RESUMO
The noncanonical IKK family member TANK-binding kinase 1 (TBK1) is activated by pro-inflammatory cytokines, but its role in controlling metabolism remains unclear. Here, we report that the kinase uniquely controls energy metabolism. Tbk1 expression is increased in adipocytes of HFD-fed mice. Adipocyte-specific TBK1 knockout (ATKO) attenuates HFD-induced obesity by increasing energy expenditure; further studies show that TBK1 directly inhibits AMPK to repress respiration and increase energy storage. Conversely, activation of AMPK under catabolic conditions can increase TBK1 activity through phosphorylation, mediated by AMPK's downstream target ULK1. Surprisingly, ATKO also exaggerates adipose tissue inflammation and insulin resistance. TBK1 suppresses inflammation by phosphorylating and inducing the degradation of the IKK kinase NIK, thus attenuating NF-κB activity. Moreover, TBK1 mediates the negative impact of AMPK activity on NF-κB activation. These data implicate a unique role for TBK1 in mediating bidirectional crosstalk between energy sensing and inflammatory signaling pathways in both over- and undernutrition.
Assuntos
Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Metabolismo Energético , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Adipócitos/patologia , Tecido Adiposo/patologia , Animais , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Linhagem Celular Transformada , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/farmacologia , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Camundongos Knockout , NF-kappa B/genética , NF-kappa B/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Proteínas Serina-Treonina Quinases/genética , Quinase Induzida por NF-kappaBRESUMO
The role of the mitochondrial electron transport chain (ETC) in regulating ferroptosis is not fully elucidated. Here, we reveal that pharmacological inhibition of the ETC complex I reduces ubiquinol levels while decreasing ATP levels and activating AMP-activated protein kinase (AMPK), the two effects known for their roles in promoting and suppressing ferroptosis, respectively. Consequently, the impact of complex I inhibitors on ferroptosis induced by glutathione peroxidase 4 (GPX4) inhibition is limited. The pharmacological inhibition of complex I in LKB1-AMPK-inactivated cells, or genetic ablation of complex I (which does not trigger apparent AMPK activation), abrogates the AMPK-mediated ferroptosis-suppressive effect and sensitizes cancer cells to GPX4-inactivation-induced ferroptosis. Furthermore, complex I inhibition synergizes with radiotherapy (RT) to selectively suppress the growth of LKB1-deficient tumors by inducing ferroptosis in mouse models. Our data demonstrate a multifaceted role of complex I in regulating ferroptosis and propose a ferroptosis-inducing therapeutic strategy for LKB1-deficient cancers.
Assuntos
Proteínas Quinases Ativadas por AMP , Complexo I de Transporte de Elétrons , Ferroptose , Animais , Feminino , Humanos , Camundongos , Quinases Proteína-Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Linhagem Celular Tumoral , Complexo I de Transporte de Elétrons/metabolismo , Complexo I de Transporte de Elétrons/genética , Ferroptose/genética , Ferroptose/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/genética , Mitocôndrias/efeitos dos fármacos , Neoplasias/genética , Neoplasias/patologia , Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The health of an organism is orchestrated by a multitude of molecular and biochemical networks responsible for ensuring homeostasis within cells and tissues. However, upon aging, a progressive failure in the maintenance of this homeostatic balance occurs in response to a variety of endogenous and environmental stresses, allowing the accumulation of damage, the physiological decline of individual tissues, and susceptibility to diseases. What are the molecular and cellular signaling events that control the aging process and how can this knowledge help design therapeutic strategies to combat age-associated diseases? Here we provide a comprehensive overview of the evolutionarily conserved biological processes that alter the rate of aging and discuss their link to disease prevention and the extension of healthy life span.
