RESUMEN
Activating mutations in leucine-rich repeat kinase 2 (LRRK2) represent the most common cause of monogenic Parkinson's disease. LRRK2 is a large multidomain protein kinase that phosphorylates a specific subset of the â¼65 human Rab GTPases, which are master regulators of the secretory and endocytic pathways. After phosphorylation by LRRK2, Rabs lose the capacity to bind cognate effector proteins and guanine nucleotide exchange factors. Moreover, the phosphorylated Rabs cannot interact with their cognate prenyl-binding retrieval proteins (also known as guanine nucleotide dissociation inhibitors) and, thus, they become trapped on membrane surfaces. Instead, they gain the capacity to bind phospho-Rab-specific effector proteins, such as RILPL1, with resulting pathological consequences. Rab proteins also act upstream of LRRK2 by controlling its activation and recruitment onto membranes. LRRK2 signaling is counteracted by the phosphoprotein phosphatase PPM1H, which selectively dephosphorylates phospho-Rab proteins. We present here our current understanding of the structure, biochemical properties, and cell biology of LRRK2 and its related paralog LRRK1 and discuss how this information guides the generation of LRRK2 inhibitors for the potential benefit of patients.
Asunto(s)
Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina , Enfermedad de Parkinson , Proteínas de Unión al GTP rab , Humanos , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/metabolismo , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/genética , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/química , Fosforilación , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/patología , Proteínas de Unión al GTP rab/metabolismo , Proteínas de Unión al GTP rab/genética , Proteínas de Unión al GTP rab/química , Animales , Transducción de Señal , Mutación , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/química , Unión Proteica , Fosfoproteínas Fosfatasas/metabolismo , Fosfoproteínas Fosfatasas/genética , Fosfoproteínas Fosfatasas/químicaRESUMEN
Enabling and constraining immune activation is of fundamental importance in maintaining cellular homeostasis. Depleting BAK1 and SERK4, the co-receptors of multiple pattern recognition receptors (PRRs), abolishes pattern-triggered immunity but triggers intracellular NOD-like receptor (NLR)-mediated autoimmunity with an elusive mechanism. By deploying RNAi-based genetic screens in Arabidopsis, we identified BAK-TO-LIFE 2 (BTL2), an uncharacterized receptor kinase, sensing BAK1/SERK4 integrity. BTL2 induces autoimmunity through activating Ca2+ channel CNGC20 in a kinase-dependent manner when BAK1/SERK4 are perturbed. To compensate for BAK1 deficiency, BTL2 complexes with multiple phytocytokine receptors, leading to potent phytocytokine responses mediated by helper NLR ADR1 family immune receptors, suggesting phytocytokine signaling as a molecular link connecting PRR- and NLR-mediated immunity. Remarkably, BAK1 constrains BTL2 activation via specific phosphorylation to maintain cellular integrity. Thus, BTL2 serves as a surveillance rheostat sensing the perturbation of BAK1/SERK4 immune co-receptors in promoting NLR-mediated phytocytokine signaling to ensure plant immunity.
Asunto(s)
Arabidopsis , Inmunidad de la Planta , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas Quinasas/genética , Proteínas Serina-Treonina Quinasas/genética , Receptores de Reconocimiento de Patrones , Transducción de SeñalRESUMEN
TANK binding kinase 1 (TBK1) regulates IFN-I, NF-κB, and TNF-induced RIPK1-dependent cell death (RCD). In mice, biallelic loss of TBK1 is embryonically lethal. We discovered four humans, ages 32, 26, 7, and 8 from three unrelated consanguineous families with homozygous loss-of-function mutations in TBK1. All four patients suffer from chronic and systemic autoinflammation, but not severe viral infections. We demonstrate that TBK1 loss results in hypomorphic but sufficient IFN-I induction via RIG-I/MDA5, while the system retains near intact IL-6 induction through NF-κB. Autoinflammation is driven by TNF-induced RCD as patient-derived fibroblasts experienced higher rates of necroptosis in vitro, and CC3 was elevated in peripheral blood ex vivo. Treatment with anti-TNF dampened the baseline circulating inflammatory profile and ameliorated the clinical condition in vivo. These findings highlight the plasticity of the IFN-I response and underscore a cardinal role for TBK1 in the regulation of RCD.
