RESUMEN
Cellular form and function emerge from complex mechanochemical systems within the cytoplasm. Currently, no systematic strategy exists to infer large-scale physical properties of a cell from its molecular components. This is an obstacle to understanding processes such as cell adhesion and migration. Here, we develop a data-driven modeling pipeline to learn the mechanical behavior of adherent cells. We first train neural networks to predict cellular forces from images of cytoskeletal proteins. Strikingly, experimental images of a single focal adhesion (FA) protein, such as zyxin, are sufficient to predict forces and can generalize to unseen biological regimes. Using this observation, we develop two approaches-one constrained by physics and the other agnostic-to construct data-driven continuum models of cellular forces. Both reveal how cellular forces are encoded by two distinct length scales. Beyond adherent cell mechanics, our work serves as a case study for integrating neural networks into predictive models for cell biology.
Asunto(s)
Proteínas del Citoesqueleto , Aprendizaje Automático , Adhesión Celular , Citoplasma/metabolismo , Proteínas del Citoesqueleto/metabolismo , Adhesiones Focales/metabolismo , Modelos BiológicosRESUMEN
Understanding cellular force transmission dynamics is crucial in mechanobiology. We developed the DNA-based ForceChrono probe to measure force magnitude, duration, and loading rates at the single-molecule level within living cells. The ForceChrono probe circumvents the limitations of in vitro single-molecule force spectroscopy by enabling direct measurements within the dynamic cellular environment. Our findings reveal integrin force loading rates of 0.5-2 pN/s and durations ranging from tens of seconds in nascent adhesions to approximately 100 s in mature focal adhesions. The probe's robust and reversible design allows for continuous monitoring of these dynamic changes as cells undergo morphological transformations. Additionally, by analyzing how mutations, deletions, or pharmacological interventions affect these parameters, we can deduce the functional roles of specific proteins or domains in cellular mechanotransduction. The ForceChrono probe provides detailed insights into the dynamics of mechanical forces, advancing our understanding of cellular mechanics and the molecular mechanisms of mechanotransduction.
Asunto(s)
Mecanotransducción Celular , Imagen Individual de Molécula , Animales , Humanos , Ratones , Fenómenos Biomecánicos , Adhesión Celular , ADN/química , ADN/metabolismo , Adhesiones Focales/metabolismo , Integrinas/metabolismo , Microscopía de Fuerza Atómica/métodos , Imagen Individual de Molécula/métodos , Línea Celular , Supervivencia Celular , Emparejamiento Base , CalibraciónRESUMEN
Integrins link the extracellular environment to the actin cytoskeleton in cell migration and adhesiveness. Rapid coordination between events outside and inside the cell is essential. Single-molecule fluorescence dynamics show that ligand binding to the bent-closed integrin conformation, which predominates on cell surfaces, is followed within milliseconds by two concerted changes, leg extension and headpiece opening, to give the high-affinity integrin conformation. The extended-closed integrin conformation is not an intermediate but can be directly accessed from the extended-open conformation and provides a pathway for ligand dissociation. In contrast to ligand, talin, which links the integrin ß-subunit cytoplasmic domain to the actin cytoskeleton, modestly stabilizes but does not induce extension or opening. Integrin activation is thus initiated by outside-in signaling and followed by inside-out signaling. Our results further imply that talin binding is insufficient for inside-out integrin activation and that tensile force transmission through the ligand-integrin-talin-actin cytoskeleton complex is required.
Asunto(s)
Integrinas , Talina , Animales , Humanos , Ratones , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/química , Adhesión Celular , Células CHO , Cricetulus , Integrinas/metabolismo , Integrinas/química , Ligandos , Unión Proteica , Conformación Proteica , Transducción de Señal , Imagen Individual de Molécula , Talina/metabolismo , Talina/químicaRESUMEN
Gasdermins are a family of structurally related proteins originally described for their role in pyroptosis. Gasdermin B (GSDMB) is currently the least studied, and while its association with genetic susceptibility to chronic mucosal inflammatory disorders is well established, little is known about its functional relevance during active disease states. Herein, we report increased GSDMB in inflammatory bowel disease, with single-cell analysis identifying epithelial specificity to inflamed colonocytes/crypt top colonocytes. Surprisingly, mechanistic experiments and transcriptome profiling reveal lack of inherent GSDMB-dependent pyroptosis in activated epithelial cells and organoids but instead point to increased proliferation and migration during in vitro wound closure, which arrests in GSDMB-deficient cells that display hyper-adhesiveness and enhanced formation of vinculin-based focal adhesions dependent on PDGF-A-mediated FAK phosphorylation. Importantly, carriage of disease-associated GSDMB SNPs confers functional defects, disrupting epithelial restitution/repair, which, altogether, establishes GSDMB as a critical factor for restoration of epithelial barrier function and the resolution of inflammation.