Assuntos
Dano ao DNA , Longevidade/genética , Deficiências na Proteostase/genética , Transdução de Sinais , Encurtamento do Telômero , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Restrição Calórica , Epigênese Genética , Homeostase/genética , Humanos , Inflamação , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Mitocôndrias/metabolismo , Estresse Oxidativo , Deficiências na Proteostase/metabolismo , Deficiências na Proteostase/patologia , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismoRESUMO
N-myristoyltransferase (NMT) attaches the fatty acid myristate to the N-terminal glycine of proteins to sort them into soluble and membrane-bound fractions. Function of the energy-sensing AMP-activated protein kinase, AMPK, is myristoylation dependent. In rheumatoid arthritis (RA), pathogenic T cells shift glucose away from adenosine tri-phosphate production toward synthetic and proliferative programs, promoting proliferation, cytokine production, and tissue invasion. We found that RA T cells had a defect in NMT1 function, which prevented AMPK activation and enabled unopposed mTORC1 signaling. Lack of the myristate lipid tail disrupted the lysosomal translocation and activation of AMPK. Instead, myristoylation-incompetent RA T cells hyperactivated the mTORC1 pathway and differentiated into pro-inflammatory TH1 and TH17 helper T cells. In vivo, NMT1 loss caused robust synovial tissue inflammation, whereas forced NMT1 overexpression rescued AMPK activation and suppressed synovitis. Thus, NMT1 has tissue-protective functions by facilitating lysosomal recruitment of AMPK and dampening mTORC1 signaling.
Assuntos
Proteínas Quinases Ativadas por AMP/imunologia , Aciltransferases/imunologia , Artrite Reumatoide/imunologia , Sinovite/imunologia , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Aciltransferases/genética , Aciltransferases/metabolismo , Adulto , Animais , Artrite Reumatoide/genética , Artrite Reumatoide/metabolismo , Células Cultivadas , Ativação Enzimática/imunologia , Feminino , Humanos , Masculino , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Pessoa de Meia-Idade , Interferência de RNA , Sinovite/genética , Sinovite/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Adulto JovemRESUMO
As sessile organisms, plants must cope with abiotic stress such as soil salinity, drought, and extreme temperatures. Core stress-signaling pathways involve protein kinases related to the yeast SNF1 and mammalian AMPK, suggesting that stress signaling in plants evolved from energy sensing. Stress signaling regulates proteins critical for ion and water transport and for metabolic and gene-expression reprogramming to bring about ionic and water homeostasis and cellular stability under stress conditions. Understanding stress signaling and responses will increase our ability to improve stress resistance in crops to achieve agricultural sustainability and food security for a growing world population.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Produtos Agrícolas/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Estresse Fisiológico/fisiologia , Proteínas Quinases Ativadas por AMP/genética , Cloroplastos/enzimologia , Resposta ao Choque Frio , Produtos Agrícolas/enzimologia , Produtos Agrícolas/genética , Secas , Estresse do Retículo Endoplasmático , Metabolismo Energético , Abastecimento de Alimentos , Regulação da Expressão Gênica de Plantas , Resposta ao Choque Térmico , Mitocôndrias/enzimologia , Pressão Osmótica , Peroxissomos/enzimologia , Proteínas Serina-Treonina Quinases/genética , Salinidade , Transdução de Sinais , Estresse Fisiológico/genéticaRESUMO
The synthesis of type I collagen, the main component of bone matrix, precedes the expression of Runx2, the earliest determinant of osteoblast differentiation. We hypothesized that the energetic needs of osteoblasts might explain this apparent paradox. We show here that glucose, the main nutrient of osteoblasts, is transported in these cells through Glut1, whose expression precedes that of Runx2. Glucose uptake favors osteoblast differentiation by suppressing the AMPK-dependent proteasomal degradation of Runx2 and promotes bone formation by inhibiting another function of AMPK. While RUNX2 cannot induce osteoblast differentiation when glucose uptake is compromised, raising blood glucose levels restores collagen synthesis in Runx2-null osteoblasts and initiates bone formation in Runx2-deficient embryos. Moreover, RUNX2 favors Glut1 expression, and this feedforward regulation between RUNX2 and Glut1 determines the onset of osteoblast differentiation during development and the extent of bone formation throughout life. These results reveal an unexpected intricacy between bone and glucose metabolism.