Asunto(s)
Inflamación/enzimología , Proteínas Serina-Treonina Quinasas/deficiencia , Factor de Necrosis Tumoral alfa/farmacología , Células A549 , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Apoptosis , Autoinmunidad/efectos de los fármacos , Encéfalo/diagnóstico por imagen , Muerte Celular/efectos de los fármacos , Citocinas/metabolismo , Enzima Desubiquitinante CYLD/metabolismo , Femenino , Células HEK293 , Homocigoto , Humanos , Quinasa I-kappa B/metabolismo , Inmunofenotipificación , Inflamación/patología , Interferón Tipo I/metabolismo , Interferón gamma/metabolismo , Mutación con Pérdida de Función/genética , Masculino , Linaje , Fosforilación/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Receptores de Reconocimiento de Patrones/metabolismo , Receptor Toll-Like 3/metabolismo , Transcriptoma/genética , Vesiculovirus/efectos de los fármacos , Vesiculovirus/fisiologíaRESUMEN
The evolution of eukaryotic genomes has been propelled by a series of gene duplication events, leading to an expansion in new functions and pathways. While duplicate genes may retain some functional redundancy, it is clear that to survive selection they cannot simply serve as a backup but rather must acquire distinct functions required for cellular processes to work accurately and efficiently. Understanding these differences and characterizing gene-specific functions is complex. Here we explore different gene pairs and families within the context of the endoplasmic reticulum (ER), the main cellular hub of lipid biosynthesis and the entry site for the secretory pathway. Focusing on each of the ER functions, we highlight specificities of related proteins and the capabilities conferred to cells through their conservation. More generally, these examples suggest why related genes have been maintained by evolutionary forces and provide a conceptual framework to experimentally determine why they have survived selection.
Asunto(s)
Retículo Endoplásmico/metabolismo , Evolución Molecular , Duplicación de Gen , Saccharomyces cerevisiae/metabolismo , Selección Genética , Factor de Transcripción Activador 6/genética , Factor de Transcripción Activador 6/metabolismo , Animales , Antiportadores/genética , Antiportadores/metabolismo , Carboxiliasas/genética , Carboxiliasas/metabolismo , Retículo Endoplásmico/genética , Endorribonucleasas/genética , Endorribonucleasas/metabolismo , Células Eucariotas/citología , Células Eucariotas/metabolismo , Proteínas del Choque Térmico HSP40/genética , Proteínas del Choque Térmico HSP40/metabolismo , Hexosiltransferasas/genética , Hexosiltransferasas/metabolismo , Humanos , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Esfingosina N-Aciltransferasa/genética , Esfingosina N-Aciltransferasa/metabolismo , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismoRESUMEN
STK19 was proposed to be a cancer driver, and recent work by Yin et al. (2019) in Cell suggested that the frequently recurring STK19 D89N substitution represents a gain-of-function change, allowing increased phosphorylation of NRAS to enhance melanocyte transformation. Here we show that the STK19 gene has been incorrectly annotated, and that the expressed protein is 110 amino acids shorter than indicated by current databases. The "cancer driving" STK19 D89N substitution is thus outside the coding region. We also fail to detect evidence of the mutation affecting STK19 expression; instead, it is a UV signature mutation, found in the promoter of other genes as well. Furthermore, STK19 is exclusively nuclear and chromatin-associated, while no evidence for it being a kinase was found. The data in this Matters Arising article raise fundamental questions about the recently proposed role for STK19 in melanoma progression via a function as an NRAS kinase, suggested by Yin et al. (2019) in Cell. See also the response by Yin et al. (2020), published in this issue.
