Mechanosensing organelles of hair cells which respond to fluid motion or fluid pressure changes. They have various functions in many different animals, but are primarily used in hearing.
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.
Sensory cells in the organ of Corti, characterized by their apical stereocilia (hair-like projections). The inner and outer hair cells, as defined by their proximity to the core of spongy bone (the modiolus), change morphologically along the COCHLEA. Towards the cochlear apex, the length of hair cell bodies and their apical STEREOCILIA increase, allowing differential responses to various frequencies of sound.
Fibers composed of MICROFILAMENT PROTEINS, which are predominately ACTIN. They are the smallest of the cytoskeletal filaments.
Populations of thin, motile processes found covering the surface of ciliates (CILIOPHORA) or the free surface of the cells making up ciliated EPITHELIUM. Each cilium arises from a basic granule in the superficial layer of CYTOPLASM. The movement of cilia propels ciliates through the liquid in which they live. The movement of cilia on a ciliated epithelium serves to propel a surface layer of mucus or fluid. (King & Stansfield, A Dictionary of Genetics, 4th ed)
Auditory sensory cells of organ of Corti, usually placed in one row medially to the core of spongy bone (the modiolus). Inner hair cells are in fewer numbers than the OUTER AUDITORY HAIR CELLS, and their STEREOCILIA are approximately twice as thick as those of the outer hair cells.
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.
Sensory cells in the acoustic maculae with their apical STEREOCILIA embedded in a gelatinous OTOLITHIC MEMBRANE. These hair cells are stimulated by the movement of otolithic membrane, and impulses are transmitted via the VESTIBULAR NERVE to the BRAIN STEM. Hair cells in the saccule and those in the utricle sense linear acceleration in vertical and horizontal directions, respectively.
Two membranous sacs within the vestibular labyrinth of the INNER EAR. The saccule communicates with COCHLEAR DUCT through the ductus reuniens, and communicates with utricle through the utriculosaccular duct from which the ENDOLYMPHATIC DUCT arises. The utricle and saccule have sensory areas (acoustic maculae) which are innervated by the VESTIBULAR NERVE.
The part of the inner ear (LABYRINTH) that is concerned with hearing. It forms the anterior part of the labyrinth, as a snail-like structure that is situated almost horizontally anterior to the VESTIBULAR LABYRINTH.
The essential part of the hearing organ consists of two labyrinthine compartments: the bony labyrinthine and the membranous labyrinth. The bony labyrinth is a complex of three interconnecting cavities or spaces (COCHLEA; VESTIBULAR LABYRINTH; and SEMICIRCULAR CANALS) in the TEMPORAL BONE. Within the bony labyrinth lies the membranous labyrinth which is a complex of sacs and tubules (COCHLEAR DUCT; SACCULE AND UTRICLE; and SEMICIRCULAR DUCTS) forming a continuous space enclosed by EPITHELIUM and connective tissue. These spaces are filled with LABYRINTHINE FLUIDS of various compositions.
The spiral EPITHELIUM containing sensory AUDITORY HAIR CELLS and supporting cells in the cochlea. Organ of Corti, situated on the BASILAR MEMBRANE and overlaid by a gelatinous TECTORIAL MEMBRANE, converts sound-induced mechanical waves to neural impulses to the brain.
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.
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
Actin capping proteins are cytoskeletal proteins that bind to the ends of ACTIN FILAMENTS to regulate actin polymerization.
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.
A membrane, attached to the bony SPIRAL LAMINA, overlying and coupling with the hair cells of the ORGAN OF CORTI in the inner ear. It is a glycoprotein-rich keratin-like layer containing fibrils embedded in a dense amorphous substance.
Chemicals that are used to oxidize pigments and thus effect whitening.
A general term for the complete loss of the ability to hear from both ears.
A subclass of myosins originally found in the photoreceptor of DROSOPHILA. The heavy chains can occur as two alternatively spliced isoforms of 132 and 174 KDa. The amino terminal of myosin type III is highly unusual in that it contains a protein kinase domain which may be an important component of the visual process.
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.
Sensory cells of organ of Corti. In mammals, they are usually arranged in three or four rows, and away from the core of spongy bone (the modiolus), lateral to the INNER AUDITORY HAIR CELLS and other supporting structures. Their cell bodies and STEREOCILIA increase in length from the cochlear base toward the apex and laterally across the rows, allowing differential responses to various frequencies of sound.
The sensory areas on the vertical wall of the saccule and in the floor of the utricle. The hair cells in the maculae are innervated by fibers of the VESTIBULAR NERVE.
Autosomal recessive hereditary disorders characterized by congenital SENSORINEURAL HEARING LOSS and RETINITIS PIGMENTOSA. Genetically and symptomatically heterogeneous, clinical classes include type I, type II, and type III. Their severity, age of onset of retinitis pigmentosa and the degree of vestibular dysfunction are variable.
Electrical waves in the CEREBRAL CORTEX generated by BRAIN STEM structures in response to auditory click stimuli. These are found to be abnormal in many patients with CEREBELLOPONTINE ANGLE lesions, MULTIPLE SCLEROSIS, or other DEMYELINATING DISEASES.
A general term for the complete or partial loss of the ability to hear from one or both ears.
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.
The electric response of the cochlear hair cells to acoustic stimulation.
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.
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.
Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.
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.
An oval, bony chamber of the inner ear, part of the bony labyrinth. It is continuous with bony COCHLEA anteriorly, and SEMICIRCULAR CANALS posteriorly. The vestibule contains two communicating sacs (utricle and saccule) of the balancing apparatus. The oval window on its lateral wall is occupied by the base of the STAPES of the MIDDLE EAR.
Hearing loss in frequencies above 1000 hertz.
Materials used as reference points for imaging studies.
The ability or act of sensing and transducing ACOUSTIC STIMULATION to the CENTRAL NERVOUS SYSTEM. It is also called audition.
A dynamic actin-rich extension of the surface of an animal cell used for locomotion or prehension of food.
Reduced (protonated) form of THIAZOLES. They can be oxidized to THIAZOLIDINEDIONES.
Pathological processes of the snail-like structure (COCHLEA) of the inner ear (LABYRINTH) which can involve its nervous tissue, blood vessels, or fluid (ENDOLYMPH).
Mice bearing mutant genes which are phenotypically expressed in the animals.
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.
Calcium-transporting ATPases found on the PLASMA MEMBRANE that catalyze the active transport of CALCIUM from the CYTOPLASM into the extracellular space. They play a role in maintaining a CALCIUM gradient across plasma membrane.
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.
Specialized structures of the cell that extend the cell membrane and project out from the cell surface.
Chemical reaction in which monomeric components are combined to form POLYMERS (e.g., POLYMETHYLMETHACRYLATE).
Proteins that are involved in or cause CELL MOVEMENT such as the rotary structures (flagellar motor) or the structures whose movement is directed along cytoskeletal filaments (MYOSIN; KINESIN; and DYNEIN motor families).
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.
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.
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.
A family of low molecular weight proteins that bind ACTIN and control actin polymerization. They are found in eukaryotes and are ubiquitously expressed.
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.
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.
Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.
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.
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.
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)
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.
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.
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.
Catalyzes the ATP-dependent PHOSPHORYLATION of GMP to generate GDP and ADP.
Act of eliciting a response from a person or organism through physical contact.
An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.
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.
A type of non-ionizing radiation in which energy is transmitted through solid, liquid, or gas as compression waves. Sound (acoustic or sonic) radiation with frequencies above the audible range is classified as ultrasonic. Sound radiation below the audible range is classified as infrasonic.
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.
Hearing loss due to exposure to explosive loud noise or chronic exposure to sound level greater than 85 dB. The hearing loss is often in the frequency range 4000-6000 hertz.
A protein found in the thin filaments of muscle fibers. It inhibits contraction of the muscle unless its position is modified by TROPONIN.
Minute projections of cell membranes which greatly increase the surface area of the cell.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
Transport proteins that carry specific substances in the blood or across cell membranes.
A genus of the family Chinchillidae which consists of three species: C. brevicaudata, C. lanigera, and C. villidera. They are used extensively in biomedical research.
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.
Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.
A family of multisubunit cytoskeletal motor proteins that use the energy of ATP hydrolysis to power a variety of cellular functions. Dyneins fall into two major classes based upon structural and functional criteria.
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 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.
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.
Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
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.
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.
A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical position is recorded as a spring attached to the probe rises and falls in response to peaks and valleys on the surface. These deflections produce a topographic map of the sample.
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.
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 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).)
A protein complex of actin and MYOSINS occurring in muscle. It is the essential contractile substance of muscle.
Use of sound to elicit a response in the nervous system.
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.
The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.
A protein factor that regulates the length of R-actin. It is chemically similar, but immunochemically distinguishable from actin.
The quality or state of being able to be bent or creased repeatedly. (From Webster, 3d ed)
Refers to animals in the period of time just after birth.
Hearing loss resulting from damage to the COCHLEA and the sensorineural elements which lie internally beyond the oval and round windows. These elements include the AUDITORY NERVE and its connections in the BRAINSTEM.
Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).
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.
One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.
Compounds consisting of chains of AMINO ACIDS alternating with CARBOXYLIC ACIDS via ester and amide linkages. They are commonly cyclized.
The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.
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.
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.
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.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
Physical motion, i.e., a change in position of a body or subject as a result of an external force. It is distinguished from MOVEMENT, a process resulting from biological activity.
Common name for FISHES belonging to the order Perciformes and occurring in three different families.
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.
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.
A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.
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.
Established cell cultures that have the potential to propagate indefinitely.
The properties, processes, and behavior of biological systems under the action of mechanical forces.
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.
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.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
An exchange of DNA between matching or similar sequences.
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.
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.
Contractile tissue that produces movement in animals.
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.
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.
Elements of limited time intervals, contributing to particular results or situations.
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 enzymes
Any sound which is unwanted or interferes with HEARING other sounds.
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.
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.
The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
The rate dynamics in chemical or physical systems.
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.
The physiological renewal, repair, or replacement of tissue.
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.
The audibility limit of discriminating sound intensity and pitch.
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.
An individual in which both alleles at a given locus are identical.