Asunto(s)
Células Epiteliales/metabolismo , Células Epiteliales/patología , Enfermedades Inflamatorias del Intestino/metabolismo , Enfermedades Inflamatorias del Intestino/patología , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Piroptosis , Secuencia de Bases , Estudios de Casos y Controles , Adhesión Celular/efectos de los fármacos , Adhesión Celular/genética , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Movimiento Celular/efectos de los fármacos , Movimiento Celular/genética , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Células Epiteliales/efectos de los fármacos , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Células HEK293 , Células HT29 , Humanos , Enfermedades Inflamatorias del Intestino/genética , Metotrexato/farmacología , Mutación/genética , Fosforilación/efectos de los fármacos , Polimorfismo de Nucleótido Simple/genética , Piroptosis/efectos de los fármacos , Piroptosis/genética , Reproducibilidad de los Resultados , Transcriptoma/efectos de los fármacos , Transcriptoma/genética , Regulación hacia Arriba/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Cicatrización de Heridas/genéticaRESUMEN
Tissue and organ development during embryogenesis relies on the collective and coordinated action of many cells. Recent studies have revealed that tissue material properties, including transitions between fluid and solid tissue states, are controlled in space and time to shape embryonic structures and regulate cell behaviours. Although the collective cellular flows that sculpt tissues are guided by tissue-level physical changes, these ultimately emerge from cellular-level and subcellular-level molecular mechanisms. Adherens junctions are key subcellular structures, built from clusters of classical cadherin receptors. They mediate physical interactions between cells and connect biochemical signalling to the physical characteristics of cell contacts, hence playing a fundamental role in tissue morphogenesis. In this Review, we take advantage of the results of recent, quantitative measurements of tissue mechanics to relate the molecular and cellular characteristics of adherens junctions, including adhesion strength, tension and dynamics, to the emergent physical state of embryonic tissues. We focus on systems in which cell-cell interactions are the primary contributor to morphogenesis, without significant contribution from cell-matrix interactions. We suggest that emergent tissue mechanics is an important direction for future research, bridging cell biology, developmental biology and mechanobiology to provide a holistic understanding of morphogenesis in health and disease.
Asunto(s)
Uniones Adherentes , Cadherinas , Uniones Adherentes/metabolismo , Cadherinas/metabolismo , Comunicación Celular , Morfogénesis , Desarrollo Embrionario , Adhesión Celular/fisiologíaRESUMEN
We describe an approach to study the conformation of individual proteins during single particle tracking (SPT) in living cells. "Binder/tag" is based on incorporation of a 7-mer peptide (the tag) into a protein where its solvent exposure is controlled by protein conformation. Only upon exposure can the peptide specifically interact with a reporter protein (the binder). Thus, simple fluorescence localization reflects protein conformation. Through direct excitation of bright dyes, the trajectory and conformation of individual proteins can be followed. Simple protein engineering provides highly specific biosensors suitable for SPT and FRET. We describe tagSrc, tagFyn, tagSyk, tagFAK, and an orthogonal binder/tag pair. SPT showed slowly diffusing islands of activated Src within Src clusters and dynamics of activation in adhesions. Quantitative analysis and stochastic modeling revealed in vivo Src kinetics. The simplicity of binder/tag can provide access to diverse proteins.
Asunto(s)
Técnicas Biosensibles , Péptidos/química , Imagen Individual de Molécula , Animales , Adhesión Celular , Línea Celular , Supervivencia Celular , Embrión de Mamíferos/citología , Activación Enzimática , Fibroblastos/metabolismo , Transferencia Resonante de Energía de Fluorescencia , Humanos , Cinética , Ratones , Nanopartículas/química , Conformación Proteica , Familia-src Quinasas/metabolismoRESUMEN
Many embryonic organs undergo epithelial morphogenesis to form tree-like hierarchical structures. However, it remains unclear what drives the budding and branching of stratified epithelia, such as in the embryonic salivary gland and pancreas. Here, we performed live-organ imaging of mouse embryonic salivary glands at single-cell resolution to reveal that budding morphogenesis is driven by expansion and folding of a distinct epithelial surface cell sheet characterized by strong cell-matrix adhesions and weak cell-cell adhesions. Profiling of single-cell transcriptomes of this epithelium revealed spatial patterns of transcription underlying these cell adhesion differences. We then synthetically reconstituted budding morphogenesis by experimentally suppressing E-cadherin expression and inducing basement membrane formation in 3D spheroid cultures of engineered cells, which required ß1-integrin-mediated cell-matrix adhesion for successful budding. Thus, stratified epithelial budding, the key first step of branching morphogenesis, is driven by an overall combination of strong cell-matrix adhesion and weak cell-cell adhesion by peripheral epithelial cells.