Asunto(s)
Melanoma , Recurrencia Local de Neoplasia , GTP Fosfohidrolasas/metabolismo , Genes ras , Humanos , Melanoma/genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Mutación , Proteínas Nucleares , Fosforilación , Proteínas Serina-Treonina Quinasas/genética , Transducción de SeñalRESUMEN
Problems arising during translation of mRNAs lead to ribosome stalling and collisions that trigger a series of quality control events. However, the global cellular response to ribosome collisions has not been explored. Here, we uncover a function for ribosome collisions in signal transduction. Using translation elongation inhibitors and general cellular stress conditions, including amino acid starvation and UV irradiation, we show that ribosome collisions activate the stress-activated protein kinase (SAPK) and GCN2-mediated stress response pathways. We show that the MAPKKK ZAK functions as the sentinel for ribosome collisions and is required for immediate early activation of both SAPK (p38/JNK) and GCN2 signaling pathways. Selective ribosome profiling and biochemistry demonstrate that although ZAK generally associates with elongating ribosomes on polysomal mRNAs, it specifically auto-phosphorylates on the minimal unit of colliding ribosomes, the disome. Together, these results provide molecular insights into how perturbation of translational homeostasis regulates cell fate.
Asunto(s)
Ribosomas/metabolismo , Estrés Fisiológico , Transportadoras de Casetes de Unión a ATP/metabolismo , Anisomicina/farmacología , Apoptosis/efectos de los fármacos , Daño del ADN/efectos de la radiación , Activación Enzimática , Humanos , Quinasas Quinasa Quinasa PAM/deficiencia , Quinasas Quinasa Quinasa PAM/genética , Quinasas Quinasa Quinasa PAM/metabolismo , Proteína Quinasa 14 Activada por Mitógenos/antagonistas & inhibidores , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , Fosforilación , Polirribosomas/metabolismo , Isoformas de Proteínas/deficiencia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Interferencia de ARN , ARN Mensajero/metabolismo , ARN Interferente Pequeño/metabolismo , Transducción de Señal , Rayos Ultravioleta , eIF-2 Quinasa/metabolismoRESUMEN
Autophagy is required in diverse paradigms of lifespan extension, leading to the prevailing notion that autophagy is beneficial for longevity. However, why autophagy is harmful in certain contexts remains unexplained. Here, we show that mitochondrial permeability defines the impact of autophagy on aging. Elevated autophagy unexpectedly shortens lifespan in C. elegans lacking serum/glucocorticoid regulated kinase-1 (sgk-1) because of increased mitochondrial permeability. In sgk-1 mutants, reducing levels of autophagy or mitochondrial permeability transition pore (mPTP) opening restores normal lifespan. Remarkably, low mitochondrial permeability is required across all paradigms examined of autophagy-dependent lifespan extension. Genetically induced mPTP opening blocks autophagy-dependent lifespan extension resulting from caloric restriction or loss of germline stem cells. Mitochondrial permeability similarly transforms autophagy into a destructive force in mammals, as liver-specific Sgk knockout mice demonstrate marked enhancement of hepatocyte autophagy, mPTP opening, and death with ischemia/reperfusion injury. Targeting mitochondrial permeability may maximize benefits of autophagy in aging.
Asunto(s)
Envejecimiento/metabolismo , Proteínas de Transporte de Membrana Mitocondrial/fisiología , Membranas Mitocondriales/fisiología , Animales , Autofagia/fisiología , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/fisiología , Restricción Calórica , Células HEK293 , Humanos , Longevidad/fisiología , Masculino , Ratones , Ratones Noqueados , Mitocondrias , Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Poro de Transición de la Permeabilidad Mitocondrial , Permeabilidad , Cultivo Primario de Células , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/fisiología , Daño por Reperfusión/metabolismo , Transducción de SeñalRESUMEN
Tumor-associated macrophages (TAMs) display pro-tumorigenic phenotypes for supporting tumor progression in response to microenvironmental cues imposed by tumor and stromal cells. However, the underlying mechanisms by which tumor cells instruct TAM behavior remain elusive. Here, we uncover that tumor-cell-derived glucosylceramide stimulated unconventional endoplasmic reticulum (ER) stress responses by inducing reshuffling of lipid composition and saturation on the ER membrane in macrophages, which induced IRE1-mediated spliced XBP1 production and STAT3 activation. The cooperation of spliced XBP1 and STAT3 reinforced the pro-tumorigenic phenotype and expression of immunosuppressive genes. Ablation of XBP1 expression with genetic manipulation or ameliorating ER stress responses by facilitating LPCAT3-mediated incorporation of unsaturated lipids to the phosphatidylcholine hampered pro-tumorigenic phenotype and survival in TAMs. Together, we uncover the unexpected roles of tumor-cell-produced lipids that simultaneously orchestrate macrophage polarization and survival in tumors via induction of ER stress responses and reveal therapeutic targets for sustaining host antitumor immunity.
