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FAQCytoskeleton: The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.Actins: Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.Actin Cytoskeleton: Fibers composed of MICROFILAMENT PROTEINS, which are predominately ACTIN. They are the smallest of the cytoskeletal filaments.Actin Depolymerizing Factors: A family of low MOLECULAR WEIGHT actin-binding proteins found throughout eukaryotes. They remodel the actin CYTOSKELETON by severing ACTIN FILAMENTS and increasing the rate of monomer dissociation.Thiazolidines: Reduced (protonated) form of THIAZOLES. They can be oxidized to THIAZOLIDINEDIONES.Cytochalasin D: A fungal metabolite that blocks cytoplasmic cleavage by blocking formation of contractile microfilament structures resulting in multinucleated cell formation, reversible inhibition of cell movement, and the induction of cellular extrusion. Additional reported effects include the inhibition of actin polymerization, DNA synthesis, sperm motility, glucose transport, thyroid secretion, and growth hormone release.Microfilament Proteins: Monomeric subunits of primarily globular ACTIN and found in the cytoplasmic matrix of almost all cells. They are often associated with microtubules and may play a role in cytoskeletal function and/or mediate movement of the cell or the organelles within the cell.Bicyclo Compounds, Heterocyclic: A class of saturated compounds consisting of two rings only, having two or more atoms in common, containing at least one hetero atom, and that take the name of an open chain hydrocarbon containing the same total number of atoms. (From Riguady et al., Nomenclature of Organic Chemistry, 1979, p31)Cytoskeletal Proteins: Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.Actin Capping Proteins: Actin capping proteins are cytoskeletal proteins that bind to the ends of ACTIN FILAMENTS to regulate actin polymerization.rho GTP-Binding Proteins: A large family of MONOMERIC GTP-BINDING PROTEINS that are involved in regulation of actin organization, gene expression and cell cycle progression. This enzyme was formerly listed as EC 3.6.1.47.Phalloidine: Very toxic polypeptide isolated mainly from AMANITA phalloides (Agaricaceae) or death cup; causes fatal liver, kidney and CNS damage in mushroom poisoning; used in the study of liver damage.Pseudopodia: A dynamic actin-rich extension of the surface of an animal cell used for locomotion or prehension of food.Depsipeptides: Compounds consisting of chains of AMINO ACIDS alternating with CARBOXYLIC ACIDS via ester and amide linkages. They are commonly cyclized.cdc42 GTP-Binding Protein: A member of the Rho family of MONOMERIC GTP-BINDING PROTEINS. It is associated with a diverse array of cellular functions including cytoskeletal changes, filopodia formation and transport through the GOLGI APPARATUS. This enzyme was formerly listed as EC 3.6.1.47.Contractile Proteins: Proteins which participate in contractile processes. They include MUSCLE PROTEINS as well as those found in other cells and tissues. In the latter, these proteins participate in localized contractile events in the cytoplasm, in motile activity, and in cell aggregation phenomena.Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.rhoA GTP-Binding Protein: A RHO GTP-BINDING PROTEIN involved in regulating signal transduction pathways that control assembly of focal adhesions and actin stress fibers. This enzyme was formerly listed as EC 3.6.1.47.Cell Movement: The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.Stress Fibers: Bundles of actin filaments (ACTIN CYTOSKELETON) and myosin-II that span across the cell attaching to the cell membrane at FOCAL ADHESIONS and to the network of INTERMEDIATE FILAMENTS that surrounds the nucleus.rac1 GTP-Binding Protein: A rac GTP-binding protein involved in regulating actin filaments at the plasma membrane. It controls the development of filopodia and lamellipodia in cells and thereby influences cellular motility and adhesion. It is also involved in activation of NADPH OXIDASE. This enzyme was formerly listed as EC 3.6.1.47.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Profilins: A family of low molecular weight proteins that bind ACTIN and control actin polymerization. They are found in eukaryotes and are ubiquitously expressed.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Microtubules: Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.Gelsolin: A 90-kDa protein produced by macrophages that severs ACTIN filaments and forms a cap on the newly exposed filament end. Gelsolin is activated by CALCIUM ions and participates in the assembly and disassembly of actin, thereby increasing the motility of some CELLS.Actinin: A protein factor that regulates the length of R-actin. It is chemically similar, but immunochemically distinguishable from actin.Cell Adhesion: Adherence of cells to surfaces or to other cells.Cell Polarity: Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Vinculin: A cytoskeletal protein associated with cell-cell and cell-matrix interactions. The amino acid sequence of human vinculin has been determined. The protein consists of 1066 amino acid residues and its gene has been assigned to chromosome 10.rac GTP-Binding Proteins: A sub-family of RHO GTP-BINDING PROTEINS that is involved in regulating the organization of cytoskeletal filaments. This enzyme was formerly listed as EC 3.6.1.47.Wiskott-Aldrich Syndrome Protein: WASP protein is mutated in WISKOTT-ALDRICH SYNDROME and is expressed primarily in hematopoietic cells. It is the founding member of the WASP protein family and interacts with CDC42 PROTEIN to help regulate ACTIN polymerization.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Actin-Related Protein 2-3 Complex: A complex of seven proteins including ARP2 PROTEIN and ARP3 PROTEIN that plays an essential role in maintenance and assembly of the CYTOSKELETON. Arp2-3 complex binds WASP PROTEIN and existing ACTIN FILAMENTS, and it nucleates the formation of new branch point filaments.Filamins: A family of crosslinking filament proteins encoded by distinct FLN genes. Filamins are involved in cell adhesion, spreading, and migration, acting as scaffolds for over 90 binding partners including channels, receptors, intracellular signaling molecules and transcription factors. Due to the range of molecular interactions, mutations in FLN genes result in anomalies with moderate to lethal consequences.Focal Adhesions: An anchoring junction of the cell to a non-cellular substrate. It is composed of a specialized area of the plasma membrane where bundles of the ACTIN CYTOSKELETON terminate and attach to the transmembrane linkers, INTEGRINS, which in turn attach through their extracellular domains to EXTRACELLULAR MATRIX PROTEINS.rho-Associated Kinases: A group of intracellular-signaling serine threonine kinases that bind to RHO GTP-BINDING PROTEINS. They were originally found to mediate the effects of rhoA GTP-BINDING PROTEIN on the formation of STRESS FIBERS and FOCAL ADHESIONS. Rho-associated kinases have specificity for a variety of substrates including MYOSIN-LIGHT-CHAIN PHOSPHATASE and LIM KINASES.Myosins: A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind ACTINS and hydrolyze MgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and MgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain.Cell Shape: The quality of surface form or outline of CELLS.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Nucleic Acid Synthesis Inhibitors: Compounds that inhibit cell production of DNA or RNA.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Cytochalasins: 11- to 14-membered macrocyclic lactones with a fused isoindolone. Members with INDOLES attached at the C10 position are called chaetoglobosins. They are produced by various fungi. Some members interact with ACTIN and inhibit CYTOKINESIS.Lim Kinases: Serine protein kinases involved in the regulation of ACTIN polymerization and MICROTUBULE disassembly. Their activity is regulated by phosphorylation of a threonine residue within the activation loop by intracellular signaling kinases such as P21-ACTIVATED KINASES and by RHO KINASE.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Cell Surface Extensions: Specialized structures of the cell that extend the cell membrane and project out from the cell surface.Actin-Related Protein 2: A PROFILIN binding domain protein that is part of the Arp2-3 complex. It is related in sequence and structure to ACTIN and binds ATP.Protein Transport: The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.Microscopy, Confocal: A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.Polymerization: Chemical reaction in which monomeric components are combined to form POLYMERS (e.g., POLYMETHYLMETHACRYLATE).Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Actin-Related Protein 3: A component of the Arp2-3 complex that is related in sequence and structure to ACTIN and that binds ATP. It is expressed at higher levels than ARP2 PROTEIN and does not contain a PROFILIN binding domain.Cortactin: A microfilament protein that interacts with F-ACTIN and regulates cortical actin assembly and organization. It is also an SH3 DOMAIN containing phosphoprotein, and it mediates tyrosine PHOSPHORYLATION based SIGNAL TRANSDUCTION by PROTO-ONCOGENE PROTEIN PP60(C-SRC).Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Endocytosis: Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.ThiazolesPhosphoproteinsWiskott-Aldrich Syndrome Protein, Neuronal: A member of the Wiskott-Aldrich syndrome protein family that is found at high levels in NERVE CELLS. It interacts with GRB2 ADAPTOR PROTEIN and with CDC42 PROTEIN.Green Fluorescent Proteins: Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.Wiskott-Aldrich Syndrome Protein Family: A family of microfilament proteins whose name derives from the fact that mutations in members of this protein family have been associated with WISKOTT-ALDRICH SYNDROME. They are involved in ACTIN polymerization and contain a polyproline-rich region that binds to PROFILIN, and a verprolin homology domain that binds G-ACTIN.Myosin Type II: The subfamily of myosin proteins that are commonly found in muscle fibers. Myosin II is also involved a diverse array of cellular functions including cell division, transport within the GOLGI APPARATUS, and maintaining MICROVILLI structure.Cell Size: The quantity of volume or surface area of CELLS.Cadherins: Calcium-dependent cell adhesion proteins. They are important in the formation of ADHERENS JUNCTIONS between cells. Cadherins are classified by their distinct immunological and tissue specificities, either by letters (E- for epithelial, N- for neural, and P- for placental cadherins) or by numbers (cadherin-12 or N-cadherin 2 for brain-cadherin). Cadherins promote cell adhesion via a homophilic mechanism as in the construction of tissues and of the whole animal body.Adherens Junctions: Anchoring points where the CYTOSKELETON of neighboring cells are connected to each other. They are composed of specialized areas of the plasma membrane where bundles of the ACTIN CYTOSKELETON attach to the membrane through the transmembrane linkers, CADHERINS, which in turn attach through their extracellular domains to cadherins in the neighboring cell membranes. In sheets of cells, they form into adhesion belts (zonula adherens) that go all the way around a cell.Paxillin: Paxillin is a signal transducing adaptor protein that localizes to FOCAL ADHESIONS via its four LIM domains. It undergoes PHOSPHORYLATION in response to integrin-mediated CELL ADHESION, and interacts with a variety of proteins including VINCULIN; FOCAL ADHESION KINASE; PROTO-ONCOGENE PROTEIN PP60(C-SRC); and PROTO-ONCOGENE PROTEIN C-CRK.Guanine Nucleotide Exchange Factors: Protein factors that promote the exchange of GTP for GDP bound to GTP-BINDING PROTEINS.GTPase-Activating Proteins: Proteins that activate the GTPase of specific GTP-BINDING PROTEINS.Actomyosin: A protein complex of actin and MYOSINS occurring in muscle. It is the essential contractile substance of muscle.alpha Catenin: A catenin that binds F-ACTIN and links the CYTOSKELETON with BETA CATENIN and GAMMA CATENIN.Destrin: A member of the actin depolymerizing factors. Its depolymerizing activity is independent of HYDROGEN-ION CONCENTRATION.Cytochalasin B: A cytotoxic member of the CYTOCHALASINS.rhoB GTP-Binding Protein: A GTP-BINDING PROTEIN involved in regulating a signal transduction pathway that controls assembly of focal adhesions and actin stress fibers. This enzyme was formerly listed as EC 3.6.1.47.Adaptor Proteins, Signal Transducing: A broad category of carrier proteins that play a role in SIGNAL TRANSDUCTION. They generally contain several modular domains, each of which having its own binding activity, and act by forming complexes with other intracellular-signaling molecules. Signal-transducing adaptor proteins lack enzyme activity, however their activity can be modulated by other signal-transducing enzymesGTP Phosphohydrolases: Enzymes that hydrolyze GTP to GDP. EC 3.6.1.