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.
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.
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.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Compounds that contain a BENZENE ring fused to a furan ring.
Stereocilia[edit]. The stereocilia of the epididymis are long cytoplasmic projections that have an actin filament backbone.[4] ... In the caput (head) region these cells have long stereocilia that are tuft like extensions that project into the lumen.[4] The ... It is characterized histologically by a thick epithelium with long stereocilia (described below) and a little smooth muscle.[2] ... The core function of the stereocilia is to resorb 90% of this fluid as the spermatozoa start to become motile. This absorption ...
The hair bundle consists of an array of actin-based stereocilia. Each stereocilium inserts as a rootlet into a dense ... Movement of the stereocilia and kinocilium enable the hair cells of the saccula and utricle to detect motion. The semicircular ... Both types of pillar cell have thousands of cross linked microtubules and actin filaments in parallel orientation. They provide ... These microscopic structures possess stereocilia and one kinocilium which are located within the gelatinous otolithic membrane ...
This causes stereocilia channel closing which leads to hyperpolarization and OHC elongation. Below the hair bundle is an actin- ... These changes in actin polymerization do not alter NLC, showing that actin's role in the cochlear amplifier is separate from ... the stereocilia of the OHCs are deflected toward the tallest stereocilia. This causes the tip links of the OHC hair bundle to ... First, the stereocilia are deflected in the positive direction opening the MET channels and allowing for inflow of Na+, K+, and ...
"An actin molecular treadmill and myosins maintain stereocilia functional architecture and self-renewal". J. Cell Biol. 164 (6 ... The stereocilia (hair cells) of the inner ear can become subjected to bending from loud noises. Because they are not ...
A stereocilium is able to bend at its point of attachment to the apical surface of the hair cell. The actin filaments that form ... The stereocilia in a hair bundle are arranged in multiple rows of different heights. In addition to the stereocilia, a true ... When the tallest stereocilia are deflected, tension is produced in the tip links and causes the stereocilia in the other rows ... When stereocilia in the tallest row are deflected in the positive-stimulus direction, the shorter rows of stereocilia are also ...
Gene map locus 19q13.4 OMIM: 604812 KPTN: Kaptin (actin binding protein) at the tips of stereocilia. Gene map locus 19q13.4 ...
As the kinocilium does not move, microvilli surrounding it begin to elongate and form actin stereocilia. In many mammals the ... This is mostly due to the pulling force stereocilia exerts on its neighboring stereocilia via interconnecting links that hold ... Deflection of the stereocilia toward or away from the kinocilium causes an increase or decrease in the firing rate of the ... One kinocilium is the longest cilium located on the hair cell next to 40-70 stereocilia. During movement of the body, the hair ...
Stereocilia of the epididymis are not cilia because their cytoskeleton is composed of actin filaments, not microtubules. They ... "Cytoskeletal differences between stereocilia of the human sperm passageway and microvilli/stereocilia in other locations". ... Pseudostratified columnar epithelia with stereocilia are located in the epididymis. ...
... s are extracellular filaments that connect stereocilia to each other or to the kinocilium in the hair cells of the ... It is hypothesized that the tip link is attached to the myosin motor which moves along actin filaments. Neuronal encoding of ... 1984.Cross-links between stereocilia in the guinea pig organ of Corti, and their possible relation to sensory transduction. ... so it is thought that there has to be something else in the hair cells that is stretchy which allows the stereocilia to move ...
... encoding an actin-binding protein of cochlear hair cell stereocilia, is a new causal gene for autosomal recessive profound ... "The eps8 family of proteins links growth factor stimulation to actin reorganization generating functional redundancy in the Ras ... responsible for the activation of the Rac-specific GEF activity of Sos-1 and for the proper localization of the Rac-based actin ... proteins in other organisms are involved in the transduction of signals from Ras to Rac and growth factor-mediated actin ...
... a novel actin-associated protein from human blood platelets found in lamellipodia and the tips of the stereocilia of the inner ... Bearer, E. L. (1992). "An actin-associated protein present in the microtubule organizing center and the growth cones of PC-12 ... Bearer, E. L. (1991). "Direct observation of actin filament severing by gelsolin and binding by gCap39 and CapZ". The Journal ... Li, Zhi; Kim, Eric S.; Bearer, Elaine L. (2002). "Arp2/3 complex is required for actin polymerization during platelet shape ...
2000). "The deaf jerker mouse has a mutation in the gene encoding the espin actin-bundling proteins of hair cell stereocilia ... an actin-binding protein localized to the F-actin-rich junctional plaques of Sertoli cell ectoplasmic specializations". J. Cell ... 2003). "Novel espin actin-bundling proteins are localized to Purkinje cell dendritic spines and bind the Src homology 3 adapter ... 2006). "Targeted wild-type and jerker espins reveal a novel, WH2-domain-dependent way to make actin bundles in cells". J. Cell ...
... XV is necessary for the development of the actin core structure of the non-motile stereocilia located in the inner ear. ... F-actin, while processive runlengths are shorter on older (ADP-rich) F-actin.[24] ... The head domain binds the filamentous actin, and uses ATP hydrolysis to generate force and to "walk" along the filament towards ... It walks along actin filaments, travelling towards the pointed end (- end) of the filaments.[26] Myosin VI is thought to ...
... to bind and activate the small G protein Rac and may regulate the organisation of the actin cytoskeleton in the Stereocilia of ... March 2006). "An isoform of GTPase regulator DOCK4 localizes to the stereocilia in the inner ear and binds to harmonin (USH1C ...
It is usually associated with polarized actin filaments in membrane ruffles, filopodia, stereocilia and adhesion plaques. ... 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 ... Fimbrin is an actin cross-linking protein important in the formation of filopodia. Fimbrin belongs to the calponin homology (CH ...
Further, it was demonstrated the amount of actin polymerization was also limited by the area where actin had the ability to ... the stereocilia of hair cells in the inner ear, and the bristles of Drosophila. Tilney's research in Drosophila focused on the ... "Actin Filaments And Microtubules Play Different Roles During Bristle Elongation In Drosophila". Journal Of Cell Science, vol ... This represented the first time that this actin polymerization had been observed in parasites. Later research went on to show ...
Kambara T, Komaba S, Ikebe M (2007). "Human myosin III is a motor having an extremely high affinity for actin". J. Biol. Chem. ... 2006). "A new compartment at stereocilia tips defined by spatial and temporal patterns of myosin IIIa expression". J. Neurosci ... Myosins are actin-dependent motor proteins and are categorized into conventional myosins (class II) and unconventional myosins ...
... XV is necessary for the development of the actin core structure of the non-motile stereocilia located in the inner ear. ... F-actin, while processive runlengths are shorter on older (ADP-rich) F-actin.[23] ... "Actin Age Orchestrates Myosin-5 and Myosin-6 Run Lengths". Current Biology. 25: 2057-2062. doi:10.1016/j.cub.2015.06.033. PMC ... The head domain binds the filamentous actin, and uses ATP hydrolysis to generate force and to "walk" along the filament towards ...
It seems that they affect the stereocilia of the ciliated cells present in the inner ear's Organ of Corti. β-actin is the most ... beta actin ACTC1 - actin, alpha, cardiac muscle 1 ACTG1 - gamma actin 1 ACTG2 - gamma actin 2, smooth muscle, enteric Actin ... In this way there are three species of actin in a filament: ATP-Actin, ADP+Pi-Actin and ADP-Actin. The amount of each one of ... of monomeric G-actin. The Arp2/3 complex binds to actin filaments at 70 degrees to form new actin branches off existing actin ...
Like microvilli, they contain actin filaments and lack an axoneme, distinguishing them from cilia. They are found in three ... Stereocilia (or stereovilli) are non-motile apical modifications of the cell. They are distinct from cilia and microvilli, but ... the sensory (hair) cells of the inner ear (see stereocilia (inner ear) for more details) Krause J. William (July 2005). ... Some sources consider epididymal stereocilia to be a variant of microvilli, rather than their own distinct type of structure. ...
Stereocilia are composed of cytoplasm with embedded bundles of cross-linked actin filaments. The actin filaments anchor to the ... At the core of these hair-like stereocilia are rigid cross-linked actin filaments, which can renew every 48 hours. These actin ... Deflections of the stereocilia in the direction of the tallest stereocilia leads to an increased rate of opening of nonspecific ... The therapy restored stereocilia to normal lengths and eliminated the additional rows of stereocilia in newborn whirler mice. ...
... a novel actin-associated protein from human blood platelets found in lamellipodia and the tips of the stereocilia of the inner ... Bearer EL (March 1992). "An actin-associated protein present in the microtubule organizing center and the growth cones of PC-12 ... Bearer EL, Prakash JM, Li Z (2002). "Actin dynamics in platelets". International Review of Cytology. 217: 137-82. doi:10.1016/ ... "Entrez Gene: KPTN kaptin (actin binding protein)". "Body weight data for Kptn". Wellcome Trust Sanger Institute. "Glucose ...
Actin motors such as myosin move along microfilaments through interaction with actin, and microtubule motors such as dynein and ... Myosin is necessary in the process of hearing because of its role in the growth of stereocilia so defects in myosin protein ... The myosin heads bind and hydrolyze ATP, which provides the energy to walk toward the plus end of an actin filament. Myosin II ... Myosins are a superfamily of actin motor proteins that convert chemical energy in the form of ATP to mechanical energy, thus ...
It seems that they affect the stereocilia of the ciliated cells present in the inner ear's Organ of Corti. β-actin is the most ... In this way there are three species of actin in a filament: ATP-Actin, ADP+Pi-Actin and ADP-Actin.[47][60] The amount of each ... are ATP-G-Actin and ADP-F-actin.[28][29]. G-ActinEdit. Scanning electron microscope images indicate that G-actin has a globular ... of monomeric G-actin. The Arp2/3 complex binds to actin filaments at 70 degrees to form new actin branches off existing actin ...
