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.
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.
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.
Parts of the myosin molecule resulting from cleavage by proteolytic enzymes (PAPAIN; TRYPSIN; or CHYMOTRYPSIN) at well-localized regions. Study of these isolated fragments helps to delineate the functional roles of different parts of myosin. Two of the most common subfragments are myosin S-1 and myosin S-2. S-1 contains the heads of the heavy chains plus the light chains and S-2 contains part of the double-stranded, alpha-helical, heavy chain tail (myosin rod).
The smaller subunits of MYOSINS that bind near the head groups of MYOSIN HEAVY CHAINS. The myosin light chains have a molecular weight of about 20 KDa and there are usually one essential and one regulatory pair of light chains associated with each heavy chain. Many myosin light chains that bind calcium are considered "calmodulin-like" proteins.
A subclass of myosin involved in organelle transport and membrane targeting. It is abundantly found in nervous tissue and neurosecretory cells. The heavy chains of myosin V contain unusually long neck domains that are believed to aid in translocating molecules over large distances.
A nonmuscle isoform of myosin type II found predominantly in platelets, lymphocytes, neutrophils and brush border enterocytes.
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.
A nonmuscle isoform of myosin type II found predominantly in neuronal tissue.
Myosin type II isoforms found in cardiac muscle.
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.
An enzyme that phosphorylates myosin light chains in the presence of ATP to yield myosin-light chain phosphate and ADP, and requires calcium and CALMODULIN. The 20-kDa light chain is phosphorylated more rapidly than any other acceptor, but light chains from other myosins and myosin itself can act as acceptors. The enzyme plays a central role in the regulation of smooth muscle contraction.
A protein complex of actin and MYOSINS occurring in muscle. It is the essential contractile substance of muscle.
Myosin type II isoforms found in smooth muscle.
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.
'Gizzard', in a medical context, is a term rarely used but can refer to the muscular stomach of a bird, responsible for grinding and macerating food with the aid of ingested pebbles or grit.
Myosin type II isoforms found in skeletal muscle.
Contractile tissue that produces movement in animals.
A class of organic compounds containing four or more ring structures, one of which is made up of more than one kind of atom, usually carbon plus another atom. The heterocycle may be either aromatic or nonaromatic.
A phosphoprotein phosphatase that is specific for MYOSIN LIGHT CHAINS. It is composed of three subunits, which include a catalytic subunit, a myosin binding subunit, and a third subunit of unknown function.
Isoforms of MYOSIN TYPE II, specifically found in the ventricular muscle of the HEART. Defects in the genes encoding ventricular myosins result in FAMILIAL HYPERTROPHIC CARDIOMYOPATHY.
A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.
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 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.
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.
Fibers composed of MICROFILAMENT PROTEINS, which are predominately ACTIN. They are the smallest of the cytoskeletal filaments.
Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)
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.
A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .
Large woodland game BIRDS in the subfamily Meleagridinae, family Phasianidae, order GALLIFORMES. Formerly they were considered a distinct family, Melegrididae.
A protein found in the thin filaments of muscle fibers. It inhibits contraction of the muscle unless its position is modified by TROPONIN.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.
The rate dynamics in chemical or physical systems.
A group of intracellular-signaling serine threonine kinases that bind to RHO GTP-BINDING PROTEINS. They were originally found to mediate the effects of rhoA GTP-BINDING PROTEIN on the formation of STRESS FIBERS and FOCAL ADHESIONS. Rho-associated kinases have specificity for a variety of substrates including MYOSIN-LIGHT-CHAIN PHOSPHATASE and LIM KINASES.
Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.
Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.
Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.
A heat-stable, low-molecular-weight activator protein found mainly in the brain and heart. The binding of calcium ions to this protein allows this protein to bind to cyclic nucleotide phosphodiesterases and to adenyl cyclase with subsequent activation. Thereby this protein modulates cyclic AMP and cyclic GMP levels.
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
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.
A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.
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.
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.
The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.
A genus of ameboid protozoa. Characteristics include a vesicular nucleus and the formation of several lodopodia, one of which is dominant at a given time. Reproduction occurs asexually by binary fission.
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.
The repeating contractile units of the MYOFIBRIL, delimited by Z bands along its length.
Proteins which bind calmodulin. They are found in many tissues and have a variety of functions including F-actin cross-linking properties, inhibition of cyclic nucleotide phosphodiesterase and calcium and magnesium ATPases.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
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.
A genus of free-living soil amoebae that produces no flagellate stage. Its organisms are pathogens for several infections in humans and have been found in the eye, bone, brain, and respiratory tract.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.
A subclass of myosin found in ACANTHAMOEBA. It is a non-filamentous myosin containing a single 180-kDa myosin heavy chain.
Myosin type II isoforms specifically found in the atrial muscle of the heart.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
The movement of CYTOPLASM within a CELL. It serves as an internal transport system for moving essential substances throughout the cell, and in single-celled organisms, such as the AMOEBA, it is responsible for the movement (CELL MOVEMENT) of the entire cell.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Skeletal muscle fibers characterized by their expression of the Type I MYOSIN HEAVY CHAIN isoforms which have low ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment.
Developmental events leading to the formation of adult muscular system, which includes differentiation of the various types of muscle cell precursors, migration of myoblasts, activation of myogenesis and development of muscle anchorage.
Seven membered heterocyclic rings containing a NITROGEN atom.
Skeletal muscle fibers characterized by their expression of the Type II MYOSIN HEAVY CHAIN isoforms which have high ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment. Several fast types have been identified.
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 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.
The sum of the weight of all the atoms in a molecule.
Muscular contractions characterized by increase in tension without change in length.
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 large family of mollusks in the class BIVALVIA, known commonly as scallops. They possess flat, almost circular shells and are found in all seas from shallow water to great depths.
A giant elastic protein of molecular mass ranging from 2,993 kDa (cardiac), 3,300 kDa (psoas), to 3,700 kDa (soleus) having a kinase domain. The amino- terminal is involved in a Z line binding, and the carboxy-terminal region is bound to the myosin filament with an overlap between the counter-connectin filaments at the M line.
One of the minor protein components of skeletal muscle. Its function is to serve as the calcium-binding component in the troponin-tropomyosin B-actin-myosin complex by conferring calcium sensitivity to the cross-linked actin and myosin filaments.
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.
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
A powerful flexor of the thigh at the hip joint (psoas major) and a weak flexor of the trunk and lumbar spinal column (psoas minor). Psoas is derived from the Greek "psoa", the plural meaning "muscles of the loin". It is a common site of infection manifesting as abscess (PSOAS ABSCESS). The psoas muscles and their fibers are also used frequently in experiments in muscle physiology.
A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.
A group of enzymes removing the SERINE- or THREONINE-bound phosphate groups from a wide range of phosphoproteins, including a number of enzymes which have been phosphorylated under the action of a kinase. (Enzyme Nomenclature, 1992)
Carrier of aroma of butter, vinegar, coffee, and other foods.
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 process by which the CYTOPLASM of a cell is divided.

Evidence for F-actin-dependent and -independent mechanisms involved in assembly and stability of the medial actomyosin ring in fission yeast. (1/5414)

Cell division in a number of eukaryotes, including the fission yeast Schizosaccharomyces pombe, is achieved through a medially placed actomyosin-based contractile ring. Although several components of the actomyosin ring have been identified, the mechanisms regulating ring assembly are still not understood. Here, we show by biochemical and mutational studies that the S.pombe actomyosin ring component Cdc4p is a light chain associated with Myo2p, a myosin II heavy chain. Localization of Myo2p to the medial ring depended on Cdc4p function, whereas localization of Cdc4p at the division site was independent of Myo2p. Interestingly, the actin-binding and motor domains of Myo2p are not required for its accumulation at the division site although the motor activity of Myo2p is essential for assembly of a normal actomyosin ring. The initial assembly of Myo2p and Cdc4p at the division site requires a functional F-actin cytoskeleton. Once established, however, F-actin is not required for the maintenance of Cdc4p and Myo2p medial rings, suggesting that the attachment of Cdc4p and Myo2p to the division site involves proteins other than actin itself.  (+info)

Regulation of chamber-specific gene expression in the developing heart by Irx4. (2/5414)

The vertebrate heart consists of two types of chambers, the atria and the ventricles, which differ in their contractile and electrophysiological properties. Little is known of the molecular mechanisms by which these chambers are specified during embryogenesis. Here a chicken iroquois-related homeobox gene, Irx4, was identified that has a ventricle-restricted expression pattern at all stages of heart development. Irx4 protein was shown to regulate the chamber-specific expression of myosin isoforms by activating the expression of the ventricle myosin heavy chain-1 (VMHC1) and suppressing the expression of the atrial myosin heavy chain-1 (AMHC1) in the ventricles. Thus, Irx4 may play a critical role in establishing chamber-specific gene expression in the developing heart.  (+info)

Association of a myosin immunoanalogue with cell envelopes of Aspergillus fumigatus conidia and its participation in swelling and germination. (3/5414)

A myosin immunoanalogue was identified in conidia of Aspergillus fumigatus by Western blotting, indirect immunofluorescence assay, and gold immunoelectron microscopy with two different antimyosin antibodies. The distribution pattern of this protein was followed during the early stages of germination. A single 180-kDa polypeptide, detected predominantly in a cell envelope extract, was found to cross-react with monoclonal and polyclonal antibodies raised against vertebrate muscle myosin. Immunoelectron microscopy permitted precise localization of this polypeptide, indicating that myosin analogue was mainly distributed along the plasma membrane of resting and swollen conidia. In germinating conidia, indirect immunofluorescence microscopy revealed myosin analogue at the periphery of germ tubes, whereas actin appeared as dispersed punctate structures in the cytoplasm that were more concentrated at the site of germ tube emergence. A myosin ATPase inhibitor, butanedione monoxime, greatly reduced swelling and blocked germination. In contrast, when conidia were treated with cytochalasin B, an inhibitor of actin polymerization, swelling was not affected and germination was only partially reduced. Butanedione monoxime-treated conidia showed accumulation of cytoplasmic vesicles and did not achieve cell wall reorganization, unlike swollen conidia. Collectively, these results suggest an essential role for this myosin analogue in the deposition of cell wall components during germination of A. fumigatus conidia and therefore in host tissue colonization.  (+info)

Studies on a nonpolysomal ribonucleoprotein coding for myosin heavy chains from chick embryonic muscles. (4/5414)

A messenger ribonucleoprotein (mRNP) particle containing the mRNA coding for the myosin heavy chain (MHC mRNA) has been isolated from the postpolysomal fraction of homogenates of 14-day-old chick embryonic muscles. The mRNP sediments in sucrose gradient as 120 S and has a characteristic buoyant density of 1.415 g/cm3, which corresponds to an RNA:protein ratio of 1:3.8. The RNA isolated from the 120 S particle behaved like authentic MHC mRNA purified from chick embryonic muscles with respect to electrophoretic mobility and ability to program the synthesis of myosin heavy chain in a rabbit reticulocyte lysate system as judged by multi-step co-purification of the in vitro products with chick embryonic leg muscle myosin added as carrier. The RNA obtained from the 120 S particle was as effective as purified MHC mRNA in stimulating the synthesis of the complete myosin heavy chains in rabbit reticulocyte lysate under conditions where non-muscle mRNAs had no such effect. Analysis of the protein moieties of the 120 S particle by sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows the presence of seven distinct polypeptides with apparent molecular weights of 44,000, 49,000, 53,000, 81,000, 83,000, and 98,000, whereas typical ribosomal proteins are absent. These results indicate that the 120 S particles are distinct cellular entities unrelated to ribosomes or initiation complexes. The presence of muscle-specific mRNAs as cytoplasmic mRNPs suggests that these particles may be involved in translational control during myogenesis in embryonic muscles.  (+info)

