RESUMEN
The transcriptional co-activators YAP and TAZ are key regulators of organ size and tissue homeostasis, and their dysregulation contributes to human cancer. Here, we discover YAP/TAZ as bona fide downstream effectors of the alternative Wnt signaling pathway. Wnt5a/b and Wnt3a induce YAP/TAZ activation independent of canonical Wnt/ß-catenin signaling. Mechanistically, we delineate the "alternative Wnt-YAP/TAZ signaling axis" that consists of Wnt-FZD/ROR-Gα12/13-Rho GTPases-Lats1/2 to promote YAP/TAZ activation and TEAD-mediated transcription. YAP/TAZ mediate the biological functions of alternative Wnt signaling, including gene expression, osteogenic differentiation, cell migration, and antagonism of Wnt/ß-catenin signaling. Together, our work establishes YAP/TAZ as critical mediators of alternative Wnt signaling.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Fosfoproteínas/metabolismo , Vía de Señalización Wnt , Animales , Proteínas de Ciclo Celular , Línea Celular , Receptores Frizzled/metabolismo , Humanos , Ratones , Ratones Transgénicos , Transactivadores , Factores de Transcripción , Proteínas Señalizadoras YAP , beta Catenina/metabolismoRESUMEN
The Hippo pathway is a master regulator of tissue homeostasis and organ size. NF2 is a well-established tumor suppressor, and loss of NF2 severely compromises Hippo pathway activity. However, the precise mechanism of how NF2 mediates upstream signals to regulate the Hippo pathway is not clear. Here we report that, in mammalian cells, NF2's lipid-binding ability is critical for its function in activating the Hippo pathway in response to osmotic stress. Mechanistically, osmotic stress induces PI(4,5)P2 plasma membrane enrichment by activating the PIP5K family, allowing for NF2 plasma membrane recruitment and subsequent downstream Hippo pathway activation. An NF2 mutant deficient in lipid binding is unable to activate the Hippo pathway in response to osmotic stress, as measured by LATS and YAP phosphorylation. Our findings identify the PIP5K family as novel regulators upstream of Hippo signaling, and uncover the importance of phosphoinositide dynamics, specifically PI(4,5)P2, in Hippo pathway regulation.
Asunto(s)
Homeostasis/fisiología , Neurofibromina 2/metabolismo , Fosfatidilinositoles/metabolismo , Transducción de Señal , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Proteínas de Ciclo Celular/metabolismo , Línea Celular , Vía de Señalización Hippo , Humanos , Ratones , Neurofibromina 2/genética , Presión Osmótica/fisiología , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal/genética , Proteínas Señalizadoras YAPRESUMEN
Yes-associated protein (YAP) and its homolog transcriptional coactivator with PDZ-binding motif (TAZ) are key effectors of the Hippo pathway to control cell growth and organ size, of which dysregulation yields to tumorigenesis or hypertrophy. Upon activation, YAP/TAZ translocate into the nucleus and bind to TEAD transcription factors to promote transcriptional programs for proliferation or cell specification. Immediate early genes, represented by AP-1 complex, are rapidly induced and control later-phase transcriptional program to play key roles in tumorigenesis and organ maintenance. Here, we report that YAP/TAZ directly promote FOS transcription that in turn contributes to the biological function of YAP/TAZ. YAP/TAZ bind to the promoter region of FOS to stimulate its transcription. Deletion of YAP/TAZ blocks the induction of immediate early genes in response to mitogenic stimuli. FOS induction contributes to expression of YAP/TAZ downstream target genes. Genetic deletion or chemical inhibition of AP-1 suppresses growth of YAP-driven cancer cells, such as Lats1/2-deficient cancer cells as well as Gαq/11 mutated uveal melanoma. Furthermore, AP-1 inhibition almost completely abrogates the hepatomegaly induced by YAP overexpression. Our findings reveal a feed-forward interplay between immediate early transcription of AP-1 and Hippo pathway function.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Regulación Neoplásica de la Expresión Génica , Transactivadores/metabolismo , Factor de Transcripción AP-1/genética , Factor de Transcripción AP-1/metabolismo , Factores de Transcripción/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular/genética , Eliminación de Gen , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Genes fos/genética , Células HEK293 , Humanos , Hígado/metabolismo , Melanoma/fisiopatología , Ratones , Mitógenos/farmacología , Tamaño de los Órganos/genética , Regiones Promotoras Genéticas/genética , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ , Neoplasias de la Úvea/fisiopatología , Proteínas Señalizadoras YAPRESUMEN