Asunto(s)
Estrés del Retículo Endoplásmico , Retículo Endoplásmico/metabolismo , Membranas Intracelulares/metabolismo , Activación de Macrófagos , Melanoma/metabolismo , Lípidos de la Membrana/metabolismo , Neoplasias Cutáneas/metabolismo , Macrófagos Asociados a Tumores/metabolismo , Animales , Línea Celular Tumoral , Supervivencia Celular , Retículo Endoplásmico/ultraestructura , Glucosilceramidasa/metabolismo , Membranas Intracelulares/ultraestructura , Melanoma/genética , Melanoma/ultraestructura , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Transgénicos , Fenotipo , Fosforilación , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/ultraestructura , Escape del Tumor , Microambiente Tumoral , Macrófagos Asociados a Tumores/ultraestructura , Proteína 1 de Unión a la X-Box/genética , Proteína 1 de Unión a la X-Box/metabolismoRESUMEN
Patients with myelodysplastic syndromes (MDSs) display severe anemia but the mechanisms underlying this phenotype are incompletely understood. Right open-reading-frame kinase 2 (RIOK2) encodes a protein kinase located at 5q15, a region frequently lost in patients with MDS del(5q). Here we show that hematopoietic cell-specific haploinsufficient deletion of Riok2 (Riok2f/+Vav1cre) led to reduced erythroid precursor frequency leading to anemia. Proteomic analysis of Riok2f/+Vav1cre erythroid precursors suggested immune system activation, and transcriptomic analysis revealed an increase in p53-dependent interleukin (IL)-22 in Riok2f/+Vav1cre CD4+ T cells (TH22). Further, we discovered that the IL-22 receptor, IL-22RA1, was unexpectedly present on erythroid precursors. Blockade of IL-22 signaling alleviated anemia not only in Riok2f/+Vav1cre mice but also in wild-type mice. Serum concentrations of IL-22 were increased in the subset of patients with del(5q) MDS as well as patients with anemia secondary to chronic kidney disease. This work reveals a possible therapeutic opportunity for reversing many stress-induced anemias by targeting IL-22 signaling.
Asunto(s)
Anemia/metabolismo , Anticuerpos Neutralizantes/farmacología , Células Eritroides/metabolismo , Eritropoyesis/efectos de los fármacos , Interleucinas/antagonistas & inhibidores , Síndromes Mielodisplásicos/tratamiento farmacológico , Receptores de Interleucina/metabolismo , Anemia/sangre , Anemia/inmunología , Anemia/prevención & control , Animales , Células Cultivadas , Microambiente Celular , Modelos Animales de Enfermedad , Células Eritroides/inmunología , Humanos , Interleucinas/inmunología , Interleucinas/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Síndromes Mielodisplásicos/sangre , Síndromes Mielodisplásicos/inmunología , Síndromes Mielodisplásicos/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-vav/genética , Proteínas Proto-Oncogénicas c-vav/metabolismo , Receptores de Interleucina/genética , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/inmunología , Insuficiencia Renal Crónica/metabolismo , Transducción de Señal , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Interleucina-22RESUMEN
Metabolic reprograming toward aerobic glycolysis is a pivotal mechanism shaping immune responses. Here we show that deficiency in NF-κB-inducing kinase (NIK) impairs glycolysis induction, rendering CD8+ effector T cells hypofunctional in the tumor microenvironment. Conversely, ectopic expression of NIK promotes CD8+ T cell metabolism and effector function, thereby profoundly enhancing antitumor immunity and improving the efficacy of T cell adoptive therapy. NIK regulates T cell metabolism via a NF-κB-independent mechanism that involves stabilization of hexokinase 2 (HK2), a rate-limiting enzyme of the glycolytic pathway. NIK prevents autophagic degradation of HK2 through controlling cellular reactive oxygen species levels, which in turn involves modulation of glucose-6-phosphate dehydrogenase (G6PD), an enzyme that mediates production of the antioxidant NADPH. We show that the G6PD-NADPH redox system is important for HK2 stability and metabolism in activated T cells. These findings establish NIK as a pivotal regulator of T cell metabolism and highlight a post-translational mechanism of metabolic regulation.
