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1.
Cell ; 169(3): 457-469.e13, 2017 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-28431246

RESUMO

Fat metabolism has been linked to fertility and reproductive adaptation in animals and humans, and environmental sex determination potentially plays a role in the process. To investigate the impact of fatty acids (FA) on sex determination and reproductive development, we examined and observed an impact of FA synthesis and mobilization by lipolysis in somatic tissues on oocyte fate in Caenorhabditis elegans. The subsequent genetic analysis identified ACS-4, an acyl-CoA synthetase and its FA-CoA product, as key germline factors that mediate the role of FA in promoting oocyte fate through protein myristoylation. Further tests indicated that ACS-4-dependent protein myristoylation perceives and translates the FA level into regulatory cues that modulate the activities of MPK-1/MAPK and key factors in the germline sex-determination pathway. These findings, including a similar role of ACS-4 in a male/female species, uncover a likely conserved mechanism by which FA, an environmental factor, regulates sex determination and reproductive development.


Assuntos
Acetato-CoA Ligase/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Ácidos Graxos/metabolismo , Ácido Mirístico/metabolismo , Processamento de Proteína Pós-Traducional , Processos de Determinação Sexual , Acetato-CoA Ligase/genética , Animais , Proteínas de Caenorhabditis elegans/genética , Mutação , Oócitos/metabolismo
2.
Nature ; 630(8016): 466-474, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38839952

RESUMO

Histone acetylation regulates gene expression, cell function and cell fate1. Here we study the pattern of histone acetylation in the epithelial tissue of the Drosophila wing disc. H3K18ac, H4K8ac and total lysine acetylation are increased in the outer rim of the disc. This acetylation pattern is controlled by nuclear position, whereby nuclei continuously move from apical to basal locations within the epithelium and exhibit high levels of H3K18ac when they are in proximity to the tissue surface. These surface nuclei have increased levels of acetyl-CoA synthase, which generates the acetyl-CoA for histone acetylation. The carbon source for histone acetylation in the rim is fatty acid ß-oxidation, which is also increased in the rim. Inhibition of fatty acid ß-oxidation causes H3K18ac levels to decrease in the genomic proximity of genes involved in disc development. In summary, there is a physical mark of the outer rim of the wing and other imaginal epithelia in Drosophila that affects gene expression.


Assuntos
Acetilcoenzima A , Núcleo Celular , Cromatina , Drosophila melanogaster , Animais , Acetato-CoA Ligase/metabolismo , Acetilcoenzima A/metabolismo , Acetilação , Transporte Biológico , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cromatina/metabolismo , Cromatina/genética , Drosophila melanogaster/enzimologia , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica , Histonas/química , Histonas/metabolismo , Discos Imaginais/citologia , Discos Imaginais/crescimento & desenvolvimento , Discos Imaginais/metabolismo , Lisina/metabolismo , Oxirredução , Asas de Animais/citologia , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismo
3.
Cell ; 159(7): 1591-602, 2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25525877

RESUMO

Acetyl-CoA represents a central node of carbon metabolism that plays a key role in bioenergetics, cell proliferation, and the regulation of gene expression. Highly glycolytic or hypoxic tumors must produce sufficient quantities of this metabolite to support cell growth and survival under nutrient-limiting conditions. Here, we show that the nucleocytosolic acetyl-CoA synthetase enzyme, ACSS2, supplies a key source of acetyl-CoA for tumors by capturing acetate as a carbon source. Despite exhibiting no gross deficits in growth or development, adult mice lacking ACSS2 exhibit a significant reduction in tumor burden in two different models of hepatocellular carcinoma. ACSS2 is expressed in a large proportion of human tumors, and its activity is responsible for the majority of cellular acetate uptake into both lipids and histones. These observations may qualify ACSS2 as a targetable metabolic vulnerability of a wide spectrum of tumors.


Assuntos
Acetato-CoA Ligase/metabolismo , Acetatos/metabolismo , Neoplasias/metabolismo , Acetato-CoA Ligase/análise , Acetato-CoA Ligase/genética , Acetilcoenzima A/metabolismo , Animais , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/metabolismo , Camundongos , Neoplasias/química , Neoplasias/patologia , Tomografia por Emissão de Pósitrons , Neoplasias de Mama Triplo Negativas/química , Neoplasias de Mama Triplo Negativas/patologia
4.
Cell ; 159(7): 1603-14, 2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25525878

RESUMO

Glioblastomas and brain metastases are highly proliferative brain tumors with short survival times. Previously, using (13)C-NMR analysis of brain tumors resected from patients during infusion of (13)C-glucose, we demonstrated that there is robust oxidation of glucose in the citric acid cycle, yet glucose contributes less than 50% of the carbons to the acetyl-CoA pool. Here, we show that primary and metastatic mouse orthotopic brain tumors have the capacity to oxidize [1,2-(13)C]acetate and can do so while simultaneously oxidizing [1,6-(13)C]glucose. The tumors do not oxidize [U-(13)C]glutamine. In vivo oxidation of [1,2-(13)C]acetate was validated in brain tumor patients and was correlated with expression of acetyl-CoA synthetase enzyme 2, ACSS2. Together, the data demonstrate a strikingly common metabolic phenotype in diverse brain tumors that includes the ability to oxidize acetate in the citric acid cycle. This adaptation may be important for meeting the high biosynthetic and bioenergetic demands of malignant growth.