Mammalian cells are surrounded by neighbouring cells and extracellular matrix (ECM), which provide cells with structural support and mechanical cues that influence diverse biological processes1. The Hippo pathway effectors YAP (also known as YAP1) and TAZ (also known as WWTR1) are regulated by mechanical cues and mediate cellular responses to ECM stiffness2,3. Here we identified the Ras-related GTPase RAP2 as a key intracellular signal transducer that relays ECM rigidity signals to control mechanosensitive cellular activities through YAP and TAZ. RAP2 is activated by low ECM stiffness, and deletion of RAP2 blocks the regulation of YAP and TAZ by stiffness signals and promotes aberrant cell growth. Mechanistically, matrix stiffness acts through phospholipase Cγ1 (PLCγ1) to influence levels of phosphatidylinositol 4,5-bisphosphate and phosphatidic acid, which activates RAP2 through PDZGEF1 and PDZGEF2 (also known as RAPGEF2 and RAPGEF6). At low stiffness, active RAP2 binds to and stimulates MAP4K4, MAP4K6, MAP4K7 and ARHGAP29, resulting in activation of LATS1 and LATS2 and inhibition of YAP and TAZ. RAP2, YAP and TAZ have pivotal roles in mechanoregulated transcription, as deletion of YAP and TAZ abolishes the ECM stiffness-responsive transcriptome. Our findings show that RAP2 is a molecular switch in mechanotransduction, thereby defining a mechanosignalling pathway from ECM stiffness to the nucleus.
Asunto(s)
Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Proteínas de Unión al GTP rap/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Transformación Celular Neoplásica , Matriz Extracelular/química , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Femenino , Proteínas Activadoras de GTPasa/metabolismo , Quinasas del Centro Germinal , Factores de Intercambio de Guanina Nucleótido/metabolismo , Células HEK293 , Vía de Señalización Hippo , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Ratones Endogámicos NOD , Ratones Desnudos , Ratones SCID , Proteínas del Tejido Nervioso/metabolismo , Fosfolipasa C gamma/metabolismo , Fosfoproteínas/metabolismo , Transactivadores , Factores de Transcripción , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ , Transcriptoma , Proteínas Señalizadoras YAP , Proteínas de Unión al GTP rap/genéticaRESUMEN
The Hippo pathway is important for regulating tissue homeostasis, and its dysregulation has been implicated in human cancer. However, it is not well understood how the Hippo pathway becomes dysregulated because few mutations in core Hippo pathway components have been identified. Therefore, much work in the Hippo field has focused on identifying upstream regulators, and a complex Hippo interactome has been identified. Nevertheless, it is not always clear which components are the most physiologically relevant in regulating YAP/TAZ. To provide an overview of important Hippo pathway components, we created knockout cell lines for many of these components and compared their relative contributions to YAP/TAZ regulation in response to a wide range of physiological signals. By this approach, we provide an overview of the functional importance of many Hippo pathway components and demonstrate NF2 and RHOA as important regulators of YAP/TAZ and TAOK1/3 as direct kinases for LATS1/2.
Asunto(s)
Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica/fisiología , Transducción de Señal/genética , Aciltransferasas , Proteínas de Ciclo Celular , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Técnicas de Silenciamiento del Gen , Células HEK293 , Vía de Señalización Hippo , Humanos , Neurofibromina 2 , Proteínas Nucleares , Fosforilación , Proteínas Serina-Treonina Quinasas , Factores de Transcripción , Proteínas Supresoras de Tumor , Proteína de Unión al GTP rhoARESUMEN
Cytosolic RNA/DNA sensing elicits primary defense against viral pathogens. Interferon regulatory factor 3 (IRF3), a key signal mediator/transcriptional factor of the antiviral-sensing pathway, is indispensible for interferon production and antiviral defense. However, how the status of IRF3 activation is controlled remains elusive. Through a functional screen of the human kinome, we found that mammalian sterile 20-like kinase 1 (Mst1), but not Mst2, profoundly inhibited cytosolic nucleic acid sensing. Mst1 associated with IRF3 and directly phosphorylated IRF3 at Thr75 and Thr253. This Mst1-mediated phosphorylation abolished activated IRF3 homodimerization, its occupancy on chromatin, and subsequent IRF3-mediated transcriptional responses. In addition, Mst1 also impeded virus-induced activation of TANK-binding kinase 1 (TBK1), further attenuating IRF3 activation. As a result, Mst1 depletion or ablation enabled an enhanced antiviral response and defense in cells and mice. Therefore, the identification of Mst1 as a novel physiological negative regulator of IRF3 activation provides mechanistic insights into innate antiviral defense and potential antiviral prevention strategies.