Asunto(s)
Linfocitos T CD8-positivos/enzimología , Neoplasias del Colon/enzimología , Metabolismo Energético , Activación de Linfocitos , Linfocitos Infiltrantes de Tumor/enzimología , Melanoma Experimental/enzimología , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/trasplante , Línea Celular Tumoral , Neoplasias del Colon/inmunología , Neoplasias del Colon/patología , Neoplasias del Colon/terapia , Citotoxicidad Inmunológica , Estabilidad de Enzimas , Femenino , Glucosafosfato Deshidrogenasa/metabolismo , Glucólisis , Hexoquinasa/genética , Hexoquinasa/metabolismo , Inmunoterapia Adoptiva , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/trasplante , Masculino , Melanoma Experimental/inmunología , Melanoma Experimental/patología , Melanoma Experimental/terapia , Ratones Endogámicos C57BL , Ratones Noqueados , NADP/metabolismo , Fenotipo , Proteínas Serina-Treonina Quinasas/deficiencia , Proteínas Serina-Treonina Quinasas/genética , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Microambiente Tumoral , Quinasa de Factor Nuclear kappa BRESUMEN
Adipose tissue group 2 innate lymphoid cells (ILC2s) help maintain metabolic homeostasis by sustaining type 2 immunity and promoting adipose beiging. Although impairment of the ILC2 compartment contributes to obesity-associated insulin resistance, the underlying mechanisms have not been elucidated. Here, we found that ILC2s in obese mice and humans exhibited impaired liver kinase B1 (LKB1) activation. Genetic ablation of LKB1 disrupted ILC2 mitochondrial metabolism and suppressed ILC2 responses, resulting in exacerbated insulin resistance. Mechanistically, LKB1 deficiency induced aberrant PD-1 expression through activation of NFAT, which in turn enhanced mitophagy by suppressing Bcl-xL expression. Blockade of PD-1 restored the normal functions of ILC2s and reversed obesity-induced insulin resistance in mice. Collectively, these data present the LKB1-PD-1 axis as a promising therapeutic target for the treatment of metabolic disease.
Asunto(s)
Tejido Adiposo , Homeostasis , Resistencia a la Insulina , Linfocitos , Mitocondrias , Obesidad , Receptor de Muerte Celular Programada 1 , Proteínas Serina-Treonina Quinasas , Animales , Resistencia a la Insulina/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Ratones , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Mitocondrias/metabolismo , Humanos , Tejido Adiposo/metabolismo , Tejido Adiposo/inmunología , Obesidad/inmunología , Obesidad/metabolismo , Linfocitos/inmunología , Linfocitos/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Inmunidad Innata , Masculino , Mitofagia/inmunología , Quinasas de la Proteína-Quinasa Activada por el AMPRESUMEN
The ubiquitin-binding endoribonuclease N4BP1 potently suppresses cytokine production by Toll-like receptors (TLRs) that signal through the adaptor MyD88 but is inactivated via caspase-8-mediated cleavage downstream of death receptors, TLR3, or TLR4. Here, we examined the mechanism whereby N4BP1 limits inflammatory responses. In macrophages, deletion of N4BP1 prolonged activation of inflammatory gene transcription at late time points after TRIF-independent TLR activation. Optimal suppression of inflammatory cytokines by N4BP1 depended on its ability to bind polyubiquitin chains, as macrophages and mice-bearing inactivating mutations in a ubiquitin-binding motif in N4BP1 displayed increased TLR-induced cytokine production. Deletion of the noncanonical IκB kinases (ncIKKs), Tbk1 and Ikke, or their adaptor Tank phenocopied N4bp1 deficiency and enhanced macrophage responses to TLR1/2, TLR7, or TLR9 stimulation. Mechanistically, N4BP1 acted in concert with the ncIKKs to limit the duration of canonical IκB kinase (IKKα/ß) signaling. Thus, N4BP1 and the ncIKKs serve as an important checkpoint against over-exuberant innate immune responses.