Asunto(s)
Uniones Célula-Matriz/metabolismo , Morfogénesis , Animales , Membrana Basal/metabolismo , Adhesión Celular , División Celular , Movimiento Celular , Rastreo Celular , Embrión de Mamíferos/citología , Células Epiteliales/citología , Células Epiteliales/metabolismo , Epitelio , Regulación del Desarrollo de la Expresión Génica , Células HEK293 , Humanos , Integrinas/metabolismo , Ratones , Modelos Biológicos , Glándulas Salivales/citología , Glándulas Salivales/embriología , Glándulas Salivales/metabolismo , Transcriptoma/genéticaRESUMEN
Embryo morphogenesis is impacted by dynamic changes in tissue material properties, which have been proposed to occur via processes akin to phase transitions (PTs). Here, we show that rigidity percolation provides a simple and robust theoretical framework to predict material/structural PTs of embryonic tissues from local cell connectivity. By using percolation theory, combined with directly monitoring dynamic changes in tissue rheology and cell contact mechanics, we demonstrate that the zebrafish blastoderm undergoes a genuine rigidity PT, brought about by a small reduction in adhesion-dependent cell connectivity below a critical value. We quantitatively predict and experimentally verify hallmarks of PTs, including power-law exponents and associated discontinuities of macroscopic observables. Finally, we show that this uniform PT depends on blastoderm cells undergoing meta-synchronous divisions causing random and, consequently, uniform changes in cell connectivity. Collectively, our theoretical and experimental findings reveal the structural basis of material PTs in an organismal context.
Asunto(s)
Embrión no Mamífero/fisiología , Desarrollo Embrionario , Animales , Blastodermo/citología , Blastodermo/fisiología , Cadherinas/antagonistas & inhibidores , Cadherinas/genética , Cadherinas/metabolismo , Adhesión Celular , Embrión no Mamífero/citología , Morfolinos/metabolismo , Reología , Viscosidad , Pez Cebra/crecimiento & desarrolloRESUMEN
Environmental light cycles entrain circadian feeding behaviors in animals that produce rhythms in exposure to foodborne bacteria. Here, we show that the intestinal microbiota generates diurnal rhythms in innate immunity that synchronize with feeding rhythms to anticipate microbial exposure. Rhythmic expression of antimicrobial proteins was driven by daily rhythms in epithelial attachment by segmented filamentous bacteria (SFB), members of the mouse intestinal microbiota. Rhythmic SFB attachment was driven by the circadian clock through control of feeding rhythms. Mechanistically, rhythmic SFB attachment activated an immunological circuit involving group 3 innate lymphoid cells. This circuit triggered oscillations in epithelial STAT3 expression and activation that produced rhythmic antimicrobial protein expression and caused resistance to Salmonella Typhimurium infection to vary across the day-night cycle. Thus, host feeding rhythms synchronize with the microbiota to promote rhythms in intestinal innate immunity that anticipate exogenous microbial exposure.
Asunto(s)
Relojes Circadianos/fisiología , Ritmo Circadiano/fisiología , Microbioma Gastrointestinal , Inmunidad Innata , Animales , Péptidos Catiónicos Antimicrobianos/metabolismo , Adhesión Bacteriana , Adhesión Celular , Células Epiteliales/microbiología , Conducta Alimentaria , Intestino Delgado/microbiología , Intestino Delgado/ultraestructura , Linfocitos/metabolismo , Ratones Endogámicos C57BL , Muramidasa/metabolismo , Proteínas Asociadas a Pancreatitis/metabolismo , Factor de Transcripción STAT3/metabolismo , Salmonelosis Animal/microbiología , Transducción de SeñalRESUMEN
RTN4-binding proteins were widely studied as "NoGo" receptors, but their physiological interactors and roles remain elusive. Similarly, BAI adhesion-GPCRs were associated with numerous activities, but their ligands and functions remain unclear. Using unbiased approaches, we observed an unexpected convergence: RTN4 receptors are high-affinity ligands for BAI adhesion-GPCRs. A single thrombospondin type 1-repeat (TSR) domain of BAIs binds to the leucine-rich repeat domain of all three RTN4-receptor isoforms with nanomolar affinity. In the 1.65 Å crystal structure of the BAI1/RTN4-receptor complex, C-mannosylation of tryptophan and O-fucosylation of threonine in the BAI TSR-domains creates a RTN4-receptor/BAI interface shaped by unusual glycoconjugates that enables high-affinity interactions. In human neurons, RTN4 receptors regulate dendritic arborization, axonal elongation, and synapse formation by differential binding to glial versus neuronal BAIs, thereby controlling neural network activity. Thus, BAI binding to RTN4/NoGo receptors represents a receptor-ligand axis that, enabled by rare post-translational modifications, controls development of synaptic circuits.