-.Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Talin: A 235-kDa cytoplasmic protein that is also found in platelets. It has been localized to regions of cell-substrate adhesion. It binds to INTEGRINS; VINCULIN; and ACTINS and appears to participate in generating a transmembrane connection between the extracellular matrix and the cytoskeleton.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Tropomyosin: A protein found in the thin filaments of muscle fibers. It inhibits contraction of the muscle unless its position is modified by TROPONIN.Intercellular Junctions: Direct contact of a cell with a neighboring cell. Most such junctions are too small to be resolved by light microscopy, but they can be visualized by conventional or freeze-fracture electron microscopy, both of which show that the interacting CELL MEMBRANE and often the underlying CYTOPLASM and the intervening EXTRACELLULAR SPACE are highly specialized in these regions. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p792)Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Transfection: The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.Dictyostelium: A genus of protozoa, formerly also considered a fungus. Its natural habitat is decaying forest leaves, where it feeds on bacteria. D. discoideum is the best-known species and is widely used in biomedical research.Epithelial Cells: Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.Fibroblasts: Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.Phosphatidylinositol 4,5-Diphosphate: A phosphoinositide present in all eukaryotic cells, particularly in the plasma membrane. It is the major substrate for receptor-stimulated phosphoinositidase C, with the consequent formation of inositol 1,4,5-triphosphate and diacylglycerol, and probably also for receptor-stimulated inositol phospholipid 3-kinase. (Kendrew, The Encyclopedia of Molecular Biology, 1994)Saccharomyces cerevisiae Proteins: Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.Polymers: Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).Microscopy, Video: Microscopy in which television cameras are used to brighten magnified images that are otherwise too dark to be seen with the naked eye. It is used frequently in TELEPATHOLOGY.COS Cells: CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)Cell Adhesion Molecules: Surface ligands, usually glycoproteins, that mediate cell-to-cell adhesion. Their functions include the assembly and interconnection of various vertebrate systems, as well as maintenance of tissue integration, wound healing, morphogenic movements, cellular migrations, and metastasis.Two-Hybrid System Techniques: Screening techniques first developed in yeast to identify genes encoding interacting proteins. Variations are used to evaluate interplay between proteins and other molecules. Two-hybrid techniques refer to analysis for protein-protein interactions, one-hybrid for DNA-protein interactions, three-hybrid interactions for RNA-protein interactions or ligand-based interactions. Reverse n-hybrid techniques refer to analysis for mutations or other small molecules that dissociate known interactions.Biopolymers: Polymers synthesized by living organisms. They play a role in the formation of macromolecular structures and are synthesized via the covalent linkage of biological molecules, especially AMINO ACIDS; NUCLEOTIDES; and CARBOHYDRATES.Tubulin: A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.p21-Activated Kinases: A family of serine-threonine kinases that bind to and are activated by MONOMERIC GTP-BINDING PROTEINS such as RAC GTP-BINDING PROTEINS and CDC42 GTP-BINDING PROTEIN. They are intracellular signaling kinases that play a role the regulation of cytoskeletal organization.3T3 Cells: Cell lines whose original growing procedure consisted being transferred (T) every 3 days and plated at 300,000 cells per plate (J Cell Biol 17:299-313, 1963). Lines have been developed using several different strains of mice. Tissues are usually fibroblasts derived from mouse embryos but other types and sources have been developed as well. The 3T3 lines are valuable in vitro host systems for oncogenic virus transformation studies, since 3T3 cells possess a high sensitivity to CONTACT INHIBITION.cdc42 GTP-Binding Protein, Saccharomyces cerevisiae: A member of the Rho family of MONOMERIC GTP-BINDING PROTEINS from SACCHAROMYCES CEREVISIAE. It is involved in morphological events related to the cell cycle. This enzyme was formerly listed as EC 3.6.1.47.Intracellular Signaling Peptides and Proteins: Proteins and peptides that are involved in SIGNAL TRANSDUCTION within the cell. Included here are peptides and proteins that regulate the activity of TRANSCRIPTION FACTORS and cellular processes in response to signals from CELL SURFACE RECEPTORS. Intracellular signaling peptide and proteins may be part of an enzymatic signaling cascade or act through binding to and modifying the action of other signaling factors.Protein-Serine-Threonine Kinases: A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.GTP-Binding Proteins: Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.Luminescent Proteins: Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.Cofilin 1: Cofilin 1 is a member of the cofilin family of proteins that is expressed in non-muscle CELLS. It has ACTIN depolymerization activity that is dependent on HYDROGEN-ION CONCENTRATION.Enzyme Activation: Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Fungal Proteins: Proteins found in any species of fungus.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Cytoplasm: The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Colchicine: A major alkaloid from Colchicum autumnale L. and found also in other Colchicum species. Its primary therapeutic use is in the treatment of gout, but it has been used also in the therapy of familial Mediterranean fever (PERIODIC DISEASE).Protein Isoforms: Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.Nerve Tissue Proteinssrc Homology Domains: Regions of AMINO ACID SEQUENCE similarity in the SRC-FAMILY TYROSINE KINASES that fold into specific functional tertiary structures. The SH1 domain is a CATALYTIC DOMAIN. SH2 and SH3 domains are protein interaction domains. SH2 usually binds PHOSPHOTYROSINE-containing proteins and SH3 interacts with CYTOSKELETAL PROTEINS.Myosin Type I: A subclass of myosins found generally associated with actin-rich membrane structures such as filopodia. Members of the myosin type I family are ubiquitously expressed in eukaryotes. The heavy chains of myosin type I lack coiled-coil forming sequences in their tails and therefore do not dimerize.Integrins: A family of transmembrane glycoproteins (MEMBRANE GLYCOPROTEINS) consisting of noncovalent heterodimers. They interact with a wide variety of ligands including EXTRACELLULAR MATRIX PROTEINS; COMPLEMENT, and other cells, while their intracellular domains interact with the CYTOSKELETON. The integrins consist of at least three identified families: the cytoadhesin receptors(RECEPTORS, CYTOADHESIN), the leukocyte adhesion receptors (RECEPTORS, LEUKOCYTE ADHESION), and the VERY LATE ANTIGEN RECEPTORS. Each family contains a common beta-subunit (INTEGRIN BETA CHAINS) combined with one or more distinct alpha-subunits (INTEGRIN ALPHA CHAINS). These receptors participate in cell-matrix and cell-cell adhesion in many physiologically important processes, including embryological development; HEMOSTASIS; THROMBOSIS; WOUND HEALING; immune and nonimmune defense mechanisms; and oncogenic transformation.Intermediate Filaments: Cytoplasmic filaments intermediate in diameter (about 10 nanometers) between the microfilaments and the microtubules. They may be composed of any of a number of different proteins and form a ring around the cell nucleus.Wiskott-Aldrich Syndrome: A rare, X-linked immunodeficiency syndrome characterized by ECZEMA; LYMPHOPENIA; and, recurrent pyogenic infection. It is seen exclusively in young boys. Typically, IMMUNOGLOBULIN M levels are low and IMMUNOGLOBULIN A and IMMUNOGLOBULIN E levels are elevated. Lymphoreticular malignancies are common.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Focal Adhesion Protein-Tyrosine Kinases: A family of non-receptor, PROLINE-rich protein-tyrosine kinases.HeLa Cells: The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.Spectrin: A high molecular weight (220-250 kDa) water-soluble protein which can be extracted from erythrocyte ghosts in low ionic strength buffers. The protein contains no lipids or carbohydrates, is the predominant species of peripheral erythrocyte membrane proteins, and exists as a fibrous coating on the inner, cytoplasmic surface of the membrane.Marine Toxins: Toxic or poisonous substances elaborated by marine flora or fauna. They include also specific, characterized poisons or toxins for which there is no more specific heading, like those from poisonous FISHES.Drosophila Proteins: Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Focal Adhesion Kinase 1: A non-receptor protein tyrosine kinase that is localized to FOCAL ADHESIONS and is a central component of integrin-mediated SIGNAL TRANSDUCTION PATHWAYS. Focal adhesion kinase 1 interacts with PAXILLIN and undergoes PHOSPHORYLATION in response to adhesion of cell surface integrins to the EXTRACELLULAR MATRIX. Phosphorylated p125FAK protein binds to a variety of SH2 DOMAIN and SH3 DOMAIN containing proteins and helps regulate CELL ADHESION and CELL MIGRATION.Zyxin: A zinc-binding phosphoprotein that concentrates at focal adhesions and along the actin cytoskeleton. Zyxin has an N-terminal proline-rich domain and three LIM domains in its C-terminal half.NIH 3T3 Cells: A continuous cell line of high contact-inhibition established from NIH Swiss mouse embryo cultures. The cells are useful for DNA transfection and transformation studies. (From ATCC [Internet]. Virginia: American Type Culture Collection; c2002 [cited 2002 Sept 26]. Available from http://www.atcc.org/)Membrane Microdomains: Detergent-insoluble CELL MEMBRANE components. They are enriched in SPHINGOLIPIDS and CHOLESTEROL and clustered with glycosyl-phosphatidylinositol (GPI)-anchored proteins.Octoxynol: Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Octoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide.Mechanotransduction, Cellular: The process by which cells convert mechanical stimuli into a chemical response. It can occur in both cells specialized for sensing mechanical cues such as MECHANORECEPTORS, and in parenchymal cells whose primary function is not mechanosensory.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Nocodazole: Nocodazole is an antineoplastic agent which exerts its effect by depolymerizing microtubules.Immunoprecipitation: The aggregation of soluble ANTIGENS with ANTIBODIES, alone or with antibody binding factors such as ANTI-ANTIBODIES or STAPHYLOCOCCAL PROTEIN A, into complexes large enough to fall out of solution.Protein-Tyrosine Kinases: Protein kinases that catalyze the PHOSPHORYLATION of TYROSINE residues in proteins with ATP or other nucleotides as phosphate donors.Cytokinesis: The process by which the CYTOPLASM of a cell is divided.Morphogenesis: The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.Myosin Type V: A subclass of myosin involved in organelle transport and membrane targeting. It is abundantly found in nervous tissue and neurosecretory cells. The heavy chains of myosin V contain unusually long neck domains that are believed to aid in translocating molecules over large distances.