Myosin II-independent F-actin flow contributes to cell locomotion in dictyostelium. (5/5414)

While the treadmilling and retrograde flow of F-actin are believed to be responsible for the protrusion of leading edges, little is known about the mechanism that brings the posterior cell body forward. To elucidate the mechanism for global cell locomotion, we examined the organizational changes of filamentous (F-) actin in live Dictyostelium discoideum. We labeled F-actin with a trace amount of fluorescent phalloidin and analyzed its dynamics in nearly two-dimensional cells by using a sensitive, high-resolution charge-coupled device. We optically resolved a cyclic mode of tightening and loosening of fibrous cortical F-actin and quantitated its flow by measuring temporal and spatial intensity changes. The rate of F-actin flow was evaluated with respect to migration velocity and morphometric changes. In migrating monopodial cells, the cortical F-actin encircling the posterior cell body gradually accumulated into the tail end at a speed of 0.35 microm/minute. We show qualitatively and quantitatively that the F-actin flow is closely associated with cell migration. Similarly, in dividing cells, the cortical F-actin accumulated into the cleavage furrow. Although five times slower than the wild type, the F-actin also flows rearward in migrating mhcA- cells demonstrating that myosin II ('conventional' myosin) is not absolutely required for the observed dynamics of F-actin. Yet consistent with the reported transportation of ConA-beads, the direction of observed F-actin flow in Dictyostelium is conceptually opposite from a barbed-end binding to the plasma membrane. This study suggests that the posterior end of the cell has a unique motif that tugs the cortical actin layer rearward by means of a mechanism independent from myosin II; this mechanism may be also involved in cleavage furrow formation.  (+info)

(CTG)n repeats markedly inhibit differentiation of the C2C12 myoblast cell line: implications for congenital myotonic dystrophy. (6/5414)

Although the mutation for myotonic dystrophy has been identified as a (CTG)n repeat expansion located in the 3'-untranslated region of a gene located on chromosome 19, the mechanism of disease pathogenesis is not understood. The objective of this study was to assess the effect of (CTG)n repeats on the differentiation of myoblasts in cell culture. We report here that C2C12 myoblast cell lines permanently transfected with plasmid expressing 500 bases long CTG repeat sequences, exhibited a drastic reduction in their ability to fuse and differentiate into myotubes. The percentage of cells fused into myotubes in C2 C12 cells (53.4+/-4.4%) was strikingly different from those in the two CTG repeat carrying clones (1.8+/-0.4% and 3.3+/-0. 7%). Control C2C12 cells permanently transfected with vector alone did not show such an effect. This finding may have important implications in understanding the pathogenesis of congenital myotonic dystrophy.  (+info)

Activation of myosin phosphatase targeting subunit by mitosis-specific phosphorylation. (7/5414)

It has been demonstrated previously that during mitosis the sites of myosin phosphorylation are switched between the inhibitory sites, Ser 1/2, and the activation sites, Ser 19/Thr 18 (Yamakita, Y., S. Yamashiro, and F. Matsumura. 1994. J. Cell Biol. 124:129- 137; Satterwhite, L.L., M.J. Lohka, K.L. Wilson, T.Y. Scherson, L.J. Cisek, J.L. Corden, and T.D. Pollard. 1992. J. Cell Biol. 118:595-605), suggesting a regulatory role of myosin phosphorylation in cell division. To explore the function of myosin phosphatase in cell division, the possibility that myosin phosphatase activity may be altered during cell division was examined. We have found that the myosin phosphatase targeting subunit (MYPT) undergoes mitosis-specific phosphorylation and that the phosphorylation is reversed during cytokinesis. MYPT phosphorylated either in vivo or in vitro in the mitosis-specific way showed higher binding to myosin II (two- to threefold) compared to MYPT from cells in interphase. Furthermore, the activity of myosin phosphatase was increased more than twice and it is suggested this reflected the increased affinity of myosin binding. These results indicate the presence of a unique positive regulatory mechanism for myosin phosphatase in cell division. The activation of myosin phosphatase during mitosis would enhance dephosphorylation of the myosin regulatory light chain, thereby leading to the disassembly of stress fibers during prophase. The mitosis-specific effect of phosphorylation is lost on exit from mitosis, and the resultant increase in myosin phosphorylation may act as a signal to activate cytokinesis.  (+info)

Calculation of a Gap restoration in the membrane skeleton of the red blood cell: possible role for myosin II in local repair. (8/5414)

Human red blood cells contain all of the elements involved in the formation of nonmuscle actomyosin II complexes (V. M. Fowler. 1986. J. Cell. Biochem. 31:1-9; 1996. Curr. Opin. Cell Biol. 8:86-96). No clear function has yet been attributed to these complexes. Using a mathematical model for the structure of the red blood cell spectrin skeleton (M. J. Saxton. 1992. J. Theor. Biol. 155:517-536), we have explored a possible role for myosin II bipolar minifilaments in the restoration of the membrane skeleton, which may be locally damaged by major mechanical or chemical stress. We propose that the establishment of stable links between distant antiparallel actin protofilaments after a local myosin II activation may initiate the repair of the disrupted area. We show that it is possible to define conditions in which the calculated number of myosin II minifilaments bound to actin protofilaments is consistent with the estimated number of myosin II minifilaments present in the red blood cells. A clear restoration effect can be observed when more than 50% of the spectrin polymers of a defined area are disrupted. It corresponds to a significant increase in the spectrin density in the protein free region of the membrane. This may be involved in a more complex repair process of the red blood cell membrane, which includes the vesiculation of the bilayer and the compaction of the disassembled spectrin network.  (+info)

Myosins are a large family of motor proteins that play a crucial role in various cellular processes, including muscle contraction and intracellular transport. They consist of heavy chains, which contain the motor domain responsible for generating force and motion, and light chains, which regulate the activity of the myosin. Based on their structural and functional differences, myosins are classified into over 35 classes, with classes II, V, and VI being the most well-studied.

Class II myosins, also known as conventional myosins, are responsible for muscle contraction in skeletal, cardiac, and smooth muscles. They form filaments called thick filaments, which interact with actin filaments to generate force and movement during muscle contraction.

Class V myosins, also known as unconventional myosins, are involved in intracellular transport and organelle positioning. They have a long tail that can bind to various cargoes, such as vesicles, mitochondria, and nuclei, and a motor domain that moves along actin filaments to transport the cargoes to their destinations.

Class VI myosins are also unconventional myosins involved in intracellular transport and organelle positioning. They have two heads connected by a coiled-coil tail, which can bind to various cargoes. Class VI myosins move along actin filaments in a unique hand-over-hand motion, allowing them to transport their cargoes efficiently.

Overall, myosins are essential for many cellular functions and have been implicated in various diseases, including cardiovascular diseases, neurological disorders, and cancer.

Myosin Heavy Chains are the large, essential components of myosin molecules, which are responsible for the molecular motility in muscle cells. These heavy chains have a molecular weight of approximately 200 kDa and form the motor domain of myosin, which binds to actin filaments and hydrolyzes ATP to generate force and movement during muscle contraction. There are several different types of myosin heavy chains, each with specific roles in various tissues and cellular functions. In skeletal and cardiac muscles, for example, myosin heavy chains have distinct isoforms that contribute to the contractile properties of these tissues.

Myosin Type II, also known as myosin II or heavy meromyosin, is a type of motor protein involved in muscle contraction and other cellular movements. It is a hexameric protein composed of two heavy chains and four light chains. The heavy chains have a head domain that binds to actin filaments and an tail domain that forms a coiled-coil structure, allowing the formation of filaments. Myosin II uses the energy from ATP hydrolysis to move along actin filaments, generating force and causing muscle contraction or other cell movements. It plays a crucial role in various cellular processes such as cytokinesis, cell motility, and maintenance of cell shape.

Myosin subfragments refer to the smaller components that result from the dissociation or proteolytic digestion of myosin, a motor protein involved in muscle contraction. The two main subfragments are called S1 and S2.

S1 is the "head" of the myosin molecule, which contains the actin-binding site, ATPase activity, and the ability to generate force and motion during muscle contraction. It has a molecular weight of approximately 120 kDa.

S2 is the "tail" of the myosin molecule, which has a molecular weight of about 350 kDa and is responsible for forming the backbone of the thick filament in muscle sarcomeres. S2 can be further divided into light meromyosin (LMM) and heavy meromyosin (HMM). HMM consists of S1 and part of S2, while LMM comprises the remaining portion of S2.

These subfragments are essential for understanding myosin's structure, function, and interactions with other muscle components at a molecular level.

Myosin light chains are regulatory proteins that bind to the myosin head region of myosin molecules, which are involved in muscle contraction. There are two types of myosin light chains, essential and regulatory, that have different functions. The essential light chains are necessary for the assembly and stability of the myosin filaments, while the regulatory light chains control the calcium-sensitive activation of the myosin ATPase activity during muscle contraction. Phosphorylation of the regulatory light chains plays a critical role in regulating muscle contraction and relaxation.

Myosin Type V is an molecular motor protein involved in the intracellular transport of various cargoes, including vesicles and organelles. It belongs to the family of myosins, which are actin-based motors that convert chemical energy into mechanical work through the hydrolysis of ATP.

Myosin V is characterized by its long tail domain, which allows it to form dimers or higher-order oligomers, and its head domain, which binds to actin filaments and hydrolyzes ATP to generate force and movement. The protein moves in a hand-over-hand manner along the actin filament, allowing it to transport cargoes over long distances within the cell.

Myosin V has been implicated in various cellular processes, including exocytosis, endocytosis, and organelle positioning. Mutations in the MYO5A gene, which encodes Myosin Type V, have been associated with several human genetic disorders, such as Griscelli syndrome type 1 and familial progressive arthro-ophthalmopathy.

Nonmuscle Myosin Type IIA (NMIIA) is a type of non-muscle myosin protein that belongs to the myosin II family. These motor proteins are responsible for generating contractile forces in non-muscle cells, which allows them to change shape and move. NMIIA is widely expressed in various tissues and plays crucial roles in numerous cellular processes, including cytokinesis (cell division), maintenance of cell shape, and intracellular transport.

NMIIA consists of two heavy chains, two regulatory light chains, and two essential light chains. The heavy chains have a motor domain that binds to actin filaments and hydrolyzes ATP to generate force for movement along the actin filament. The regulatory and essential light chains regulate the activity and assembly of NMIIA.

