lipid droplets that could be relevant in many different biological contexts.
Assuntos
Drosophila/citologia , Drosophila/metabolismo , Gotículas Lipídicas/metabolismo , Nicho de Células-Tronco/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Proliferação de Células , Drosophila/crescimento & desenvolvimento , Ácidos Graxos Insaturados/farmacologia , Larva/citologia , Larva/crescimento & desenvolvimento , Larva/metabolismo , Neuroglia/metabolismo , Estresse Oxidativo , Oxigênio/metabolismo , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacosRESUMO
The initial rise of molecular oxygen (O2) shortly after the Archaean-Proterozoic transition 2.5 billion years ago was more complex than the single step-change once envisioned. Sulfur mass-independent fractionation records suggest that the rise of atmospheric O2 was oscillatory, with multiple returns to an anoxic state until perhaps 2.2 billion years ago1-3. Yet few constraints exist for contemporaneous marine oxygenation dynamics, precluding a holistic understanding of planetary oxygenation. Here we report thallium (Tl) isotope ratio and redox-sensitive element data for marine shales from the Transvaal Supergroup, South Africa. Synchronous with sulfur isotope evidence of atmospheric oxygenation in the same shales3, we found lower authigenic 205Tl/203Tl ratios indicative of widespread manganese oxide burial on an oxygenated seafloor and higher redox-sensitive element abundances consistent with expanded oxygenated waters. Both signatures disappear when the sulfur isotope data indicate a brief return to an anoxic atmospheric state. Our data connect recently identified atmospheric O2 dynamics on early Earth with the marine realm, marking an important turning point in Earth's redox history away from heterogeneous and highly localized 'oasis'-style oxygenation.