... along filopodial actin filaments and can bind to filopodial actin filaments to be carried slowly rearward by retrograde actin ... and inner ear stereocilia. The slime mold Dictyostelium expresses a MyTH4-FERM myosin known as myosin-7 that is involved in ... Myo10 is an actin-based motor protein that can localize to the tips of the finger-like cellular protrusions known as filopodia ... The N-terminal head or myosin motor domain can bind to an actin filament, hydrolyze ATP, and produce force. The neck or light ...
... which activates actin and cytoskeleton architecture in the cell. For the Rac branch, DVL activates the Rac GTPase.[3] ... and stereocilia orientation in the inner ear.[7] ...
Like microvilli, they contain actin filaments, distinguishing them from microtubule-containing cilia. ... the epididymis (see stereocilia (epididymis) for more details). Some sources consider epididymal stereocilia to be a variant of ... Stereocilia (or stereovilli) are non-motile apical modifications of the cell, which are distinct from cilia and microvilli, but ... "Stereocilia" - news · newspapers · books · scholar · JSTOR (December 2009) (Learn how and when to remove this template message ...
Sound waves are able to bend the stereocilia and open up ion channels leading to the creation of nerve impulses. These channels ... "Cross-talk between the mechano-gated K-2P channel TREK-1 and the actin cytoskeleton". EMBO Reports. 6 (7): 642-648. doi:10.1038 ... When a wave of sound deflects the stereocilia, the channel opens. This is an instance of the Spring-like Tether gating ... Furthermore, mechanically gated ion channels are also found in the stereocilia of the inner ear. ...
The nucleation of actin fibers occurs as a response to external stimuli, allowing a cell to alter its shape to suit a ... Brush border Cilia Flagellum Intestinal villus Stereocilia Terminal web Krause J. William (July 2005). Krause's Essential Human ... Actin filaments, present in the cytosol, are most abundant near the cell surface. These filaments are thought to determine the ... Myosin 1a functions through a binding site for filamentous actin on one end and a lipid binding domain on the other. The plus ...
Finally, twinfilin 2, a putative modulator of actin polymerization, was found at the tips of stereocilia. In order to determine ... A hair bundle proteomics approach to discovering actin regulatory proteins in inner ear stereocilia. Research and Teaching ... StarD10, a putative phospholipid binding protein, was detectable along the shaft of stereocilia. Nebulin, a putative F-actin ... A hair bundle proteomics approach to discovering actin regulatory proteins in inner ear stereocilia. Download ...
The organization of actin filaments in the stereocilia of cochlear hair cells.. L G Tilney, D J Derosier, M J Mulroy ... Within each tapering stereocilium of the cochlea of the alligator lizard is a bundle of actin filaments with , 3,000 filaments ... A careful examination of the packing of the actin filaments in the stereocilia by thin sectin and by optical diffraction ... The organization of actin filaments in the stereocilia of cochlear hair cells. ...
Actin filaments, stereocilia and hair cells of the bird cochlea. VI. How the number and arrangement of stereocilia are ... Actin filaments, stereocilia and hair cells of the bird cochlea. VI. How the number and arrangement of stereocilia are ... Actin filaments, stereocilia and hair cells of the bird cochlea. VI. How the number and arrangement of stereocilia are ... Actin filaments, stereocilia and hair cells of the bird cochlea. VI. How the number and arrangement of stereocilia are ...
... ... Both myosin IIIa and espin 1 are expressed in the inner ear hair cells and colocalize at stereocilia tips, the site of actin ... We confirmed that myosin IIIb transports espin 1 to stereocilia tips and promotes actin polymerization, consistent with the ... and espin 1 and their influence on stereocilia length unravels a novel molecular complex at the polymerizing end of F-actin and ...
6. TilneyLGDeRosierDJ 1986 Actin filaments, stereocilia, and hair cells of the bird cochlea. IV. How the actin filaments become ... Accordingly, espins are not the only actin-bundling proteins in hair cell stereocilia. The other actin-bundling proteins ... Espins versus other actin-bundling proteins. Parallel actin bundles in cells typically contain multiple classes of actin- ... The parallel actin bundle, which consists of hexagonally packed unidirectional actin filaments cross-linked by actin-bundling ...
... stereocilia of sensory hair cells demonstrate the importance of cellular actin protrusions. ... stereocilia of sensory hair cells demonstrate the importance of cellular actin protrusions. Actin packing in stereocilia is ... Surprisingly, although wild-type stereocilia had random liquid packing of their actin filaments, stereocilia lacking PLS1 had ... Although all three cross-linkers are required for stereocilia structure and function, PLS1 biases actin toward liquid packing, ...
Beroe; Ctenophora; F-actin; Mnemiopsis; Pleurobrachia; Stereocilia; apical organ; cell atlas; cilia; development; evolution; ...
Correlation of actin crosslinker and capper expression levels with stereocilia growth phases. Molecular and Cellular Proteomics ... Correlation of actin crosslinker and capper expression levels with stereocilia growth phases. / Avenarius, Matthew R.; Saylor, ... Capping protein, a barbed-end actin capper, is located at stereocilia tips; it is abundant during growth phase II, when ... Although actin crosslinkers are readily detected by electron microscopy in developing chick cochlea stereocilia, quantitative ...
It seems that they affect the stereocilia of the ciliated cells present in the inner ears Organ of Corti. β-actin is the most ... beta actin ACTC1 - actin, alpha, cardiac muscle 1 ACTG1 - gamma actin 1 ACTG2 - gamma actin 2, smooth muscle, enteric Actin ... In this way there are three species of actin in a filament: ATP-Actin, ADP+Pi-Actin and ADP-Actin. The amount of each one of ... of monomeric G-actin. The Arp2/3 complex binds to actin filaments at 70 degrees to form new actin branches off existing actin ...
Stereocilia[edit]. The stereocilia of the epididymis are long cytoplasmic projections that have an actin filament backbone.[4] ... In the caput (head) region these cells have long stereocilia that are tuft like extensions that project into the lumen.[4] The ... It is characterized histologically by a thick epithelium with long stereocilia (described below) and a little smooth muscle.[2] ... The core function of the stereocilia is to resorb 90% of this fluid as the spermatozoa start to become motile. This absorption ...
In addition, stereocilia integrity may hinge on immobilizing actin, which outside of a small region at stereocilia tips turns ... This process requires both β-actin and γ-actin as knock-out mice lacking either isoform develop distinct stereocilia pathology ... Here, we establish that β-actin and the actin crosslinking protein fascin-2 cooperate to maintain stereocilia length and ... Fascin-2 binds β-actin and γ-actin filaments with similar affinity in vitro and fascin-2 does not depend on β-actin for ...
Live-cell imaging of actin dynamics reveals mechanisms of stereocilia length regulation in the inner ear. Drummond, Meghan C ... "Live-cell imaging of actin dynamics reveals mechanisms of stereocilia length regulation in the inner ear." Nature ...
Study 1.2 Epithelium and Glands flashcards from User Unknown
Their hypothesis was that since espin promotes f-actin linking in stereocilia, more espin would lengthen the stereocilia and ... The stereocilia bundles in green have been over-expressing espin, resulting in abnormally long stereocilia. Normal stereocilia ... Structural Polymorphism of the Actin-Espin System: A Prototypical System of Filaments and Linkers in Stereocilia. Physical ... It organizes filimentous actin (f-actin) into bundles and links them, providing the necessary structural framework for ...
Stereocilia/Stereovilli Long microvilli; 120 um. No villin in the tip. Ezrin anchors actin to cell membrane (no myosin I). ... villin: anchors actin to the tip. myosin I anchors actin to cell membrane. Has fuzzy coat of glycoproteins with enzymatic ... Actin filaments facilitate attachment to adjacent cells. alpha-actinin - an actin-binding protein also found in the Z-line of ... Core of actin filaments. Anchored in terminal web (contractile). Intermediate filaments = cytokeratin. Other cross-linking ...
It seems that they affect the stereocilia of the ciliated cells present in the inner ears Organ of Corti. β-actin is the most ... In this way there are three species of actin in a filament: ATP-Actin, ADP+Pi-Actin and ADP-Actin.[47][60] The amount of each ... are ATP-G-Actin and ADP-F-actin.[28][29]. G-ActinEdit. Scanning electron microscope images indicate that G-actin has a globular ... of monomeric G-actin. The Arp2/3 complex binds to actin filaments at 70 degrees to form new actin branches off existing actin ...
Actin-bundling protein TRIOBP forms resilient rootlets of hair cell stereocilia essential for hearing. Cell. 2010. 141(5):786- ... Gamma-actin is required for cytoskeletal maintenance but not development. Proc Natl Acad Sci U S A. 2009. 106(24):9703-8.. ...
B) Stereocilia bundles of the inner ear. Actin-rich stereoclila bundles form a V-shape whose vertex is positioned just below a ... The wing blade of Drosophila is decorated with actin-based hairs, or trichomes, the point in a distal direction. The core PCP ... The PCP effectors then recruit Mwh, which represses actin polymerization activities, and restricts wing hair formation to the ...
Like microvilli, they contain actin filaments, distinguishing them from microtubule-containing cilia. ... the epididymis (see stereocilia (epididymis) for more details). Some sources consider epididymal stereocilia to be a variant of ... Stereocilia (or stereovilli) are non-motile apical modifications of the cell, which are distinct from cilia and microvilli, but ... "Stereocilia" - news · newspapers · books · scholar · JSTOR (December 2009) (Learn how and when to remove this template message ...
The localized formation of TARA and TRIO complexes coordinates the amount of F-actin present in stress fibers. May also serve ... cell spreading and cell contraction by directly binding and stabilizing filamentous F-actin. ... as a linker protein to recruit proteins required for F-actin formation and turnover. ... stereocilium base Source: MGI ,p>Inferred from Direct Assay,/p> ,p>Used to indicate a direct assay for the function, process or ...
This is called actin tread-milling, and the rate directly varies with the length of the stereocilia. Myosin XVa appears to be a ... Stereocilia are primarily made up of long actin filaments cross-linked to each other to provide both strength and flexibility. ... New actin monofilaments are continuously added at the stereocilia tips and old filaments are depolymerized at a commensurate ... Stereocilia morphogenesis and maintenance through regulation of actin stability. Semin Cell Dev Biol. 2017 May. 65:88-95. [ ...