Assuntos
Diferenciação Celular , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Glucose/metabolismo , Osteoblastos/metabolismo , Osteogênese , Proteínas Quinases Ativadas por AMP/antagonistas & inibidores , Proteínas Quinases Ativadas por AMP/genética , Sequência de Aminoácidos , Animais , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Homeostase , Camundongos , Osteoblastos/citologia , Alinhamento de Sequência , Crânio/citologiaRESUMO
Nutrient sensing and damage sensing are two fundamental processes in living organisms. While hyperglycemia is frequently linked to diabetes-related vulnerability to microbial infection, how body glucose levels affect innate immune responses to microbial invasion is not fully understood. Here, we surprisingly found that viral infection led to a rapid and dramatic decrease in blood glucose levels in rodents, leading to robust AMPK activation. AMPK, once activated, directly phosphorylates TBK1 at S511, which triggers IRF3 recruitment and the assembly of MAVS or STING signalosomes. Consistently, ablation or inhibition of AMPK, knockin of TBK1-S511A, or increased glucose levels compromised nucleic acid sensing, while boosting AMPK-TBK1 cascade by AICAR or TBK1-S511E knockin improves antiviral immunity substantially in various animal models. Thus, we identify TBK1 as an AMPK substrate, reveal the molecular mechanism coupling a dual sensing of glucose and nuclei acids, and report its physiological necessity in antiviral defense.
Assuntos
Proteínas Quinases Ativadas por AMP , Ácidos Nucleicos , Animais , Proteínas Quinases Ativadas por AMP/genética , Imunidade Inata , Antivirais , GlucoseRESUMO
Maintenance of energy level to drive movements and material exchange with the environment is a basic principle of life. AMP-activated protein kinase (AMPK) senses energy level and is a major regulator of cellular energy responses. The gamma subunit of AMPK senses elevated ratio of AMP to ATP and allosterically activates the alpha catalytic subunit to phosphorylate downstream effectors. Here, we report that knockout of AMPKγ, but not AMPKα, suppressed phosphorylation of eukaryotic translation elongation factor 2 (eEF2) induced by energy starvation. We identified PPP6C as an AMPKγ-regulated phosphatase of eEF2. AMP-bound AMPKγ sequesters PPP6C, thereby blocking dephosphorylation of eEF2 and thus inhibiting translation elongation to preserve energy and to promote cell survival. Further phosphoproteomic analysis identified additional targets of PPP6C regulated by energy stress in an AMPKγ-dependent manner. Thus, AMPKγ senses cellular energy availability to regulate not only AMPKα kinase, but also PPP6C phosphatase and possibly other effectors.
Assuntos
Proteínas Quinases Ativadas por AMP , Biossíntese de Proteínas , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Fosforilação , Fator 2 de Elongação de Peptídeos/metabolismoRESUMO
γδ T cells are potent anticancer effectors with the potential to target tumours broadly, independent of patient-specific neoantigens or human leukocyte antigen background1-5. γδ T cells can sense conserved cell stress signals prevalent in transformed cells2,3, although the mechanisms behind the targeting of stressed target cells remain poorly characterized. Vγ9Vδ2 T cells-the most abundant subset of human γδ T cells4-recognize a protein complex containing butyrophilin 2A1 (BTN2A1) and BTN3A1 (refs. 6-8), a widely expressed cell surface protein that is activated by phosphoantigens abundantly produced by tumour cells. Here we combined genome-wide CRISPR screens in target cancer cells to identify pathways that regulate γδ T cell killing and BTN3A cell surface expression. The screens showed previously unappreciated multilayered regulation of BTN3A abundance on the cell surface and triggering of γδ T cells through transcription, post-translational modifications and membrane trafficking. In addition, diverse genetic perturbations and inhibitors disrupting metabolic pathways in the cancer cells, particularly ATP-producing processes, were found to alter BTN3A levels. This induction of both BTN3A and BTN2A1 during metabolic crises is dependent on AMP-activated protein kinase (AMPK). Finally, small-molecule activation of AMPK in a cell line model and in patient-derived tumour organoids led to increased expression of the BTN2A1-BTN3A complex and increased Vγ9Vδ2 T cell receptor-mediated killing. This AMPK-dependent mechanism of metabolic stress-induced ligand upregulation deepens our understanding of γδ T cell stress surveillance and suggests new avenues available to enhance γδ T cell anticancer activity.
Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Neoplasias , Receptores de Antígenos de Linfócitos T gama-delta , Linfócitos T , Humanos , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Linhagem Celular , Membrana Celular/metabolismo , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
The evolution of AMPK and its homologs enabled exquisite responsivity and control of cellular energetic homeostasis. Recent work has been critical in establishing the mechanisms that determine AMPK activity, novel targets of AMPK action, and the distribution of AMPK-mediated control networks across the cellular landscape. The role of AMPK as a hub of metabolic control has led to intense interest in pharmacologic activation as a therapeutic avenue for a number of disease states, including obesity, diabetes, and cancer. As such, critical work on the compartmentalization of AMPK, its downstream targets, and the systems it influences has progressed in recent years. The variegated distribution of AMPK-mediated control of metabolic homeostasis has revealed key insights into AMPK in normal biology and future directions for AMPK-based therapeutic strategies.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Animais , Citoplasma/metabolismo , Metabolismo Energético , Homeostase , Humanos , Mitocôndrias/metabolismo , Domínios Proteicos , Transdução de Sinais , Relação Estrutura-AtividadeRESUMO
As a master regulator of metabolism, AMP-activated protein kinase (AMPK) is activated upon energy and glucose shortage but suppressed upon overnutrition. Exaggerated negative regulation of AMPK signaling by nutrient overload plays a crucial role in metabolic diseases. However, the mechanism underlying the negative regulation is poorly understood. Here, we demonstrate that high glucose represses AMPK signaling via MG53 (also called TRIM72) E3-ubiquitin-ligase-mediated AMPKα degradation and deactivation. Specifically, high-glucose-stimulated reactive oxygen species (ROS) signals AKT to phosphorylate AMPKα at S485/491, which facilitates the recruitment of MG53 and the subsequent ubiquitination and degradation of AMPKα. In addition, high glucose deactivates AMPK by ROS-dependent suppression of phosphorylation of AMPKα at T172. These findings not only delineate the mechanism underlying the impairment of AMPK signaling in overnutrition-related diseases but also highlight the significance of keeping the yin-yang balance of AMPK signaling in the maintenance of metabolic homeostasis.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Diabetes Mellitus/enzimologia , Glucose/farmacologia , Proteínas de Membrana/metabolismo , Músculo Esquelético/efeitos dos fármacos , Obesidade/enzimologia , Quinases Proteína-Quinases Ativadas por AMP , Proteínas Quinases Ativadas por AMP/genética , Animais , Glicemia/metabolismo , Diabetes Mellitus/sangue , Diabetes Mellitus/genética , Modelos Animais de Doenças , Células HEK293 , Humanos , Macaca mulatta , Masculino , Proteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Músculo Esquelético/enzimologia , Obesidade/sangue , Obesidade/genética , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Proteólise , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , UbiquitinaçãoRESUMO
Aberrant energy status contributes to multiple metabolic diseases, including obesity, diabetes, and cancer, but the underlying mechanism remains elusive. Here, we report that ketogenic-diet-induced changes in energy status enhance the efficacy of anti-CTLA-4 immunotherapy by decreasing PD-L1 protein levels and increasing expression of type-I interferon (IFN) and antigen presentation genes. Mechanistically, energy deprivation activates AMP-activated protein kinase (AMPK), which in turn, phosphorylates PD-L1 on Ser283, thereby disrupting its interaction with CMTM4 and subsequently triggering PD-L1 degradation. In addition, AMPK phosphorylates EZH2, which disrupts PRC2 function, leading to enhanced IFNs and antigen presentation gene expression. Through these mechanisms, AMPK agonists or ketogenic diets enhance the efficacy of anti-CTLA-4 immunotherapy and improve the overall survival rate in syngeneic mouse tumor models. Our findings reveal a pivotal role for AMPK in regulating the immune response to immune-checkpoint blockade and advocate for combining ketogenic diets or AMPK agonists with anti-CTLA4 immunotherapy to combat cancer.