Assuntos
Acetato-CoA Ligase/metabolismo , Acetatos/metabolismo , Neoplasias Encefálicas/metabolismo , Ciclo do Ácido Cítrico , Glioblastoma/metabolismo , Acetato-CoA Ligase/genética , Animais , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/secundário , Modelos Animais de Doenças , Glioblastoma/patologia , Ácido Glutâmico/metabolismo , Humanos , Camundongos , Metástase Neoplásica/patologia
5.
Proc Natl Acad Sci U S A ; 121(41): e2410995121, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39361653

RESUMO

Approximately two-thirds of the estimated one-billion metric tons of methane produced annually by methanogens is derived from the cleavage of acetate. Acetate is broken down by a Ni-Fe-S-containing A-cluster within the enzyme acetyl-CoA synthase (ACS) to carbon monoxide (CO) and a methyl group (CH3+). The methyl group ultimately forms the greenhouse gas methane, whereas CO is converted to the greenhouse gas carbon dioxide (CO2) by a Ni-Fe-S-containing C-cluster within the enzyme carbon monoxide dehydrogenase (CODH). Although structures have been solved of CODH/ACS from acetogens, which use these enzymes to make acetate from CO2, no structure of a CODH/ACS from a methanogen has been reported. In this work, we use cryo-electron microscopy to reveal the structure of a methanogenic CODH and CODH/ACS from Methanosarcina thermophila (MetCODH/ACS). We find that the N-terminal domain of acetogenic ACS, which is missing in all methanogens, is replaced by a domain of CODH. This CODH domain provides a channel for CO to travel between the two catalytic Ni-Fe-S clusters. It generates the binding surface for ACS and creates a remarkably similar CO alcove above the A-cluster using residues from CODH rather than ACS. Comparison of our MetCODH/ACS structure with our MetCODH structure reveals a molecular mechanism to restrict gas flow from the CO channel when ACS departs, preventing CO escape into the cell. Overall, these long-awaited structures of a methanogenic CODH/ACS reveal striking functional similarities to their acetogenic counterparts despite a substantial difference in domain organization.


Assuntos
Acetato-CoA Ligase , Aldeído Oxirredutases , Microscopia Crioeletrônica , Metano , Methanosarcina , Complexos Multienzimáticos , Aldeído Oxirredutases/metabolismo , Aldeído Oxirredutases/química , Microscopia Crioeletrônica/métodos , Methanosarcina/enzimologia , Methanosarcina/metabolismo , Metano/metabolismo , Complexos Multienzimáticos/metabolismo , Complexos Multienzimáticos/química , Complexos Multienzimáticos/ultraestrutura , Acetato-CoA Ligase/metabolismo , Acetato-CoA Ligase/química , Acetato-CoA Ligase/genética , Monóxido de Carbono/metabolismo , Modelos Moleculares
6.
Nature ; 579(7800): 586-591, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32214246

RESUMO

Consumption of fructose has risen markedly in recent decades owing to the use of sucrose and high-fructose corn syrup in beverages and processed foods1, and this has contributed to increasing rates of obesity and non-alcoholic fatty liver disease2-4. Fructose intake triggers de novo lipogenesis in the liver4-6, in which carbon precursors of acetyl-CoA are converted into fatty acids. The ATP citrate lyase (ACLY) enzyme cleaves cytosolic citrate to generate acetyl-CoA, and is upregulated after consumption of carbohydrates7. Clinical trials are currently pursuing the inhibition of ACLY as a treatment for metabolic diseases8. However, the route from dietary fructose to hepatic acetyl-CoA and lipids remains unknown. Here, using in vivo isotope tracing, we show that liver-specific deletion of Acly in mice is unable to suppress fructose-induced lipogenesis. Dietary fructose is converted to acetate by the gut microbiota9, and this supplies lipogenic acetyl-CoA independently of ACLY10. Depletion of the microbiota or silencing of hepatic ACSS2, which generates acetyl-CoA from acetate, potently suppresses the conversion of bolus fructose into hepatic acetyl-CoA and fatty acids. When fructose is consumed more gradually to facilitate its absorption in the small intestine, both citrate cleavage in hepatocytes and microorganism-derived acetate contribute to lipogenesis. By contrast, the lipogenic transcriptional program is activated in response to fructose in a manner that is independent of acetyl-CoA metabolism. These data reveal a two-pronged mechanism that regulates hepatic lipogenesis, in which fructolysis within hepatocytes provides a signal to promote the expression of lipogenic genes, and the generation of microbial acetate feeds lipogenic pools of acetyl-CoA.