Asunto(s)
Citosol/inmunología , Inmunidad Innata/genética , Factor 3 Regulador del Interferón/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Infecciones por Rhabdoviridae/enzimología , Infecciones por Rhabdoviridae/inmunología , Animales , Línea Celular , Activación Enzimática/genética , Células HEK293 , Humanos , Factor 3 Regulador del Interferón/genética , Ratones , Ratones Endogámicos C57BL , Fosforilación , Unión Proteica , Serina-Treonina Quinasa 3 , Vesiculovirus/inmunología , Pez Cebra/inmunologíaRESUMEN
YAP (Yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif) are major downstream effectors of the Hippo pathway that influences tissue homeostasis, organ size, and cancer development. Aberrant hyperactivation of YAP/TAZ causes tissue overgrowth and tumorigenesis, whereas their inactivation impairs tissue development and regeneration. Dynamic and precise control of YAP/TAZ activity is thus important to ensure proper physiological regulation and homeostasis of the cells. Here, we show that YAP/TAZ activation results in activation of their negative regulators, LATS1/2 (large tumor suppressor 1/2) kinases, to constitute a negative feedback loop of the Hippo pathway in both cultured cells and mouse tissues. YAP/TAZ in complex with the transcription factor TEAD (TEA domain family member) directly induce LATS2 expression. Furthermore, YAP/TAZ also stimulate the kinase activity of LATS1/2 through inducing NF2 (neurofibromin 2). This feedback regulation is responsible for the transient activation of YAP upon lysophosphatidic acid (LPA) stimulation and the inhibition of YAP-induced cell migration. Thus, this LATS-mediated feedback loop provides an efficient mechanism to establish the robustness and homeostasis of YAP/TAZ regulation.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Retroalimentación Fisiológica/fisiología , Homeostasis/fisiología , Neurofibromina 2/metabolismo , Fosfoproteínas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Factores de Transcripción/metabolismo , Aciltransferasas , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Proteínas de Ciclo Celular , Movimiento Celular , Células Cultivadas , Proteínas de Unión al ADN/metabolismo , Activación Enzimática/fisiología , Femenino , Regulación de la Expresión Génica , Células HEK293 , Vía de Señalización Hippo , Homeostasis/genética , Humanos , Hígado/metabolismo , Masculino , Ratones , Fosfoproteínas/genética , Proteínas Serina-Treonina Quinasas/genética , Factores de Transcripción/genética , Proteínas Supresoras de Tumor/genética , Proteínas Señalizadoras YAPRESUMEN
The Hippo pathway plays an important role in regulating tissue homeostasis, and its effectors, the transcriptional co-activators Yes-associated protein (YAP) and WW domain-containing transcription regulator 1 (WWTR1 or TAZ), are responsible for mediating the vast majority of its physiological functions. Although YAP and TAZ are thought to be largely redundant and similarly regulated by Hippo signaling, they have developmental, structural, and physiological differences that suggest they may differ in their regulation and downstream functions. To better understand the functions of YAP and TAZ in the Hippo pathway, using CRISPR/Cas9, we generated YAP KO, TAZ KO, and YAP/TAZ KO cell lines in HEK293A cells. We evaluated them in response to many environmental conditions and stimuli and used RNA-Seq to compare their transcriptional profiles. We found that YAP inactivation has a greater effect on cellular physiology (namely, cell spreading, volume, granularity, glucose uptake, proliferation, and migration) than TAZ inactivation. However, functional redundancy between YAP and TAZ was also observed. In summary, our findings confirm that the Hippo pathway effectors YAP and TAZ are master regulators for multiple cellular processes but also reveal that YAP has a stronger influence than TAZ.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Fenómenos Fisiológicos Celulares , Fosfoproteínas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Aciltransferasas , Proteínas Adaptadoras Transductoras de Señales/antagonistas & inhibidores , Proteínas Adaptadoras Transductoras de Señales/genética , Sistemas CRISPR-Cas , Perfilación de la Expresión Génica , Células HEK293 , Vía de Señalización Hippo , Homeostasis , Humanos , Fosfoproteínas/antagonistas & inhibidores , Fosfoproteínas/genética , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/genética , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/genética , Proteínas Supresoras de Tumor/antagonistas & inhibidores , Proteínas Supresoras de Tumor/genética , Proteínas Señalizadoras YAPRESUMEN