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Calmodulin-Binding Proteins: Proteins which bind calmodulin. They are found in many tissues and have a variety of functions including F-actin cross-linking properties, inhibition of cyclic nucleotide phosphodiesterase and calcium and magnesium ATPases.Fluorescence Recovery After Photobleaching: A method used to study the lateral movement of MEMBRANE PROTEINS and LIPIDS. A small area of a cell membrane is bleached by laser light and the amount of time necessary for unbleached fluorescent marker-tagged proteins to diffuse back into the bleached site is a measurement of the cell membrane's fluidity. The diffusion coefficient of a protein or lipid in the membrane can be calculated from the data. (From Segen, Current Med Talk, 1995).Tyrosine: A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Podocytes: Highly differentiated epithelial cells of the visceral layer of BOWMAN CAPSULE of the KIDNEY. They are composed of a cell body with major CELL SURFACE EXTENSIONS and secondary fingerlike extensions called pedicels. They enwrap the KIDNEY GLOMERULUS capillaries with their cell surface extensions forming a filtration structure. The pedicels of neighboring podocytes interdigitate with each other leaving between them filtration slits that are bridged by an extracellular structure impermeable to large macromolecules called the slit diaphragm, and provide the last barrier to protein loss in the KIDNEY.Kinetics: The rate dynamics in chemical or physical systems.Exocytosis: Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.Tight Junctions: Cell-cell junctions that seal adjacent epithelial cells together, preventing the passage of most dissolved molecules from one side of the epithelial sheet to the other. (Alberts et al., Molecular Biology of the Cell, 2nd ed, p22)Time Factors: Elements of limited time intervals, contributing to particular results or situations.Dynamins: A family of high molecular weight GTP phosphohydrolases that play a direct role in vesicle transport. They associate with microtubule bundles (MICROTUBULES) and are believed to produce mechanical force via a process linked to GTP hydrolysis. This enzyme was formerly listed as EC 3.6.1.50.ADP Ribose Transferases: Enzymes that transfer the ADP-RIBOSE group of NAD or NADP to proteins or other small molecules. Transfer of ADP-ribose to water (i.e., hydrolysis) is catalyzed by the NADASES. The mono(ADP-ribose)transferases transfer a single ADP-ribose. POLY(ADP-RIBOSE) POLYMERASES transfer multiple units of ADP-ribose to protein targets, building POLY ADENOSINE DIPHOSPHATE RIBOSE in linear or branched chains.Botulinum Toxins: Toxic proteins produced from the species CLOSTRIDIUM BOTULINUM. The toxins are synthesized as a single peptide chain which is processed into a mature protein consisting of a heavy chain and light chain joined via a disulfide bond. The botulinum toxin light chain is a zinc-dependent protease which is released from the heavy chain upon ENDOCYTOSIS into PRESYNAPTIC NERVE ENDINGS. Once inside the cell the botulinum toxin light chain cleaves specific SNARE proteins which are essential for secretion of ACETYLCHOLINE by SYNAPTIC VESICLES. This inhibition of acetylcholine release results in muscular PARALYSIS.Growth Cones: Bulbous enlargement of the growing tip of nerve axons and dendrites. They are crucial to neuronal development because of their pathfinding ability and their role in synaptogenesis.RNA Interference: A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.Cytoplasmic Streaming: The movement of CYTOPLASM within a CELL. It serves as an internal transport system for moving essential substances throughout the cell, and in single-celled organisms, such as the AMOEBA, it is responsible for the movement (CELL MOVEMENT) of the entire cell.RNA, Small Interfering: Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.Enzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.Cercopithecus aethiops: A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.Immunoblotting: Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.Cell Line, Tumor: A cell line derived from cultured tumor cells.Amides: Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)Microtubule-Associated Proteins: High molecular weight proteins found in the MICROTUBULES of the cytoskeletal system. Under certain conditions they are required for TUBULIN assembly into the microtubules and stabilize the assembled microtubules.Myosin Light Chains: The smaller subunits of MYOSINS that bind near the head groups of MYOSIN HEAVY CHAINS. The myosin light chains have a molecular weight of about 20 KDa and there are usually one essential and one regulatory pair of light chains associated with each heavy chain. Many myosin light chains that bind calcium are considered "calmodulin-like" proteins.src-Family Kinases: A PROTEIN-TYROSINE KINASE family that was originally identified by homology to the Rous sarcoma virus ONCOGENE PROTEIN PP60(V-SRC). They interact with a variety of cell-surface receptors and participate in intracellular signal transduction pathways. Oncogenic forms of src-family kinases can occur through altered regulation or expression of the endogenous protein and by virally encoded src (v-src) genes.Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.Extracellular Matrix: A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.Dendritic Spines: Spiny processes on DENDRITES, each of which receives excitatory input from one nerve ending (NERVE ENDINGS). They are commonly found on PURKINJE CELLS and PYRAMIDAL CELLS.Papaver: A genus of Eurasian herbaceous plants, the poppies (family PAPAVERACEAE of the dicotyledon class Magnoliopsida), that yield OPIUM from the latex of the unripe seed pods.Phosphatidylinositol Phosphates: Phosphatidylinositols in which one or more alcohol group of the inositol has been substituted with a phosphate group.Vimentin: An intermediate filament protein found in most differentiating cells, in cells grown in tissue culture, and in certain fully differentiated cells. Its insolubility suggests that it serves a structural function in the cytoplasm. MW 52,000.Phosphatidylinositol 3-Kinases: Phosphotransferases that catalyzes the conversion of 1-phosphatidylinositol to 1-phosphatidylinositol 3-phosphate. Many members of this enzyme class are involved in RECEPTOR MEDIATED SIGNAL TRANSDUCTION and regulation of vesicular transport with the cell. Phosphatidylinositol 3-Kinases have been classified both according to their substrate specificity and their mode of action within the cell.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Subcellular Fractions: Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)ras GTPase-Activating Proteins: PROTEINS that specifically activate the GTP-phosphohydrolase activity of RAS PROTEINS.Heterocyclic Compounds with 4 or More Rings: A class of organic compounds containing four or more ring structures, one of which is made up of more than one kind of atom, usually carbon plus another atom. The heterocycle may be either aromatic or nonaromatic.Time-Lapse Imaging: Recording serial images of a process at regular intervals spaced out over a longer period of time than the time in which the recordings will be played back.Protein Kinase C: An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.Cell Cycle Proteins: Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Drosophila: A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Antigens, CD29: Integrin beta-1 chains which are expressed as heterodimers that are noncovalently associated with specific alpha-chains of the CD49 family (CD49a-f). CD29 is expressed on resting and activated leukocytes and is a marker for all of the very late activation antigens on cells. (from: Barclay et al., The Leukocyte Antigen FactsBook, 1993, p164)Catenins: A family of cytoskeletal proteins that play essential roles in CELL ADHESION at ADHERENS JUNCTIONS by linking CADHERINS to the ACTIN FILAMENTS of the CYTOSKELETON.ADP-Ribosylation Factors: MONOMERIC GTP-BINDING PROTEINS that were initially recognized as allosteric activators of the MONO(ADP-RIBOSE) TRANSFERASE of the CHOLERA TOXIN catalytic subunit. They are involved in vesicle trafficking and activation of PHOSPHOLIPASE D. This enzyme was formerly listed as EC 3.6.1.47Pinocytosis: The engulfing of liquids by cells by a process of invagination and closure of the cell membrane to form fluid-filled vacuoles.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Fibronectins: Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins.Rho Guanine Nucleotide Exchange Factors: Signaling proteins which function as master molecular switches by activating Rho GTPases through conversion of guanine nucleotides. Rho GTPases in turn control many aspects of cell behavior through the regulation of multiple downstream signal transduction pathways.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Embryo, Nonmammalian: The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.Chemotaxis: The movement of cells or organisms toward or away from a substance in response to its concentration gradient.Nonmuscle Myosin Type IIA: A nonmuscle isoform of myosin type II found predominantly in platelets, lymphocytes, neutrophils and brush border enterocytes.Sulfanilamides: Compounds based on 4-aminobenzenesulfonamide. The '-anil-' part of the name refers to aniline.LIM Domain Proteins: A large class of structurally-related proteins that contain one or more LIM zinc finger domains. Many of the proteins in this class are involved in intracellular signaling processes and mediate their effects via LIM domain protein-protein interactions. The name LIM is derived from the first three proteins in which the motif was found: LIN-11, Isl1 and Mec-3.Myosin Heavy Chains: The larger subunits of MYOSINS. The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS. The heavy chains possess actin-binding and ATPase activity.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Rhodamines: A family of 3,6-di(substituted-amino)-9-benzoate derivatives of xanthene that are used as dyes and as indicators for various metals; also used as fluorescent tracers in histochemistry.Tubulin Modulators: Agents that interact with TUBULIN to inhibit or promote polymerization of MICROTUBULES.
(1/3815) Properties of filament-bound myosin light chain kinase.
Myosin light chain kinase binds to actin-containing filaments from cells with a greater affinity than to F-actin. However, it is not known if this binding in cells is regulated by Ca2+/calmodulin as it is with F-actin. Therefore, the binding properties of the kinase to stress fibers were examined in smooth muscle-derived A7r5 cells. Full-length myosin light chain kinase or a truncation mutant lacking residues 2-142 was expressed as chimeras containing green fluorescent protein at the C terminus. In intact cells, the full-length kinase bound to stress fibers, whereas the truncated kinase showed diffuse fluorescence in the cytoplasm. After permeabilization with saponin, the fluorescence from the truncated kinase disappeared, whereas the fluorescence of the full-length kinase was retained on stress fibers. Measurements of fluorescence intensities and fluorescence recovery after photobleaching of the full-length myosin light chain kinase in saponin-permeable cells showed that Ca2+/calmodulin did not dissociate the kinase from these filaments. However, the filament-bound kinase was sufficient for Ca2+-dependent phosphorylation of myosin regulatory light chain and contraction of stress fibers. Thus, dissociation of myosin light chain kinase from actin-containing thin filaments is not necessary for phosphorylation of myosin light chain in thick filaments. We note that the distance between the N terminus and the catalytic core of the kinase is sufficient to span the distance between thin and thick filaments. (+info)
(2/3815) RhoA activity is required for fibronectin assembly and counteracts beta1B integrin inhibitory effect in FRT epithelial cells.
FRT thyroid epithelial cells synthesize fibronectin and organize a network of fibronectin fibrils at the basal surface of the cells. Fibronectin fibril formation is enhanced by the overexpression of the ubiquitous beta1A integrin and is inhibited by the expression of the dominant-negative beta1B subunit. We tested the hypotheses that RhoA activity might mediate the integrin-dependent fibronectin fibrillogenesis and might counteract beta1B integrin inhibitory effect. FRT-beta1A cells were transfected with a vector carrying a dominant negative form of RhoA (RhoAN19) or treated with the C3 transferase exoenzyme. Both treatments inhibited fibronectin assembly and caused loss of actin microfilaments and adhesion plaques. On the other hand, FRT-beta1B cells were transfected with the constitutively activated form of RhoA (RhoAV14) or treated with the E. coli cytotoxic necrotizing factor 1, which directly activates RhoA. Either treatment restored microfilament and adhesion plaque assembly and promoted fibronectin fibril organization. A great increase in fibronectin fibril assembly was also obtained by treatment of FRT-beta1B cells with TGF-beta. Our data indicate that RhoA is required to promote fibronectin matrix assembly in FRT cells and that the activation of the signal transduction pathway downstream of RhoA can overcome the inhibitory effect of beta1B integrin. (+info)
(3/3815) Filament assembly from profilin-actin.