Assuntos
Acetatos/metabolismo , Açúcares da Dieta/metabolismo , Frutose/metabolismo , Microbioma Gastrointestinal/fisiologia , Lipogênese , Fígado/metabolismo , ATP Citrato (pro-S)-Liase/deficiência , ATP Citrato (pro-S)-Liase/genética , ATP Citrato (pro-S)-Liase/metabolismo , Acetato-CoA Ligase/deficiência , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/metabolismo , Acetilcoenzima A/metabolismo , Animais , Ácido Cítrico/metabolismo , Açúcares da Dieta/administração & dosagem , Açúcares da Dieta/farmacologia , Ácidos Graxos/metabolismo , Frutose/administração & dosagem , Frutose/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Hepatócitos/metabolismo , Marcação por Isótopo , Lipogênese/efeitos dos fármacos , Lipogênese/genética , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Camundongos , Especificidade por Substrato
7.
J Biol Chem ; 300(8): 107503, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38944127

RESUMO

One of the seven natural CO2 fixation pathways, the anaerobic Wood-Ljungdahl pathway (WLP) is unique in generating CO as a metabolic intermediate, operating through organometallic intermediates, and in conserving (versus utilizing) net ATP. The key enzyme in the WLP is acetyl-CoA synthase (ACS), which uses an active site [2Ni-4Fe-4S] cluster (A-cluster), a CO tunnel, and an organometallic (Ni-CO, Ni-methyl, and Ni-acetyl) reaction sequence to generate acetyl-CoA. Here, we reveal that an alcove, which interfaces the tunnel and the A-cluster, is essential for CO2 fixation and autotrophic growth by the WLP. In vitro spectroscopy, kinetics, binding, and in vivo growth experiments reveal that a Phe229A substitution at one wall of the alcove decreases CO affinity thirty-fold and abolishes autotrophic growth; however, a F229W substitution enhances CO binding 80-fold. Our results indicate that the structure of the alcove is exquisitely tuned to concentrate CO near the A-cluster; protect ACS from CO loss during catalysis, provide a haven for inhibitory CO, and stabilize the tetrahedral coordination at the Nip site where CO binds. The directing, concentrating, and protective effects of the alcove explain the inability of F209A to grow autotrophically. The alcove also could help explain current controversies over whether ACS binds CO and methyl through a random or ordered mechanism. Our work redefines what we historically refer to as the metallocenter "active site". The alcove is so crucial for enzymatic function that we propose it is part of the active site. The community should now look for such alcoves in all "gas handling" metalloenzymes.


Assuntos
Acetato-CoA Ligase , Monóxido de Carbono , Domínio Catalítico , Níquel , Níquel/metabolismo , Níquel/química , Acetato-CoA Ligase/metabolismo , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/química , Monóxido de Carbono/metabolismo , Monóxido de Carbono/química , Ciclo do Carbono , Anaerobiose , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Dióxido de Carbono/metabolismo , Dióxido de Carbono/química
8.
Mol Cell ; 66(5): 684-697.e9, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28552616

RESUMO

Overcoming metabolic stress is a critical step in tumor growth. Acetyl coenzyme A (acetyl-CoA) generated from glucose and acetate uptake is important for histone acetylation and gene expression. However, how acetyl-CoA is produced under nutritional stress is unclear. We demonstrate here that glucose deprivation results in AMP-activated protein kinase (AMPK)-mediated acetyl-CoA synthetase 2 (ACSS2) phosphorylation at S659, which exposed the nuclear localization signal of ACSS2 for importin α5 binding and nuclear translocation. In the nucleus, ACSS2 binds to transcription factor EB and translocates to lysosomal and autophagy gene promoter regions, where ACSS2 incorporates acetate generated from histone acetylation turnover to locally produce acetyl-CoA for histone H3 acetylation in these regions and promote lysosomal biogenesis, autophagy, cell survival, and brain tumorigenesis. In addition, ACSS2 S659 phosphorylation positively correlates with AMPK activity in glioma specimens and grades of glioma malignancy. These results underscore the significance of nuclear ACSS2-mediated histone acetylation in maintaining cell homeostasis and tumor development.