"An actin molecular treadmill and myosins maintain stereocilia functional architecture and self-renewal". J. Cell Biol. 164 (6 ... The stereocilia (hair cells) of the inner ear can become subjected to bending from loud noises. Because they are not ...
Defective Gpsm2/Gαi3 signalling disrupts stereocilia development and growth cone actin dynamics in Chudley-McCullough syndrome ... Correction: Author Correction: Defective Gpsm2/Gαi3 signalling disrupts stereocilia development and growth cone actin dynamics ... signalling disrupts stereocilia development and growth cone actin dynamics in Chudley-McCullough syndrome . Opens in a new ... signalling disrupts stereocilia development and growth cone actin dynamics in Chudley-McCullough syndrome . Opens in a new ...
Cell projection , stereocilium membrane. Colocalizes with CABP1 and CIB1 at cell margin, membrane ruffles and punctate regions ... Myosins are actin-based motor molecules with ATPase activity. Unconventional myosins serve in intracellular movements. Their ... Colocalizes in nucleoplasm with RPS6 and actin that are in contact with RNP particles. Colocalizes with RPS6 at the nuclear ... Colocalizes in adipocytes with GLUT4 in actin-based membranes. Localizes transiently at cell membrane to region known to be ...
The hair bundle consists of an array of actin-based stereocilia. Each stereocilium inserts as a rootlet into a dense ... Movement of the stereocilia and kinocilium enable the hair cells of the saccula and utricle to detect motion. The semicircular ... Both types of pillar cell have thousands of cross linked microtubules and actin filaments in parallel orientation. They provide ... These microscopic structures possess stereocilia and one kinocilium which are located within the gelatinous otolithic membrane ...
A protein called actin is within bundles of stereocilia and is stained yellow. Actin helps the bundles to stand upright, so ...
Involved in the maintenance of the hair bundle ankle region, which connects stereocilia in cochlear hair cells of the inner ear ... Necessary for elongation and maintenance of inner and outer hair cell stereocilia in the organ of Corti in the inner ear. ... Localizes to both tip and ankle-link stereocilia regions. Colocalizes with the growing ends of actin filaments. Colocalizes ... auditory receptor cell stereocilium organization Source: GO_Central ,p>Inferred from Biological aspect of Ancestor,/p> ,p>A ...
Myosin III is an actin-based motor protein with protein kinase activity [PMID: 12672820]. It has been shown to play a role in ... Class III myosins shape the auditory hair bundles by limiting microvilli and stereocilia growth.. J. Cell Biol. 212 231-44 2016 ... They are thought to be crucial for photoreceptor and stereocilia ultrastructure maintenance [PMID: 10722876]. Class III myosins ...
... myosin molecules are the only motor proteins known to move on actin. Actin in stereocilia is oriented such that the myosin ... short stereocilia had as much total myosin-Iβ immunoreactivity as long stereocilia, on average. If stereocilia have a certain ... for 21 stereocilia labeled with myosin-Iβ antibody, for 27 stereocilia labeled with myosin-VI antibody, and for 21 stereocilia ... The actin within stereocilia is polarized such that myosins would tend to move upward, from proximal to distal, if allowed to ...
... actin and gamma(cyto)-actin are ubiquitous proteins thought to be essential building blocks of the cytoskeleton in all non- ... Despite this widely held supposition, we show that gamma(cyto)-actin null mice (Actg1(-/-)) are viable. However, they suffer ... actin-deficient stereocilia form normally, we found that they cannot maintain the integrity of the stereocilia actin core. In ... actin localizes along the length of stereocilia but re-distributes to sites of F-actin core disruptions resulting from animal ...
  • The organization of actin filaments in the stereocilia of cochlear hair cells. (rupress.org)
  • Decoration of the hair cells with subfragment 1 of myosin reveals that all the filaments in the stereocilia, including those that extend into the cuticular plate forming the rootlet, have unidirectional polarity, with the arrowheads pointing towards the cell center. (rupress.org)
  • The rest of the cuticular plate is composed of actin filaments that show random polarity, and numerous fine, 30 A filaments that connect the rootlet filaments to each other, to the cuticular plate, and to the membrane. (rupress.org)
  • A careful examination of the packing of the actin filaments in the stereocilia by thin sectin and by optical diffraction reveals that the filaments are packed in a paracrystalline array with the crossover points of all the actin helices in hear-perfect register. (rupress.org)
  • In transverse sections, the actin filaments are not hexagonally packed but, rather, are arranged in scalloped rows that present a festooned profile. (rupress.org)
  • From our results, we conclude that the stereocilia of the ear, unlike the brush border of intestinal epithelial cells, are not designed to shorten, nor do the filaments appear to slide past one another. (rupress.org)
  • Actin filaments, stereocilia and hair cells of the bird cochlea. (biologists.org)
  • Mean stereociliary diameter did not increase beyond ∼0.10-0.14 µm, making stereocilia ∼30%-60% thinner than wild type and suggesting that they contained ∼50%-85% fewer actin filaments. (prolekare.cz)
  • The parallel actin bundle, which consists of hexagonally packed unidirectional actin filaments cross-linked by actin-bundling proteins to produce a regular ∼12-13 nm (center-to-center) interfilament spacing, exhibits the properties of a molecular scaffold that sets the dimensions of stereocilia and influences their mechanical properties [3] - [5] . (prolekare.cz)
  • Surprisingly, although wild-type stereocilia had random liquid packing of their actin filaments, stereocilia lacking PLS1 had orderly hexagonal packing. (jpt.com)
  • Fascin-2 binds β-actin and γ-actin filaments with similar affinity in vitro and fascin-2 does not depend on β-actin for localization in vivo. (jax.org)
  • Because the fascin-2 p.R109H mutant binds but fails to efficiently crosslink actin filaments, we propose that fascin-2 crosslinks function to slow actin depolymerization at stereocilia tips to maintain stereocilia length. (jax.org)
  • An actin protein is the monomeric subunit of two types of filaments in cells: microfilaments, one of the three major components of the cytoskeleton, and thin filaments, part of the contractile apparatus in muscle cells. (wikipedia.org)
  • It is believed that the diverse range of structures formed by actin enabling it to fulfill such a large range of functions is regulated through the binding of tropomyosin along the filaments. (wikipedia.org)
  • Actin homologs from prokaryotes and archaea polymerize into different helical or linear filaments consisting of one or multiple strands. (wikipedia.org)
  • [4] These filaments have been visualized at high resolution using fluorescent phalloidin that binds to actin filaments. (wikipedia.org)
  • Their highly divergent tails are presumed to bind to membranous compartments, which would be moved relative to actin filaments. (abcam.com)
  • Like microvilli, they contain actin filaments , distinguishing them from microtubule-containing cilia. (wikipedia.org)
  • The mechanically gated channels are located near the tip of the F-actin-based stereocilia [ 2 ], where tiny vibrations open and close the transduction channels tethered to the cross-linked parallel actin filaments [ 2 ]. (hindawi.com)
  • Researchers believe that myosins use long filaments of actin as tracks along which to transport other molecules. (medlineplus.gov)
  • at the other end, several short filaments extend to the tip link from the shorter stereocilium. (pnas.org)
  • A stereocilium is not a true cilium but contains a highly cross-linked, paracrystalline array of actin filaments ( 2 ) that confers a high flexural rigidity ( 3 , 4 ). (pnas.org)
  • Each stereocilium tapers at its base, reducing the number of actin filaments at its insertion into the hair cell's apical surface ( 1 ). (pnas.org)
  • The spring constant of the pivot accords with the number and flexural rigidity of the actin filaments at the insertion ( 3 - 5 ). (pnas.org)
  • Each hair cell has tiny projections called stereocilia, which are arranged in a bundle with rows of increasing height like a staircase and are connected to each other by tiny filaments called tip-links. (elifesciences.org)
  • Myosins are a large super-family of motor proteins that move along actin filaments, while hydrolyzing ATP to forms of mechanical energy that can be used for a variety of functions such as muscle movement and contraction. (wikibooks.org)
  • Skeletal muscles contain many muscle fibers and these muscle fibers are actually made up of myofibrils, bundles of thick myosin filaments and thin actin filaments. (wikibooks.org)
  • The counterpart of A-bands is the I-bands that only contain actin filaments. (wikibooks.org)
  • Actin filaments from the I-bands become very short while myosin filaments from the A-bands do not change in length. (wikibooks.org)
  • The actin filaments are actually sliding towards the H-zone and the A-bands thus creating an overlap of myosin and actin filaments. (wikibooks.org)
  • As this overlap occurs, myosin filaments are binding to the actin filaments, allowing myosin to function as the driving motor of filament sliding. (wikibooks.org)
  • The motor proteins are involving actin filaments that hydrolyze ATP. (wikibooks.org)
  • Myosin I appears to cross-link actin filaments to control the tension inside each stereocilium. (wikibooks.org)
  • The ratcheting activity of this myosin motor along the actin filaments may adjust the sensitivity of the hair cells to different sounds. (wikibooks.org)
  • Other types of myosin use their motor activity to redistribute cellular constituents along the length of the actin filaments. (wikibooks.org)
  • Actin filaments contain two ends, termed the 'pointed end' and 'barbed end', that each has distinct properties. (embopress.org)
  • The stereocilia are filled with filaments made of the protein actin. (hearinghealthfoundation.org)
  • 2003). The shaker2 phenotype suggests that myosin 15 promotes the growth of stereocilia, presumably by working as an actual motor that interacts with actin filaments (Bird et al. (hearinghealthfoundation.org)
  • FIM5 decorates actin filaments throughout pollen grains and tubes. (plantcell.org)
  • Actin filaments become redistributed in fim5 pollen grains and disorganized in fim5 pollen tubes. (plantcell.org)
  • Additionally, loss of FIM5 function rendered pollen germination and tube growth hypersensitive to the actin-depolymerizing drug latrunculin B. In vitro biochemical analyses indicated that FIM5 exhibits actin bundling activity and stabilizes actin filaments. (plantcell.org)