Profilin plays a major role in the assembly of actin filament at the barbed ends. The thermodynamic and kinetic parameters for barbed end assembly from profilin-actin have been measured turbidimetrically. Filament growth from profilin-actin requires MgATP to be bound to actin. No assembly is observed from profilin-CaATP-actin. The rate constant for association of profilin-actin to barbed ends is 30% lower than that of actin, and the critical concentration for F-actin assembly from profilin-actin units is 0.3 microM under physiological ionic conditions. Barbed ends grow from profilin-actin with an ADP-Pi cap. Profilin does not cap the barbed ends and is not detectably incorporated into filaments. The EDC-cross-linked profilin-actin complex (PAcov) both copolymerizes with F-actin and undergoes spontaneous self-assembly, following a nucleation-growth process characterized by a critical concentration of 0.2 microM under physiological conditions. The PAcov polymer is a helical filament that displays the same diffraction pattern as F-actin, with layer lines at 6 and 36 nm. The PAcov filaments bound phalloidin with the same kinetics as F-actin, bound myosin subfragment-1, and supported actin-activated ATPase of myosin subfragment-1, but they did not translocate in vitro along myosin-coated glass surfaces. These results are discussed in light of the current models of actin structure. (+info)
(4/3815) Origin of contractile dysfunction in heart failure: calcium cycling versus myofilaments.
BACKGROUND: Chronic congestive heart failure is a common, often lethal disorder of cardiac contractility. The fundamental pathophysiology of the contractile failure remains unclear, the focus being on abnormal Ca2+ cycling despite emerging evidence for depressed myofilament function. METHODS AND RESULTS: We measured intracellular Ca2+ concentration ([Ca2+]i) and contractile force in intact ventricular muscle from SHHF rats with spontaneous heart failure and from age-matched controls. At physiological concentrations of extracellular Ca2+ ([Ca2+]o), [Ca2+]i transients were equal in amplitude in the 2 groups, but [Ca2+]i peaked later in SHHF muscles. Twitch force peaked slowly and was equivalent or modestly decreased in amplitude relative to controls. Steady-state analysis revealed a much greater (53%) depression of maximal Ca2+-activated force in SHHF muscles, which, had other factors been equal, would have produced an equivalent suppression of twitch force. Phase-plane analysis reveals that the slowing of Ca2+ cycling prolongs the time available for Ca2+ to activate the myofilaments in failing muscle, partially compensating for the marked dysfunction of the contractile machinery. CONCLUSIONS: Our results indicate that myofilament activation is severely blunted in heart failure, but concomitant changes in [Ca2+]i kinetics minimize the contractile depression. These results challenge prevailing concepts regarding the pathophysiology of heart failure: the myofilaments emerge as central players, whereas changes in Ca2+ cycling are reinterpreted as compensatory rather than causative. (+info)
(5/3815) Fast inactivation of a brain K+ channel composed of Kv1.1 and Kvbeta1.1 subunits modulated by G protein beta gamma subunits.
Modulation of A-type voltage-gated K+ channels can produce plastic changes in neuronal signaling. It was shown that the delayed-rectifier Kv1.1 channel can be converted to A-type upon association with Kvbeta1.1 subunits; the conversion is only partial and is modulated by phosphorylation and microfilaments. Here we show that, in Xenopus oocytes, expression of Gbeta1gamma2 subunits concomitantly with the channel (composed of Kv1.1 and Kvbeta1.1 subunits), but not after the channel's expression in the plasma membrane, increases the extent of conversion to A-type. Conversely, scavenging endogenous Gbetagamma by co-expression of the C-terminal fragment of the beta-adrenergic receptor kinase reduces the extent of conversion to A-type. The effect of Gbetagamma co-expression is occluded by treatment with dihydrocytochalasin B, a microfilament-disrupting agent shown previously by us to enhance the extent of conversion to A-type, and by overexpression of Kvbeta1.1. Gbeta1gamma2 subunits interact directly with GST fusion fragments of Kv1.1 and Kvbeta1.1. Co-expression of Gbeta1gamma2 causes co-immunoprecipitation with Kv1.1 of more Kvbeta1.1 subunits. Thus, we suggest that Gbeta1gamma2 directly affects the interaction between Kv1.1 and Kvbeta1.1 during channel assembly which, in turn, disrupts the ability of the channel to interact with microfilaments, resulting in an increased extent of A-type conversion. (+info)
(6/3815) Syndecan-4 signals cooperatively with integrins in a Rho-dependent manner in the assembly of focal adhesions and actin stress fibers.
The assembly of focal adhesions and actin stress fibers by cells plated on fibronectin depends on adhesion-mediated signals involving both integrins and cell-surface heparan sulfate proteoglycans. These two cell-surface receptors interact with different domains of fibronectin. To attempt to identify the heparan sulfate proteoglycans involved, we used fibronectin-null (FN-/-) mouse fibroblasts to eliminate the contribution of endogenous fibronectin during the analysis. FN-/- fibroblasts plated on the cell-binding domain of fibronectin or on antibodies directed against mouse beta1 integrin chains attach but fail to spread and do not form focal adhesions or actin stress fibers. When such cells are treated with antibodies directed against the ectodomain of mouse syndecan-4, they spread fully and assemble focal adhesions and actin stress fibers indistinguishable from those seen in cells plated on intact fibronectin. These results identify syndecan-4 as a heparan sulfate proteoglycan involved in the assembly process. The antibody-stimulated assembly of focal adhesions and actin stress fibers in cells plated on the cell-binding domain of fibronectin can be blocked with C3 exotransferase, an inhibitor of the small GTP-binding protein Rho. Treatment of cells with lysophosphatidic acid, which activates Rho, results in full spreading and assembly of focal adhesions and actin stress fibers in fibroblasts plated on the cell-binding domain of fibronectin. We conclude that syndecan-4 and integrins can act cooperatively in generating signals for cell spreading and for the assembly of focal adhesions and actin stress fibers. We conclude further that these joint signals are regulated in a Rho-dependent manner. (+info)
(7/3815) Radiation induced endothelial cell retraction in vitro: correlation with acute pulmonary edema.
We determined the effects of low dose radiation (<200 cGy) on the cell-cell integrity of confluent monolayers of pulmonary microvascular endothelial cells (PMEC). We observed dose- and time-dependent reversible radiation induced injuries to PMEC monolayers characterized by retraction (loss of cell-cell contact) mediated by cytoskeletal F-actin reorganization. Radiation induced reorganization of F-actin microfilament stress fibers was observed > or =30 minutes post irradiation and correlated positively with loss of cell-cell integrity. Cells of irradiated monolayers recovered to form contact inhibited monolayers > or =24 hours post irradiation; concomitantly, the depolymerized microfilaments organized to their pre-irradiated state as microfilament stress fibers arrayed parallel to the boundaries of adjacent contact-inhibited cells. Previous studies by other investigators have measured slight but significant increases in mouse lung wet weight >1 day post thoracic or whole body radiation (> or =500 cGy). Little or no data is available concerning time intervals <1 day post irradiation, possibly because of the presumption that edema is mediated, at least in part, by endothelial cell death or irreversible loss of barrier permeability functions which may only arise 1 day post irradiation. However, our in vitro data suggest that loss of endothelial barrier function may occur rapidly and at low dose levels (< or =200 cGy). Therefore, we determined radiation effects on lung wet weight and observed significant increases in wet weight (standardized per dry weight or per mouse weight) in < or =5 hours post thoracic exposure to 50 200 cGy x-radiation. We suggest that a single fraction of radiation even at low dose levels used in radiotherapy, may induce pulmonary edema by a reversible loss of endothelial cell-cell integrity and permeability barrier function. (+info)
(8/3815) Locomotory behaviour of epitheliocytes and fibroblasts on metallic grids.
Behaviour of epitheliocytes and fibroblasts on special discontinuous substrata (metallic grids with square openings of 45x45 microm2) was examined in order to compare the ability of these cells to spread in two mutually perpendicular directions and to stretch over the void spaces. Two cell types with typical fibroblastic morphology, the AGO 1523 line of human foreskin fibroblasts and secondary cultures of mouse embryo fibroblasts, and three cell types with typical epithelial morphology, primary mouse hepatocytes, the IAR-2 line of rat liver cells and the MDCK line of canine kidney epithelial cells (clone 20) were used. We also examined the epitheliocytes (MDCK cells, clone 20) transformed to fibroblast-like morphology by treatment with hepatocyte growth factor/scatter factor (HGF/SF). Time-lapse video microscopy, scanning electron microscopy and immunofluorescence microscopy were used to examine cell reorganizations at various stages of spreading. It was found that early stages of spreading of fibroblasts and epitheliocytes were similar: the cell spread along two bars, perpendicular to each other (bar and crossbar), with the formation of a small triangular lamellar cytoplasm stretched over the opening. Later central parts of the bodies of the fibroblasts retracted from the bars so that the cells remained attached only by their polar lamellae. Successive expansions and partial retractions of these lamellae led to elongation of the cell body crossing several openings of the grid. Epitheliocytes, in contrast to fibroblasts, at the late stages of spreading did not retract their bodies and did not contract polar lamellae. As a result, their central lamellae stretched progressively over the openings. As a result of the treatment of MDCK epitheliocytes with HGF/SF the behaviour of the cells on the grids became similar to that of fibroblasts. It is suggested that these distinct spreading patterns of epitheliocytes and fibroblasts are due to the type-specific differences in the actin-myosin cortex. Experiments with microtubule-specific drugs, colcemid and taxol, indicate that the organization of this cortex is under microtubular control. (+info)
Myosin light chain kinase binds to actin-containing filaments from cells with a greater affinity than to F-actin. However, it is not known if this binding in cells is regulated by Ca2+/calmodulin as it is with F-actin. Therefore, the binding properties of the kinase to stress fibers were examined in smooth muscle-derived A7r5 cells. Full-length myosin light chain kinase or a truncation mutant lacking residues 2-142 was expressed as chimeras containing green fluorescent protein at the C terminus. In intact cells, the full-length kinase bound to stress fibers, whereas the truncated kinase showed diffuse fluorescence in the cytoplasm. After permeabilization with saponin, the fluorescence from the truncated kinase disappeared, whereas the fluorescence of the full-length kinase was retained on stress fibers. Measurements of fluorescence intensities and fluorescence recovery after photobleaching of the full-length myosin light chain kinase in saponin-permeable cells showed that Ca2+/calmodulin did not dissociate the kinase from these filaments. However, the filament-bound kinase was sufficient for Ca2+-dependent phosphorylation of myosin regulatory light chain and contraction of stress fibers. Thus, dissociation of myosin light chain kinase from actin-containing thin filaments is not necessary for phosphorylation of myosin light chain in thick filaments. We note that the distance between the N terminus and the catalytic core of the kinase is sufficient to span the distance between thin and thick filaments. (+info)
(2/3815) RhoA activity is required for fibronectin assembly and counteracts beta1B integrin inhibitory effect in FRT epithelial cells.