Mutations in the gene encoding NMIIA (MYH9) have been associated with several human genetic disorders, such as May-Hegglin anomaly, Fechtner syndrome, and Delletten-Patterson syndrome, which are characterized by thrombocytopenia, bleeding disorders, and hearing loss.

Myosin Type I, also known as myosin-IA, is a type of motor protein found in non-muscle cells. It is involved in various cellular processes such as organelle transport, cell division, and maintenance of cell shape. Myosin-IA consists of a heavy chain, light chains, and a cargo-binding tail domain. The heavy chain contains the motor domain that binds to actin filaments and hydrolyzes ATP to generate force and movement along the actin filament.

Myosin-I is unique among myosins because it can move in both directions along the actin filament, whereas most other myosins can only move in one direction. Additionally, myosin-I has a high duty ratio, meaning that it spends a larger proportion of its ATP hydrolysis cycle bound to the actin filament, making it well-suited for processes requiring sustained force generation or precise positioning.

Nonmuscle Myosin Type IIB (NMMIIB) is a type of motor protein that belongs to the myosin superfamily. It is involved in various cellular processes, including cell division, adhesion, migration, and maintenance of cell shape. NMMIIB is composed of two heavy chains, two regulatory light chains, and two essential light chains. The heavy chains have a motor domain that enables the protein to move along actin filaments, generating force and movement.

NMMIIB is widely expressed in non-muscle tissues, and its activity is regulated by phosphorylation and dephosphorylation of the regulatory light chains. Phosphorylation activates NMMIIB, leading to contractile forces that can alter cell shape and promote cell motility. In contrast, dephosphorylation inactivates NMMIIB, allowing for relaxation of the contractile forces.

Abnormal regulation of NMMIIB has been implicated in various pathological conditions, including cancer metastasis, cardiovascular diseases, and neurological disorders. Therefore, understanding the molecular mechanisms that regulate NMMIIB function is an important area of research with potential therapeutic implications.

Cardiac myosins are a type of myosin protein that are specifically expressed in the cardiac muscle cells (or cardiomyocytes) of the heart. These proteins play a crucial role in the contraction and relaxation of heart muscles, which is essential for proper heart function and blood circulation.

Myosins are molecular motors that use chemical energy from ATP to generate force and movement. In the context of cardiac muscle cells, cardiac myosins interact with another protein called actin to form sarcomeres, which are the basic contractile units of muscle fibers. During contraction, the heads of cardiac myosin molecules bind to actin filaments and pull them together, causing the muscle fiber to shorten and generate force.

There are different isoforms of cardiac myosins that can vary in their structure and function. Mutations in the genes encoding these proteins have been linked to various forms of cardiomyopathy, which are diseases of the heart muscle that can lead to heart failure and other complications. Therefore, understanding the structure and function of cardiac myosins is an important area of research for developing therapies and treatments for heart disease.

Actin is a type of protein that forms part of the contractile apparatus in muscle cells, and is also found in various other cell types. It is a globular protein that polymerizes to form long filaments, which are important for many cellular processes such as cell division, cell motility, and the maintenance of cell shape. In muscle cells, actin filaments interact with another type of protein called myosin to enable muscle contraction. Actins can be further divided into different subtypes, including alpha-actin, beta-actin, and gamma-actin, which have distinct functions and expression patterns in the body.

Myosin-Light-Chain Kinase (MLCK) is an enzyme that plays a crucial role in muscle contraction. It phosphorylates the regulatory light chains of myosin, a protein involved in muscle contraction, leading to the activation of myosin and the initiation of the contractile process. MLCK is activated by calcium ions and calmodulin, and its activity is essential for various cellular processes, including cytokinesis, cell motility, and maintenance of cell shape. In addition to its role in muscle contraction, MLCK has been implicated in several pathological conditions, such as hypertension, atherosclerosis, and cancer.

Actomyosin is a contractile protein complex that consists of actin and myosin filaments. It plays an essential role in muscle contraction, cell motility, and cytokinesis (the process of cell division where the cytoplasm is divided into two daughter cells). The interaction between actin and myosin generates force and movement through a mechanism called sliding filament theory. In this process, myosin heads bind to actin filaments and then undergo a power stroke, which results in the sliding of one filament relative to the other and ultimately leads to muscle contraction or cellular movements. Actomyosin complexes are also involved in various non-muscle cellular processes such as cytoplasmic streaming, intracellular transport, and maintenance of cell shape.

Smooth muscle myosin is a type of motor protein that is responsible for the contraction and relaxation of smooth muscles, which are found in various organs such as the bladder, blood vessels, and digestive tract. Smooth muscle myosin is composed of two heavy chains and four light chains, forming a hexameric structure. The heavy chains have an N-terminal head domain that contains the ATPase activity and a C-terminal tail domain that mediates filament assembly.

The smooth muscle myosin molecule has several unique features compared to other types of myosins, such as skeletal or cardiac myosin. For example, smooth muscle myosin has a longer lever arm, which allows for greater force generation during contraction. Additionally, the regulatory mechanism of smooth muscle myosin is different from that of skeletal or cardiac myosin. In smooth muscles, the contractile activity is regulated by phosphorylation of the light chains, which is mediated by a specific kinase called myosin light chain kinase (MLCK).

Overall, the proper regulation and function of smooth muscle myosin are critical for maintaining normal physiological functions in various organs. Dysregulation or mutations in smooth muscle myosin can lead to several diseases, such as hypertension, atherosclerosis, and gastrointestinal motility disorders.

Myosin III is a type of molecular motor protein found in cells, responsible for providing cellular movement and organization. More specifically, Myosin III is involved in the regulation of actin filament dynamics and contributes to various cellular functions such as vesicle transport, maintenance of cell shape, and signal transduction.

Myosin III has a unique motor domain that allows it to move along actin filaments while generating force. It also contains a protein kinase domain, which enables it to phosphorylate target proteins and regulate their activity. Mutations in the MYO3 gene have been associated with certain inherited diseases, such as Usher syndrome type 1F, a condition characterized by hearing loss and retinitis pigmentosa, leading to vision loss.

In human anatomy, a "gizzard" does not exist as it is not part of the human digestive system. However, in veterinary medicine, the gizzard refers to a part of the stomach in birds and some other animals, such as crocodiles and alligators. It is a muscular, thick-walled portion where food is stored and mechanically broken down by grinding and mixing it with grit that the animal has swallowed. This action helps in the digestion process, especially for birds that do not have teeth to chew their food.

Skeletal muscle myosin, also known as myosin II, is a type of motor protein that plays a crucial role in muscle contraction. It is a hexameric protein composed of two heavy chains and four light chains. The heavy chains have a head region, which contains the ATPase activity and binds to actin filaments, and a tail region, which forms a coiled-coil structure that allows myosin molecules to self-associate into thick filaments.

During muscle contraction, the myosin heads bind to actin filaments in the sarcomere and undergo a power stroke, which results in the sliding of the actin filaments relative to the myosin filaments and thus shortening of the sarcomere. The ATP hydrolysis provides the energy for this power stroke.

Skeletal muscle myosin is essential for generating force and movement in skeletal muscles, and its dysfunction can lead to various muscle diseases and disorders.

A muscle is a soft tissue in our body that contracts to produce force and motion. It is composed mainly of specialized cells called muscle fibers, which are bound together by connective tissue. There are three types of muscles: skeletal (voluntary), smooth (involuntary), and cardiac. Skeletal muscles attach to bones and help in movement, while smooth muscles are found within the walls of organs and blood vessels, helping with functions like digestion and circulation. Cardiac muscle is the specific type that makes up the heart, allowing it to pump blood throughout the body.

Heterocyclic compounds with 4 or more rings refer to a class of organic compounds that contain at least four aromatic or non-aromatic rings in their structure, where one or more of the rings contains atoms other than carbon (heteroatoms) such as nitrogen, oxygen, sulfur, or selenium. These compounds are widely found in nature and have significant importance in medicinal chemistry due to their diverse biological activities. Many natural and synthetic drugs, pigments, vitamins, and antibiotics contain heterocyclic structures with four or more rings. The properties of these compounds depend on the size, shape, and nature of the rings, as well as the presence and position of functional groups.

Myosin-Light-Chain Phosphatase (MLCP) is an enzyme complex that plays a crucial role in the regulation of muscle contraction and relaxation. It is responsible for dephosphorylating the myosin light chains, which are key regulatory components of the contractile apparatus in muscles.

The phosphorylation state of the myosin light chains regulates the interaction between actin and myosin filaments, which is necessary for muscle contraction. When the myosin light chains are phosphorylated, they bind more strongly to actin, leading to increased contractile force. Conversely, when the myosin light chains are dephosphorylated by MLCP, the interaction between actin and myosin is weakened, allowing for muscle relaxation.

MLCP is composed of three subunits: a catalytic subunit (PP1cδ), a regulatory subunit (MYPT1), and a small subunit (M20). The regulatory subunit contains binding sites for various signaling molecules that can modulate the activity of MLCP, such as calcium/calmodulin, protein kinase C, and Rho-associated protein kinase (ROCK). Dysregulation of MLCP has been implicated in various muscle disorders, including hypertrophic cardiomyopathy, dilated cardiomyopathy, and muscle atrophy.

Ventricular myosins are the type of myosin proteins that are primarily found in the cardiac muscle cells (cardiomyocytes) of the heart ventricles. These myosin filaments are responsible for generating the mechanical force needed for cardiac muscle contraction and relaxation, which is essential for pumping blood throughout the body.

More specifically, ventricular myosins are part of the sarcomere structure in cardiomyocytes, where they interact with actin filaments to form cross-bridges during muscle contraction. The formation and breaking of these cross-bridges result in the sliding of actin and myosin filaments relative to each other, leading to muscle shortening and force generation.

Mutations or dysfunction in ventricular myosins can lead to various cardiac diseases, including hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and heart failure. Therefore, understanding the structure and function of ventricular myosins is crucial for developing new therapeutic strategies to treat these conditions.

Adenosine triphosphatases (ATPases) are a group of enzymes that catalyze the conversion of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and inorganic phosphate. This reaction releases energy, which is used to drive various cellular processes such as muscle contraction, transport of ions across membranes, and synthesis of proteins and nucleic acids.

ATPases are classified into several types based on their structure, function, and mechanism of action. Some examples include:

1. P-type ATPases: These ATPases form a phosphorylated intermediate during the reaction cycle and are involved in the transport of ions across membranes, such as the sodium-potassium pump and calcium pumps.
2. F-type ATPases: These ATPases are found in mitochondria, chloroplasts, and bacteria, and are responsible for generating a proton gradient across the membrane, which is used to synthesize ATP.
3. V-type ATPases: These ATPases are found in vacuolar membranes and endomembranes, and are involved in acidification of intracellular compartments.
4. A-type ATPases: These ATPases are found in the plasma membrane and are involved in various functions such as cell signaling and ion transport.

Overall, ATPases play a crucial role in maintaining the energy balance of cells and regulating various physiological processes.

Molecular motor proteins are a type of protein that convert chemical energy into mechanical work at the molecular level. They play a crucial role in various cellular processes, such as cell division, muscle contraction, and intracellular transport. There are several types of molecular motor proteins, including myosin, kinesin, and dynein.