Asunto(s)
Inhibidores de la Angiogénesis/metabolismo , Encéfalo/metabolismo , Neurogénesis , Neuronas/metabolismo , Proteínas Nogo/metabolismo , Receptores Nogo/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Adipoquinas/metabolismo , Secuencia de Aminoácidos , Animales , Axones/metabolismo , Adhesión Celular , Moléculas de Adhesión Celular Neuronal/metabolismo , Complemento C1q/metabolismo , Dendritas/metabolismo , Glicosilación , Células HEK293 , Células Madre Embrionarias Humanas/metabolismo , Humanos , Ligandos , Ratones Endogámicos C57BL , Red Nerviosa/metabolismo , Polisacáridos/metabolismo , Unión Proteica , Dominios Proteicos , Eliminación de Secuencia , Sinapsis/metabolismo , Transmisión Sináptica/fisiologíaRESUMEN
Since the proposal of the differential adhesion hypothesis, scientists have been fascinated by how cell adhesion mediates cellular self-organization to form spatial patterns during development. The search for molecular tool kits with homophilic binding specificity resulted in a diverse repertoire of adhesion molecules. Recent understanding of the dominant role of cortical tension over adhesion binding redirects the focus of differential adhesion studies to the signaling function of adhesion proteins to regulate actomyosin contractility. The broader framework of differential interfacial tension encompasses both adhesion and nonadhesion molecules, sharing the common function of modulating interfacial tension during cell sorting to generate diverse tissue patterns. Robust adhesion-based patterning requires close coordination between morphogen signaling, cell fate decisions, and changes in adhesion. Current advances in bridging theoretical and experimental approaches present exciting opportunities to understand molecular, cellular, and tissue dynamics during adhesion-based tissue patterning across multiple time and length scales.
Asunto(s)
Citoesqueleto de Actina , Actomiosina , Adhesión CelularRESUMEN
Immune cell locomotion is associated with amoeboid migration, a flexible mode of movement, which depends on rapid cycles of actin polymerization and actomyosin contraction1. Many immune cells do not necessarily require integrins, the major family of adhesion receptors in mammals, to move productively through three-dimensional tissue spaces2,3. Instead, they can use alternative strategies to transmit their actin-driven forces to the substrate, explaining their migratory adaptation to changing external environments4-6. However, whether these generalized concepts apply to all immune cells is unclear. Here, we show that the movement of mast cells (immune cells with important roles during allergy and anaphylaxis) differs fundamentally from the widely applied paradigm of interstitial immune cell migration. We identify a crucial role for integrin-dependent adhesion in controlling mast cell movement and localization to anatomical niches rich in KIT ligand, the major mast cell growth and survival factor. Our findings show that substrate-dependent haptokinesis is an important mechanism for the tissue organization of resident immune cells.
Asunto(s)
Actinas , Integrinas , Animales , Integrinas/metabolismo , Actinas/metabolismo , Mastocitos/metabolismo , Movimiento Celular , Leucocitos/metabolismo , Adhesión Celular , Mamíferos/metabolismoRESUMEN
The ability of animal cells to sense, adhere to and remodel their local extracellular matrix (ECM) is central to control of cell shape, mechanical responsiveness, motility and signalling, and hence to development, tissue formation, wound healing and the immune response. Cell-ECM interactions occur at various specialized, multi-protein adhesion complexes that serve to physically link the ECM to the cytoskeleton and the intracellular signalling apparatus. This occurs predominantly via clustered transmembrane receptors of the integrin family. Here we review how the interplay of mechanical forces, biochemical signalling and molecular self-organization determines the composition, organization, mechanosensitivity and dynamics of these adhesions. Progress in the identification of core multi-protein modules within the adhesions and characterization of rearrangements of their components in response to force, together with advanced imaging approaches, has improved understanding of adhesion maturation and turnover and the relationships between adhesion structures and functions. Perturbations of adhesion contribute to a broad range of diseases and to age-related dysfunction, thus an improved understanding of their molecular nature may facilitate therapeutic intervention in these conditions.