Assuntos
Proteínas Quinases Ativadas por AMP/genética , Antígeno B7-H1/genética , Neoplasias da Mama/genética , Antígeno CTLA-4/genética , Neoplasias Colorretais/genética , Inibidores de Checkpoint Imunológico , Proteínas Quinases Ativadas por AMP/imunologia , Aloenxertos , Animais , Anticorpos Neutralizantes/farmacologia , Antineoplásicos/farmacologia , Antígeno B7-H1/imunologia , Compostos de Bifenilo/farmacologia , Neoplasias da Mama/imunologia , Neoplasias da Mama/mortalidade , Neoplasias da Mama/terapia , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/imunologia , Linhagem Celular Tumoral , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/terapia , Dieta Cetogênica/métodos , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/imunologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imunoterapia/métodos , Proteínas com Domínio MARVEL/genética , Proteínas com Domínio MARVEL/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Pironas/farmacologia , Transdução de Sinais , Análise de Sobrevida , Tiofenos/farmacologiaRESUMO
The mechanisms of cellular energy sensing and AMPK-mediated mTORC1 inhibition are not fully delineated. Here, we discover that RIPK1 promotes mTORC1 inhibition during energetic stress. RIPK1 is involved in mediating the interaction between AMPK and TSC2 and facilitate TSC2 phosphorylation at Ser1387. RIPK1 loss results in a high basal mTORC1 activity that drives defective lysosomes in cells and mice, leading to accumulation of RIPK3 and CASP8 and sensitization to cell death. RIPK1-deficient cells are unable to cope with energetic stress and are vulnerable to low glucose levels and metformin. Inhibition of mTORC1 rescues the lysosomal defects and vulnerability to energetic stress and prolongs the survival of RIPK1-deficient neonatal mice. Thus, RIPK1 plays an important role in the cellular response to low energy levels and mediates AMPK-mTORC1 signaling. These findings shed light on the regulation of mTORC1 during energetic stress and unveil a point of crosstalk between pro-survival and pro-death pathways.
Assuntos
Proteína 5 Relacionada à Autofagia/genética , Proteína de Domínio de Morte Associada a Fas/genética , Intestino Grosso/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Animais Recém-Nascidos , Proteína 5 Relacionada à Autofagia/deficiência , Caspase 8/genética , Caspase 8/metabolismo , Morte Celular/genética , Proteína de Domínio de Morte Associada a Fas/deficiência , Regulação da Expressão Gênica , Glucose/antagonistas & inibidores , Glucose/farmacologia , Células HEK293 , Células HT29 , Humanos , Intestino Grosso/efeitos dos fármacos , Intestino Grosso/patologia , Células Jurkat , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Lisossomos/patologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Metformina/antagonistas & inibidores , Metformina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação , Proteína Serina-Treonina Quinases de Interação com Receptores/deficiência , Transdução de Sinais , Sirolimo/farmacologia , Proteína 2 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/metabolismoRESUMO
AMPK is a central regulator of metabolism and autophagy. Here we show how lysosomal damage activates AMPK. This occurs via a hitherto unrecognized signal transduction system whereby cytoplasmic sentinel lectins detect membrane damage leading to ubiquitination responses. Absence of Galectin 9 (Gal9) or loss of its capacity to recognize lumenal glycans exposed during lysosomal membrane damage abrogate such ubiquitination responses. Proteomic analyses with APEX2-Gal9 have revealed global changes within the Gal9 interactome during lysosomal damage. Gal9 association with lysosomal glycoproteins increases whereas interactions with a newly identified Gal9 partner, deubiquitinase USP9X, diminishes upon lysosomal injury. In response to damage, Gal9 displaces USP9X from complexes with TAK1 and promotes K63 ubiquitination of TAK1 thus activating AMPK on damaged lysosomes. This triggers autophagy and contributes to autophagic control of membrane-damaging microbe Mycobacterium tuberculosis. Thus, galectin and ubiquitin systems converge to activate AMPK and autophagy during endomembrane homeostasis.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia , Metabolismo Energético , Galectinas/metabolismo , Lisossomos/enzimologia , Ubiquitina/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Adolescente , Adulto , Animais , Autofagia/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Ativação Enzimática , Feminino , Galectinas/genética , Células HEK293 , Células HeLa , Humanos , Hipoglicemiantes/farmacologia , Lisossomos/efeitos dos fármacos , Lisossomos/microbiologia , Lisossomos/patologia , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Masculino , Metformina/farmacologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mycobacterium tuberculosis/patogenicidade , Transdução de Sinais , Células THP-1 , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismo , Ubiquitinação , Adulto JovemAssuntos