Myosin is responsible for muscle contraction and movement along actin filaments in the cytoplasm. Kinesin and dynein are involved in intracellular transport along microtubules, moving cargo such as vesicles, organelles, and mRNA to various destinations within the cell.

These motor proteins move in a stepwise fashion, with each step driven by the hydrolysis of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and inorganic phosphate (Pi). The directionality and speed of movement are determined by the structure and regulation of the motor proteins, as well as the properties of the tracks along which they move.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

"Chickens" is a common term used to refer to the domesticated bird, Gallus gallus domesticus, which is widely raised for its eggs and meat. However, in medical terms, "chickens" is not a standard term with a specific definition. If you have any specific medical concern or question related to chickens, such as food safety or allergies, please provide more details so I can give a more accurate answer.

The actin cytoskeleton is a complex, dynamic network of filamentous (threadlike) proteins that provides structural support and shape to cells, allows for cell movement and division, and plays a role in intracellular transport. Actin filaments are composed of actin monomers that polymerize to form long, thin fibers. These filaments can be organized into different structures, such as stress fibers, which provide tension and support, or lamellipodia and filopodia, which are involved in cell motility. The actin cytoskeleton is constantly remodeling in response to various intracellular and extracellular signals, allowing for changes in cell shape and behavior.

Smooth muscle, also known as involuntary muscle, is a type of muscle that is controlled by the autonomic nervous system and functions without conscious effort. These muscles are found in the walls of hollow organs such as the stomach, intestines, bladder, and blood vessels, as well as in the eyes, skin, and other areas of the body.

Smooth muscle fibers are shorter and narrower than skeletal muscle fibers and do not have striations or sarcomeres, which give skeletal muscle its striped appearance. Smooth muscle is controlled by the autonomic nervous system through the release of neurotransmitters such as acetylcholine and norepinephrine, which bind to receptors on the smooth muscle cells and cause them to contract or relax.

Smooth muscle plays an important role in many physiological processes, including digestion, circulation, respiration, and elimination. It can also contribute to various medical conditions, such as hypertension, gastrointestinal disorders, and genitourinary dysfunction, when it becomes overactive or underactive.

'Dictyostelium' is a genus of social amoebae that are commonly found in soil and decaying organic matter. These microscopic organisms have a unique life cycle, starting as individual cells that feed on bacteria. When food becomes scarce, the cells undergo a developmental process where they aggregate together to form a multicellular slug-like structure called a pseudoplasmodium or grex. This grex then moves and differentiates into a fruiting body that can release spores for further reproduction.

Dictyostelium discoideum is the most well-studied species in this genus, serving as a valuable model organism for research in various fields such as cell biology, developmental biology, and evolutionary biology. The study of Dictyostelium has contributed significantly to our understanding of fundamental biological processes like chemotaxis, signal transduction, and cell differentiation.

Muscle contraction is the physiological process in which muscle fibers shorten and generate force, leading to movement or stability of a body part. This process involves the sliding filament theory where thick and thin filaments within the sarcomeres (the functional units of muscles) slide past each other, facilitated by the interaction between myosin heads and actin filaments. The energy required for this action is provided by the hydrolysis of adenosine triphosphate (ATP). Muscle contractions can be voluntary or involuntary, and they play a crucial role in various bodily functions such as locomotion, circulation, respiration, and posture maintenance.

Phosphorylation is the process of adding a phosphate group (a molecule consisting of one phosphorus atom and four oxygen atoms) to a protein or other organic molecule, which is usually done by enzymes called kinases. This post-translational modification can change the function, localization, or activity of the target molecule, playing a crucial role in various cellular processes such as signal transduction, metabolism, and regulation of gene expression. Phosphorylation is reversible, and the removal of the phosphate group is facilitated by enzymes called phosphatases.

Myofibrils are the basic contractile units of muscle fibers, composed of highly organized arrays of thick and thin filaments. They are responsible for generating the force necessary for muscle contraction. The thick filaments are primarily made up of the protein myosin, while the thin filaments are mainly composed of actin. Myofibrils are surrounded by a membrane called the sarcolemma and are organized into repeating sections called sarcomeres, which are the functional units of muscle contraction.

I'm not aware of any recognized medical term or condition specifically referred to as "turkeys." The term "turkey" is most commonly used in a non-medical context to refer to the large, bird-like domesticated fowl native to North America, scientifically known as Meleagris gallopavo.

However, if you are referring to a medical condition called "turkey neck," it is a colloquial term used to describe sagging or loose skin around the neck area, which can resemble a turkey's wattle. This condition is not a formal medical diagnosis but rather a descriptive term for an aesthetic concern some people may have about their appearance.

If you meant something else by "turkeys," please provide more context so I can give you a more accurate answer.

Tropomyosin is a protein that plays a crucial role in muscle contraction. It is a long, thin filamentous protein that runs along the length of actin filaments in muscle cells, forming part of the troponin-tropomyosin complex. This complex regulates the interaction between actin and myosin, which are the other two key proteins involved in muscle contraction.

In a relaxed muscle, tropomyosin blocks the myosin-binding sites on actin, preventing muscle contraction from occurring. When a signal is received to contract, calcium ions are released into the muscle cell, which binds to troponin and causes a conformational change that moves tropomyosin out of the way, exposing the myosin-binding sites on actin. This allows myosin to bind to actin and generate force, leading to muscle contraction.

Tropomyosin is composed of two alpha-helical chains that wind around each other in a coiled-coil structure. There are several isoforms of tropomyosin found in different types of muscle cells, including skeletal, cardiac, and smooth muscle. Mutations in the genes encoding tropomyosin have been associated with various inherited muscle disorders, such as hypertrophic cardiomyopathy and distal arthrogryposis.

Adenosine Triphosphate (ATP) is a high-energy molecule that stores and transports energy within cells. It is the main source of energy for most cellular processes, including muscle contraction, nerve impulse transmission, and protein synthesis. ATP is composed of a base (adenine), a sugar (ribose), and three phosphate groups. The bonds between these phosphate groups contain a significant amount of energy, which can be released when the bond between the second and third phosphate group is broken, resulting in the formation of adenosine diphosphate (ADP) and inorganic phosphate. This process is known as hydrolysis and can be catalyzed by various enzymes to drive a wide range of cellular functions. ATP can also be regenerated from ADP through various metabolic pathways, such as oxidative phosphorylation or substrate-level phosphorylation, allowing for the continuous supply of energy to cells.

Skeletal muscle, also known as striated or voluntary muscle, is a type of muscle that is attached to bones by tendons or aponeuroses and functions to produce movements and support the posture of the body. It is composed of long, multinucleated fibers that are arranged in parallel bundles and are characterized by alternating light and dark bands, giving them a striped appearance under a microscope. Skeletal muscle is under voluntary control, meaning that it is consciously activated through signals from the nervous system. It is responsible for activities such as walking, running, jumping, and lifting objects.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Rho-associated kinases (ROCKs) are serine/threonine kinases that are involved in the regulation of various cellular processes, including actin cytoskeleton organization, cell migration, and gene expression. They are named after their association with the small GTPase RhoA, which activates them upon binding.

ROCKs exist as two isoforms, ROCK1 and ROCK2, which share a high degree of sequence homology and have similar functions. They contain several functional domains, including a kinase domain, a coiled-coil region that mediates protein-protein interactions, and a Rho-binding domain (RBD) that binds to active RhoA.

Once activated by RhoA, ROCKs phosphorylate a variety of downstream targets, including myosin light chain (MLC), LIM kinase (LIMK), and moesin, leading to the regulation of actomyosin contractility, stress fiber formation, and focal adhesion turnover. Dysregulation of ROCK signaling has been implicated in various pathological conditions, such as cancer, cardiovascular diseases, neurological disorders, and fibrosis. Therefore, ROCKs have emerged as promising therapeutic targets for the treatment of these diseases.

Protein isoforms are different forms or variants of a protein that are produced from a single gene through the process of alternative splicing, where different exons (or parts of exons) are included in the mature mRNA molecule. This results in the production of multiple, slightly different proteins that share a common core structure but have distinct sequences and functions. Protein isoforms can also arise from genetic variations such as single nucleotide polymorphisms or mutations that alter the protein-coding sequence of a gene. These differences in protein sequence can affect the stability, localization, activity, or interaction partners of the protein isoform, leading to functional diversity and specialization within cells and organisms.

Adenosine diphosphate (ADP) is a chemical compound that plays a crucial role in energy transfer within cells. It is a nucleotide, which consists of a adenosine molecule (a sugar molecule called ribose attached to a nitrogenous base called adenine) and two phosphate groups.

In the cell, ADP functions as an intermediate in the conversion of energy from one form to another. When a high-energy phosphate bond in ADP is broken, energy is released and ADP is converted to adenosine triphosphate (ATP), which serves as the main energy currency of the cell. Conversely, when ATP donates a phosphate group to another molecule, it is converted back to ADP, releasing energy for the cell to use.

ADP also plays a role in blood clotting and other physiological processes. In the coagulation cascade, ADP released from damaged red blood cells can help activate platelets and initiate the formation of a blood clot.

Skeletal muscle fibers, also known as striated muscle fibers, are the type of muscle cells that make up skeletal muscles, which are responsible for voluntary movements of the body. These muscle fibers are long, cylindrical, and multinucleated, meaning they contain multiple nuclei. They are surrounded by a connective tissue layer called the endomysium, and many fibers are bundled together into fascicles, which are then surrounded by another layer of connective tissue called the perimysium.

Skeletal muscle fibers are composed of myofibrils, which are long, thread-like structures that run the length of the fiber. Myofibrils contain repeating units called sarcomeres, which are responsible for the striated appearance of skeletal muscle fibers. Sarcomeres are composed of thick and thin filaments, which slide past each other during muscle contraction to shorten the sarcomere and generate force.

Skeletal muscle fibers can be further classified into two main types based on their contractile properties: slow-twitch (type I) and fast-twitch (type II). Slow-twitch fibers have a high endurance capacity and are used for sustained, low-intensity activities such as maintaining posture. Fast-twitch fibers, on the other hand, have a higher contractile speed and force generation capacity but fatigue more quickly and are used for powerful, explosive movements.

Calmodulin is a small, ubiquitous calcium-binding protein that plays a critical role in various intracellular signaling pathways. It functions as a calcium sensor, binding to and regulating the activity of numerous target proteins upon calcium ion (Ca^2+^) binding. Calmodulin is expressed in all eukaryotic cells and participates in many cellular processes, including muscle contraction, neurotransmitter release, gene expression, metabolism, and cell cycle progression.

The protein contains four EF-hand motifs that can bind Ca^2+^ ions. Upon calcium binding, conformational changes occur in the calmodulin structure, exposing hydrophobic surfaces that facilitate its interaction with target proteins. Calmodulin's targets include enzymes (such as protein kinases and phosphatases), ion channels, transporters, and cytoskeletal components. By modulating the activity of these proteins, calmodulin helps regulate essential cellular functions in response to changes in intracellular Ca^2+^ concentrations.

Calmodulin's molecular weight is approximately 17 kDa, and it consists of a single polypeptide chain with 148-150 amino acid residues. The protein can be found in both the cytoplasm and the nucleus of cells. In addition to its role as a calcium sensor, calmodulin has been implicated in various pathological conditions, including cancer, neurodegenerative diseases, and cardiovascular disorders.