Assuntos
Acetato-CoA Ligase/metabolismo , Autofagia , Neoplasias Encefálicas/enzimologia , Núcleo Celular/enzimologia , Glioblastoma/enzimologia , Histonas/metabolismo , Lisossomos/metabolismo , Biogênese de Organelas , Transcrição Gênica , Proteínas Quinases Ativadas por AMP/metabolismo , Acetato-CoA Ligase/genética , Acetilcoenzima A/metabolismo , Acetilação , Transporte Ativo do Núcleo Celular , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Sítios de Ligação , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Núcleo Celular/patologia , Sobrevivência Celular , Metabolismo Energético , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosforilação , Regiões Promotoras Genéticas , Ligação Proteica , Processamento de Proteína Pós-Traducional , Interferência de RNA , Estresse Fisiológico , Transfecção , alfa Carioferinas/genética , alfa Carioferinas/metabolismo
9.
Proc Natl Acad Sci U S A ; 119(32): e2114758119, 2022 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-35921439

RESUMO

Histone acetylation is a key component in the consolidation of long-term fear memories. Histone acetylation is fueled by acetyl-coenzyme A (acetyl-CoA), and recently, nuclear-localized metabolic enzymes that produce this metabolite have emerged as direct and local regulators of chromatin. In particular, acetyl-CoA synthetase 2 (ACSS2) mediates histone acetylation in the mouse hippocampus. However, whether ACSS2 regulates long-term fear memory remains to be determined. Here, we show that Acss2 knockout is well tolerated in mice, yet the Acss2-null mouse exhibits reduced acquisition of long-term fear memory. Loss of Acss2 leads to reductions in both histone acetylation and expression of critical learning and memory-related genes in the dorsal hippocampus, specifically following fear conditioning. Furthermore, systemic administration of blood-brain barrier-permeable Acss2 inhibitors during the consolidation window reduces fear-memory formation in mice and rats and reduces anxiety in a predator-scent stress paradigm. Our findings suggest that nuclear acetyl-CoA metabolism via ACSS2 plays a critical, previously unappreciated, role in the formation of fear memories.


Assuntos
Acetato-CoA Ligase , Acetilcoenzima A , Condicionamento Clássico , Medo , Histonas , Consolidação da Memória , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/metabolismo , Acetilcoenzima A/metabolismo , Acetilação , Animais , Condicionamento Clássico/fisiologia , Medo/fisiologia , Hipocampo/enzimologia , Histonas/metabolismo , Camundongos , Camundongos Knockout , Ratos
10.
J Am Chem Soc ; 146(30): 21034-21043, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39023163

RESUMO

Acetyl coenzyme A synthase (ACS) catalyzes the formation and deconstruction of the key biological metabolite, acetyl coenzyme A (acetyl-CoA). The active site of ACS features a {NiNi} cluster bridged to a [Fe4S4]n+ cubane known as the A-cluster. The mechanism by which the A-cluster functions is debated, with few model complexes able to replicate the oxidation states, coordination features, or reactivity proposed in the catalytic cycle. In this work, we isolate the first bimetallic models of two hypothesized intermediates on the paramagnetic pathway of the ACS function. The heteroligated {Ni2+Ni1+} cluster, [K(12-crown-4)2][1], effectively replicates the coordination number and oxidation state of the proposed "Ared" state of the A-cluster. Addition of carbon monoxide to [1]- allows for isolation of a dinuclear {Ni2+Ni1+(CO)} complex, [K(12-crown-2)n][2] (n = 1-2), which bears similarity to the "ANiFeC" enzyme intermediate. Structural and electronic properties of each cluster are elucidated by X-ray diffraction, nuclear magnetic resonance, cyclic voltammetry, and UV/vis and electron paramagnetic resonance spectroscopies, which are supplemented by density functional theory (DFT) calculations. Calculations indicate that the pseudo-T-shaped geometry of the three-coordinate nickel in [1]- is more stable than the Y-conformation by 22 kcal mol-1, and that binding of CO to Ni1+ is barrierless and exergonic by 6 kcal mol-1. UV/vis absorption spectroscopy on [2]- in conjunction with time-dependent DFT calculations indicates that the square-planar nickel site is involved in electron transfer to the CO π*-orbital. Further, we demonstrate that [2]- promotes thioester synthesis in a reaction analogous to the production of acetyl coenzyme A by ACS.


Assuntos
Níquel , Níquel/química , Níquel/metabolismo , Acetato-CoA Ligase/química , Acetato-CoA Ligase/metabolismo , Modelos Moleculares , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Oxirredução , Acetilcoenzima A/metabolismo , Acetilcoenzima A/química
11.
Am J Physiol Gastrointest Liver Physiol ; 326(6): G697-G711, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38591127