Asunto(s)
Adhesión Celular , Citoesqueleto , Matriz Extracelular , Integrinas , Animales , Adhesión Celular/fisiología , Citoesqueleto/metabolismo , Matriz Extracelular/metabolismo , Adhesiones Focales/metabolismo , Integrinas/metabolismo , Transducción de Señal , Adherencias Tisulares/patologíaRESUMEN
The ability of cells to organize into multicellular structures in precise patterns requires that they "recognize" one another with high specificity. We discuss recent progress in understanding the molecular basis of cell-cell recognition, including unique phenomena associated with neuronal interactions. We describe structures of select adhesion receptor complexes and their assembly into larger intercellular junction structures and discuss emerging principles that relate cell-cell organization to the binding specificities and energetics of adhesion receptors. Armed with these insights, advances in protein design and gene editing should pave the way for breakthroughs toward understanding the molecular basis of cell patterning in vivo.
Asunto(s)
Tipificación del Cuerpo/fisiología , Adhesión Celular/fisiología , Comunicación Celular/fisiología , Animales , Adhesión Celular/genética , Comunicación Celular/genética , Humanos , Estructura Molecular , ProteínasRESUMEN
This year's Canada Gairdner International Prize is shared by Rolf Kemler and Masatoshi Takeichi for the discovery of the cadherin family of Ca2+-dependent cell-cell adhesion proteins, which play essential roles in animal evolution, tissue development, and homeostasis, and are disrupted in human cancers.
Asunto(s)
Cadherinas/metabolismo , Cadherinas/fisiología , Comunicación Celular/fisiología , Animales , Distinciones y Premios , Fenómenos Biofísicos , Canadá , Adhesión Celular/fisiología , Historia del Siglo XX , Historia del Siglo XXI , Homeostasis/fisiología , Humanos , MasculinoRESUMEN
Collective metastasis is defined as the cohesive migration and metastasis of multicellular tumor cell clusters. Disrupting various cell adhesion genes markedly reduces cluster formation and colonization efficiency, yet the downstream signals transmitted by clustering remain largely unknown. Here, we use mouse and human breast cancer models to identify a collective signal generated by tumor cell clusters supporting metastatic colonization. We show that tumor cell clusters produce the growth factor epigen and concentrate it within nanolumina-intercellular compartments sealed by cell-cell junctions and lined with microvilli-like protrusions. Epigen knockdown profoundly reduces metastatic outgrowth and switches clusters from a proliferative to a collective migratory state. Tumor cell clusters from basal-like 2, but not mesenchymal-like, triple-negative breast cancer cell lines have increased epigen expression, sealed nanolumina, and impaired outgrowth upon nanolumenal junction disruption. We propose that nanolumenal signaling could offer a therapeutic target for aggressive metastatic breast cancers.
Asunto(s)
Neoplasias de la Mama/fisiopatología , Uniones Intercelulares/patología , Metástasis de la Neoplasia/fisiopatología , Animales , Adhesión Celular/fisiología , Línea Celular Tumoral , Movimiento Celular/fisiología , Epigen/metabolismo , Transición Epitelial-Mesenquimal/genética , Humanos , Ratones , Células Neoplásicas Circulantes/patología , Transducción de Señal/fisiología , Neoplasias de la Mama Triple Negativas/patologíaRESUMEN
Teneurins are ancient metazoan cell adhesion receptors that control brain development and neuronal wiring in higher animals. The extracellular C terminus binds the adhesion GPCR Latrophilin, forming a trans-cellular complex with synaptogenic functions. However, Teneurins, Latrophilins, and FLRT proteins are also expressed during murine cortical cell migration at earlier developmental stages. Here, we present crystal structures of Teneurin-Latrophilin complexes that reveal how the lectin and olfactomedin domains of Latrophilin bind across a spiraling beta-barrel domain of Teneurin, the YD shell. We couple structure-based protein engineering to biophysical analysis, cell migration assays, and in utero electroporation experiments to probe the importance of the interaction in cortical neuron migration. We show that binding of Latrophilins to Teneurins and FLRTs directs the migration of neurons using a contact repulsion-dependent mechanism. The effect is observed with cell bodies and small neurites rather than their processes. The results exemplify how a structure-encoded synaptogenic protein complex is also used for repulsive cell guidance.