The cytoskeleton is a complex network of various protein filaments that provides structural support, shape, and stability to the cell. It plays a crucial role in maintaining cellular integrity, intracellular organization, and enabling cell movement. The cytoskeleton is composed of three major types of protein fibers: microfilaments (actin filaments), intermediate filaments, and microtubules. These filaments work together to provide mechanical support, participate in cell division, intracellular transport, and help maintain the cell's architecture. The dynamic nature of the cytoskeleton allows cells to adapt to changing environmental conditions and respond to various stimuli.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Mollusca is not a medical term per se, but a major group of invertebrate animals that includes snails, clams, octopuses, and squids. However, medically, some mollusks can be relevant as they can act as vectors for various diseases, such as schistosomiasis (transmitted by freshwater snails) and fascioliasis (transmitted by aquatic snails). Therefore, a medical definition might describe Mollusca as a phylum of mostly marine invertebrates that can sometimes play a role in the transmission of certain infectious diseases.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Muscle proteins are a type of protein that are found in muscle tissue and are responsible for providing structure, strength, and functionality to muscles. The two major types of muscle proteins are:

1. Contractile proteins: These include actin and myosin, which are responsible for the contraction and relaxation of muscles. They work together to cause muscle movement by sliding along each other and shortening the muscle fibers.
2. Structural proteins: These include titin, nebulin, and desmin, which provide structural support and stability to muscle fibers. Titin is the largest protein in the human body and acts as a molecular spring that helps maintain the integrity of the sarcomere (the basic unit of muscle contraction). Nebulin helps regulate the length of the sarcomere, while desmin forms a network of filaments that connects adjacent muscle fibers together.

Overall, muscle proteins play a critical role in maintaining muscle health and function, and their dysregulation can lead to various muscle-related disorders such as muscular dystrophy, myopathies, and sarcopenia.

An Amoeba is a type of single-celled organism that belongs to the kingdom Protista. It's known for its ability to change shape and move through its environment using temporary extensions of cytoplasm called pseudopods. Amoebas are found in various aquatic and moist environments, and some species can even live as parasites within animals, including humans.

In a medical context, the term "Amoeba" often refers specifically to Entamoeba histolytica, a pathogenic species that can cause amoebiasis, a type of infectious disease. This parasite typically enters the human body through contaminated food or water and can lead to symptoms such as diarrhea, stomach pain, and weight loss. In severe cases, it may invade the intestinal wall and spread to other organs, causing potentially life-threatening complications.

It's important to note that while many species of amoebas exist in nature, only a few are known to cause human disease. Proper hygiene practices, such as washing hands thoroughly and avoiding contaminated food and water, can help prevent the spread of amoebic infections.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

A sarcomere is the basic contractile unit in a muscle fiber, and it's responsible for generating the force necessary for muscle contraction. It is composed of several proteins, including actin and myosin, which slide past each other to shorten the sarcomere during contraction. The sarcomere extends from one Z-line to the next in a muscle fiber, and it is delimited by the Z-discs where actin filaments are anchored. Sarcomeres play a crucial role in the functioning of skeletal, cardiac, and smooth muscles.

Calmodulin-binding proteins are a diverse group of proteins that have the ability to bind to calmodulin, a ubiquitous calcium-binding protein found in eukaryotic cells. Calmodulin plays a critical role in various cellular processes by regulating the activity of its target proteins in a calcium-dependent manner.

Calmodulin-binding proteins contain specific domains or motifs that enable them to interact with calmodulin. These domains can be classified into two main categories: IQ motifs and CaM motifs. The IQ motif is a short amino acid sequence that contains the consensus sequence IQXXXRGXXR, where X represents any amino acid. This motif binds to the C-lobe of calmodulin in a calcium-dependent manner. On the other hand, CaM motifs are longer sequences that can bind to both lobes of calmodulin with high affinity and in a calcium-dependent manner.

Calmodulin-binding proteins play crucial roles in various cellular functions, including signal transduction, gene regulation, cytoskeleton organization, and ion channel regulation. For example, calmodulin-binding proteins such as calcineurin and CaM kinases are involved in the regulation of immune responses, learning, and memory. Similarly, myosin regulatory light chains, which contain IQ motifs, play a critical role in muscle contraction by regulating the interaction between actin and myosin filaments.

In summary, calmodulin-binding proteins are a diverse group of proteins that interact with calmodulin to regulate various cellular processes. They contain specific domains or motifs that enable them to bind to calmodulin in a calcium-dependent manner, thereby modulating the activity of their target proteins.

Electrophoresis, polyacrylamide gel (EPG) is a laboratory technique used to separate and analyze complex mixtures of proteins or nucleic acids (DNA or RNA) based on their size and electrical charge. This technique utilizes a matrix made of cross-linked polyacrylamide, a type of gel, which provides a stable and uniform environment for the separation of molecules.

In this process:

1. The polyacrylamide gel is prepared by mixing acrylamide monomers with a cross-linking agent (bis-acrylamide) and a catalyst (ammonium persulfate) in the presence of a buffer solution.
2. The gel is then poured into a mold and allowed to polymerize, forming a solid matrix with uniform pore sizes that depend on the concentration of acrylamide used. Higher concentrations result in smaller pores, providing better resolution for separating smaller molecules.
3. Once the gel has set, it is placed in an electrophoresis apparatus containing a buffer solution. Samples containing the mixture of proteins or nucleic acids are loaded into wells on the top of the gel.
4. An electric field is applied across the gel, causing the negatively charged molecules to migrate towards the positive electrode (anode) while positively charged molecules move toward the negative electrode (cathode). The rate of migration depends on the size, charge, and shape of the molecules.
5. Smaller molecules move faster through the gel matrix and will migrate farther from the origin compared to larger molecules, resulting in separation based on size. Proteins and nucleic acids can be selectively stained after electrophoresis to visualize the separated bands.

EPG is widely used in various research fields, including molecular biology, genetics, proteomics, and forensic science, for applications such as protein characterization, DNA fragment analysis, cloning, mutation detection, and quality control of nucleic acid or protein samples.

Electron microscopy (EM) is a type of microscopy that uses a beam of electrons to create an image of the sample being examined, resulting in much higher magnification and resolution than light microscopy. There are several types of electron microscopy, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and reflection electron microscopy (REM).

In TEM, a beam of electrons is transmitted through a thin slice of the sample, and the electrons that pass through the sample are focused to form an image. This technique can provide detailed information about the internal structure of cells, viruses, and other biological specimens, as well as the composition and structure of materials at the atomic level.

In SEM, a beam of electrons is scanned across the surface of the sample, and the electrons that are scattered back from the surface are detected to create an image. This technique can provide information about the topography and composition of surfaces, as well as the structure of materials at the microscopic level.

REM is a variation of SEM in which the beam of electrons is reflected off the surface of the sample, rather than scattered back from it. This technique can provide information about the surface chemistry and composition of materials.

Electron microscopy has a wide range of applications in biology, medicine, and materials science, including the study of cellular structure and function, disease diagnosis, and the development of new materials and technologies.

Acanthamoeba is a genus of free-living, ubiquitous amoebae found in various environments such as soil, water, and air. These microorganisms have a characteristic morphology with thin, flexible pseudopods and large, rounded cells that contain endospores. They are known to cause two major types of infections in humans: Acanthamoeba keratitis, an often painful and potentially sight-threatening eye infection affecting the cornea; and granulomatous amoebic encephalitis (GAE), a rare but severe central nervous system infection primarily impacting individuals with weakened immune systems.

Acanthamoeba keratitis typically occurs through contact lens wearers accidentally introducing the organism into their eyes, often via contaminated water sources or inadequately disinfected contact lenses and solutions. Symptoms include eye pain, redness, sensitivity to light, tearing, and blurred vision. Early diagnosis and treatment are crucial for preventing severe complications and potential blindness.

Granulomatous amoebic encephalitis is an opportunistic infection that affects people with compromised immune systems, such as those with HIV/AIDS, cancer, or organ transplant recipients. The infection spreads hematogenously (through the bloodstream) to the central nervous system, where it causes inflammation and damage to brain tissue. Symptoms include headache, fever, stiff neck, seizures, altered mental status, and focal neurological deficits. GAE is associated with high mortality rates due to its severity and the challenges in diagnosing and treating the infection effectively.

Prevention strategies for Acanthamoeba infections include maintaining good hygiene practices, regularly replacing contact lenses and storage cases, using sterile saline solution or disposable contact lenses, and avoiding swimming or showering while wearing contact lenses. Early detection and appropriate medical intervention are essential for managing these infections and improving patient outcomes.

A peptide fragment is a short chain of amino acids that is derived from a larger peptide or protein through various biological or chemical processes. These fragments can result from the natural breakdown of proteins in the body during regular physiological processes, such as digestion, or they can be produced experimentally in a laboratory setting for research or therapeutic purposes.

Peptide fragments are often used in research to map the structure and function of larger peptides and proteins, as well as to study their interactions with other molecules. In some cases, peptide fragments may also have biological activity of their own and can be developed into drugs or diagnostic tools. For example, certain peptide fragments derived from hormones or neurotransmitters may bind to receptors in the body and mimic or block the effects of the full-length molecule.

The myocardium is the middle layer of the heart wall, composed of specialized cardiac muscle cells that are responsible for pumping blood throughout the body. It forms the thickest part of the heart wall and is divided into two sections: the left ventricle, which pumps oxygenated blood to the rest of the body, and the right ventricle, which pumps deoxygenated blood to the lungs.

The myocardium contains several types of cells, including cardiac muscle fibers, connective tissue, nerves, and blood vessels. The muscle fibers are arranged in a highly organized pattern that allows them to contract in a coordinated manner, generating the force necessary to pump blood through the heart and circulatory system.

Damage to the myocardium can occur due to various factors such as ischemia (reduced blood flow), infection, inflammation, or genetic disorders. This damage can lead to several cardiac conditions, including heart failure, arrhythmias, and cardiomyopathy.

Myosin type IV, also known as myosin-1c, is a member of the unconventional myosin family. It is an actin-based molecular motor protein that plays a role in intracellular transport, organelle positioning, and cell signaling. Myosin-1c has a single head domain, which can bind to actin filaments and hydrolyze ATP to generate force and motion. It is widely expressed in various tissues, including the heart, skeletal muscle, and brain. Mutations in the gene that encodes myosin-1c have been associated with several human diseases, such as deafness, cardiomyopathy, and neurological disorders.

Atrial myosins refer to the protein filaments in the muscle cells (myocytes) of the heart's upper chambers, the atria. These myosin filaments are a crucial component of the sarcomeres, which are the basic contractile units of muscle fibers. They play a vital role in generating the force necessary for atrial contraction and pumping blood into the lower chambers of the heart (the ventricles).

Myosins consist of two major components: heavy chains and light chains. The heavy chains have a head region that binds to actin filaments, forming cross-bridges during muscle contraction, and a tail region that forms the backbone of the myosin filament. Light chains are regulatory proteins that modulate the activity of the myosin heads.