RESUMO

Sterol regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) is a widely expressed membrane glycoprotein that acts as an important modulator of lipid metabolism and inflammatory stress. N-glycosylation of SCAP has been suggested to modulate cancer development, but its role in nonalcoholic steatohepatitis (NASH) is poorly understood. In this study, the N-glycosylation of SCAP was analyzed by using sequential trypsin proteolysis and glycosidase treatment. The liver cell lines expressing wild-type and N-glycosylation sites mutated SCAP were constructed to investigate the N-glycosylation role of SCAP in regulating inflammation and lipid accumulation as well as the underlying mechanisms. The hepatic SCAP protein levels were significantly increased in C57BL/6J mice fed with Western diet and sugar water (WD + SW) and diabetic db/db mice, which exhibited typical liver steatosis and inflammation accompanied with hyperglycemia. In vitro, the enhanced N-glycosylation by high glucose increased the protein stability of SCAP and hence increased its total protein levels, whereas the ablation of N-glycosylation significantly decreased SCAP protein stability and alleviated lipid accumulation and inflammation in hepatic cell lines. Mechanistically, SCAP N-glycosylation increased not only the SREBP-1-mediated acetyl-CoA synthetase 2 (ACSS2) transcription but also the AMPK-mediated S659 phosphorylation of ACCS2 protein, causing the enhanced ACSS2 levels in nucleus and hence increasing the histone H3K27 acetylation (H3K27ac), which is a key epigenetic modification associated with NASH. Modulating ACSS2 expression or its location in the nuclear abolished the effects of SCAP N-glycosylation on H3K27ac and lipid accumulation and inflammation. In conclusion, SCAP N-glycosylation aggravates inflammation and lipid accumulation through enhancing ACSS2-mediated H3K27ac in hepatocytes.NEW & NOTEWORTHY N-glycosylation of SCAP exacerbates inflammation and lipid accumulation in hepatocytes through ACSS2-mediated H3K27ac. Our data suggest that SCAP N-glycosylation plays a key role in regulating histone H3K27 acetylation and targeting SCAP N-glycosylation may be a new strategy for treating nonalcoholic steatohepatitis (NASH).


Assuntos
Acetato-CoA Ligase , Histonas , Peptídeos e Proteínas de Sinalização Intracelular , Metabolismo dos Lipídeos , Proteínas de Membrana , Hepatopatia Gordurosa não Alcoólica , Animais , Camundongos , Acetilação , Glicosilação , Histonas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Metabolismo dos Lipídeos/fisiologia , Fígado/metabolismo , Fígado/patologia , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Acetato-CoA Ligase/metabolismo
12.
Angew Chem Int Ed Engl ; 63(31): e202405120, 2024 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-38743001

RESUMO

The bifunctional CO-dehydrogenase/acetyl-CoA synthase (CODH/ACS) complex couples the reduction of CO2 to the condensation of CO with a methyl moiety and CoA to acetyl-CoA. Catalysis occurs at two sites connected by a tunnel transporting the CO. In this study, we investigated how the bifunctional complex and its tunnel support catalysis using the CODH/ACS from Carboxydothermus hydrogenoformans as a model. Although CODH/ACS adapted to form a stable bifunctional complex with a secluded substrate tunnel, catalysis and CO transport is even more efficient when two monofunctional enzymes are coupled. Efficient CO channeling appears to be ensured by hydrophobic binding sites for CO, which act in a bucket-brigade fashion rather than as a simple tube. Tunnel remodeling showed that opening the tunnel increased activity but impaired directed transport of CO. Constricting the tunnel impaired activity and CO transport, suggesting that the tunnel evolved to sequester CO rather than to maximize turnover.


Assuntos
Acetilcoenzima A , Dióxido de Carbono , Oxirredução , Dióxido de Carbono/química , Dióxido de Carbono/metabolismo , Acetilcoenzima A/metabolismo , Acetilcoenzima A/química , Monóxido de Carbono/metabolismo , Monóxido de Carbono/química , Aldeído Oxirredutases/metabolismo , Aldeído Oxirredutases/química , Acetato-CoA Ligase/metabolismo , Acetato-CoA Ligase/química , Biocatálise , Complexos Multienzimáticos/metabolismo , Complexos Multienzimáticos/química , Modelos Moleculares
13.
Gastroenterology ; 163(5): 1281-1293.e1, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35777482

RESUMO

BACKGROUND & AIMS: Rapid deconditioning, also called cachexia, and metabolic reprogramming are two hallmarks of pancreatic cancer. Acetyl-coenzyme A synthetase short-chain family member 2 (ACSS2) is an acetyl-enzyme A synthetase that contributes to lipid synthesis and epigenetic reprogramming. However, the role of ACSS2 on the nonselective macropinocytosis and cancer cachexia in pancreatic cancer remains elusive. In this study, we demonstrate that ACSS2 potentiates macropinocytosis and muscle wasting through metabolic reprogramming in pancreatic cancer. METHODS: Clinical significance of ACSS2 was analyzed using samples from patients with pancreatic cancer. ACSS2-knockout cells were established using the clustered regularly interspaced short palindromic repeats-associated protein 9 system. Single-cell RNA sequencing data from genetically engineered mouse models was analyzed. The macropinocytotic index was evaluated by dextran uptake assay. Chromatin immunoprecipitation assay was performed to validate transcriptional activation. ACSS2-mediated tumor progression and muscle wasting were examined in orthotopic xenograft models. RESULTS: Metabolic stress induced ACSS2 expression, which is associated with worse prognosis in pancreatic cancer. ACSS2 knockout significantly suppressed cell proliferation in 2-dimensional and 3-dimensional models. Macropinocytosis-associated genes are upregulated in tumor tissues and are correlated with worse prognosis. ACSS2 knockout inhibited macropinocytosis. We identified Zrt- and Irt-like protein 4 (ZIP4) as a downstream target of ACSS2, and knockdown of ZIP4 reversed ACSS2-induced macropinocytosis. ACSS2 upregulated ZIP4 through ETV4-mediated transcriptional activation. ZIP4 induces macropinocytosis through cyclic adenosine monophosphate response element-binding protein-activated syndecan 1 (SDC1) and dynamin 2 (DNM2). Meanwhile, ZIP4 drives muscle wasting and cachexia via glycogen synthase kinase-ß (GSK3ß)-mediated secretion of tumor necrosis factor superfamily member 10 (TRAIL or TNFSF10). ACSS2 knockout attenuated muscle wasting and extended survival in orthotopic mouse models. CONCLUSIONS: ACSS2-mediated metabolic reprogramming activates the ZIP4 pathway, and promotes macropinocytosis via SDC1/DNM2 and drives muscle wasting through the GSK3ß/TRAIL axis, which potentially provides additional nutrients for macropinocytosis in pancreatic cancer.