FRT thyroid epithelial cells synthesize fibronectin and organize a network of fibronectin fibrils at the basal surface of the cells. Fibronectin fibril formation is enhanced by the overexpression of the ubiquitous beta1A integrin and is inhibited by the expression of the dominant-negative beta1B subunit. We tested the hypotheses that RhoA activity might mediate the integrin-dependent fibronectin fibrillogenesis and might counteract beta1B integrin inhibitory effect. FRT-beta1A cells were transfected with a vector carrying a dominant negative form of RhoA (RhoAN19) or treated with the C3 transferase exoenzyme. Both treatments inhibited fibronectin assembly and caused loss of actin microfilaments and adhesion plaques. On the other hand, FRT-beta1B cells were transfected with the constitutively activated form of RhoA (RhoAV14) or treated with the E. coli cytotoxic necrotizing factor 1, which directly activates RhoA. Either treatment restored microfilament and adhesion plaque assembly and promoted fibronectin fibril organization. A great increase in fibronectin fibril assembly was also obtained by treatment of FRT-beta1B cells with TGF-beta. Our data indicate that RhoA is required to promote fibronectin matrix assembly in FRT cells and that the activation of the signal transduction pathway downstream of RhoA can overcome the inhibitory effect of beta1B integrin. (+info)
(3/3815) Filament assembly from profilin-actin.
Profilin plays a major role in the assembly of actin filament at the barbed ends. The thermodynamic and kinetic parameters for barbed end assembly from profilin-actin have been measured turbidimetrically. Filament growth from profilin-actin requires MgATP to be bound to actin. No assembly is observed from profilin-CaATP-actin. The rate constant for association of profilin-actin to barbed ends is 30% lower than that of actin, and the critical concentration for F-actin assembly from profilin-actin units is 0.3 microM under physiological ionic conditions. Barbed ends grow from profilin-actin with an ADP-Pi cap. Profilin does not cap the barbed ends and is not detectably incorporated into filaments. The EDC-cross-linked profilin-actin complex (PAcov) both copolymerizes with F-actin and undergoes spontaneous self-assembly, following a nucleation-growth process characterized by a critical concentration of 0.2 microM under physiological conditions. The PAcov polymer is a helical filament that displays the same diffraction pattern as F-actin, with layer lines at 6 and 36 nm. The PAcov filaments bound phalloidin with the same kinetics as F-actin, bound myosin subfragment-1, and supported actin-activated ATPase of myosin subfragment-1, but they did not translocate in vitro along myosin-coated glass surfaces. These results are discussed in light of the current models of actin structure. (+info)
(4/3815) Origin of contractile dysfunction in heart failure: calcium cycling versus myofilaments.
BACKGROUND: Chronic congestive heart failure is a common, often lethal disorder of cardiac contractility. The fundamental pathophysiology of the contractile failure remains unclear, the focus being on abnormal Ca2+ cycling despite emerging evidence for depressed myofilament function. METHODS AND RESULTS: We measured intracellular Ca2+ concentration ([Ca2+]i) and contractile force in intact ventricular muscle from SHHF rats with spontaneous heart failure and from age-matched controls. At physiological concentrations of extracellular Ca2+ ([Ca2+]o), [Ca2+]i transients were equal in amplitude in the 2 groups, but [Ca2+]i peaked later in SHHF muscles. Twitch force peaked slowly and was equivalent or modestly decreased in amplitude relative to controls. Steady-state analysis revealed a much greater (53%) depression of maximal Ca2+-activated force in SHHF muscles, which, had other factors been equal, would have produced an equivalent suppression of twitch force. Phase-plane analysis reveals that the slowing of Ca2+ cycling prolongs the time available for Ca2+ to activate the myofilaments in failing muscle, partially compensating for the marked dysfunction of the contractile machinery. CONCLUSIONS: Our results indicate that myofilament activation is severely blunted in heart failure, but concomitant changes in [Ca2+]i kinetics minimize the contractile depression. These results challenge prevailing concepts regarding the pathophysiology of heart failure: the myofilaments emerge as central players, whereas changes in Ca2+ cycling are reinterpreted as compensatory rather than causative. (+info)
(5/3815) Fast inactivation of a brain K+ channel composed of Kv1.1 and Kvbeta1.1 subunits modulated by G protein beta gamma subunits.
Modulation of A-type voltage-gated K+ channels can produce plastic changes in neuronal signaling. It was shown that the delayed-rectifier Kv1.1 channel can be converted to A-type upon association with Kvbeta1.1 subunits; the conversion is only partial and is modulated by phosphorylation and microfilaments. Here we show that, in Xenopus oocytes, expression of Gbeta1gamma2 subunits concomitantly with the channel (composed of Kv1.1 and Kvbeta1.1 subunits), but not after the channel's expression in the plasma membrane, increases the extent of conversion to A-type. Conversely, scavenging endogenous Gbetagamma by co-expression of the C-terminal fragment of the beta-adrenergic receptor kinase reduces the extent of conversion to A-type. The effect of Gbetagamma co-expression is occluded by treatment with dihydrocytochalasin B, a microfilament-disrupting agent shown previously by us to enhance the extent of conversion to A-type, and by overexpression of Kvbeta1.1. Gbeta1gamma2 subunits interact directly with GST fusion fragments of Kv1.1 and Kvbeta1.1. Co-expression of Gbeta1gamma2 causes co-immunoprecipitation with Kv1.1 of more Kvbeta1.1 subunits. Thus, we suggest that Gbeta1gamma2 directly affects the interaction between Kv1.1 and Kvbeta1.1 during channel assembly which, in turn, disrupts the ability of the channel to interact with microfilaments, resulting in an increased extent of A-type conversion. (+info)
(6/3815) Syndecan-4 signals cooperatively with integrins in a Rho-dependent manner in the assembly of focal adhesions and actin stress fibers.
The assembly of focal adhesions and actin stress fibers by cells plated on fibronectin depends on adhesion-mediated signals involving both integrins and cell-surface heparan sulfate proteoglycans. These two cell-surface receptors interact with different domains of fibronectin. To attempt to identify the heparan sulfate proteoglycans involved, we used fibronectin-null (FN-/-) mouse fibroblasts to eliminate the contribution of endogenous fibronectin during the analysis. FN-/- fibroblasts plated on the cell-binding domain of fibronectin or on antibodies directed against mouse beta1 integrin chains attach but fail to spread and do not form focal adhesions or actin stress fibers. When such cells are treated with antibodies directed against the ectodomain of mouse syndecan-4, they spread fully and assemble focal adhesions and actin stress fibers indistinguishable from those seen in cells plated on intact fibronectin. These results identify syndecan-4 as a heparan sulfate proteoglycan involved in the assembly process. The antibody-stimulated assembly of focal adhesions and actin stress fibers in cells plated on the cell-binding domain of fibronectin can be blocked with C3 exotransferase, an inhibitor of the small GTP-binding protein Rho. Treatment of cells with lysophosphatidic acid, which activates Rho, results in full spreading and assembly of focal adhesions and actin stress fibers in fibroblasts plated on the cell-binding domain of fibronectin. We conclude that syndecan-4 and integrins can act cooperatively in generating signals for cell spreading and for the assembly of focal adhesions and actin stress fibers. We conclude further that these joint signals are regulated in a Rho-dependent manner. (+info)
(7/3815) Radiation induced endothelial cell retraction in vitro: correlation with acute pulmonary edema.
We determined the effects of low dose radiation (<200 cGy) on the cell-cell integrity of confluent monolayers of pulmonary microvascular endothelial cells (PMEC). We observed dose- and time-dependent reversible radiation induced injuries to PMEC monolayers characterized by retraction (loss of cell-cell contact) mediated by cytoskeletal F-actin reorganization. Radiation induced reorganization of F-actin microfilament stress fibers was observed > or =30 minutes post irradiation and correlated positively with loss of cell-cell integrity. Cells of irradiated monolayers recovered to form contact inhibited monolayers > or =24 hours post irradiation; concomitantly, the depolymerized microfilaments organized to their pre-irradiated state as microfilament stress fibers arrayed parallel to the boundaries of adjacent contact-inhibited cells. Previous studies by other investigators have measured slight but significant increases in mouse lung wet weight >1 day post thoracic or whole body radiation (> or =500 cGy). Little or no data is available concerning time intervals <1 day post irradiation, possibly because of the presumption that edema is mediated, at least in part, by endothelial cell death or irreversible loss of barrier permeability functions which may only arise 1 day post irradiation. However, our in vitro data suggest that loss of endothelial barrier function may occur rapidly and at low dose levels (< or =200 cGy). Therefore, we determined radiation effects on lung wet weight and observed significant increases in wet weight (standardized per dry weight or per mouse weight) in < or =5 hours post thoracic exposure to 50 200 cGy x-radiation. We suggest that a single fraction of radiation even at low dose levels used in radiotherapy, may induce pulmonary edema by a reversible loss of endothelial cell-cell integrity and permeability barrier function. (+info)
(8/3815) Locomotory behaviour of epitheliocytes and fibroblasts on metallic grids.
Behaviour of epitheliocytes and fibroblasts on special discontinuous substrata (metallic grids with square openings of 45x45 microm2) was examined in order to compare the ability of these cells to spread in two mutually perpendicular directions and to stretch over the void spaces. Two cell types with typical fibroblastic morphology, the AGO 1523 line of human foreskin fibroblasts and secondary cultures of mouse embryo fibroblasts, and three cell types with typical epithelial morphology, primary mouse hepatocytes, the IAR-2 line of rat liver cells and the MDCK line of canine kidney epithelial cells (clone 20) were used. We also examined the epitheliocytes (MDCK cells, clone 20) transformed to fibroblast-like morphology by treatment with hepatocyte growth factor/scatter factor (HGF/SF). Time-lapse video microscopy, scanning electron microscopy and immunofluorescence microscopy were used to examine cell reorganizations at various stages of spreading. It was found that early stages of spreading of fibroblasts and epitheliocytes were similar: the cell spread along two bars, perpendicular to each other (bar and crossbar), with the formation of a small triangular lamellar cytoplasm stretched over the opening. Later central parts of the bodies of the fibroblasts retracted from the bars so that the cells remained attached only by their polar lamellae. Successive expansions and partial retractions of these lamellae led to elongation of the cell body crossing several openings of the grid. Epitheliocytes, in contrast to fibroblasts, at the late stages of spreading did not retract their bodies and did not contract polar lamellae. As a result, their central lamellae stretched progressively over the openings. As a result of the treatment of MDCK epitheliocytes with HGF/SF the behaviour of the cells on the grids became similar to that of fibroblasts. It is suggested that these distinct spreading patterns of epitheliocytes and fibroblasts are due to the type-specific differences in the actin-myosin cortex. Experiments with microtubule-specific drugs, colcemid and taxol, indicate that the organization of this cortex is under microtubular control. (+info)
ACTC1
Polymerization of globular actin (G-actin) leads to a structural filament (F-actin) in the form of a two-stranded helix. Each ... Cell Motility and the Cytoskeleton. 35 (3): 175-87. doi:10.1002/(SICI)1097-0169(1996)35:3. 3.0.CO;2-8. PMID 8913639. Mass ... Cardiac alpha actin is a 42.0 kDa protein composed of 377 amino acids. Cardiac alpha actin is a filamentous protein extending ... Actins are highly conserved proteins; the alpha actins are found in muscle tissues and are a major constituent of the ...