Atrial myosins have distinct structural and functional properties compared to ventricular myosins, which are found in the heart's lower chambers. These differences reflect the unique mechanical demands placed on atrial and ventricular muscle cells during the cardiac cycle. For example, atrial myosins generally have a higher ATPase activity than ventricular myosins, allowing for faster cross-bridge cycling and more rapid relaxation of the atria between contractions.

Understanding the properties and regulation of atrial myosins is essential for developing therapies to treat various cardiac diseases, such as atrial fibrillation and heart failure.

Protein conformation refers to the specific three-dimensional shape that a protein molecule assumes due to the spatial arrangement of its constituent amino acid residues and their associated chemical groups. This complex structure is determined by several factors, including covalent bonds (disulfide bridges), hydrogen bonds, van der Waals forces, and ionic bonds, which help stabilize the protein's unique conformation.

Protein conformations can be broadly classified into two categories: primary, secondary, tertiary, and quaternary structures. The primary structure represents the linear sequence of amino acids in a polypeptide chain. The secondary structure arises from local interactions between adjacent amino acid residues, leading to the formation of recurring motifs such as α-helices and β-sheets. Tertiary structure refers to the overall three-dimensional folding pattern of a single polypeptide chain, while quaternary structure describes the spatial arrangement of multiple folded polypeptide chains (subunits) that interact to form a functional protein complex.

Understanding protein conformation is crucial for elucidating protein function, as the specific three-dimensional shape of a protein directly influences its ability to interact with other molecules, such as ligands, nucleic acids, or other proteins. Any alterations in protein conformation due to genetic mutations, environmental factors, or chemical modifications can lead to loss of function, misfolding, aggregation, and disease states like neurodegenerative disorders and cancer.

Cytoplasmic streaming, also known as cyclosis, is the movement or flow of cytoplasm and organelles within a eukaryotic cell. It is a type of intracellular transport that occurs in many types of cells, but it is particularly prominent in large, single-celled organisms such as algae and fungi.

During cytoplasmic streaming, the cytoplasm moves in a coordinated and organized manner, often in circular or spiral patterns. This movement is driven by the action of motor proteins, such as myosin, which interact with filamentous structures called actin filaments. The movement of the motor proteins along the actin filaments generates force, causing the cytoplasm and organelles to move.

Cytoplasmic streaming serves several functions in cells. It helps to distribute nutrients and metabolic products throughout the cell, and it also plays a role in the movement of organelles and other cellular components to specific locations within the cell. Additionally, cytoplasmic streaming can help to maintain the structural integrity of large, single-celled organisms by ensuring that their cytoplasm is evenly distributed.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Slow-twitch muscle fibers, also known as type I muscle fibers, are specialized skeletal muscle cells that contract relatively slowly and generate less force than fast-twitch fibers. However, they can maintain contraction for longer periods of time and have a higher resistance to fatigue. These fibers primarily use oxygen and aerobic metabolism to produce energy, making them highly efficient during prolonged, lower-intensity activities such as long-distance running or cycling. Slow-twitch muscle fibers also have an abundant blood supply, which allows for efficient delivery of oxygen and removal of waste products.

Muscle development, also known as muscle hypertrophy, refers to the increase in size and mass of the muscles through a process called myofiber growth. This is primarily achieved through resistance or strength training exercises that cause micro-tears in the muscle fibers, leading to an inflammatory response and the release of hormones that promote muscle growth. As the muscles repair themselves, they become larger and stronger than before. Proper nutrition, including adequate protein intake, and rest are also essential components of muscle development.

It is important to note that while muscle development can lead to an increase in strength and muscular endurance, it does not necessarily result in improved athletic performance or overall fitness. A well-rounded exercise program that includes cardiovascular activity, flexibility training, and resistance exercises is recommended for optimal health and fitness outcomes.

Azepines are heterocyclic chemical compounds that contain a seven-membered ring with one nitrogen atom and six carbon atoms. The term "azepine" refers to the basic structure, and various substituted azepines exist with different functional groups attached to the carbon and nitrogen atoms.

Azepines are not typically used in medical contexts as a therapeutic agent or a target for drug design. However, some azepine derivatives have been investigated for their potential biological activities, such as anti-inflammatory, antiviral, and anticancer properties. These compounds may be the subject of ongoing research, but they are not yet established as medical treatments.

It's worth noting that while azepines themselves are not a medical term, some of their derivatives or analogs may have medical relevance. Therefore, it is essential to consult medical literature and databases for accurate and up-to-date information on the medical use of specific azepine compounds.

Fast-twitch muscle fibers, also known as type II fibers, are a type of skeletal muscle fiber that are characterized by their rapid contraction and relaxation rates. These fibers have a larger diameter and contain a higher concentration of glycogen, which serves as a quick source of energy for muscle contractions. Fast-twitch fibers are further divided into two subcategories: type IIa and type IIb (or type IIx). Type IIa fibers have a moderate amount of mitochondria and can utilize both aerobic and anaerobic metabolic pathways, making them fatigue-resistant. Type IIb fibers, on the other hand, have fewer mitochondria and primarily use anaerobic metabolism, leading to faster fatigue. Fast-twitch fibers are typically used in activities that require quick, powerful movements such as sprinting or weightlifting.

Microfilament proteins are a type of structural protein that form part of the cytoskeleton in eukaryotic cells. They are made up of actin monomers, which polymerize to form long, thin filaments. These filaments are involved in various cellular processes such as muscle contraction, cell division, and cell motility. Microfilament proteins also interact with other cytoskeletal components like intermediate filaments and microtubules to maintain the overall shape and integrity of the cell. Additionally, they play a crucial role in the formation of cell-cell junctions and cell-matrix adhesions, which are essential for tissue structure and function.

Tertiary protein structure refers to the three-dimensional arrangement of all the elements (polypeptide chains) of a single protein molecule. It is the highest level of structural organization and results from interactions between various side chains (R groups) of the amino acids that make up the protein. These interactions, which include hydrogen bonds, ionic bonds, van der Waals forces, and disulfide bridges, give the protein its unique shape and stability, which in turn determines its function. The tertiary structure of a protein can be stabilized by various factors such as temperature, pH, and the presence of certain ions. Any changes in these factors can lead to denaturation, where the protein loses its tertiary structure and thus its function.

Molecular weight, also known as molecular mass, is the mass of a molecule. It is expressed in units of atomic mass units (amu) or daltons (Da). Molecular weight is calculated by adding up the atomic weights of each atom in a molecule. It is a useful property in chemistry and biology, as it can be used to determine the concentration of a substance in a solution, or to calculate the amount of a substance that will react with another in a chemical reaction.

Isometric contraction is a type of muscle activation where the muscle contracts without any change in the length of the muscle or movement at the joint. This occurs when the force generated by the muscle matches the external force opposing it, resulting in a balanced state with no visible movement. It is commonly experienced during activities such as holding a heavy object in static position or trying to push against an immovable object. Isometric contractions are important in maintaining posture and providing stability to joints.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

Fluorescence microscopy is a type of microscopy that uses fluorescent dyes or proteins to highlight and visualize specific components within a sample. In this technique, the sample is illuminated with high-energy light, typically ultraviolet (UV) or blue light, which excites the fluorescent molecules causing them to emit lower-energy, longer-wavelength light, usually visible light in the form of various colors. This emitted light is then collected by the microscope and detected to produce an image.

Fluorescence microscopy has several advantages over traditional brightfield microscopy, including the ability to visualize specific structures or molecules within a complex sample, increased sensitivity, and the potential for quantitative analysis. It is widely used in various fields of biology and medicine, such as cell biology, neuroscience, and pathology, to study the structure, function, and interactions of cells and proteins.

There are several types of fluorescence microscopy techniques, including widefield fluorescence microscopy, confocal microscopy, two-photon microscopy, and total internal reflection fluorescence (TIRF) microscopy, each with its own strengths and limitations. These techniques can provide valuable insights into the behavior of cells and proteins in health and disease.

"Pectinidae" is not a medical term. It is a taxonomic category in the field of biology, specifically a family of marine bivalve mollusks commonly known as scallops. The members of this family are characterized by their fan-shaped shells and their ability to swim by clapping their valves together. If you have any questions about a medical term, I would be happy to help with that instead.

Connectin is also known as titin, which is a giant protein that plays a crucial role in the elasticity and stiffness of muscle fibers. It is the largest protein in humans, spanning half the length of a muscle cell's sarcomere, the basic unit of muscle contraction. Connectin/titin has several domains with different functions, including binding to other proteins, regulating muscle contraction, and signaling within the muscle cell. Mutations in the connectin/titin gene have been associated with various forms of muscular dystrophy and cardiomyopathy.

Troponin is a protein complex found in cardiac and skeletal muscle cells that plays a critical role in muscle contraction. It consists of three subunits: troponin C, which binds calcium ions; troponin I, which inhibits the interaction between actin and myosin in the absence of calcium; and troponin T, which binds to tropomyosin and helps anchor the complex to the muscle filament.

In clinical medicine, "troponin" usually refers to cardiac-specific isoforms of these proteins (cTnI and cTnT) that are released into the bloodstream following damage to the heart muscle, such as occurs in myocardial infarction (heart attack). Measurement of troponin levels in the blood is a sensitive and specific biomarker for the diagnosis of acute myocardial infarction.

Phalloidine is not a medical term, but it is often referenced in the field of toxicology and mycology. Phalloidine is a toxin found in certain species of mushrooms, including the death cap (Amanita phalloides) and the destroying angel (Amanita virosa). It is one of the most potent and deadly toxins known to affect humans.

Phalloidine is a cyclic peptide that inhibits the function of actin, a protein involved in cell movement and division. By interfering with actin's normal functioning, phalloidine causes severe damage to the liver, kidneys, and other organs, leading to symptoms such as vomiting, diarrhea, dehydration, electrolyte imbalances, and potentially fatal organ failure.

It is important to note that phalloidine poisoning can be difficult to diagnose and treat, and it often requires prompt medical attention and supportive care to manage the symptoms and prevent long-term damage or death.

Magnesium is an essential mineral that plays a crucial role in various biological processes in the human body. It is the fourth most abundant cation in the body and is involved in over 300 enzymatic reactions, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Magnesium also contributes to the structural development of bones and teeth.

In medical terms, magnesium deficiency can lead to several health issues, such as muscle cramps, weakness, heart arrhythmias, and seizures. On the other hand, excessive magnesium levels can cause symptoms like diarrhea, nausea, and muscle weakness. Magnesium supplements or magnesium-rich foods are often recommended to maintain optimal magnesium levels in the body.

Some common dietary sources of magnesium include leafy green vegetables, nuts, seeds, legumes, whole grains, and dairy products. Magnesium is also available in various forms as a dietary supplement, including magnesium oxide, magnesium citrate, magnesium chloride, and magnesium glycinate.

The psoas muscles are a pair of muscles that are located in the lower lumbar region of the spine and run through the pelvis to attach to the femur (thigh bone). They are deep muscles, meaning they are located close to the body's core, and are surrounded by other muscles, bones, and organs.