YAP is the major downstream effector of the Hippo pathway, which controls cell growth, tissue homeostasis, and organ size. Aberrant YAP activation, resulting from dysregulation of the Hippo pathway, is frequently observed in human cancers. YAP is a transcription co-activator, and the key mechanism of YAP regulation is its nuclear and cytoplasmic translocation. The Hippo pathway component, LATS, inhibits YAP by phosphorylating YAP at Ser127, leading to 14-3-3 binding and cytoplasmic retention of YAP Here, we report that osmotic stress stimulates transient YAP nuclear localization and increases YAP activity even when YAP Ser127 is phosphorylated. Osmotic stress acts via the NLK kinase to induce YAP Ser128 phosphorylation. Phosphorylation of YAP at Ser128 interferes with its ability to bind to 14-3-3, resulting in YAP nuclear accumulation and induction of downstream target gene expression. This osmotic stress-induced YAP activation enhances cellular stress adaptation. Our findings reveal a critical role for NLK-mediated Ser128 phosphorylation in YAP regulation and a crosstalk between osmotic stress and the Hippo pathway.
Asunto(s)
Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Nucleares/metabolismo , Presión Osmótica , Proteínas Serina-Treonina Quinasas/metabolismo , Serina/metabolismo , Factores de Transcripción/metabolismo , Ciclo Celular , Proteínas de Ciclo Celular , Nucléolo Celular , Citoplasma/metabolismo , Activación Enzimática , Células HEK293 , Humanos , Péptidos y Proteínas de Señalización Intracelular/química , Fosforilación , Unión Proteica , Proteínas Serina-Treonina Quinasas/química , Transporte de Proteínas , Serina/química , Transducción de SeñalRESUMEN
The Hippo pathway plays a crucial role in regulating tissue homeostasis and organ size, and its deregulation is frequently observed in human cancer. Yap is the major effector of and is inhibited by the Hippo pathway. In mouse model studies, inducible Yap expression in multiple tissues results in organ overgrowth. In the liver, knockout of upstream Hippo pathway components or transgenic expression of Yap leads to liver enlargement and hepatocellular carcinoma. In the small intestine or colon, deletion of upstream Hippo pathway components also results in expansion of intestinal progenitor cells and eventual development of adenomas. Genetic deletion of Yap in the intestine does not change the intestinal structure, but Yap is essential for intestinal repair upon certain types of tissue injury. The function of the Hippo pathway has also been studied in other gastrointestinal tissues, including the pancreas and stomach. Here we provide a brief overview of the Hippo pathway and discuss the physiological and pathological functions of this tumor suppressor pathway in gastrointestinal tissues.
Asunto(s)
Tracto Gastrointestinal/fisiología , Homeostasis/fisiología , Proteínas Serina-Treonina Quinasas/fisiología , Regeneración/fisiología , Transducción de Señal/fisiología , Aciltransferasas , Proteínas Adaptadoras Transductoras de Señales/fisiología , Animales , Proteínas de Ciclo Celular , Modelos Animales de Enfermedad , Neoplasias Gastrointestinales/fisiopatología , Vía de Señalización Hippo , Humanos , Ratones , Fosfoproteínas/fisiología , Factores de Transcripción/fisiología , Proteínas Señalizadoras YAPRESUMEN
Transcription unlocked: A synthetic chemical biology approach involving unlocked nucleic acids was used to dissect the contribution of sugar backbone integrity to the RNA Polymeraseâ II (Polâ II) transcription process. An unexpected dominant role for sugar-ring integrity in Polâ II transcriptional efficiency and fidelity was revealed.