Calponin 2
Published version Rong Liu, J-P Jin (9 March 2016). "Calponin isoforms CNN1, CNN2 and CNN3: Regulators for actin cytoskeleton ... In vitro protein binding studies have demonstrated that calponin binds actin and cross-links actin filaments. Calponin also ... "h2-Calponin is regulated by mechanical tension and modifies the function of actin cytoskeleton". The Journal of Biological ... This low cytoskeleton tension-induced degradation of calponin 2 in collapsed lung was completely prevented in post mortem mouse ...
Gelsolin
The N-terminal is directly involved in the severing of actin. S2 and S3 bind to the actin before the binding of S1 severs actin ... Cytoskeleton (Hoboken). 70 (11): 775-95. doi:10.1002/cm.21149. PMID 24155256. CS1 maint: Uses authors parameter (link) Sun HQ, ... Actin can be cross-linked into a gel by actin cross-linking proteins. Gelsolin can turn this gel into a sol, hence the name ... Gelsolin is an actin-binding protein that is a key regulator of actin filament assembly and disassembly. Gelsolin is one of the ...
Actin, alpha 1
Bretscher A, Weber K (1980). "Villin is a major protein of the microvillus cytoskeleton which binds both G and F actin in a ... Actin alpha 1 which is expressed in skeletal muscle is one of six different actin isoforms which have been identified. Actins ... Alpha actins are a major constituent of the contractile apparatus. Skeletal alpha actin expression is induced by stimuli and ... Actin, alpha 1 has been shown to interact with TMSB4X, MIB2 and PRKCE. Actin ACTB GRCh38: Ensembl release 89: ENSG00000143632 ...
Fimbrin
Lodish H, Berk A, Zipursky L, Matsudaira P, Baltimore D, Darnell J (1999). "Section 18.1: The Actin Cytoskeleton". Molecular ... Structural comparison of actin filaments and fimbrin CH domain-decorated actin filaments has revealed changes in the actin ... Owing to the close proximity of its tandem actin-binding domains, fimbrin directs the formation of tightly bundled actin ... affinity for other actin-binding proteins and may be part of the regulation of the cytoskeleton itself. In humans, three highly ...
Immune system
May RC, Machesky LM (Mar 2001). "Phagocytosis and the actin cytoskeleton". Journal of Cell Science. 114 (Pt 6): 1061-77. PMID ...
Lamellipodium
Hall, Alan (1998). "Rho GTPases and the actin cytoskeleton". Science. 279 (5350): 509-514. doi:10.1126/science.279.5350.509. ... The lamellipodium is born of actin nucleation in the plasma membrane of the cell and is the primary area of actin incorporation ... "Cortactin localization to sites of actin assembly in lamellipodia requires interactions with F-actin and the Arp2/3 complex". ... This, together with actin-polymerisation there, helps extend the lamella forward and thus advance the cell's front. It thus ...
Rho family of GTPases
Cofilin's function is to reorganize the actin cytoskeleton of a cell; namely, it depolymerizes actin segments and thus inhibits ... G-actin) or filamentous (F-actin) forms. The role of Rho family of GTPases and its effects in the stability of actin and spine ... phagocytosis requires the actin cytoskeleton in order to engulf other items. The actin filaments control the formation of the ... One method of maintaining the spatial zones of activation is through anchoring to the actin cytoskeleton, keeping the membrane- ...
Peptidoglycan
CS1 maint: Uses authors parameter (link) van den Ent F, Amos LA, Löwe J (2001). "Prokaryotic origin of the actin cytoskeleton ... van den Ent F, Johnson CM, Persons L, de Boer P, Löwe J (2010). "Bacterial actin MreB assembles in complex with cell shape ...
Cellular microbiology
Many microbes modify and influence the synthesis or degradation of the host-cell cytoskeleton, in particular the actin network ... Dramsi S & Cossart P (1998). "Intracellular pathogens and the actin cytoskeleton". Annu Rev Cell Dev Biol. 14 (1): 137-166. doi ... Intracellular microbes, such as the bacteria Salmonella and Shigella, elicit actin polymerization in host cells that otherwise ... Bacteria such as Yersinia inhibit actin polymerization in phagocytes, thereby preventing their uptake. Cellular microbiology ...
Cell cortex
Olson, M.F.; Sahai, Eric (April 2009). "The actin cytoskeleton in cancer cell motility". Clinical and Experimental Metastasis. ... the cortex is an actin-rich network consisting of F-actin filaments, myosin motors, and actin-binding proteins. The actomyosin ... Spectrin helps to create a network by cross-linked actin filaments. The proportions of spectrin and actin vary with cell type. ... In mitosis, F-actin and myosin II form a highly contractile and uniform cortex to drive mitotic cell rounding. The surface ...
Plakoglobin
... links cadherins to the actin cytoskeleton. Plakoglobin binds to conserved regions of desmoglein and desmocollin at ... "The epidermal growth factor receptor modulates the interaction of E-cadherin with the actin cytoskeleton". The Journal of ... "A mutation in alpha-catenin disrupts adhesion in clone A cells without perturbing its actin and beta-catenin binding activity ...
Polar auxin transport
The latter involves the actin actin cytoskeleton. In research, 1-N-Naphthylphthalamic acid (NPA) and 2,3,5-triiodobenzoic acid ...
RAI14
Ankycorbin has been associated with the cortical actin cytoskeleton structures in terminal web, cell-cell adhesion sites as ... a novel actin cytoskeleton-associated protein". Genes Cells. 5 (12): 1001-8. doi:10.1046/j.1365-2443.2000.00381.x. PMID ...
Tropomyosin 3
Gunning PW, Schevzov G, Kee AJ, Hardeman EC (2006). "Tropomyosin isoforms: divining rods for actin cytoskeleton function". ... family of actin-binding proteins involved in the contractile system of striated and smooth muscles and the cytoskeleton of non- ... Tropomyosins are dimers of coiled-coil proteins that polymerize end-to-end along the major groove in most actin filaments. They ... In muscle cells, they regulate muscle contraction by controlling the binding of myosin heads to the actin filament. Mutations ...
PTPRM
Catenins, in turn, bind to the actin cytoskeleton. Binding of these proteins to the actin cytoskeleton prevents actin from ...
Integrin
These adhesion complexes attach to the actin cytoskeleton. The integrins thus serve to link two networks across the plasma ... Integrins couple the ECM outside a cell to the cytoskeleton (in particular, the microfilaments) inside the cell. Which ligand ... As previously stated, these complexes connect the extracellular matrix to actin bundles. Cryo-electron tomography reveals that ... Clustering and activation of the integrins/actin complexes strengthen the focal adhesion interaction and initiate the framework ...
Cadherin-catenin complex in learning and memory
For example, the cadherin-α-catenin complex binds the actin cytoskeleton, though whether it binds via binding proteins or ... 2011). "Subversion of the actin cytoskeleton during viral infection". Nat. Rev. Microbiol. 9 (6): 427-439. doi:10.1038/ ... In homodimeric form, α-catenins do not bind β- catenins, but preferentially bind F-actin and other proteins promoting F-actin ... Using an in vivo dentate gyrus LTP model, it was shown that LTP induction is associated with an increase in F-actin in the ...
Talin protein
It is capable of linking integrins to the actin cytoskeleton either directly or indirectly by interacting with vinculin and ... Talin, in turn, links integrins to the actin cytoskeleton. The consensus sequence for vinculin binding sites is ... The actin binding site2 is shown to be the major site for sensing the extracellular matrix rigidity. Vinculin binding sites are ... TLN1; TLN2; Actin-binding protein Merlin (protein) an acronym for "Moesin-Ezrin-Radixin-Like Protein" Burridge K, Connell L ( ...
Vinculin
... and actin cytoskeleton. The complex at the focal adhesions consists of several proteins such as vinculin, α-actin, paxillin, ... Talin, in turn, links integrins to the actin cytoskeleton. The consensus sequence for Vinculin binding sites is ... "The epidermal growth factor receptor modulates the interaction of E-cadherin with the actin cytoskeleton". J. Biol. Chem. 273 ( ... "The epidermal growth factor receptor modulates the interaction of E-cadherin with the actin cytoskeleton". J. Biol. Chem. 273 ( ...
PI(4,5)P2 Cycle
"Regulation of the actin cytoskeleton by PIP2 in cytokinesis". Biology of the Cell. 98 (6): 377-388. doi:10.1042/BC20050081. ...
SLC9A5
Regulation by phosphatidylinositol 3'-kinase and the actin cytoskeleton". J. Biol. Chem. 277 (45): 42623-32. doi:10.1074/jbc. ...
RHPN2
... regulates actin cytoskeleton organization". J. Biol. Chem. 277 (46): 43924-32. doi:10.1074/jbc.M203569200. PMID 12221077. " ...
Calponin 3, acidic
Liu R, Jin JP (2016). "Calponin Isoforms CNN1, CNN2 and CNN3: Regulators for Actin Cytoskeleton Functions in Smooth Muscle and ... Calponin 3 has been shown to participate in actin cytoskeleton-based activities such as that in embryonic development and ... Regulators for actin cytoskeleton functions in smooth muscle and non-muscle cells". Gene. 585 (1): 143-153. doi:10.1016/J.GENE. ... where it may function in regulating the actin cytoskeleton with a proposed role in the plasticity of neural tissues. Calponin 3 ...
RhoG
In mammalian cells these include cell motility (through regulation of the actin cytoskeleton), gene transcription, endocytosis ... "RhoG regulates gene expression and the actin cytoskeleton in lymphocytes". Oncogene. 22 (3): 330-42. doi:10.1038/sj.onc.1206116 ... "Rho GTPases and actin dynamics in membrane protrusions and vesicle trafficking". Trends in Cell Biology. 16 (10): 522-9. doi: ...
SGCA
... a group of proteins that are critical to the stability of muscle fiber membranes and to the linking of the actin cytoskeleton ...
WAVE regulatory complex
"The WAVE Regulatory Complex Links Diverse Receptors to the Actin Cytoskeleton". Cell. 156 (1-2): 195-207. doi:10.1016/j.cell. ... family involved in the formation of the actin cytoskeleton through interaction with the Arp2/3 complex. The holocomplex ... WRC recruitment to the sites of actin nucleation events at the cell periphery is mediated by the binding of a number of ligands ... This allows the V domain of the WAVE1 component to interact with the actin monomers while its CA domain interacts with the Arp2 ...