The psoas muscles are composed of two separate muscles: the psoas major and the psoas minor. The psoas major is the larger of the two muscles and originates from the lumbar vertebrae (T12 to L5) and runs through the pelvis to attach to the lesser trochanter of the femur. The psoas minor, which is smaller and tends to be absent in some people, originates from the lower thoracic vertebrae (T12) and upper lumbar vertebrae (L1-L3) and runs down to attach to the iliac fascia and the pectineal line of the pubis.

The primary function of the psoas muscles is to flex the hip joint, which means they help to bring the knee towards the chest. They also play a role in stabilizing the lumbar spine and pelvis during movement. Tightness or weakness in the psoas muscles can contribute to lower back pain, postural issues, and difficulty with mobility and stability.

Potassium chloride is an essential electrolyte that is often used in medical settings as a medication. It's a white, crystalline salt that is highly soluble in water and has a salty taste. In the body, potassium chloride plays a crucial role in maintaining fluid and electrolyte balance, nerve function, and muscle contraction.

Medically, potassium chloride is commonly used to treat or prevent low potassium levels (hypokalemia) in the blood. Hypokalemia can occur due to various reasons such as certain medications, kidney diseases, vomiting, diarrhea, or excessive sweating. Potassium chloride is available in various forms, including tablets, capsules, and liquids, and it's usually taken by mouth.

It's important to note that potassium chloride should be used with caution and under the supervision of a healthcare provider, as high levels of potassium (hyperkalemia) can be harmful and even life-threatening. Hyperkalemia can cause symptoms such as muscle weakness, irregular heartbeat, and cardiac arrest.

Phosphoprotein phosphatases (PPPs) are a family of enzymes that play a crucial role in the regulation of various cellular processes by removing phosphate groups from serine, threonine, and tyrosine residues on proteins. Phosphorylation is a post-translational modification that regulates protein function, localization, and stability, and dephosphorylation by PPPs is essential for maintaining the balance of this regulation.

The PPP family includes several subfamilies, such as PP1, PP2A, PP2B (also known as calcineurin), PP4, PP5, and PP6. Each subfamily has distinct substrate specificities and regulatory mechanisms. For example, PP1 and PP2A are involved in the regulation of metabolism, signal transduction, and cell cycle progression, while PP2B is involved in immune response and calcium signaling.

Dysregulation of PPPs has been implicated in various diseases, including cancer, neurodegenerative disorders, and cardiovascular disease. Therefore, understanding the function and regulation of PPPs is important for developing therapeutic strategies to target these diseases.

Diacetyl is a volatile, yellow-green liquid that is a byproduct of fermentation and is used as a butter flavoring in foods. The chemical formula for diacetyl is CH3COCH3. It has a buttery or creamy taste and is often added to microwave popcorn, margarine, and other processed foods to give them a buttery flavor.

Diacetyl can also be found in some alcoholic beverages, such as beer and wine, where it is produced naturally during fermentation. In high concentrations, diacetyl can have a strong, unpleasant odor and taste.

There has been concern about the potential health effects of diacetyl, particularly for workers in factories that manufacture artificial butter flavorings. Some studies have suggested that exposure to diacetyl may increase the risk of developing lung disease, including bronchiolitis obliterans, a serious and sometimes fatal condition characterized by scarring and narrowing of the airways in the lungs. However, more research is needed to fully understand the health effects of diacetyl and to determine safe levels of exposure.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Cytokinesis is the part of the cell division process (mitosis or meiosis) in which the cytoplasm of a single eukaryotic cell divides into two daughter cells. It usually begins after telophase, and it involves the constriction of a contractile ring composed of actin filaments and myosin motor proteins that forms at the equatorial plane of the cell. This results in the formation of a cleavage furrow, which deepens and eventually leads to the physical separation of the two daughter cells. Cytokinesis is essential for cell reproduction and growth in multicellular organisms, and its failure can lead to various developmental abnormalities or diseases.