Asunto(s)
Carbohidratos/química , Oligonucleótidos/metabolismo , ARN Polimerasa II/metabolismo , Transcripción Genética , Biocatálisis , Cinética , Oligonucleótidos/química , ARN Polimerasa II/química , ARN Polimerasa II/genética , Especificidad por SustratoRESUMEN
Uveal melanoma (UM) is the most common intraocular tumor in adults. Recurrent mutations in BRCA1-associated protein 1 (BAP1) and splicing factor 3B subunit 1 (SF3B1) display a mutually exclusive pattern in UM, but the underlying mechanism is unknown. We show that combined BAP1 deficiency and SF3B1 hotspot mutation lead to senescence and growth arrest in human UM cells. Although p53 protein expression is induced, deletion of TP53 (encoding p53) only modestly rescues the observed senescent phenotype. UM cells with BAP1 loss or SF3B1 mutation are more sensitive to chemotherapeutic drugs compared with their isogenic parental cells. Transcriptome analysis shows that DNA-repair genes are downregulated upon co-occurrence of BAP1 deletion and SF3B1 mutation, thus leading to impaired DNA damage response and the induction of senescence. The co-occurrence of these two mutations reduces invasion of UM cells in zebrafish xenograft models and suppresses growth of melanoma xenografts in nude mice. Our findings provide a mechanistic explanation for the mutual exclusivity of BAP1 and SF3B1 mutations in human UM.
Asunto(s)
Melanoma , Fosfoproteínas , Factores de Empalme de ARN , Proteínas Supresoras de Tumor , Ubiquitina Tiolesterasa , Neoplasias de la Úvea , Animales , Senescencia Celular/genética , Análisis Mutacional de ADN , Humanos , Melanoma/patología , Ratones , Ratones Desnudos , Mutación/genética , Fosfoproteínas/metabolismo , Factores de Empalme de ARN/genética , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Ubiquitina Tiolesterasa/genética , Ubiquitina Tiolesterasa/metabolismo , Neoplasias de la Úvea/genética , Neoplasias de la Úvea/metabolismo , Neoplasias de la Úvea/patología , Pez Cebra/genética , Pez Cebra/metabolismoRESUMEN
Protein phosphorylation is one of the most important posttranslational modifications in cell signaling and regulation. Protein phosphorylation can be detected by site-specific phospho-antibodies, but generating these antibodies can be costly, time-consuming, and difficult. Recently, Phos-tag technology has been developed to detect protein phosphorylation. Here, we describe our method for using Phos-tag gels to compare the phosphorylation status of YAP and TAZ, the most important downstream effectors of the Hippo pathway.
Asunto(s)
Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinasas , Transducción de Señal , Factores de Transcripción/metabolismo , Aciltransferasas , Proteínas de Ciclo Celular , Vía de Señalización Hippo , Humanos , Fosforilación , Procesamiento Proteico-PostraduccionalRESUMEN
In this Letter, the authors neglected to acknowledge funding from the Yonsei University Future-leading Research Initiative of 2017 (2017-22-007) awarded to H.W.P.