Assuntos
Acetato-CoA Ligase , Caquexia , Neoplasias Pancreáticas , Animais , Humanos , Camundongos , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/metabolismo , Monofosfato de Adenosina , Caquexia/genética , Linhagem Celular Tumoral , Dextranos , Dinamina II , Glicogênio Sintase Quinase 3 beta , Lipídeos , Músculos/metabolismo , Músculos/patologia , Neoplasias Pancreáticas/complicações , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Sindecana-1 , Fatores de Necrose Tumoral , Neoplasias Pancreáticas
14.
Liver Int ; 43(8): 1729-1740, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37183518

RESUMO

BACKGROUND AND AIMS: Steatosis is the early pathological change in alcohol-associated liver disease. However, its precise mechanism is still unclear. The present study is aimed to explore the role and mechanism of acetyl-CoA synthetase 2 (ACSS2) in acute alcohol-induced lipogenesis. METHODS: The increase in ACSS2 nuclear import and histone H3 acetylation were observed in mice after intraperitoneally injected with 2 g/kg ethanol or oral administration of 5 g/kg ethanol and also validated in hepatocytes stimulated with ethanol or acetate. The role of ACSS2 was further explored in liver-specific ACSS2 knockdown mice fed with ethanol-containing diet. RESULTS: Alcohol challenge induced hepatic lipid deposition and upregulated lipogenic genes in mice. It also promoted ACSS2 nuclear import and increased histone H3 acetylation. In hepatocytes, ethanol induced similar phenomena whereas ACSS2 knockdown blocked histone acetylation and lipogenic gene induction. P300/CBP associated factor (PCAF), but not general control nonderepressible 5, CREB-binding protein (CBP) and p300, facilitated H3K9 acetylation responding to ethanol challenge. CUT&RUN assay showed the enrichment of acetylated histone H3K9 surrounding Fasn and Acaca promoters. These results indicated that ethanol metabolism promoted ACSS2 nuclear import to support lipogenesis via H3K9 acetylation. In alcohol-feeding mice, liver-specific ACSS2 knockdown blocked the interaction between PCAF and H3K9 and suppressed lipogenic gene induction in the liver, demonstrating the critical role of ACSS2 in lipogenesis. CONCLUSIONS: Our study demonstrated that alcohol metabolism generated acetyl-CoA in the nucleus dependently on nuclear ACSS2, contributing to epigenetic regulation of lipogenesis in hepatic steatosis. Targeting ACSS2 may be a potential therapeutical strategy for acute alcoholic liver steatosis.


Assuntos
Acetato-CoA Ligase , Fígado Gorduroso Alcoólico , Fígado Gorduroso , Hepatopatias Alcoólicas , Animais , Camundongos , Acetilcoenzima A/genética , Acetilcoenzima A/metabolismo , Epigênese Genética , Etanol , Fígado Gorduroso/genética , Fígado Gorduroso Alcoólico/genética , Histonas , Lipogênese/genética , Fígado/metabolismo , Hepatopatias Alcoólicas/metabolismo , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/metabolismo
15.
Nature ; 546(7658): 381-386, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28562591

RESUMO

Metabolic production of acetyl coenzyme A (acetyl-CoA) is linked to histone acetylation and gene regulation, but the precise mechanisms of this process are largely unknown. Here we show that the metabolic enzyme acetyl-CoA synthetase 2 (ACSS2) directly regulates histone acetylation in neurons and spatial memory in mammals. In a neuronal cell culture model, ACSS2 increases in the nuclei of differentiating neurons and localizes to upregulated neuronal genes near sites of elevated histone acetylation. A decrease in ACSS2 lowers nuclear acetyl-CoA levels, histone acetylation, and responsive expression of the cohort of neuronal genes. In adult mice, attenuation of hippocampal ACSS2 expression impairs long-term spatial memory, a cognitive process that relies on histone acetylation. A decrease in ACSS2 in the hippocampus also leads to defective upregulation of memory-related neuronal genes that are pre-bound by ACSS2. These results reveal a connection between cellular metabolism, gene regulation, and neural plasticity and establish a link between acetyl-CoA generation 'on-site' at chromatin for histone acetylation and the transcription of key neuronal genes.