Proteínas Quinases Ativadas por AMP , Fígado , Animais , Humanos , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Camundongos , Fígado/metabolismo , Fígado/enzimologia , Músculo Esquelético/metabolismo , Músculo Esquelético/enzimologia , Metabolismo EnergéticoAssuntos
Proteínas Quinases Ativadas por AMP , Fígado , Animais , Humanos , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Fígado/metabolismo , Fígado/enzimologia , Camundongos , Músculo Esquelético/metabolismo , Músculo Esquelético/enzimologia , Metabolismo Energético , Fosfoproteínas Fosfatases/metabolismo , Fosfoproteínas Fosfatases/genéticaRESUMO
Through transcriptional control of the evolutionarily conserved heat shock, or proteotoxic stress, response, heat shock factor 1 (HSF1) preserves proteomic stability. Here, we show that HSF1, a physiological substrate for AMP-activated protein kinase (AMPK), constitutively suppresses this central metabolic sensor. By physically evoking conformational switching of AMPK, HSF1 impairs AMP binding to the γ subunits and enhances the PP2A-mediated de-phosphorylation, but it impedes the LKB1-mediated phosphorylation of Thr172, and retards ATP binding to the catalytic α subunits. These immediate and manifold regulations empower HSF1 to both repress AMPK under basal conditions and restrain its activation by diverse stimuli, thereby promoting lipogenesis, cholesterol synthesis, and protein cholesteroylation. In vivo, HSF1 antagonizes AMPK to control body fat mass and drive the lipogenic phenotype and growth of melanomas independently of its intrinsic transcriptional action. Thus, the physical AMPK-HSF1 interaction epitomizes a reciprocal kinase-substrate regulation whereby lipid metabolism and proteomic stability intertwine.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Metabolismo Energético , Fatores de Transcrição de Choque Térmico/metabolismo , Proteínas Quinases Ativadas por AMP/química , Proteínas Quinases Ativadas por AMP/genética , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Adiposidade , Animais , Sítios de Ligação , Proliferação de Células , Colesterol/biossíntese , Células HEK293 , Células HeLa , Fatores de Transcrição de Choque Térmico/deficiência , Fatores de Transcrição de Choque Térmico/genética , Humanos , Lipogênese , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Camundongos da Linhagem 129 , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Fosforilação , Conformação Proteica , Estabilidade Proteica , Transdução de Sinais , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Relação Estrutura-AtividadeRESUMO
Abnormal processing of stressed replication forks by nucleases can cause fork collapse, genomic instability, and cell death. Despite its importance, it is poorly understood how the cell properly controls nucleases to prevent detrimental fork processing. Here, we report a signaling pathway that controls the activity of exonuclease Exo1 to prevent aberrant fork resection during replication stress. Our results indicate that replication stress elevates intracellular Ca2+ concentration ([Ca2+]i), leading to activation of CaMKK2 and the downstream kinase 5' AMP-activated protein kinase (AMPK). Following activation, AMPK directly phosphorylates Exo1 at serine 746 to promote 14-3-3 binding and inhibit Exo1 recruitment to stressed replication forks, thereby avoiding unscheduled fork resection. Disruption of this signaling pathway results in excessive ssDNA, chromosomal instability, and hypersensitivity to replication stress inducers. These findings reveal a link between [Ca2+]i and the replication stress response as well as a function of the Ca2+-CaMKK2-AMPK signaling axis in safeguarding fork structure to maintain genome stability.