RESUMEN
The role of YAP (Yes-associated protein 1) and MRTF-A (myocardin-related transcription factor A), two transcriptional co-activators regulated downstream of GPCRs (G protein-coupled receptors) and RhoA, in the growth of glioblastoma cells and in vivo glioblastoma multiforme (GBM) tumor development was explored using human glioblastoma cell lines and tumor-initiating cells derived from patient-derived xenografts (PDX). Knockdown of these co-activators in GSC-23 PDX cells using short hairpin RNA significantly attenuated in vitro self-renewal capability assessed by limiting dilution, oncogene expression, and neurosphere formation. Orthotopic xenografts of the MRTF-A and YAP knockdown PDX cells formed significantly smaller tumors and were of lower morbidity than wild-type cells. In vitro studies used PDX and 1321N1 glioblastoma cells to examine functional responses to sphingosine 1-phosphate (S1P), a GPCR agonist that activates RhoA signaling, demonstrated that YAP signaling was required for cell migration and invasion, whereas MRTF-A was required for cell adhesion; both YAP and MRTF-A were required for proliferation. Gene expression analysis by RNA-sequencing of S1P-treated MRTF-A or YAP knockout cells identified 44 genes that were induced through RhoA and highly dependent on YAP, MRTF-A, or both. Knockdown of F3 (tissue factor (TF)), a target gene regulated selectively through YAP, blocked cell invasion and migration, whereas knockdown of HBEGF (heparin-binding epidermal growth factor-like growth factor), a gene selectively induced through MRTF-A, prevented cell adhesion in response to S1P. Proliferation was sensitive to knockdown of target genes regulated through either or both YAP and MRTF-A. Expression of TF and HBEGF was also selectively decreased in tumors from PDX cells lacking YAP or MRTF-A, indicating that these transcriptional pathways are regulated in preclinical GBM models and suggesting that their activation through GPCRs and RhoA contributes to growth and maintenance of human GBM.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Neoplasias Encefálicas/patología , Regulación Neoplásica de la Expresión Génica/genética , Glioblastoma/patología , Fosfoproteínas/genética , Transactivadores/genética , Animales , Neoplasias Encefálicas/genética , Glioblastoma/genética , Xenoinjertos , Humanos , Ratones , Ratones Desnudos , Factores de Transcripción , Proteínas Señalizadoras YAP , Proteína de Unión al GTP rhoA/biosíntesis , Proteína de Unión al GTP rhoA/genéticaRESUMEN
The Hippo pathway is a universal governor of organ size, tissue homeostasis, and regeneration. A growing body of work has advanced our understanding of Hippo pathway regulation of cell proliferation, differentiation, and spatial patterning not only in organ development but also upon injury-induced regeneration. The pathway's central role in stem cell biology thus implicates its potential for therapeutic manipulation in mammalian organ regeneration. In this review, we survey recent literature linking the Hippo pathway to the development, homeostasis, and regeneration of various organs, including Hippo-independent roles for YAP, defined here as YAP functions that are not regulated by the Hippo pathway kinases LATS1/2.
Asunto(s)
Homeostasis/fisiología , Tamaño de los Órganos/fisiología , Proteínas Serina-Treonina Quinasas/fisiología , Transducción de Señal , Humanos , RegeneraciónRESUMEN
The Hippo pathway controls organ size and tissue homeostasis, with deregulation leading to cancer. The core Hippo components in mammals are composed of the upstream serine/threonine kinases Mst1/2, MAPK4Ks and Lats1/2. Inactivation of these upstream kinases leads to dephosphorylation, stabilization, nuclear translocation and thus activation of the major functional transducers of the Hippo pathway, YAP and its paralogue TAZ. YAP/TAZ are transcription co-activators that regulate gene expression primarily through interaction with the TEA domain DNA-binding family of transcription factors (TEAD). The current paradigm for regulation of this pathway centres on phosphorylation-dependent nucleocytoplasmic shuttling of YAP/TAZ through a complex network of upstream components. However, unlike other transcription factors, such as SMAD, NF-κB, NFAT and STAT, the regulation of TEAD nucleocytoplasmic shuttling has been largely overlooked. In the present study, we show that environmental stress promotes TEAD cytoplasmic translocation via p38 MAPK in a Hippo-independent manner. Importantly, stress-induced TEAD inhibition predominates YAP-activating signals and selectively suppresses YAP-driven cancer cell growth. Our data reveal a mechanism governing TEAD nucleocytoplasmic shuttling and show that TEAD localization is a critical determinant of Hippo signalling output.