Asunto(s)
Endorribonucleasas , Quinasa I-kappa B , Inflamación , Macrófagos , Proteínas Serina-Treonina Quinasas , Receptores Toll-Like , Animales , Ratones , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Citocinas/metabolismo , Endorribonucleasas/metabolismo , Endorribonucleasas/genética , Quinasa I-kappa B/metabolismo , Quinasa I-kappa B/genética , Inflamación/inmunología , Inflamación/metabolismo , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Transducción de Señal , Receptores Toll-Like/metabolismo , Ubiquitina/metabolismoRESUMEN
During mitosis, chromatin condensation shapes chromosomes as separate, rigid, and compact sister chromatids to facilitate their segregation. Here, we show that, unlike wild-type yeast chromosomes, non-chromosomal DNA circles and chromosomes lacking a centromere fail to condense during mitosis. The centromere promotes chromosome condensation strictly in cis through recruiting the kinases Aurora B and Bub1, which trigger the autonomous condensation of the entire chromosome. Shugoshin and the deacetylase Hst2 facilitated spreading the condensation signal to the chromosome arms. Targeting Aurora B to DNA circles or centromere-ablated chromosomes or releasing Shugoshin from PP2A-dependent inhibition bypassed the centromere requirement for condensation and enhanced the mitotic stability of DNA circles. Our data indicate that yeast cells license the chromosome-autonomous condensation of their chromatin in a centromere-dependent manner, excluding from this process non-centromeric DNA and thereby inhibiting their propagation.
Asunto(s)
Centrómero/genética , Cromosomas Fúngicos/genética , Mitosis , Saccharomyces cerevisiae/genética , Aurora Quinasa B/genética , Aurora Quinasa B/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteína Fosfatasa 2/genética , Proteína Fosfatasa 2/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Sirtuina 2/genética , Sirtuina 2/metabolismoRESUMEN
Land plants evolved from charophytic algae, among which Charophyceae possess the most complex body plans. We present the genome of Chara braunii; comparison of the genome to those of land plants identified evolutionary novelties for plant terrestrialization and land plant heritage genes. C. braunii employs unique xylan synthases for cell wall biosynthesis, a phragmoplast (cell separation) mechanism similar to that of land plants, and many phytohormones. C. braunii plastids are controlled via land-plant-like retrograde signaling, and transcriptional regulation is more elaborate than in other algae. The morphological complexity of this organism may result from expanded gene families, with three cases of particular note: genes effecting tolerance to reactive oxygen species (ROS), LysM receptor-like kinases, and transcription factors (TFs). Transcriptomic analysis of sexual reproductive structures reveals intricate control by TFs, activity of the ROS gene network, and the ancestral use of plant-like storage and stress protection proteins in the zygote.
Asunto(s)
Chara/genética , Genoma de Planta , Evolución Biológica , Pared Celular/metabolismo , Chara/crecimiento & desarrollo , Embryophyta/genética , Redes Reguladoras de Genes , Pentosiltransferasa/genética , Reguladores del Crecimiento de las Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , TranscriptomaRESUMEN
Aging is a major risk factor for both genetic and sporadic neurodegenerative disorders. However, it is unclear how aging interacts with genetic predispositions to promote neurodegeneration. Here, we investigate how partial loss of function of TBK1, a major genetic cause for amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) comorbidity, leads to age-dependent neurodegeneration. We show that TBK1 is an endogenous inhibitor of RIPK1 and the embryonic lethality of Tbk1-/- mice is dependent on RIPK1 kinase activity. In aging human brains, another endogenous RIPK1 inhibitor, TAK1, exhibits a marked decrease in expression. We show that in Tbk1+/- mice, the reduced myeloid TAK1 expression promotes all the key hallmarks of ALS/FTD, including neuroinflammation, TDP-43 aggregation, axonal degeneration, neuronal loss, and behavior deficits, which are blocked upon inhibition of RIPK1. Thus, aging facilitates RIPK1 activation by reducing TAK1 expression, which cooperates with genetic risk factors to promote the onset of ALS/FTD.