Toxofilin upregulates the host cortical actin cytoskeleton dynamics facilitating Toxoplasma invasion | Journal of Cell Science
Toxofilin upregulates the host cortical actin cytoskeleton dynamics facilitating Toxoplasma invasion Message Subject (Your Name ... Toxofilin upregulates the host cortical actin cytoskeleton dynamics facilitating Toxoplasma invasion. Violaine Delorme-Walker, ... Toxofilin upregulates the host cortical actin cytoskeleton dynamics facilitating Toxoplasma invasion. Violaine Delorme-Walker, ... Toxofilin upregulates the host cortical actin cytoskeleton dynamics facilitating Toxoplasma invasion. Violaine Delorme-Walker, ...
http://jcs.biologists.org/content/early/2012/07/02/jcs.103648
Vav1 Phosphorylation Is Induced by β2 Integrin Engagement on Natural Killer Cells Upstream of Actin Cytoskeleton and Lipid Raft...
Role of Actin Cytoskeleton and of Lipid Rafts in Vav1 Phosphorylation.. Work in T cells has demonstrated that actin ... Vav1/Rac-dependent actin cytoskeleton reorganization is required for lipid raft clustering in T cells. J. Cell Biol. 155:331- ... An open question is how Vav1 becomes activated and what receptor can signal upstream of actin cytoskeleton rearrangement upon ... Vav1 Phosphorylation Is Induced by β2 Integrin Engagement on Natural Killer Cells Upstream of Actin Cytoskeleton and Lipid Raft ...
http://jem.rupress.org/content/198/3/469
Tropomyosin - master regulator of actin filament function in the cytoskeleton. - Kent Academic Repository
Third, Tpms achieve these functional outputs by regulating the interaction of actin filaments with myosin motors and actin- ... master regulator of actin filament function in the cytoskeleton. Journal of Cell Science, 128 (16). pp. 2965-2974. ISSN 0021- ... Tpms are coiled-coil parallel dimers that form a head-to-tail polymer along the length of actin filaments. Yeast only has two ... Each cytoskeletal actin filament contains a homopolymer of Tpm homodimers, resulting in a filament of uniform Tpm composition ...
https://kar.kent.ac.uk/50202/
Intracellular pathogens and the actin cytoskeleton. - PubMed - NCBI
Intracellular pathogens and the actin cytoskeleton.. Dramsi S1, Cossart P.. Author information. 1. Unité des Interactions ... Thus pathogens are convenient systems in which to study actin cytoskeleton rearrangements in response to stimuli at the plasma ... Another step during which pathogens harness the actin cytoskeleton takes place in the cytosol, within which some bacteria ( ... Many pathogens actively exploit the actin cytoskeleton during infection. This exploitation may take place during entry into ...
https://www.ncbi.nlm.nih.gov/pubmed/9891781?dopt=Abstract
actin cytoskeleton morphology: abnormal | SGD
The Saccharomyces Genome Database (SGD) provides comprehensive integrated biological information for the budding yeast Saccharomyces cerevisiae.
https://www.yeastgenome.org/phenotype/abnormal_actin_cytoskeleton_morphology
9781615043880 - The Actin Cytoskeleton and the | eCampus.com
9781615043880 Our cheapest price for The Actin Cytoskeleton and the Regulation of Cell Migration is $54.00. Free shipping on ... The Actin Cytoskeleton and the Regulation of Cell Migration. by Lee, Jonathan M. *ISBN13: 9781615043880. ...
https://www.ecampus.com/actin-cytoskeleton-regulation-cell/bk/9781615043880
Probing the Plant Actin Cytoskeleton duri... & related info | Mendeley
Probing the Plant Actin Cytoskeleton during Cytokinesis and Interphase by Profilin Microinjection.. *Valster A ... phalloidin staining in vivo revealed that high levels of microinjected profilin induced a degradation of the actin cytoskeleton ... However, some cortical actin filaments remained intact. The data demonstrate that profilin has the ability to act as a ... These results add new evidence supporting the hypothesis that actin filaments play a crucial role in the formation of the cell ...
https://www.mendeley.com/research-papers/probing-plant-actin-cytoskeleton-during-cytokinesis-interphase-profilin-microinjection/
Rho GTPases and the Actin Cytoskeleton | Science
The actin cytoskeleton mediates a variety of essential biological functions in all eukaryotic cells. In addition to providing a ... A driving force for this morphogenetic movement is a change in the actin cytoskeleton at the leading edge of the migrating ... Activation of Cdc42 and Rac in macrophages has similar effects on the actin cytoskeleton as it does in fibroblasts and neurons ... It would seem, then, that this is an excellent candidate for mediating Rho-induced changes to the actin cytoskeleton (30). ...
https://science.sciencemag.org/content/279/5350/509?ijkey=0b847ded0e42940ae33b0fc408320d3fd141dd5a&keytype2=tf_ipsecsha Rho GTPases and the Actin Cytoskeleton | Science
The actin cytoskeleton mediates a variety of essential biological functions in all eukaryotic cells. In addition to providing a ... A driving force for this morphogenetic movement is a change in the actin cytoskeleton at the leading edge of the migrating ... Activation of Cdc42 and Rac in macrophages has similar effects on the actin cytoskeleton as it does in fibroblasts and neurons ... It would seem, then, that this is an excellent candidate for mediating Rho-induced changes to the actin cytoskeleton (30). ...
https://science.sciencemag.org/content/279/5350/509?ijkey=35790b315c2a956a70b52f90b5e0fe85a838e8f5&keytype2=tf_ipsecsha Pathways linking endocytosis and actin cytoskeleton in mammalian cells. - PubMed - NCBI
Pathways linking endocytosis and actin cytoskeleton in mammalian cells.. Lanzetti L1, Di Fiore PP, Scita G. ...
https://www.ncbi.nlm.nih.gov/pubmed/11697881?dopt=Abstract
The Arf GTPase-activating protein ASAP1 regulates the actin cytoskeleton | PNAS
The Arf GTPase-activating protein ASAP1 regulates the actin cytoskeleton. Paul A. Randazzo, Josefa Andrade, Koichi Miura, Megan ... The Arf GTPase-activating protein ASAP1 regulates the actin cytoskeleton. Paul A. Randazzo, Josefa Andrade, Koichi Miura, Megan ... The Arf GTPase-activating protein ASAP1 regulates the actin cytoskeleton Message Subject (Your Name) has sent you a message ... The Arf GTPase-activating protein ASAP1 regulates the actin cytoskeleton. Paul A. Randazzo, Josefa Andrade, Koichi Miura, Megan ...
https://www.pnas.org/content/97/8/4011.abstract A mechanical-biochemical feedback loop regulates remodeling in the actin cytoskeleton | PNAS
Mechanosensitivity of Actin Turnover Regulates Actin Filament Overlap in SF Sarcomeres.. In resting SFs we found that the actin ... SFs Shed Half of Their Actin During Recoil but the Actin Density Increases.. During recoil, 51 ± 21% (n = 16) of the SF actin ... Actin Disassembly Occurs Only After Actin Density Increases.. To test whether actin density and disassembly are causally ... S1), forcing actin filaments in the sarcomere to overlap a distance xolap = 2lact - xsarc and creating a stress per actin ...
https://www.pnas.org/content/111/49/17528?ijkey=71da5981464a6f15872b6348539340e0055b1663&keytype2=tf_ipsecsha
CiteSeerX - Citation Query The yeast actin cytoskeleton: from cellular function to biochemical mechanism
The yeast actin cytoskeleton: from cellular function to biochemical mechanism ... The actin cytoskeleton plays an important role in this growth. Until now, there have been no tools to visualize actin or the ... The actin cytoskeleton plays an important role in this growth. Until now, there have been no tools to visualize actin or the ... The yeast actin cytoskeleton: from cellular function to biochemical mechanism (0) by James B Moseley, Bruce L Goode ...
http://citeseer.ist.psu.edu/showciting?cid=20821374 Regulation of Actin Cytoskeleton (Homo sapiens) - WikiPathways
Pathway:Human:Regulation of Actin Cytoskeleton KEGG]] moved to [[Pathway:Homo sapiens:Regulation of Actin Cytoskeleton KEGG]]: ... Actin polymerization. stress fiber. RTK. RAS. GPCR. +p. PI3K. GPCR. ?. stress fiber. Actin polymerization. Filipodia. ... gpml file for [[Human:Regulation_of_Actin_Cytoskeleton_KEGG]]. External references DataNodes. View all...", "View last 5...")' ... Pathway:Homo sapiens:Regulation of Actin Cytoskeleton KEGG]] moved to [[Pathway:WP51]]: Moved to stable identifier. 14231. view ...
https://www.wikipathways.org/index.php/Pathway:WP51
Podocytes and the actin cytoskeleton as a feasible therapeutic target
Importantly, podocyte injury is a consequence of the dysregulation of the actin cytoskeleton. In diverse animal models of... ... Podocytes and the actin cytoskeleton as a feasible therapeutic target. Sanja Sever ; Harvard Medical School and Massachusetts ... Sever, S., Gu, C. (2016). Podocytes and the actin cytoskeleton as a feasible therapeutic target. Periodicum biologorum, 118(4) ... In this review, we focus on the premise of targeting the actin cytoskeleton as a feasible therapeutics for treating chronic ...
https://hrcak.srce.hr/index.php?show=clanak&id_clanak_jezik=261716
Visualization of Endothelial Actin Cytoskeleton in the Mouse Retina
Oktober 2012): Visualization of Endothelial Actin Cytoskeleton in the Mouse Retina. In: PLOS ONE 7(10), e47488 ... Angiogenesis requires coordinated changes in cell shape of endothelial cells (ECs), orchestrated by the actin cytoskeleton. The ... Lifeact-EGFP labels actin associated with cell-cell junctions, apical and basal membranes and highlights actin-based structures ... F-actin) structures with sufficient resolution. Here, we use transgenic mice expressing Lifeact-EGFP to visualize F-actin in ...
https://epub.ub.uni-muenchen.de/14947/
Frontiers | Actin Cytoskeleton Affects Schwann Cell Migration and Peripheral Nerve Regeneration | Physiology
... the spatio-temporal expression patterns of actin cytoskeleton-related genes and the specific roles of actin cytoskeleton ... the spatio-temporal expression patterns of actin cytoskeleton-related genes and the specific roles of actin cytoskeleton ... changes of actin cytoskeleton-related genes following peripheral nerve injury and stated the importance of actin cytoskeleton ... changes of actin cytoskeleton-related genes following peripheral nerve injury and stated the importance of actin cytoskeleton ...
https://www.frontiersin.org/articles/10.3389/fphys.2018.00023/full
A Morphogenesis Checkpoint Monitors the Actin Cytoskeleton in Yeast | JCB
... the actin cytoskeleton can polarize and build a bud. In swe1Δ cells, the actin cytoskeleton is similarly competent to build a ... A Swe1p-dependent Cell Cycle Delay in Cells with a Compromised Actin Cytoskeleton. Several mutants in actin cytoskeletal ... the checkpoint monitors the actin cytoskeleton itself, or perhaps a process that is tightly linked to correct actin ... we propose that the morphogenesis checkpoint monitors the integrity or organization of the actin cytoskeleton. Because actin ...