  • Thus, we propose that FIM5 regulates actin dynamics and organization during pollen germination and tube growth via stabilizing actin filaments and organizing them into higher-order structures. (plantcell.org)
  • Furthermore, imaging of actin filaments has shown that distinct actin structures form in pollen tubes across different species. (plantcell.org)
  • Transduction channels thus specify and maintain row identity, control addition of new actin filaments to increase stereocilia diameter, and coordinate stereocilia height within rows. (stanford.edu)
  • The cytoskeleton is a key component of eukaryotic cells and is comprised of intermediate filaments, actin filaments and microtubules. (northwestern.edu)
  • In eukaryotic motile cells, protrusion of the lamellipodium - a type of cell margin - requires the assembly of free actin monomers into actin filaments at the cell margin. (biomedcentral.com)
  • In contrast, stored actin that is available for protrusion in cells which are already motile (for example, migrating cells) and have already initially polymerized filaments, may be more limiting and in this case free monomer may preferentially come directly from filament disassembly. (biomedcentral.com)
  • Maintenance of long filaments required, for example, in filopodia, microvilli, and stereocilia can clearly work by uncapping pre-existing filament plus ends. (biomedcentral.com)
  • In microfilaments, however, which are also often referred to as actin filaments, long polymerized chains of the molecules are intertwined in a helix, creating a filamentous form of the protein ( F-actin ). (fsu.edu)
  • In the cells of living organisms, however, the actin filaments are usually organized into larger, much stronger structures by various accessory proteins. (fsu.edu)
  • This, along with the fact that all eukaryotic cells heavily depend upon the integrity of their actin filaments in order to be able to survive the many stresses they are faced with in their environment, makes actin an excellent target for organisms seeking to injure cells. (fsu.edu)
  • The death cap mushroom, for example, produces a substance called phalloidin that binds to and stabilizes actin filaments, which can be fatal to cells. (fsu.edu)
  • Because there is little knowledge in the areas of stereocilia development, maintenance, and function in the hearing system, I decided to pursue a proteomics-based approach to discover proteins that play a role in stereocilia function. (mit.edu)
  • I verified the presence of 21 out of 34 (62%) existing proteins known to be present in stereocilia. (mit.edu)
  • Next, I selected three proteins and localized them to murine cochlear stereocilia. (mit.edu)
  • My thesis also confirmed the proteomics screen I developed as an efficient method for identifying proteins in stereocilia. (mit.edu)
  • Overexpression of these proteins in hair cells produce an increase in stereocilia length, and when both are co-expressed together they produce a length increase greater than when each one are overexpressed individually. (umd.edu)
  • These results suggest that these proteins interact and influence stereocilia length regulation. (umd.edu)
  • We observed that when co-expressed, these proteins promote elongation of filopodial actin protrusions in a synergistic manner. (umd.edu)
  • We compared stereocilia in wild-type CBA/CaJ mice, jerker homozygotes that lack espin proteins owing to a frameshift mutation in the espin gene, and jerker heterozygotes that contain reduced espin levels. (prolekare.cz)
  • We conclude that the espin actin-bundling proteins are required for the assembly and stabilization of the stereociliary parallel actin bundle. (prolekare.cz)
  • We used mass spectrometry to identify and quantify major actin-associated proteins of the cochlear sensory epithelium from E14 to E21, when stereocilia widen and lengthen. (elsevier.com)
  • Actin is a family of globular multi-functional proteins that form microfilaments. (wikipedia.org)
  • The evolutionary origin of actin can be traced to prokaryotic cells, which have equivalent proteins. (wikipedia.org)
  • A large number of illnesses and diseases are caused by mutations in alleles of the genes that regulate the production of actin or of its associated proteins. (wikipedia.org)
  • Realizing that Banga's coagulating myosin preparations contained actin as well, Szent-Györgyi called the mixture of both proteins actomyosin. (wikipedia.org)
  • May also serve as a linker protein to recruit proteins required for F-actin formation and turnover. (uniprot.org)
  • myosin molecules are the only motor proteins known to move on actin. (jneurosci.org)
  • Beta(cyto)-actin and gamma(cyto)-actin are ubiquitous proteins thought to be essential building blocks of the cytoskeleton in all non-muscle cells. (nih.gov)
  • The normal functions of the hair cells require high levels of ATP and consequently glucose for the modulation and maintenance of F-actin and related cytoskeletal proteins [ 1 ]. (hindawi.com)
  • The espin actin-bundling proteins, which are the target of the jerker deafness mutation, caused a dramatic, concentration-dependent lengthening of LLC-PK1-CL4 cell microvilli and their parallel actin bundles. (sigmaaldrich.com)
  • We examined localization and proximity of one of each of the three different types of USH1 proteins: transmembrane (Cdh23), scaffold (Harmonin) and actin-based motor (Myo7a). (biologists.org)
  • In this study, we observed shear stress-mediated changes in the expression of complement regulatory proteins CD46, CD55, and CD59 on human EPCs and focused on the mechanical transmission mechanism in transformed cells in response to the ECM-F-actin pathway in vitro. (bireme.br)
  • More research is needed to identify which structural proteins cause the stereocilia shape changes and to work out exactly how calcium ions are involved. (elifesciences.org)
  • Data indicate that that CIB2 localizes to stereocilia and interacts with the USH proteins myosin VIIa and whirlin, suggesting CIB2 is a Ca2+-buffering protein essential for calcium homeostasis in the mechanosensory stereocilia of inner ear hair cells. (antikoerper-online.de)
  • The deaf jerker mouse has a mutation in the gene encoding the espin actin-bundling proteins of hair cell stereocilia and lacks espins. (jax.org)
  • The PTPRQ protein, localized in the basal region of the stereocilia membrane, is one of the membrane proteins which composed of 2299 amino acids. (hindawi.com)
  • There are a number of studies that suggest there are about 30 of these 100 genes essential for hearing that encode proteins interacting directly or indirectly with actin . (hearinghealthmatters.org)
  • A large number of proteins sit at the interface between actin networks and membranes, playing diverse roles such as initiation of actin polymerization, modulation of membrane curvature, and signaling. (springer.com)
  • Here, we review the structure and function of mammalian BAR domain proteins and the many ways in which they are interconnected with the actin cytoskeleton. (springer.com)
  • Cdh23 is one of the tip-link proteins involved in transducer function, a key component of mechanoelectrical transduction and stereocilia-based amplification. (biomedcentral.com)
  • The altered distribution of marker proteins in transduction mutants was accompanied by increased variability in stereocilia length. (stanford.edu)
  • The role of actin cross-linking proteins in cortical dynamics is still incompletely understood. (rupress.org)
  • The research in my lab is centered on the "espins," a novel family of actin-bundling proteins and the elucidation of their roles in the stereocilia of sensory hair cells in the inner ear. (northwestern.edu)
  • My research is focused on sensory neuroscience with special interest in espins, a novel family of multifunctional actin-bundling proteins. (northwestern.edu)
  • These proteins are present at high concentration in the parallel actin bundle of hair cell stereocilia, in the microvilli of taste receptor cells, solitary chemoreceptor cells, vomeronasal sensory neurons and Merkel cells. (northwestern.edu)
  • Eukaryotes have several highly conserved actin-binding proteins that crosslink filamentous actin into compact ordered bundles present in distinct cytoskeletal processes, including microvilli, stereocilia and filopodia. (elsevier.com)
  • An important outstanding question regards the molecular basis for the unique localization and functional properties of fascin compared with other actin crosslinking proteins. (elsevier.com)
  • This review describes structure and functions of the group of actin-binding proteins--the filamins. (nih.gov)
  • Both myosin IIIa and espin 1 are expressed in the inner ear hair cells and colocalize at stereocilia tips, the site of actin polymerization. (umd.edu)
  • Live and fixed cell imaging shows that myosin IIIa transports espin 1 to the filopodia tips where espin 1 promotes actin polymerizations through its WH2 domain. (umd.edu)
  • Myosin IIIb, encoded by a distinct gene, lacks a C-terminal actin-binding domain shown to be essential for myosin IIIa filopodia tip localization. (umd.edu)
  • We observed that myosin IIIb localizes at stereocilia tips and is expressed at an earlier stage than myosin IIIa. (umd.edu)
  • We confirmed that myosin IIIb transports espin 1 to stereocilia tips and promotes actin polymerization, consistent with the hypothesis that it partially compensates for myosin IIIa. (umd.edu)
  • Following up on the discovery of Ilona Banga & Szent-Györgyi in 1941 that the coagulation only occurs in some mysosin extractions and was reversed upon the addition of ATP, Straub identified and purified actin from those myosin preparations that did coagulate. (wikipedia.org)
  • Since Straub's protein was necessary to activate the coagulation of myosin, it was dubbed actin. (wikipedia.org)
  • Myosin III is an actin-based motor protein with protein kinase activity [ PMID: 12672820 ]. (ebi.ac.uk)
  • Previously, confocal and electron microscopy of bullfrog saccular hair cells using an anti-myosin-Iβ antibody labeled the tips of stereocilia. (jneurosci.org)
  • Also, stereocilia of differing lengths had approximately the same number of total particles, suggesting equal targeting of myosin-Iβ to all stereocilia. (jneurosci.org)
  • Finally, particles tended to clump in clusters of two to five particles in the distal two-thirds of stereocilia, suggesting a tendency for self-assembly of myosin-Iβ. (jneurosci.org)
  • Unloaded muscle myosin moves along stereocilia at 1-2 μm/sec, a speed similar to that of the adaptation motor ( Assad and Corey, 1992 ). (jneurosci.org)
  • Design of active transport must be highly intricate: a possible role of myosin and Ena/VASP for G-actin transport in filopodia. (semanticscholar.org)
  • A new compartment at stereocilia tips defined by spatial and temporal patterns of myosin IIIa expression. (berkeley.edu)
  • Myosin 3A transgene expression produces abnormal actin filament bundles in transgenic Xenopus laevis rod photoreceptors. (berkeley.edu)