Assuntos
Proteínas Quinases Ativadas por AMP/genética , Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina/genética , Cálcio/metabolismo , Enzimas Reparadoras do DNA/genética , Reparo do DNA , Replicação do DNA , Exodesoxirribonucleases/genética , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Sinalização do Cálcio/genética , Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina/metabolismo , Linhagem Celular Tumoral , Quinase 1 do Ponto de Checagem/genética , Quinase 1 do Ponto de Checagem/metabolismo , Cromatina/química , Cromatina/metabolismo , Dano ao DNA , Enzimas Reparadoras do DNA/metabolismo , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/metabolismo , Exodesoxirribonucleases/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Células HEK293 , Células HeLa , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Camundongos , Osteoblastos/citologia , Osteoblastos/metabolismo , Fosforilação , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
Dendritic outgrowth in immature neurons is enhanced by neuronal activity and is considered one of the mechanisms of neural circuit optimization. It is known that calcium signals affect transcriptional regulation and cytoskeletal remodeling necessary for dendritic outgrowth. Here, we demonstrate that activity-dependent calcium signaling also controls mitochondrial homeostasis via AMP-activated protein kinase (AMPK) in growing dendrites of differentiating mouse hippocampal neurons. We found that the inhibition of neuronal activity induced dendritic hypotrophy with abnormally elongated mitochondria. In growing dendrites, AMPK is activated by neuronal activity and dynamically oscillates in synchrony with calcium spikes, and this AMPK oscillation was inhibited by CaMKK2 knockdown. AMPK activation led to phosphorylation of MFF and ULK1, which initiate mitochondrial fission and mitophagy, respectively. Dendritic mitochondria in AMPK-depleted neurons exhibited impaired fission and mitophagy and displayed multiple signs of dysfunction. Genetic inhibition of fission led to dendritic hypoplasia that was reminiscent of AMPK-deficient neurons. Thus, AMPK activity is finely tuned by the calcium-CaMKK2 pathway and regulates mitochondrial homeostasis by facilitating removal of damaged components of mitochondria in growing neurons during normal brain development.
Assuntos
Proteínas Quinases Ativadas por AMP , Cálcio , Camundongos , Animais , Fosforilação , Proteínas Quinases Ativadas por AMP/genética , Cálcio/metabolismo , Neurônios/metabolismo , Mitocôndrias/metabolismo , Dendritos/metabolismo , HomeostaseRESUMO
In T lymphocytes, the mitogen-activated protein kinase (MAPK) p38 regulates pleiotropic functions and is activated by canonical MAPK signaling or the alternative activation pathway downstream of the T cell antigen receptor (TCR). Here we found that senescent human T cells lacked the canonical and alternative pathways for the activation of p38 but spontaneously engaged the metabolic master regulator AMPK to trigger recruitment of p38 to the scaffold protein TAB1, which caused autophosphorylation of p38. Signaling via this pathway inhibited telomerase activity, T cell proliferation and the expression of key components of the TCR signalosome. Our findings identify a previously unrecognized mode for the activation of p38 in T cells driven by intracellular changes such as low-nutrient and DNA-damage signaling (an 'intrasensory' pathway). The proliferative defect of senescent T cells was reversed by blockade of AMPK-TAB1-dependent activation of p38.