Assuntos
Acetato-CoA Ligase/metabolismo , Hipocampo/enzimologia , Hipocampo/fisiologia , Histonas/metabolismo , Memória/fisiologia , Plasticidade Neuronal/genética , Ativação Transcricional , Acetato-CoA Ligase/deficiência , Acetato-CoA Ligase/genética , Acetilcoenzima A/metabolismo , Acetilação , Animais , Diferenciação Celular , Núcleo Celular/metabolismo , Células Cultivadas , Cromatina/enzimologia , Cromatina/genética , Cromatina/metabolismo , Regulação Enzimológica da Expressão Gênica , Hipocampo/metabolismo , Histonas/química , Consolidação da Memória/fisiologia , Camundongos , Plasticidade Neuronal/fisiologia , Neurônios/citologia , Neurônios/metabolismo , Regulação para Cima
16.
Mol Cell ; 58(2): 203-15, 2015 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-25818647

RESUMO

Acetylation of histones at DNA regulatory elements plays a critical role in transcriptional activation. Histones are also modified by other acyl moieties, including crotonyl, yet the mechanisms that govern acetylation versus crotonylation and the functional consequences of this "choice" remain unclear. We show that the coactivator p300 has both crotonyltransferase and acetyltransferase activities, and that p300-catalyzed histone crotonylation directly stimulates transcription to a greater degree than histone acetylation. Levels of histone crotonylation are regulated by the cellular concentration of crotonyl-CoA, which can be altered through genetic and environmental perturbations. In a cell-based model of transcriptional activation, increasing or decreasing the cellular concentration of crotonyl-CoA leads to enhanced or diminished gene expression, respectively, which correlates with the levels of histone crotonylation flanking the regulatory elements of activated genes. Our findings support a general principle wherein differential histone acylation (i.e., acetylation versus crotonylation) couples cellular metabolism to the regulation of gene expression.


Assuntos
Acil Coenzima A/metabolismo , Proteína p300 Associada a E1A/metabolismo , Histonas/metabolismo , Macrófagos/imunologia , RNA Mensageiro/metabolismo , Ativação Transcricional , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/metabolismo , Acetilação , Acil Coenzima A/genética , Linhagem Celular , Sistema Livre de Células , Proteína p300 Associada a E1A/genética , Células HEK293 , Células HeLa , Humanos , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Dados de Sequência Molecular
17.
Int J Mol Sci ; 24(4)2023 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-36835088

RESUMO

The coordination of cellular biological processes is regulated in part via metabolic enzymes acting to match cellular metabolism to current conditions. The acetate activating enzyme, acyl-coenzyme A synthetase short-chain family member 2 (Acss2), has long been considered to have a predominantly lipogenic function. More recent evidence suggests that this enzyme has regulatory functions in addition to its role in providing acetyl-CoA for lipid synthesis. We used Acss2 knockout mice (Acss2-/-) to further investigate the roles this enzyme plays in three physiologically distinct organ systems that make extensive use of lipid synthesis and storage, including the liver, brain, and adipose tissue. We examined the resulting transcriptomic changes resulting from Acss2 deletion and assessed these changes in relation to fatty acid constitution. We find that loss of Acss2 leads to dysregulation of numerous canonical signaling pathways, upstream transcriptional regulatory molecules, cellular processes, and biological functions, which were distinct in the liver, brain, and mesenteric adipose tissues. The detected organ-specific transcriptional regulatory patterns reflect the complementary functional roles of these organ systems within the context of systemic physiology. While alterations in transcriptional states were evident, the loss of Acss2 resulted in few changes in fatty acid constitution in all three organ systems. Overall, we demonstrate that Acss2 loss institutes organ-specific transcriptional regulatory patterns reflecting the complementary functional roles of these organ systems. Collectively, these findings provide further confirmation that Acss2 regulates key transcription factors and pathways under well-fed, non-stressed conditions and acts as a transcriptional regulatory enzyme.