  • In the inner ear, myosin VIIA plays a role in the development and maintenance of hairlike projections called stereocilia. (medlineplus.gov)
  • A lack of myosin VIIA in the inner ear disrupts the normal development and function of stereocilia, which leads to hearing loss and difficulty with balance and coordination. (medlineplus.gov)
  • Myosin VIIa (MYO7A) is detectable in the stereocilia and the ankle links. (egms.de)
  • One main characteristic of myosin is its ability to bind very specifically with actin. (wikibooks.org)
  • When myosin and actin are combined together, that makes the muscle produce force. (wikibooks.org)
  • This relative movement between myosin and actin is what results in muscle contraction. (wikibooks.org)
  • This induces a conformational change (cocking of the head) resulting in myosin weakly binding to actin. (wikibooks.org)
  • ADP dissociation leaves the myosin head tightly bound to actin. (wikibooks.org)
  • Binding of a new molecule of ATP to myosin head triggers it to let go of actin and the cycle starts all over again. (wikibooks.org)
  • Gpsm2 defines an approximately 200 nm nanodomain at the tips of stereocilia and this localization requires the presence of Galphai3, myosin 15 and whirlin. (antikoerper-online.de)
  • It has been reported that PTPRQ may have key roles in hair cells: establishing the membrane at the base of the stereocilia, regulating actin dynamics, and tethering the stereocilia membrane to the cytoskeleton with Myosin VI [ 3 - 5 ]. (hindawi.com)
  • Channel attached to myosin motor that asociates with actin core of the sterocilia. (cueflash.com)
  • The shaker2 mutation effects both isoforms of myosin 15 and prevents the stereocilia growing beyond a certain height (Probst et al. (hearinghealthfoundation.org)
  • Experiments with an antibody that recognizes both isoforms suggest that myosin 15 is located at the tips of the stereocilia (Belyantseva et al. (hearinghealthfoundation.org)
  • The presence of actin and myosin confirmed the ability of hair cells and stereocilia to respond to external stimuli by changing their mechanical properties. (cdc.gov)
  • The proper organization of the stereocilia involves actin , a form of myosin (called myosin VIIA), and cadherins . (biology-pages.info)
  • In the past few years genetic, biochemical, and cytolocalization data have implicated members of the myosin superfamily of actin-based molecular motors in a variety of cellular functions including membrane trafficking, cell movements, and signal transduction. (sciencemag.org)
  • Mutations in Myo6, the gene encoding the (F-actin) minus end-directed unconventional myosin, myosin VI, cause hereditary deafness in mice (Snell's waltzer) and humans. (whiterose.ac.uk)
  • In the sensory hair cells of the cochlea, myosin VI is expressed in the cell bodies and along the stereocilia that project from the cells' apical surface. (whiterose.ac.uk)
  • When overexpressed, I found that twinfilin 2 causes a shortening of microvilli in LLC-PK1/CL4 cells and in native cochlear stereocilia. (mit.edu)
  • Class III myosins shape the auditory hair bundles by limiting microvilli and stereocilia growth. (ebi.ac.uk)
  • Stereocilia (or stereovilli ) are non-motile apical modifications of the cell, which are distinct from cilia and microvilli , but closely related to the latter. (wikipedia.org)
  • Some sources consider epididymal stereocilia to be a variant of microvilli, [1] rather than their own distinct type of structure. (wikipedia.org)
  • Dynamics and morphology of microvilli driven by actin polymerization. (semanticscholar.org)
  • article{Gov2006DynamicsAM, title={Dynamics and morphology of microvilli driven by actin polymerization. (semanticscholar.org)
  • Actin-bundling protein found in intestinal microvilli, hair cell stereocilia, and fibroblast filopodia. (abcam.com)
  • The sense of hearing depends on stereocilia, the microvilli-like mechanosensory projections at the apical surface of inner ear hair cells. (elifesciences.org)
  • Actin-rich structures, like stereocilia and microvilli, are assembled with precise control of length, diameter, and relative spacing. (stanford.edu)
  • It organizes filimentous actin (f-actin) into bundles and links them, providing the necessary structural framework for stereocillia to function. (scienceblogs.com)
  • The stereocilia bundles in green have been over-expressing espin, resulting in abnormally long stereocilia. (scienceblogs.com)
  • (B) Stereocilia bundles of the inner ear. (nih.gov)
  • Actin-rich stereoclila bundles form a V-shape whose vertex is positioned just below a microtubule-based kinocilium. (nih.gov)
  • Disrupted actin bundles that form the stereocilia may result in impaired hearing and balance [ 3 ]. (hindawi.com)
  • The retina-specific protein, fascin 2 is an actin crosslinker associated with actin bundles in photoreceptor inner segments and calycal processes. (berkeley.edu)
  • Espin cross-links cause the elongation of microvillus-type parallel actin bundles in vivo. (sigmaaldrich.com)
  • Elimination of an actin monomer-binding WASP homology 2 domain and a profilin-binding proline-rich domain from espin did not decrease lengthening, but made it possible to demonstrate that actin incorporation was restricted to the microvillar tip and that bundles continued to undergo actin treadmilling at approximately 1.5 s-1 during and after lengthening. (sigmaaldrich.com)
  • Hair bundles consist of many stereocilia and one kinocilium. (egms.de)
  • If the N-terminal extension in the large isoform is absent in mice, hair bundles form normally but some of the stereocilia in the first two rows degenerate in older animals (bottom). (hearinghealthfoundation.org)
  • It is required for maintaining the structural integrity of the mechanosensitive hair bundles formed by the stereocilia. (whiterose.ac.uk)
  • Stereocilia are fingerlike projections that contain a specialized cytoskeletal element, the parallel actin bundle [3] , aligned axially at their core. (prolekare.cz)
  • Gamma-actin is required for cytoskeletal maintenance but not development. (case.edu)
  • May regulate actin cytoskeletal organization, cell spreading and cell contraction by directly binding and stabilizing filamentous F-actin. (uniprot.org)
  • The surprising viability and normal hearing of young Actg1(-/-) mice means that beta(cyto)-actin can likely build all essential non-muscle actin-based cytoskeletal structures including mechanosensory stereocilia of hair cells that are necessary for hearing. (nih.gov)
  • Actin is the most abundant cytoskeletal protein in eukaryotic cells and forms a double‐stranded helical filament ( Oda et al , 2009 ). (embopress.org)
  • Illustrated in Figure 2 is a fluorescence digital image of an Indian Muntjac deer skin fibroblast cell stained with fluorescent probes targeting the nucleus (blue) and the actin cytoskeletal network (green). (fsu.edu)
  • The serine/threonine kinase p21-activated kinase 1 (Pak1) controls the actin cytoskeletal and ruffle formation through mechanisms that are independent of GTPase activity. (nih.gov)
  • LIM-kinase 1 (LIMK1) and LIM-kinase 2 (LIMK2) regulate actin cytoskeletal reorganization via cofilin phosphorylation downstream of distinct Rho family GTPases. (nih.gov)
  • Finally, twinfilin 2, a putative modulator of actin polymerization, was found at the tips of stereocilia. (mit.edu)
  • Note the intense binding of Myo1c to receptors at the tips of stereocilia, the site of hair-cell transduction, as well as binding within the soma. (jneurosci.org)
  • What connects the tips of stereocilia? (cueflash.com)
  • A stunning example of cytoskeleton-mediated morphogenesis is the formation of hair cell stereocilia, which act as primary mechanosensory detectors in the auditory and vestibular systems [1] , [2] . (prolekare.cz)
  • The beta and gamma actins coexist in most cell types as components of the cytoskeleton, and as mediators of internal cell motility. (wikipedia.org)
  • Binds phosphoinositides and links the actin cytoskeleton to cellular membranes. (abcam.com)
  • We conclude that gamma(cyto)-actin is required for reinforcement and long-term stability of F-actin-based structures but is not an essential building block of the developing cytoskeleton. (nih.gov)
  • McMahon and Gallop, 2005 ) as well as force generation by the cortical actin cytoskeleton. (biologists.org)
  • The actin cytoskeleton is a key regulator of barrier structure and function, controlling the assembly and permeability of epithelial adherens and tight junctions. (frontiersin.org)
  • The actin cytoskeleton is a key regulator of epithelial homeostasis. (frontiersin.org)
  • The actin cytoskeleton participates in virtually all housekeeping and specialized epithelial functions. (frontiersin.org)
  • Our results show that FIM5 is required for the organization of actin cytoskeleton in pollen grains and pollen tubes, and FIM5 loss-of-function associates with a delay of pollen germination and inhibition of pollen tube growth. (plantcell.org)
  • Most members of this family have been implicated in cellular functions that require dynamic remodeling of the actin cytoskeleton, such as endocytosis, organelle trafficking, cell motility, and T-tubule biogenesis in muscle cells. (springer.com)
  • Aspenstrom P (1997) A Cdc42 target protein with homology to the non-kinase domain of FER has a potential role in regulating the actin cytoskeleton. (springer.com)
  • The biological actions of insulin are associated with a rapid reorganization of the actin cytoskeleton within cells in culture. (nih.gov)
  • The stereocilia of the epididymis are long cytoplasmic projections that have an actin filament backbone. (wikipedia.org)
  • To determine whether the gating spring is the tip link, a filament interconnecting two stereocilia along the axis of mechanical sensitivity, we examined the tip link's structure at high resolution by using rapid-freeze, deep-etch electron microscopy. (pnas.org)
  • The best candidate for the gating spring is the tip link, an extracellular filament that joins a stereocilium to its tallest neighbor, parallel to the bundle's axis of mechanical sensitivity ( 3 ). (pnas.org)
  • A gating spring is probably a tip link ( 8 ), an extracellular filament that interconnects two stereocilia along the bundle's axis of maximal sensitivity. (pnas.org)
  • The actin filament has clear polarity where one end, the pointed end, has a much slower polymerization and depolymerization rate than the other end, the barbed end. (embopress.org)
  • Here, we present the structure of the actin filament pointed end obtained using a single particle analysis of cryo‐electron micrographs. (embopress.org)
  • The polarity of the actin filament controls the actin dynamics in the cell where elongation of the filament by polymerization occurs at the barbed end, and shortening by depolymerization occurs at the pointed end. (embopress.org)
  • Actin filament assembly typically occurs in association with cellular membranes. (springer.com)