Asunto(s)
Apoptosis , Proteínas Serina-Treonina Quinasas/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Adulto , Anciano , Envejecimiento , Animales , Apoptosis/efectos de los fármacos , Axones/metabolismo , Conducta Animal , Encéfalo/citología , Encéfalo/metabolismo , Células Cultivadas , Humanos , Quinasa I-kappa B/metabolismo , Ratones , Ratones Noqueados , Microglía/citología , Microglía/efectos de los fármacos , Microglía/metabolismo , Fosforilación/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/deficiencia , Proteínas Serina-Treonina Quinasas/genética , Proteína Serina-Treonina Quinasas de Interacción con Receptores/deficiencia , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Médula Espinal/metabolismo , Estaurosporina/farmacología , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
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.
Asunto(s)
Adipocitos/metabolismo , Tejido Adiposo/metabolismo , Metabolismo Energético , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Adipocitos/patología , Tejido Adiposo/patología , Animales , Homólogo de la Proteína 1 Relacionada con la Autofagia/genética , Homólogo de la Proteína 1 Relacionada con la Autofagia/metabolismo , Línea Celular Transformada , Grasas de la Dieta/efectos adversos , Grasas de la Dieta/farmacología , Inflamación/inducido químicamente , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Ratones , Ratones Noqueados , FN-kappa B/genética , FN-kappa B/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Fosforilación/efectos de los fármacos , Fosforilación/genética , Proteínas Serina-Treonina Quinasas/genética , Quinasa de Factor Nuclear kappa BRESUMEN
The innate immune system functions as the first line of defense against invading bacteria and viruses. In this context, the cGAS/STING [cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase/STING] signaling axis perceives the nonself DNA associated with bacterial and viral infections, as well as the leakage of self DNA by cellular dysfunction and stresses, to elicit the host's immune responses. In this pathway, the noncanonical cyclic dinucleotide 2',3'-cyclic GMP-AMP (2',3'-cGAMP) functions as a second messenger for signal transduction: 2',3'-cGAMP is produced by the enzyme cGAS upon its recognition of double-stranded DNA, and then the 2',3'-cGAMP is recognized by the receptor STING to induce the phosphorylation of downstream factors, including TBK1 (TANK binding kinase 1) and IRF3 (interferon regulatory factor 3). Numerous crystal structures of the components of this cGAS/STING signaling axis have been reported and these clarify the structural basis for their signal transduction mechanisms. In this review, we summarize recent progress made in the structural dissection of this signaling pathway and indicate possible directions of forthcoming research.
Asunto(s)
ADN/inmunología , Inmunidad Innata , Nucleótidos Cíclicos/inmunología , Nucleotidiltransferasas/inmunología , Sistemas de Mensajero Secundario/inmunología , Animales , Bacterias , Cristalografía por Rayos X , Citosol/química , Citosol/inmunología , ADN/química , ADN/genética , Regulación de la Expresión Génica , Humanos , Factor 3 Regulador del Interferón/química , Factor 3 Regulador del Interferón/genética , Factor 3 Regulador del Interferón/inmunología , Modelos Moleculares , Nucleótidos Cíclicos/química , Nucleótidos Cíclicos/genética , Nucleotidiltransferasas/química , Nucleotidiltransferasas/genética , Fosforilación , Conformación Proteica , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/inmunología , Sistemas de Mensajero Secundario/genéticaRESUMEN
Severe changes in the environmental redox potential, and resulting alterations in the oxidation states of intracellular metabolites and enzymes, have historically been considered negative stressors, requiring responses that are strictly defensive. However, recent work in diverse organisms has revealed that more subtle changes in the intracellular redox state can act as signals, eliciting responses with benefits beyond defense and detoxification. Changes in redox state have been shown to influence or trigger chromosome segregation, sporulation, aerotaxis, and social behaviors, including luminescence as well as biofilm establishment and dispersal. Connections between redox state and complex behavior allow bacteria to link developmental choices with metabolic state and coordinate appropriate responses. Promising future directions for this area of study include metabolomic analysis of species- and condition-dependent changes in metabolite oxidation states and elucidation of the mechanisms whereby the redox state influences circadian regulation.