http://jcb.rupress.org/content/142/6/1487
A Cdc42-regulated actin cytoskeleton mediates Drosophila oocyte polarization | Development
... aPKC or Baz display a disrupted actin cytoskeleton at the anterolateral cortex; and (4) disrupting the actin cytoskeleton with ... Similarly, disrupting the actin cytoskeleton with drugs or by knockdown of actin-binding proteins has been shown to result in ... A Cdc42-regulated actin cytoskeleton mediates Drosophila oocyte polarization Message Subject (Your Name) has sent you a message ... The actin cytoskeleton is marked by fluorescently labeled phalloidin. Dashed lines encircle young cysts in the germarium. (B) ...
http://dev.biologists.org/content/140/2/362
Evolvability of the actin cytoskeleton in oligodendrocytes during central nervous system development and aging | SpringerLink
The organization of actin filaments into a wide range of subcellular structures is a defining feature of cell shape and ... Gourlay CW, Carpp LN, Timpson P, Winder SJ, Ayscough KR (2004) A role for the actin cytoskeleton in cell death and aging in ... Amberg D, Leadsham JE, Kotiadis V, Gourlay CW (2012) Cellular ageing and the actin cytoskeleton. Subcell Biochem 57:331-352 ... Evolvability of the actin cytoskeleton in oligodendrocytes during central nervous system development and aging. ...
https://link.springer.com/article/10.1007%2Fs00018-018-2915-8FilamentsFibersFilamentRegulationRoles of actinImportance of actinDynamicsContractile actin-myosinPolarized actin polymerizationMotilityEndocytosisRegulatorsSelf-organizationProteinPathwayBundlesAxonalCytokinesisCellularFimbrinVisualizeCofilinIntegrityMechanicalStructuresFilamentousMembranesMolecularDynamicFormationRoleLargelyVivoEmergentMachinery
- Tropomyosin (Tpm) isoforms are the master regulators of the functions of individual actin filaments in fungi and metazoans. (kent.ac.uk)
- Tpms are coiled-coil parallel dimers that form a head-to-tail polymer along the length of actin filaments. (kent.ac.uk)
- First, spatially and functionally distinct actin filaments contain different Tpm isoforms, and recent data suggest that members of the formin family of actin filament nucleators can specify which Tpm isoform is added to the growing actin filament. (kent.ac.uk)
- Third, Tpms achieve these functional outputs by regulating the interaction of actin filaments with myosin motors and actin-binding proteins in an isoform-specific manner. (kent.ac.uk)
- Last, the assembly of complex structures, such as stress fibers and podosomes involves the collaboration of multiple types of actin filament specified by their Tpm composition. (kent.ac.uk)
- master regulator of actin filament function in the cytoskeleton. (kent.ac.uk)
- Tropomyosin - master regulator of actin filament function in the cytoskeleton. (kent.ac.uk)
- Each cytoskeletal actin filament contains a homopolymer of Tpm homodimers, resulting in a filament of uniform Tpm composition along its length. (kent.ac.uk)
- This allows the cell to specify actin filament function in time and space by simply specifying their Tpm isoform composition. (kent.ac.uk)
- To address this question, we made rat sciatic nerve crush surgery, collected injured sciatic nerve stumps, analyzed RNA deep sequencing outcomes, and specifically studied two significantly involved canonical pathways that were related with actin, actin cytoskeleton signaling and regulation of actin-based motility by Rho. (frontiersin.org)
- The proper control of the segregation of neurotransmitter receptors at these synapses is directly correlated with the intact regulation of the postsynaptic cytoskeleton. (hindawi.com)
- We investigated the roles of actin (ActA) and fimbrin (FimA) in hyphal growth in Aspergillus nidulans. (psu.edu)
- However, the spatio-temporal expression patterns of actin cytoskeleton-related genes and the specific roles of actin cytoskeleton following peripheral nerve injury have not been fully revealed. (frontiersin.org)
- Overall, our data revealed the changes of actin cytoskeleton-related genes following peripheral nerve injury and stated the importance of actin cytoskeleton during peripheral nerve regeneration. (frontiersin.org)
- Furthermore, it remains unclear at which stages of development microtubule and actin dynamics are important to maintain polarity. (biologists.org)
- In this review, we discuss how structure and dynamics of the actin cytoskeleton is a defining feature of myelinating oligodendrocytes' biology and function. (springer.com)
- Azevedo MM, Domingues HS, Cordelieres FP, Sampaio P, Seixas AI, Relvas JB (2018) Jmy regulates oligodendrocyte differentiation via modulation of actin cytoskeleton dynamics. (springer.com)
- Recent studies show that activation of synaptic receptors during fear and drug-related learning leads to alteration in actin cytoskeleton dynamics and structure in amygdala. (frontiersin.org)
- In my seminar I will focus on the active self-organization of contractile actin-myosin 2 networks. (ens-lyon.fr)
- Movement is coupled to a polarized actin polymerization process, with the formation of characteristic actin tails. (nih.gov)
- The cytoskeleton, cellular motility and the reductionist agenda. (wikipathways.org)
- Pathways linking endocytosis and actin cytoskeleton in mammalian cells. (nih.gov)
- Our data support a novel apical recycling model which indicates a critical role for actin patch-mediated endocytosis to maintain polarized growth at the apex. (psu.edu)
- An Arf GTPase-activating protein of the centaurin β family, ASAP1 (also known as centaurin β4), binds Arf and two other known regulators of the actin cytoskeleton, the tyrosine kinase Src and phosphatidylinositol 4,5-bisphosphate. (pnas.org)
- Cellular chirality arising from the self-organization of the actin cytoskeleton. (sigmaaldrich.com)
- Here, the development of a chiral pattern of actomyosin was revealed by studying actin cytoskeleton self-organization in cells with isotropic circular shape. (sigmaaldrich.com)
- Thus, actin cytoskeleton self-organization provides built-in machinery that potentially allows cells to develop left-right asymmetry. (sigmaaldrich.com)
- Until now, there have been no tools to visualize actin or the actin-binding protein fimbrin in live cells of a filamentous fungus. (psu.edu)
- Actin is an abundant protein that can be found in essentially all eukaryotic cells. (frontiersin.org)
- Our data show that Cdc42 ensures the integrity of the oocyte actin network and that disruption of this network with Latrunculin A phenocopies loss of Cdc42 or Par protein function in early stages of oogenesis. (biologists.org)
- Here, we demonstrated that the WASp-interacting protein (WIP) bridges DOCK8 to WASp and actin in T cells. (jci.org)
- Fimbrin is an actin cross-linking protein important in the formation of filopodia. (wikipedia.org)
- This structural study of the fimbrin core represents the first detailed structural description of a functional actin cross-linking protein. (wikipedia.org)
- It was concluded that Rho acts as a molecular switch to control a signal transduction pathway that links membrane receptors to the cytoskeleton. (sciencemag.org)
- We identified a pathway where the two types of signaling work in harmony to remodel actomyosin stress fibers in the cell's cytoskeleton. (pnas.org)
- These results indicate that DOCK8 and WASp are in the same signaling pathway that links TCRs to the actin cytoskeleton in TCR-driven actin assembly. (jci.org)
- A radially symmetrical system of actin bundles consisting of α-actinin-enriched radial fibres (RFs) and myosin-IIA-enriched transverse fibres (TFs) evolved spontaneously into the chiral system as a result of the unidirectional tilting of all RFs, which was accompanied by a tangential shift in the retrograde movement of TFs. (sigmaaldrich.com)
- Oligodendrocytes are specialized glia that extend multiple actin-based protrusions to form the multilayered myelin membrane that spirally wraps around axons, increasing conduction speed and promoting long-term axonal integrity. (springer.com)
- Probing the Plant Actin Cytoskeleton during Cytokinesis and Interphase by Profilin Microinjection. (mendeley.com)
- Although actin rearrangements are a common feature of most internalization events (e.g. entry of Listeria, Salmonella, Shigella, Yersinia, Neisseria, and Bartonella), bacterial and other cellular factors involved in entry are specific to each bacterium. (nih.gov)
- Platelets are produced in huge cellular factories called megakaryocytes, which need to have a flexible and dynamic internal skeleton or cytoskeleton to produce the platelets. (elifesciences.org)
- Structure of the actin crosslinking core of fimbrin" (PDF). (wikipedia.org)
- The mechanisms that regulate this rearrangement in vivo are poorly understood - largely because of the difficulty to visualize filamentous actin (F-actin) structures with sufficient resolution. (uni-muenchen.de)
- Here, we use transgenic mice expressing Lifeact-EGFP to visualize F-actin in ECs. (uni-muenchen.de)
- Phosphorylation at serine3 renders n-cofilin unable to depolymerize F-actin, thereby stabilizing the cytoskeleton. (jneurosci.org)
- In diverse animal models of proteinuric glomerular disease, recovering the integrity of the actin structure in podocytes resulted in beneficial effects. (srce.hr)
- We determined that the guanine nucleotide exchange factor activity of DOCK8 is essential for the integrity of the subcortical actin cytoskeleton as well as for TCR-driven WASp activation, F-actin assembly, immune synapse formation, actin foci formation, mechanotransduction, T cell transendothelial migration, and homing to lymph nodes, all of which also depend on WASp. (jci.org)
- We show with fluorescence microscopy that the motors generate ring-like actin structures whose size and shape depends both on motor and crosslink density. (ens-lyon.fr)
- There exist two forms of actin, G-actin, the globular monomeric form, and F-actin, the filamentous polymeric form. (frontiersin.org)
- We also review "old and new" concepts to reflect on the potential role of the cytoskeleton in balancing life and death of myelin membranes and oligodendrocytes in the aging central nervous system. (springer.com)
- We systematically adjust the myosin activity and processivity and the level of crosslinking, to find out how molecular parameters change the emergent properties (structure and mechanics) of the model cytoskeleton. (ens-lyon.fr)
- Generally, these two forms of actin present in a dynamic balanced state. (frontiersin.org)
- Nervous system function requires morphological and functional plasticity of neurons and glial cells, which is largely determined by the dynamic reorganization of the actin cytoskeleton in response to intrinsic and extracellular signals. (springer.com)
- In a poer2 mutants, but not vldlr mutants, late generated neurons are unable to pass early-generated cells and remain close to the subventricular zone, suggesting that Reelin signaling via ApoER2 influences the cytoskeleton to undergo dynamic changes during migration. (jneurosci.org)
- Such changes in actin cytoskeleton in amygdala are essential for fear and drug-related memories formation. (frontiersin.org)
- The actin cytoskeleton plays an important role in this growth. (psu.edu)
- Wilson R, Brophy PJ (1989) Role for the oligodendrocyte cytoskeleton in myelination. (springer.com)
- We show that in the retina, Lifeact-EGFP expression is largely restricted to ECs allowing detailed visualization of F-actin in ECs in situ. (uni-muenchen.de)
- Confocal laser scanning microscopy of rhodamine-phalloidin staining in vivo revealed that high levels of microinjected profilin induced a degradation of the actin cytoskeleton in the phragmoplast, the perinuclear zone, and the cytoplasmic strands. (mendeley.com)