  • Less well understood, however, is the importance of actin-filament disassembly in this process, and this was addressed in several studies reported at the American Society of Cell Biology annual meeting [ http://www.faseb.org/ascb/meetings/am99/main99mtg.htm ]. (biomedcentral.com)
  • That this coupling is rapid in migrating fibroblasts may reflect a situation whereby actin filament assembly directly uses free actin monomer derived from filament disassembly in preference to stored monomer. (biomedcentral.com)
  • Irrespective of the source of free monomer, the authors of the cofilin work favour a model where the severing activity of cofilin also provides the free 'plus ends' (barbed, or rapidly growing) required for actin filament assembly. (biomedcentral.com)
  • I speculate that the relative importance of filament disassembly will turn out to depend on cell activity and on spatial regulation of the concentration of actin polymer and monomer pools in cells. (biomedcentral.com)
  • Thus, cells that must turn frequently, such as neurons navigating during development, must be able to reposition the site of new actin filament growth. (biomedcentral.com)
  • In contrast, filament severing in these structures would destroy required actin organization. (biomedcentral.com)
  • Hearing and vestibular function depend on mechanosensory staircase collections of hair cell stereocilia, which are produced from microvillus-like precursors as their parallel actin bundle scaffolds increase in diameter and elongate or shorten. (prolekare.cz)
  • These characteristics indicate a requirement for espins in the appositional growth and differential elongation of the stereociliary parallel actin bundle and fit the known biological activities of espins in vitro and in transfected cells. (prolekare.cz)
  • We observed that mice expressing mutant fascin-2 (p.R109H) or mice lacking β-actin share a common phenotype including progressive, high-frequency hearing loss together with shortening of a defined subset of stereocilia in the hair cell bundle. (jax.org)
  • Involved in the maintenance of the hair bundle ankle region, which connects stereocilia in cochlear hair cells of the inner ear. (uniprot.org)
  • When a hair cell is stimulated by positive deflection of its hair bundle, increased tension in gating springs opens transduction channels, permitting cations to enter stereocilia and depolarize the cell. (pnas.org)
  • In the bullfrog's sacculus, the hair bundle comprises ≈60 stereocilia and a single kinocilium ( 1 ). (pnas.org)
  • Deflection of the bundle therefore causes a stereocilium to pivot about its insertion rather than to flex along its length. (pnas.org)
  • Thus, through relatively subtle effects on actin polymerization/depolymerization reactions in a treadmilling parallel actin bundle, espin cross-links cause pronounced barbed-end elongation and, thereby, make a longer bundle without joining shorter modules. (sigmaaldrich.com)
  • Filamentous actin is stained in red to delineate the actin-filled stereocilia that comprise the mechanosensitive hair bundle. (jneurosci.org)
  • a) Hair bundle of an isolated bullfrog hair cell stained with phalloidin in order to detect F-actin. (egms.de)
  • Surprisingly, these drugs made profound changes in the shape of individual stereocilia and the staircase architecture of the stereocilia bundle. (elifesciences.org)
  • These findings show that the flow of calcium ions into the sterocilia via mechanotransduction channels controls the exquisite staircase-like architecture of the stereocilia bundle. (elifesciences.org)
  • A hair cell bundle consists of stereocilia rows with precisely graded heights according to the cell's location along the cochlea, suggesting that the exact shape of the bundle is crucial for the normal function of the hair cell ( Engström and Engström, 1978 ). (elifesciences.org)
  • The mechanosensory structure of the hair cell is the stereocilia ("hair") bundle located on the apical surface of the cell. (nature.com)
  • Each hair bundle consists of a collection of smaller hair-like structures called stereocilia that line up in rows within the bundle to form a structure that resembles a staircase ( Figure 1 ). (hearinghealthfoundation.org)
  • Schematic depiction showing the three rows of stereocilia in a normal hair bundle, with the first row (dark green) being the shortest and the third row (pale purple) being the tallest. (hearinghealthfoundation.org)
  • The mechanosensitive organelle of the hair cell is the hair bundle, an apical collection of actin-filled stereocilia arranged in a staircase fashion. (elifesciences.org)
  • They are present at high concentration in the parallel actin bundle scaffold at the core of hair cell stereocilia and are the target of deafness mutations in mice and humans. (northwestern.edu)
  • Soma is indicated by asterisk ( K ). An enlarged view of a hair bundle from an anterior macula ( O ) is shown with regions of interest (ROI) selected for the stereocilia (orange line) and the cuticular plate (blue line). (zfin.org)
  • Leah Keshet, Actin dynamics and cell motility, U Victoria Applied Mathematics Colloquium Mar 16, 2006. (ubc.ca)
  • This intrinsic difference of the ends significantly affects all actin dynamics in the cell, which has central roles in a wide spectrum of cellular functions. (embopress.org)
  • Sequence conservation also indicates highly conserved surface patches near the putative actin-binding domains of fascin, which conformational dynamics analysis suggests to be coupled via an allosteric mechanism that might have important functional implications for F-actin crosslinking by fascin. (elsevier.com)
  • Extracellular signals regulate actin dynamics through small GTPases of the Rho/Rac/Cdc42 (p21) family. (nih.gov)
  • Lengthening was blocked by 100 nM cytochalasin D. Espin cross-links slowed actin depolymerization in vitro less than twofold. (sigmaaldrich.com)
  • Shear stress-mediated changes in the expression of complement regulatory protein CD59 on human endothelial progenitor cells by ECM-integrinα -F-actin pathway in vitro. (bireme.br)
  • Our previous in vitro studies demonstrated that these actin isoforms play distinctive roles in establishing the intestinal epithelial barrier, by controlling the organization of different junctional complexes. (frontiersin.org)
  • binds to polymerized actin in vitro and stains the leading edge of platelets, fibroblast lamellipodia, epithelial stereocilia and neurite growth cones. (alzforum.org)
  • The interplay of myosins IIIa, IIIb, and espin 1 and their influence on stereocilia length unravels a novel molecular complex at the polymerizing end of F-actin and a framework to understand the cause of DFNB30 and DFNB36 deafnesses. (umd.edu)
  • To investigate the roles of the espin class of actin-bundling protein, we used a genetic approach that benefited from a judicious selection of mouse background strain and an examination of the effects of heterozygosity. (prolekare.cz)
  • Actin packing in stereocilia is mediated by cross-linkers of the plastin, fascin, and espin families. (jpt.com)
  • Tight actin crosslinkers (i.e. fascins, plastins, and espin) are expressed dynamically during cochlear epithelium development between E7 and E21, with FSCN2 replacing FSCN1 and plastins remaining low in abundance. (elsevier.com)
  • Their hypothesis was that since espin promotes f-actin linking in stereocilia, more espin would lengthen the stereocilia and less espin would shorten them. (scienceblogs.com)
  • Compared to the normal espin expression levels (A), decreased espin expression in mouse mutants also reduces stereocilia length, making them abnormally short. (scienceblogs.com)
  • Espin level was also positively correlated with stereocilium length in hair cells. (sigmaaldrich.com)
  • The espin COOH-terminal peptide, which contains the actin-bundling module, was necessary and sufficient for lengthening. (sigmaaldrich.com)
  • In order to determine the function of twinfilin 2, I localized the protein predominately to the tips of shorter stereocilia where it is up-regulated during the final phase of elongation. (mit.edu)
  • The lack of espins radically impaired stereociliary morphogenesis, resulting in stereocilia that were abnormally thin and short, with reduced differential elongation to form a staircase. (prolekare.cz)
  • Capping protein levels then decline during growth phase III, when stereocilia reinitiate barbed-end elongation. (elsevier.com)
  • Necessary for elongation and maintenance of inner and outer hair cell stereocilia in the organ of Corti in the inner ear. (uniprot.org)
  • Defects in whirlin, a PDZ domain molecule involved in stereocilia elongation, cause deafness in the whirler mouse and families with DFNB31. (antikoerper-online.de)
  • For elongation, the loop‐to‐loop contacts also inhibit the incorporation of another actin monomer at the pointed end. (embopress.org)
  • We model these structures as arising from the balance between the force of actin polymerization and the restoring force of the membrane. (semanticscholar.org)
  • These actin based protrusion structures are essential for hearing. (hearinghealthmatters.org)
  • These distinct actin structures are believed to perform distinct functions. (plantcell.org)
  • The highest particle density occurred at stereocilia bases, close to the cuticular plate. (jneurosci.org)
  • The cuticular plate (CP) is a stiff actin-based structure that functions as an anchor for the stereocilia. (hindawi.com)
  • Each hair cell has a staircase array of stereocilia (actin-filled villi) located at the apical surface of the cell body. (biomedcentral.com)
  • The apical surface of the hair cells contains an array of stereocilia , which give the hair cells their name. (biology-pages.info)
  • Consequently, microfilaments play a key role in development of various cell surface projections (as illustrated in Figure 2), including filopodia, lamellipodia, and stereocilia. (fsu.edu)
  • Fascin is an actin-binding protein that is present predominantly in filopodia, which are believed to play a central role in normal and aberrant cell migration. (elsevier.com)
  • They are thought to be crucial for photoreceptor and stereocilia ultrastructure maintenance [ PMID: 10722876 ]. (ebi.ac.uk)
  • The PCP effectors then recruit Mwh, which represses actin polymerization activities, and restricts wing hair formation to the distal side. (nih.gov)
  • Furthermore, shear stress also promotes the rearrangement and polymerization of F-actin. (bireme.br)
  • However, shear stress-induced CD59 expression was reduced when the F-actin stress fiber formation process was delayed by Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP) or destroyed by cytochalasin D (Cyto D), while Jasplakinolide (JAS) reversed the expression of CD59 through promotion of F-actin polymerization and its stabilizing capacities. (bireme.br)
  • Actin continuously cycles through the processes of polymerization and depolymerization. (embopress.org)