Asunto(s)
Biopelículas/crecimiento & desarrollo , Proteínas de Escherichia coli/metabolismo , Regulación Bacteriana de la Expresión Génica , Proteínas de la Membrana/metabolismo , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Esporas Bacterianas/metabolismo , Aliivibrio fischeri/genética , Aliivibrio fischeri/crecimiento & desarrollo , Aliivibrio fischeri/metabolismo , Bacillus subtilis/genética , Bacillus subtilis/crecimiento & desarrollo , Bacillus subtilis/metabolismo , Caulobacter crescentus/genética , Caulobacter crescentus/crecimiento & desarrollo , Caulobacter crescentus/metabolismo , Escherichia coli/genética , Escherichia coli/crecimiento & desarrollo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Glutatión/metabolismo , Proteínas de la Membrana/genética , Oxidación-Reducción , Proteínas Quinasas/genética , Proteínas Serina-Treonina Quinasas/genética , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/crecimiento & desarrollo , Pseudomonas aeruginosa/metabolismo , Transducción de Señal , Esporas Bacterianas/genética , Esporas Bacterianas/crecimiento & desarrollo , Streptomyces/genética , Streptomyces/crecimiento & desarrollo , Streptomyces/metabolismoRESUMEN
The cyclic guanosine monophosphate (GMP)-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway plays a pivotal role in innate immune responses to viral infection and inhibition of autoimmunity. Recent studies have suggested that micronuclei formed by genotoxic stress can activate innate immune signaling via the cGAS-STING pathway. Here, we investigated cGAS localization, activation, and downstream signaling from micronuclei induced by ionizing radiation, replication stress, and chromosome segregation errors. Although cGAS localized to ruptured micronuclei via binding to self-DNA, we failed to observe cGAS activation; cGAMP production; downstream phosphorylation of STING, TBK1, or IRF3; nuclear accumulation of IRF3; or expression of interferon-stimulated genes. Failure to activate the cGAS-STING pathway was observed across primary and immortalized cell lines, which retained the ability to activate the cGAS-STING pathway in response to dsDNA or modified vaccinia virus infection. We provide evidence that micronuclei formed by genotoxic insults contain histone-bound self-DNA, which we show is inhibitory to cGAS activation in cells.
Asunto(s)
Segregación Cromosómica , Proteínas de la Membrana , Micronúcleos con Defecto Cromosómico , Nucleótidos Cíclicos , Nucleotidiltransferasas , Transducción de Señal , Nucleotidiltransferasas/metabolismo , Nucleotidiltransferasas/genética , Humanos , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Micronúcleos con Defecto Cromosómico/efectos de la radiación , Nucleótidos Cíclicos/metabolismo , Fosforilación , Replicación del ADN/efectos de la radiación , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Factor 3 Regulador del Interferón/metabolismo , Factor 3 Regulador del Interferón/genética , Inmunidad Innata/efectos de la radiación , Daño del ADN , Células HEK293 , Animales , Radiación Ionizante , Células HeLaRESUMEN
TANK-binding kinase 1 (TBK1) is a potential therapeutic target in multiple cancers, including clear cell renal cell carcinoma (ccRCC). However, targeting TBK1 in clinical practice is challenging. One approach to overcome this challenge would be to identify an upstream TBK1 regulator that could be targeted therapeutically in cancer specifically. In this study, we perform a kinome-wide small interfering RNA (siRNA) screen and identify doublecortin-like kinase 2 (DCLK2) as a TBK1 regulator in ccRCC. DCLK2 binds to and directly phosphorylates TBK1 on Ser172. Depletion of DCLK2 inhibits anchorage-independent colony growth and kidney tumorigenesis in orthotopic xenograft models. Conversely, overexpression of DCLK2203, a short isoform that predominates in ccRCC, promotes ccRCC cell growth and tumorigenesis in vivo. Mechanistically, DCLK2203 elicits its oncogenic signaling via TBK1 phosphorylation and activation. Taken together, these results suggest that DCLK2 is a TBK1 activator and potential therapeutic target for ccRCC.