Assuntos
Acetato-CoA Ligase , Regulação da Expressão Gênica , Animais , Camundongos , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/metabolismo , Acetatos/metabolismo , Ácidos Graxos/metabolismo , Lipogênese , Fígado/metabolismo
18.
Trends Biochem Sci ; 43(10): 790-805, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30139647

RESUMO

Polyhydroxyalkanoates (PHAs) are diverse biopolyesters produced by numerous microorganisms and have attracted much attention as a substitute for petroleum-based polymers. Despite several decades of study, the detailed molecular mechanisms of PHA biosynthesis have remained unknown due to the lack of structural information on the key PHA biosynthetic enzyme PHA synthase. The recently determined crystal structure of PHA synthase, together with the structures of acetyl-coenzyme A (CoA) acetyltransferase and reductase, have changed this situation. Structural and biochemical studies provided important clues for the molecular mechanisms of each enzyme as well as the overall mechanism of PHA biosynthesis from acetyl-CoA. This new information and knowledge is expected to facilitate production of designed novel PHAs and also enhanced production of PHAs.


Assuntos
Poli-Hidroxialcanoatos/metabolismo , Acetato-CoA Ligase/metabolismo , Acetil-CoA C-Acetiltransferase/metabolismo , Oxirredutases do Álcool/metabolismo , Catálise , Estrutura Molecular , Poli-Hidroxialcanoatos/química , Polimerização , Especificidade por Substrato
19.
J Biol Chem ; 297(3): 101037, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34343565

RESUMO

Besides contributing to anabolism, cellular metabolites serve as substrates or cofactors for enzymes and may also have signaling functions. Given these roles, multiple control mechanisms likely ensure fidelity of metabolite-generating enzymes. Acetate-dependent acetyl CoA synthetases (ACS) are de novo sources of acetyl CoA, a building block for fatty acids and a substrate for acetyltransferases. Eukaryotic acetate-dependent acetyl CoA synthetase 2 (Acss2) is predominantly cytosolic, but is also found in the nucleus following oxygen or glucose deprivation, or upon acetate exposure. Acss2-generated acetyl CoA is used in acetylation of Hypoxia-Inducible Factor 2 (HIF-2), a stress-responsive transcription factor. Mutation of a putative nuclear localization signal in endogenous Acss2 abrogates HIF-2 acetylation and signaling, but surprisingly also results in reduced Acss2 protein levels due to unmasking of two protein destabilization elements (PDE) in the Acss2 hinge region. In the current study, we identify up to four additional PDE in the Acss2 hinge region and determine that a previously identified PDE, the ABC domain, consists of two functional PDE. We show that the ABC domain and other PDE are likely masked by intramolecular interactions with other domains in the Acss2 hinge region. We also characterize mice with a prematurely truncated Acss2 that exposes a putative ABC domain PDE, which exhibits reduced Acss2 protein stability and impaired HIF-2 signaling. Finally, using primary mouse embryonic fibroblasts, we demonstrate that the reduced stability of select Acss2 mutant proteins is due to a shortened half-life, which is a result of enhanced degradation via a nonproteasome, nonautophagy pathway.


Assuntos
Acetato-CoA Ligase/química , Acetato-CoA Ligase/metabolismo , Acetatos/metabolismo , Acetato-CoA Ligase/genética , Sequência de Aminoácidos , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fibroblastos/química , Fibroblastos/enzimologia , Humanos , Camundongos , Ligação Proteica , Domínios Proteicos , Estabilidade Proteica , Alinhamento de Sequência
20.
Microbiology (Reading) ; 168(9)2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36048631

RESUMO

Successful adaptation of Escherichia coli to constant environmental challenges demands the operation of a wide range of regulatory control mechanisms, some of which are global, while others are specific. Here, we show that the ability of acetate-negative phenotype strains of E. coli devoid of acetate kinase (AK) and phosphotransacetylase (PTA) to assimilate acetate when challenged at the end of growth on acetogenic substrates is explicable by the co-expression of acetyl CoA-synthetase (AcCoA-S) and acetate permease (AP). Furthermore, mRNA transcript measurements for acs and aceA, together with the enzymatic activities of their corresponding enzymes, acetyl CoA synthetase (AcCoA-S) and isocitrate lyase (ICL), clearly demonstrate that the expression of the two enzymes is inextricably linked and triggered in response to growth rate threshold signal (0.4 h-1± 0.03: n4). Interestingly, further restriction of carbon supply to the level of starvation led to the repression of acs (AcCoA-S), ackA (AK) and pta (PTA). Further, we provide evidence that the reaction sequence catalysed by PTA, AK and AcCoA-S is not in operation at low growth rates and that the reaction catalysed by AcCoA-S is not merely an ATP-dissipating reaction but rather advantageous, as it elevates the available free energy (ΔG°) in central metabolism. Moreover, the transcriptomic data reinforce the view that the expression of PEP carboxykinase is essential in gluconeogenic phenotypes.


Assuntos
Acetato-CoA Ligase , Escherichia coli , Acetato Quinase/genética , Acetato Quinase/metabolismo , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/metabolismo , Acetatos/metabolismo , Acetilcoenzima A/metabolismo , Escherichia coli/metabolismo , Óperon , Fosfato Acetiltransferase/genética , Fosfato Acetiltransferase/metabolismo
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