  • Abou-Kheir W, Isaac B, Yamaguchi H, Cox D (2008) Membrane targeting of WAVE2 is not sufficient for WAVE2-dependent actin polymerization: a role for IRSp53 in mediating the interaction between Rac and WAVE2. (springer.com)
  • Almeida-Souza L et al (2018) A flat BAR protein promotes actin polymerization at the base of clathrin-coated pits. (springer.com)
  • Mutations in the gene encoding a protein that helps with actin polymerization cause deafness. (biology-pages.info)
  • The kinocilium is surrounded by actin-based stereocilia. (yeastrc.org)
  • VLGR1 and usherin form the ankle links at the base of the stereocilia. (egms.de)
  • Acts as a mediator of adaptation of mechanoelectrical transduction in stereocilia of vestibular hair cells. (abcam.com)
  • This structure and the transduction channel(s) associated with them can move along the stereocilia during adaptation ( Howard and Hudspeth, 1987 ). (jneurosci.org)
  • The stereocilia of the hair cells are the sites of mechanoelectrical transduction. (hindawi.com)
  • Sound waves bend the stereocilia, stretching the tip links between them and pulling open a mechanoelectrical transduction (MET) channel [ 3 ]. (plos.org)
  • Harmonin-b, an actin-binding scaffold protein, is involved in the adaptation of mechanoelectrical transduction by sensory hair cells. (labome.org)
  • Correspondingly, Tmc1KO/KO;Tmc2KO/KO or TmieKO/KO hair cells, which lack transduction, have significantly altered stereocilia lengths and diameters, including a narrowed row 2. (stanford.edu)
  • Alterations in stereocilia dimensions and in EPS8 distribution seen in transduction mutants were mimicked by block of transduction channels of cochlear explants in culture. (stanford.edu)
  • Myosins are actin-based motor molecules with ATPase activity. (abcam.com)
  • Myosins interact with actin, a protein that is important for cell movement and shape. (medlineplus.gov)
  • The motor domains of characterized myosins bind actin in an adenosine triphosphate (ATP)-sensitive manner and generate force through the hydrolysis of ATP. (sciencemag.org)
  • stereocilium membrane. (abcam.com)
  • This moves stereocilia at the tips of the hair cells against the tectorial membrane and open potassium channels in them. (biology-pages.info)
  • By quantifying actin-core dimensions of stereocilia from phalloidin-labeled mouse cochleas, we demonstrated that inner hair cell stereocilia developed in specific stages, where a widening phase is sandwiched between twolengthening phases. (stanford.edu)
  • These effects occur only in stereocilia that harbor mechanotransducer channels, recover upon blocker washout or tip link regeneration and can be replicated by manipulations of extracellular Ca 2+ or intracellular Ca 2+ buffering. (elifesciences.org)
  • In the wild-type, gamma(cyto)-actin localizes along the length of stereocilia but re-distributes to sites of F-actin core disruptions resulting from animal exposure to damaging noise. (nih.gov)
  • Hair cell stereocilia contain multiple classes of actin-bundling protein, but little is known about what each class contributes. (prolekare.cz)
  • During development of the chick cochlea, actin crosslinkers and barbed-end cappers presumably influence growth and remodeling of the actin paracrystal of hair cell stereocilia. (elsevier.com)
  • Actin-bundling protein TRIOBP forms resilient rootlets of hair cell stereocilia essential for hearing. (case.edu)
  • the major long (WHRN-L) and short (WHRN-S) isoforms of WHRN have distinct localizations within stereocilia and also across hair cell types. (antikoerper-online.de)
  • Its mutations can cause the defects of stereocilia in hair cell, which lead to nonsyndromic sensorineural hearing loss. (hindawi.com)
  • Hearing loss resulted due to loss of hair cell bodies and stereocilia, when the ear was subjected to prolonged noise exposure. (cdc.gov)
  • It can be present as either a free monomer called G-actin (globular) or as part of a linear polymer microfilament called F-actin (filamentous), both of which are essential for such important cellular functions as the mobility and contraction of cells during cell division. (wikipedia.org)
  • When cofilin activity, which severs and disassembles filamentous actin, is inhibited in rat carcinoma cells with antibodies (Maryse Bailly, Albert Einstein College of Medicine) or by phosphorylation (Noureddine Zebda, Albert Einstein College of Medicine), lamellipodium protrusion stimulated by epidermal growth factor (EGF) is blocked. (biomedcentral.com)
  • about 30 'stereocilia', which aren't really cilia but are actin-filled projections. (cueflash.com)
  • Stereocilia are not built from the "9+2" arrangement of microtubules that are found in true cilia. (biology-pages.info)
  • Although actin crosslinkers are readily detected by electron microscopy in developing chick cochlea stereocilia, quantitative mass spectrometry of stereocilia isolated from E21 chick cochlea indicated that tight crosslinkers are present there in stoichiometric ratios relative to actin that are much lower than their ratios for vestibular stereocilia. (elsevier.com)
  • These results demonstrate the value of quantitation of global protein expression in chick cochlea during stereocilia development. (elsevier.com)
  • Inside the cochlea, there are stereocilia (often called the Hair Cells (HC)) which are deflected by sound stimulation. (hearinghealthmatters.org)
  • Stereocilia are actin-based protrusions on auditory sensory hair cells that are deflected by sound waves to initiate the conversion of mechanical energy to neuronal signals. (jax.org)
  • Stereocilia maintenance is essential because auditory hair cells are not renewed in mammals. (jax.org)
  • Here, we establish that β-actin and the actin crosslinking protein fascin-2 cooperate to maintain stereocilia length and auditory function. (jax.org)
  • In the auditory hair cells of young postnatal mice and rats, a reduction in mechanotransducer current, via pharmacological channel blockers or disruption of tip links, leads to stereocilia shape changes and shortening. (elifesciences.org)
  • Mammalian auditory hair cells do not regenerate and, therefore, have to maintain their precisely arranged stereocilia throughout the lifespan of the organism. (elifesciences.org)
  • We show that MISP directly interacts with ezrin and that SLK/LOK-activated ezrin ensures appropriate cortical MISP levels in mitosis by competing with MISP for actin-binding sites at the cell cortex. (biologists.org)
  • Here, we show that the evolutionarily conserved actin bundling/cross-linking protein plastin is instrumental for the generation of potent cortical actomyosin contractility in the Caenorhabditis elegans zygote. (rupress.org)
  • Epithelial cells express two actin isoforms: a β-cytoplasmic actin and γ-cytoplasmic actin. (frontiersin.org)
  • Mammals have six actin genes encoding different actin isoforms ( Vandekerckhove and Weber, 1978 ). (frontiersin.org)
  • When both isoforms are defective or absent, the stereocilia in the third row do not reach their normal height (top). (hearinghealthfoundation.org)
  • 2015). Surprisingly, they found that isoform 1 is restricted to the first two rows of stereocilia in inner hair cells (Figure 1). (hearinghealthfoundation.org)
  • the IHC have two to three rows of stereocilia and the OHC to have three to four rows of stereocilia. (cdc.gov)
  • With their essential role in inner ear function, stereocilia of sensory hair cells demonstrate the importance of cellular actin protrusions. (jpt.com)
  • Scanning electron microscopy revealed that sensory hair cells of both cobl- and syndapin I -morphant animals showed defects in the formation of both microtubule-dependent kinocilia and F-actin-rich stereocilia. (biologists.org)
  • Correct spindle orientation is achieved through signaling pathways that provide a molecular link between the cell cortex and spindle microtubules in an F-actin-dependent manner. (biologists.org)
  • Actin cables in pollen tubes serve as molecular tracks for cytoplasmic streaming and organelle movement and are formed by actin bundling factors like villins and fimbrins. (plantcell.org)
  • In particular, actin cables are believed to provide molecular tracks necessary for the intracellular trafficking events that support rapid tube extension. (plantcell.org)
  • Mutations in the different genes that regulate actin production in humans can cause muscular diseases, variations in the size and function of the heart as well as deafness. (wikipedia.org)
  • it is abundant during growth phase II, when stereocilia have ceased elongating and are increasing in diameter. (elsevier.com)
  • Many of these processes are mediated by extensive and intimate interactions of actin with cellular membranes. (wikipedia.org)
  • It has also been shown that the actin-binding protein MISP and the ERM family, which are activated by lymphocyte-oriented kinase (LOK, also known as STK10) and Ste20-like kinase (SLK) (hereafter, SLK/LOK) in mitosis, regulate spindle orientation. (biologists.org)
  • In contrast, slower coupling in non-migrating fibroblasts implies that free actin monomer is instead derived from stored monomer. (biomedcentral.com)
  • β-Actin and fascin-2 cooperate to maintain stereocilia length. (jax.org)
  • Nevertheless, double-mutant mice lacking β-actin and expressing fascin-2 p.R109H have a more severe phenotype suggesting that each protein has a different function in a common stereocilia maintenance pathway. (jax.org)
  • Fascin 2b is a component of stereocilia that lengthens actin-based protrusions. (berkeley.edu)
  • Fluorescence intensity profiles of stereocilia ( P ), using the orange-line ROI from O , show that the fascin 2b- (green) and phalloidin-associated (red) signals are overlapping. (zfin.org)
  • The lack of espins also led to a region-dependent degeneration of stereocilia involving shortening and collapse. (prolekare.cz)
  • Mechanotransducer channels at the tips of sensory stereocilia of inner ear hair cells are gated by the tension of 'tip links' interconnecting stereocilia. (elifesciences.org)
  • This process requires both β-actin and γ-actin as knock-out mice lacking either isoform develop distinct stereocilia pathology during aging. (jax.org)
  • Actin participates in many important cellular processes, including muscle contraction, cell motility, cell division and cytokinesis, vesicle and organelle movement, cell signaling, and the establishment and maintenance of cell junctions and cell shape. (wikipedia.org)
  • It has been shown that epithelial sodium channel ENaC that allows the flow of Na + ions into the cell is localized on stereocilia. (wikipedia.org)
  • Consistently, intestinal organoids generated from β-actin knockout mice are more sensitive to tumor necrosis factor induced cell death, ex vivo . (frontiersin.org)
  • Over the course of evolutionary history of the cell, actin has remained relatively unchanged. (fsu.edu)
  • Our lab investigated the roles of the actin and microtubule cytoskeletons in the morphogenesis and survival of vertebrate retinal photoreceptors. (berkeley.edu)