Asunto(s)
Proteínas del Tejido Nervioso/ultraestructura , Receptores de Péptidos/metabolismo , Tenascina/metabolismo , Animales , Adhesión Celular/fisiología , Cristalografía por Rayos X/métodos , Células HEK293 , Humanos , Células K562 , Proteínas Repetidas Ricas en Leucina , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/ultraestructura , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/ultraestructura , Ratones , Ratones Endogámicos C57BL/embriología , Proteínas del Tejido Nervioso/metabolismo , Neuritas/metabolismo , Neurogénesis/fisiología , Neuronas/metabolismo , Complejo GPIb-IX de Glicoproteína Plaquetaria/metabolismo , Complejo GPIb-IX de Glicoproteína Plaquetaria/ultraestructura , Unión Proteica/fisiología , Proteínas/metabolismo , Proteínas/ultraestructura , Receptores de Superficie Celular/metabolismo , Receptores de Péptidos/ultraestructura , Sinapsis/metabolismo , Tenascina/ultraestructuraRESUMEN
One of the 2019 Canada Gairdner International Awards recognizes Timothy Springer's discovery of the first immune system adhesion molecules involved in lymphocyte homing and the translation of those discoveries into therapeutics for autoimmune disease and cancer.
Asunto(s)
Adhesión Celular/fisiología , Integrinas/metabolismo , Linfocitos T/metabolismo , Citoesqueleto de Actina , Anticuerpos Monoclonales/inmunología , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/terapia , Humanos , Glicoproteínas de Membrana/metabolismo , Neoplasias/inmunología , Neoplasias/terapia , Selectina-P/metabolismo , Linfocitos T/inmunologíaRESUMEN
ROCK-Myosin II drives fast rounded-amoeboid migration in cancer cells during metastatic dissemination. Analysis of human melanoma biopsies revealed that amoeboid melanoma cells with high Myosin II activity are predominant in the invasive fronts of primary tumors in proximity to CD206+CD163+ tumor-associated macrophages and vessels. Proteomic analysis shows that ROCK-Myosin II activity in amoeboid cancer cells controls an immunomodulatory secretome, enabling the recruitment of monocytes and their differentiation into tumor-promoting macrophages. Both amoeboid cancer cells and their associated macrophages support an abnormal vasculature, which ultimately facilitates tumor progression. Mechanistically, amoeboid cancer cells perpetuate their behavior via ROCK-Myosin II-driven IL-1α secretion and NF-κB activation. Using an array of tumor models, we show that high Myosin II activity in tumor cells reprograms the innate immune microenvironment to support tumor growth. We describe an unexpected role for Myosin II dynamics in cancer cells controlling myeloid function via secreted factors.
Asunto(s)
Movimiento Celular/fisiología , Miosina Tipo II/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Animales , Adhesión Celular , Línea Celular Tumoral , Movimiento Celular/inmunología , Proteínas del Citoesqueleto , Femenino , Humanos , Interleucina-1alfa/metabolismo , Masculino , Melanoma/patología , Ratones , Ratones Endogámicos C57BL , Ratones SCID , Persona de Mediana Edad , FN-kappa B/metabolismo , Neoplasias/inmunología , Neoplasias/metabolismo , Fosforilación , Proteómica , Receptor Cross-Talk/fisiología , Transducción de Señal , Microambiente Tumoral/inmunologíaRESUMEN
Tight junctions are cell-adhesion complexes that seal tissues and are involved in cell polarity and signaling. Supra-molecular assembly and positioning of tight junctions as continuous networks of adhesion strands are dependent on the membrane-associated scaffolding proteins ZO1 and ZO2. To understand how zona occludens (ZO) proteins organize junction assembly, we performed quantitative cell biology and in vitro reconstitution experiments. We discovered that ZO proteins self-organize membrane-attached compartments via phase separation. We identified the multivalent interactions of the conserved PDZ-SH3-GuK supra-domain as the driver of phase separation. These interactions are regulated by phosphorylation and intra-molecular binding. Formation of condensed ZO protein compartments is sufficient to specifically enrich and localize tight-junction proteins, including adhesion receptors, cytoskeletal adapters, and transcription factors. Our results suggest that an active-phase transition of ZO proteins into a condensed membrane-bound compartment drives claudin polymerization and coalescence of a continuous tight-junction belt.