Asunto(s)
Citoplasma/enzimología , Proteínas de Unión al ADN/metabolismo , Proteínas Musculares/metabolismo , Neoplasias/enzimología , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular , Proteínas de Unión al ADN/genética , Células HEK293 , Vía de Señalización Hippo , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones Desnudos , Proteínas Musculares/genética , Neoplasias/genética , Neoplasias/patología , Presión Osmótica , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Fosforilación , Unión Proteica , Transporte de Proteínas , Factores de Transcripción de Dominio TEA , Factores de Tiempo , Transactivadores , Factores de Transcripción/genética , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ , Transfección , Proteínas Señalizadoras YAP , Proteínas Quinasas p38 Activadas por Mitógenos/genéticaRESUMEN
The Hippo pathway senses cellular conditions and regulates YAP/TAZ to control cellular and tissue homeostasis, while TBK1 is central for cytosolic nucleic acid sensing and antiviral defence. The correlation between cellular nutrient/physical status and host antiviral defence is interesting but not well understood. Here we find that YAP/TAZ act as natural inhibitors of TBK1 and are vital for antiviral physiology. Independent of transcriptional regulation and through the transactivation domain, YAP/TAZ associate directly with TBK1 and abolish virus-induced TBK1 activation, by preventing TBK1 Lys63-linked ubiquitylation and the binding of adaptors/substrates. Accordingly, YAP/TAZ deletion/depletion or cellular conditions inactivating YAP/TAZ through Lats1/2 kinases relieve TBK1 suppression and boost antiviral responses, whereas expression of the transcriptionally inactive YAP dampens cytosolic RNA/DNA sensing and weakens the antiviral defence in cells and zebrafish. Thus, we describe a function of YAP/TAZ and the Hippo pathway in innate immunity, by linking cellular nutrient/physical status to antiviral host defence.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Citosol/metabolismo , Ácidos Nucleicos/metabolismo , Fosfoproteínas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismo , Aciltransferasas , Proteínas Adaptadoras Transductoras de Señales/química , Animales , Antivirales/farmacología , ADN/metabolismo , Doxorrubicina/farmacología , Técnica del Anticuerpo Fluorescente , Regulación de la Expresión Génica/efectos de los fármacos , Células HEK293 , Vía de Señalización Hippo , Humanos , Factor 3 Regulador del Interferón/genética , Factor 3 Regulador del Interferón/metabolismo , Lisina/metabolismo , Ratones Endogámicos C57BL , Fosfoproteínas/química , Unión Proteica/efectos de los fármacos , Dominios Proteicos , ARN/metabolismo , Transcripción Genética/efectos de los fármacos , Activación Transcripcional/genética , Proteínas Supresoras de Tumor/metabolismo , Ubiquitinación/efectos de los fármacos , Proteínas Señalizadoras YAP , Pez Cebra/embriologíaRESUMEN
The Hippo signaling pathway is important for controlling organ size and tissue homeostasis. Originally identified in Drosophila melanogaster, the core components of the Hippo pathway are highly conserved in mammals. The Hippo pathway can be modulated by a wide range of stimuli, including G protein-coupled receptor (GPCR) signaling, changes in the actin cytoskeleton, cell-cell contact, and cell polarity. When activated, the Hippo pathway functions as a tumor suppressor to limit cell growth. However, dysregulation by genetic inactivation of core pathway components or amplification or gene fusion of its downstream effectors results in increased cell proliferation and decreased apoptosis and differentiation. Unsurprisingly, this can lead to tissue overgrowth, tumorigenesis, and many other diseases.
Asunto(s)
Proteínas de Drosophila/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Neoplasias/genética , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Transactivadores/metabolismo , Animales , Apoptosis , Carcinogénesis , Proliferación Celular , Proteínas de Drosophila/genética , Drosophila melanogaster , Regulación del Desarrollo de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Vía de Señalización Hippo , Homeostasis , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Mamíferos , Neoplasias/patología , Proteínas Nucleares/genética , Tamaño de los Órganos , Proteínas Serina-Treonina Quinasas/genética , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Transactivadores/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas Señalizadoras YAPRESUMEN
YAP and TAZ are transcriptional co-activators and function as the major effectors of the Hippo tumor suppressor pathway, which controls cell growth, tissue homeostasis, and organ size. Here we show that YAP/TAZ play an essential role in amino acid-induced mTORC1 activation, particularly under nutrient-limiting conditions. Mechanistically, YAP/TAZ act via the TEAD transcription factors to induce expression of the high-affinity leucine transporter LAT1, which is a heterodimeric complex of SLC7A5 and SLC3A2. Deletion of YAP/TAZ abolishes expression of LAT1 and reduces leucine uptake. Re-expression of SLC7A5 in YAP/TAZ knockout cells restores leucine uptake and mTORC1 activation. Moreover, SLC7A5 knockout cells phenocopies YAP/TAZ knockout cells which exhibit defective mTORC1 activation in response to amino acids. We further demonstrate that YAP/TAZ act through SLC7A5 to provide cells with a competitive growth advantage. Our study provides molecular insight into the mechanism of YAP/TAZ target genes in cell growth regulation.