MBInfo - Myosin Isoforms MBInfo - The Myosin Powerstroke Myosin Video A video of a moving myosin motor protein. Myosins at the ... Myosin X is an unconventional myosin motor, which is functional as a dimer. The dimerization of myosin X is thought to be ... Myosin VI is thought to transport endocytic vesicles into the cell. Myosin VII is an unconventional myosin with two FERM ... Myosin II (also known as conventional myosin) is the myosin type responsible for producing muscle contraction in muscle cells ...
... is a protein that in humans is encoded by the MYH11 gene. Myosin-11 is a smooth muscle myosin belonging to the myosin ... Chicken Myosin-11) at the PDBe-KB. Babu GJ, Warshaw DM, Periasamy M (2000). "Smooth muscle myosin heavy chain isoforms and ... Myosin-11 is a subunit of a hexameric protein that consists of two heavy chain subunits and two pairs of non-identical light ... Actin, desmin, myosin, and tropomyosin". Am. J. Pathol. 142 (1): 221-30. PMC 1886840. PMID 8424456. New L, Jiang Y, Zhao M, et ...
"The sequence of the myosin 50-20K loop affects Myosin's affinity for actin throughout the actin-myosin ATPase cycle and its ... Myosin Rayment I (July 1996). "The structural basis of the myosin ATPase activity". The Journal of Biological Chemistry. 271 ( ... Myosin+ATPase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Portal: Biology (Articles with short ... Myosin ATPase (EC 3.6.4.1) is an enzyme with systematic name ATP phosphohydrolase (actin-translocating). This enzyme catalyses ...
The myosin head is the part of the thick myofilament made up of myosin that acts in muscle contraction, by sliding over thin ... Myosin is the major component of the thick filaments and most myosin molecules are composed of a head, neck, and tail domain; ... The 3-D structure of the head portion of myosin has been determined and a model for actin-myosin complex has been constructed. ... There are many cell-specific isoforms of myosin heavy chains, coded for by a multi-gene family. Myosin interacts with actin to ...
... (myosin heavy chain 2) is a protein that in humans is encoded by the MYH2 gene. GRCh38: Ensembl release 89: ... "Entrez Gene: MYH2 myosin, heavy chain 2, skeletal muscle, adult". Schwartz CE, McNally E, Leinwand L, Skolnick MH (1987). "A ... 2002). "Myosin heavy chain IIa gene mutation E706K is pathogenic and its expression increases with age". Neurology. 58 (5): 780 ... Chung MC, Kawamoto S (2005). "IRF-2 is involved in up-regulation of nonmuscle myosin heavy chain II-A gene expression during ...
Myosins are actin-dependent motor proteins and are categorized into conventional myosins (class II) and unconventional myosins ... Myosin-IIIa is a protein that in humans is encoded by the MYO3A gene. The protein encoded by this gene belongs to the myosin ... "Entrez Gene: MYO3A myosin IIIA". Walsh T, Walsh V, Vreugde S, et al. (2002). "From flies' eyes to our ears: mutations in a ... Class III myosins, such as this one, have a kinase domain N-terminal to the conserved N-terminal motor domains and are ...
Rodriguez OC, Cheney RE (Mar 2002). "Human myosin-Vc is a novel class V myosin expressed in epithelial cells". Journal of Cell ... Myosin Va is highly expressed in the nervous system and it is present in almost the entire brain. MY5A perform an important ... Defects in Myosin Va are associated with Griscelli syndrome type 1, also known as Elejalde syndrome a rare autosomal recessive ... Myosin Va is highly expressed in neurons and melanocytes. MYO5A has been shown to interact with DYNLL1, RAB27A, DYNLL2, ...
... , is a protein that in humans is coded for by MYO6. Unconventional myosin-VI is a myosin molecular ... Myosin-VI's Met-Ile-Sec bonding interactions are limited to the myosin-VI long isoform but interact with clathrin in ... Human myosin-VI contains a N-terminal myosin head domain (residues 59-759), two coiled coil motifs (residues 902-984 and 986- ... Myosin-VI follows the same structure as other myosin but with two unique "inserts" allowing for its diversified properties. One ...
A myosin light chain is a light chain (small polypeptide subunit) of myosin. Myosin light chains were discovered by Chinese ... Myosin light-chain kinase Myosin-light-chain phosphatase Myosin+Light+Chains at the U.S. National Library of Medicine Medical ... Structurally, myosin light chains belong to the EF-hand family, a large family of Ca2+- binding proteins. MLCs contain two Ca2+ ... Myosin light chains (MLCs) can be broadly classified into two groups: Essential or alkali MLC (MLC1 or ELC), Regulatory MLC ( ...
Skowron JF, Bement WM, Mooseker MS (1999). "Human brush border myosin-I and myosin-Ic expression in human intestine and Caco- ... The protein encoded by this gene belongs to the myosin superfamily. Myosins are molecular motors that, upon interaction with ... and/or enzymatic activities and targets each myosin to its particular subcellular location. The myosin-Ia protein is expressed ... Each myosin has a conserved N-terminal motor domain that contains both ATP-binding and actin-binding sequences. Following the ...
This gene encodes one of the myosin light chains, a component of the hexameric ATPase cellular motor protein myosin. Myosin is ... "Entrez Gene: Myosin light chain 5". Retrieved 2017-01-24. This article incorporates text from the United States National ... Myosin light chain 5 is a protein that, in humans, is encoded by the MYL5 gene. ...
Because myosin light chain has no inherent phosphate cleaving property over active PKC prevents the dephosphorylation of myosin ... Binding of calcium ion to this domain increases the affinity of MYLK binding to myosin light chain. This myosin binding domain ... Within the cells, MYLK provides an inward pulling force, phosphorylating myosin light chain causing a contraction of the myosin ... Myosin light-chain kinase also known as MYLK or MLCK is a serine/threonine-specific protein kinase that phosphorylates a ...
When myosin phosphatase binds to myosin, it removes the phosphate group. Without the group, the myosin reverts to its original ... Myosin light-chain phosphatase, also called myosin phosphatase (EC 3.1.3.53; systematic name [myosin-light-chain]-phosphate ... that dephosphorylates the regulatory light chain of myosin II: [myosin light-chain] phosphate + H2O = [myosin light-chain] + ... Myosin II, also known as conventional myosin, has two heavy chains that consist of the head and tail domains and four light ...
... calmodulin-dependent myosin heavy chain kinase MHCK MIHC kinase myosin heavy chain kinase myosin I heavy-chain kinase myosin II ... In enzymology, a myosin-heavy-chain kinase (EC 2.7.11.7) is an enzyme that catalyzes the chemical reaction ATP + [myosin heavy- ... kinase myosin heavy chain kinase A STK6. Cote GP, Bukiejko U (1987). "Purification and characterization of a myosin heavy chain ... the two substrates of this enzyme are ATP and myosin heavy-chain, whereas its two products are ADP and myosin heavy-chain ...
"Dissecting the N-terminal myosin binding site of human cardiac myosin-binding protein C. Structure and myosin binding of domain ... cMyBP-C regulates the positioning of myosin and actin for interaction and acts as a tether to the myosin S1 heads, limiting ... cMyBP-C is a myosin-associated protein that binds at 43 nm intervals along the myosin thick filament backbone, stretching for ... Harris SP, Rostkova E, Gautel M, Moss RL (Oct 2004). "Binding of myosin binding protein-C to myosin subfragment S2 affects ...
... is a protein that in humans is encoded by the MYRIP gene. GRCh38: Ensembl release 89: ... "Entrez Gene: Myosin VIIA and Rab interacting protein". Retrieved 2016-03-29. El-Amraoui A, Schonn JS, Küssel-Andermann P, ... Blanchard S, Desnos C, Henry JP, Wolfrum U, Darchen F, Petit C (2002). "MyRIP, a novel Rab effector, enables myosin VIIa ...
A comparison of segment II with the vertebrate myosin heavy chains reveals that it is homologous to a myosin peptide in the ... The most significant sequence similarities to this 54-amino acid region are from a motif found in the heavy chains of myosins ... Segments I and III are common to tubulins (INTERPRO), but segment II aligns with myosin heavy chain sequences from Drosophila ... Segment II also contains heptad repeats which are characteristic of the myosin tail alpha-helical coiled-coils. Deletion of the ...
... although these lineages do express other MyTH4-FERM myosins such as myosin-7. Humans express 3 MyTH4-FERM myosins in addition ... Myo10 should not be confused with Myh10, which encodes the heavy chain of the class II myosin known as non-muscle myosin 2b. ... Tokuo H (2020). "Myosin X". Myosins. Advances in Experimental Medicine and Biology. Vol. 1239. pp. 391-403. doi:10.1007/978-3- ... Kerber ML, Cheney RE (November 2011). "Myosin-X: a MyTH-FERM myosin at the tips of filopodia". Journal of Cell Science. 124 (Pt ...
She chose the motor protein myosin as the topic of her Ph.D. work in the laboratories of Mark Mooseker and Peter Novick at Yale ... She developed a modified in vitro motility assay to show that both Myo2p and Myo4p class V myosins in yeast appear to be non- ... Reck-Peterson, S. L.; Tyska, M. J.; Novick, P. J.; Mooseker, M. S. (2001-05-28). "The yeast class V myosins, Myo2p and Myo4p, ... Her work focused on the class V myosins, which have multiple functions in the cell ranging from mRNA transport to cell polarity ...
Myosin-9 also known as myosin, heavy chain 9, non-muscle or non-muscle myosin heavy chain IIa (NMMHC-IIA) is a protein which in ... Myosin IIs are motor proteins that are part of a superfamily composed of more than 30 classes. Class II myosins include muscle ... The path to myosin filament formation, which is shared by NM II and smooth muscle myosin, starts with a folded inactive ... April 2010). "Heavy chain myosin 9-related disease (MYH9 -RD): neutrophil inclusions of myosin-9 as a pathognomonic sign of the ...
Kruppa AJ, Kendrick-Jones J, Buss F (2016). "Myosins, Actin and Autophagy". Traffic. 17 (8): 878-90. doi:10.1111/tra.12410. PMC ...
Kruppa AJ, Kendrick-Jones J, Buss F (2016). "Myosins, Actin and Autophagy". Traffic. 17 (8): 878-90. doi:10.1111/tra.12410. PMC ... Kruppa AJ, Kendrick-Jones J, Buss F (2016). "Myosins, Actin and Autophagy". Traffic. 17 (8): 878-90. doi:10.1111/tra.12410. PMC ...
Myosin motoring along F-actin filaments generates contractile forces in so-called actomyosin fibers, both in muscle as well as ... They also act as tracks for the movement of myosin molecules that affix to the microfilament and "walk" along them. In general ... Actin structures are controlled by the Rho family of small GTP-binding proteins such as Rho itself for contractile acto-myosin ... Cooper, Geoffrey M. (2000). "Actin, Myosin, and Cell Movement". The Cell: A Molecular Approach. 2nd Edition. Archived from the ...
Kielley WW (1961). "Myosin adenosine triphosphatase". In Boyer PD, Lardy H, Myrbäck K (eds.). The Enzymes. Vol. 5 (2nd ed.). ... myosin, kinases and other ATP-requiring enzymes and a common nucleotide binding fold". EMBO J. 1 (8): 945-51. doi:10.1002/j. ...
Myosin regulatory light polypeptide 9 is a protein that in humans is encoded by the MYL9 gene. Myosin, a structural component ... "Entrez Gene: myosin". Stelzl U, Worm U, Lalowski M, et al. (2005). "A human protein-protein interaction network: a resource for ... The protein encoded by this gene is a myosin light chain that may regulate muscle contraction by modulating the ATPase activity ... Higashihara M, Watanabe M, Usuda S, Miyazaki K (2008). "Smooth muscle type isoform of 20 kDa myosin light chain is expressed in ...
The first identified myosin, myosin II, is responsible for generating muscle contraction. Myosin II is an elongated protein ... Because myosin II is essential for muscle contraction, defects in muscular myosin predictably cause myopathies. Myosin is ... The myosin heads bind and hydrolyze ATP, which provides the energy to walk toward the plus end of an actin filament. Myosin II ... In addition to myosin II, many other myosin types are responsible for variety of movement of non-muscle cells. For example, ...
It is the enzymatic activity of the ATPase in the myosin head that cyclically hydrolyzes ATP, fueling the myosin power stroke. ... MYH7 is a gene encoding a myosin heavy chain beta (MHC-β) isoform (slow twitch) expressed primarily in the heart, but also in ... Harris SP, Lyons RG, Bezold KL (March 2011). "In the thick of it: HCM-causing mutations in myosin binding proteins of the thick ... An accepted mechanism for this process is that ADP-bound myosin attaches to actin while thrusting tropomyosin inwards, then the ...
Hodge T, Cope M (1 October 2000). "A myosin family tree". J Cell Sci. 113 (19): 3353-4. doi:10.1242/jcs.113.19.3353. PMID ... National Science Foundation's Assembling the Tree of Life Project PhyloCode A Multiple Alignment of 139 Myosin Sequences and a ...
... myosin storage; 608358; MYH7 Myopathy, nemaline, 3; 161800; ACTA1 Myopathy, proximal, with early respiratory muscle involvement ...
Myosin fought back before Chiswick Bridge to reduce the deficit, but Actin won by around two lengths. Oxford's men's trial race ... The CUWBC president, Larkin Sayre, rowed in Myosin who lost the toss and were on the Middlesex side of the river. The race was ... As such the boats were named Actin and Myosin, the proteins which make the two muscle fibres that pull against each other in ... "CUWBC: Actin vs Myosin". The Boat Race Company Limited. 16 December 2019. Retrieved 10 January 2020. "OUBC Trial Eights Crews ...
MBInfo - Myosin Isoforms MBInfo - The Myosin Powerstroke Myosin Video A video of a moving myosin motor protein. Myosins at the ... Myosin X is an unconventional myosin motor, which is functional as a dimer. The dimerization of myosin X is thought to be ... Myosin VI is thought to transport endocytic vesicles into the cell. Myosin VII is an unconventional myosin with two FERM ... Myosin II (also known as conventional myosin) is the myosin type responsible for producing muscle contraction in muscle cells ...
Myosin; Đầu myosin; Phân tử myosin; Đuôi myosin; myosins; الميوزين; Myosin; المايوزين; مايوزين; myozin; myosiny; myoziny; 肌凝蛋白 ... myosin; Miozinas; 肌球蛋白; میوزین; myosin; 肌球蛋白; مایۆسین; myosin; ميوزين; 肌球蛋白; מיוזין; organische Verbindungen, Familie von ... nowiki,miosina; miozin; Mýósín; Miosina; Миозин; Myosin; Миозин; Миозин; Miozină; ミオシン; Myosin; Міозин; 肌球蛋白; 肌球蛋白; Myosiini; ... Association-of-six-YFP-myosin-XI-tail-fusions-with-mobile-plant-cell-organelles-1471-2229-7-6-S5.ogv 20 s, 768
Actin and myosin - Download as a PDF or view online for free ... Actin, Myosin, and Cell MovementAtai Rabby8.3K. views•16. ... Ca 2+ Ca 2+ Ca 2+ Ca 2+ the myosin heads change position to achieve a lower energy state and slide the actin filaments past the ... Ca 2+ Ca 2+ Ca 2+ Ca 2+ the bulbous heads of the myosin attach to the binding sites on the actin filaments ... Actin and myosin *1. . 100s of free ppts from www.pptpoint.com library ...
Myosin storage myopathy is a condition that causes muscle weakness (myopathy) that does not worsen or worsens very slowly over ... Mutations in the beta-myosin rod cause myosin storage myopathy via multiple mechanisms. Proc Natl Acad Sci U S A. 2009 Apr 14; ... Mutations in the MYH7 gene cause myosin storage myopathy. The MYH7 gene provides instructions for making a protein known as the ... Cardiac β-myosin heavy chain is the major component of the thick filament in muscle cell structures called sarcomeres. . ...
Myosin_TH1; Unconventional myosin tail, actin- and lipid-binding. * NM_012223.5 → NP_036355.2 unconventional myosin-Ib isoform ... Myosin_TH1; Unconventional myosin tail, actin- and lipid-binding. * NM_001161819.3 → NP_001155291.1 unconventional myosin-Ib ... Myosin_TH1; Unconventional myosin tail, actin- and lipid-binding. * NM_001330237.2 → NP_001317166.1 unconventional myosin-Ib ... Myosin_TH1; Unconventional myosin tail, actin- and lipid-binding. * NM_001330238.2 → NP_001317167.1 unconventional myosin-Ib ...
Nonmuscle myosin II (NM-II) is an important motor protein involved in cell migration. Incorporation of NM-II into actin stress ... LIMCH1 regulates nonmuscle myosin-II activity and suppresses cell migration Mol Biol Cell. 2017 Apr 15;28(8):1054-1065. doi: ... Nonmuscle myosin II (NM-II) is an important motor protein involved in cell migration. Incorporation of NM-II into actin stress ... Depletion of LIMCH1 attenuated myosin regulatory light chain (MRLC) diphosphorylation in HeLa cells, which was restored by ...
Recently, molecular motor gliding assays with actin and myosin from muscle have been realized on semiconductor nanowires coated ...
... on WN Network delivers the latest Videos and Editable pages for News & Events, including Entertainment, Music, Sports, ... Myosin. Myosins (/ˈmaɪəsᵻn, -oʊ-/) comprise a family of ATP-dependent motor proteins and are best known for their role in ... Thus, although myosin was originally thought to be restricted to muscle cells (hence myo-(s) + -in), there is no single "myosin ... Latest News for: myosin. Edit Divalent ions as mediators of carbonylation in cardiac myosin binding protein C (NIST - National ...
Rabbit polyclonal heavy chain Myosin/MYH3 antibody. Validated in WB, IHC and tested in Mouse, Rat, Human. Cited in 17 ... Anti-heavy chain Myosin/MYH3 antibody. See all heavy chain Myosin/MYH3 primary antibodies. ... Each myosin heavy chain can be split into 1 light meromyosin (LMM) and 1 heavy meromyosin (HMM). It can later be split further ... All lanes : Anti-heavy chain Myosin/MYH3 antibody (ab124205) at 1 µg/ml. Lane 1 : Human skeletal muscle tissue lysate - total ...
Similar words for Myosin. Definition: noun. [ˈmaɪəsən] the commonest protein in muscle; a globulin that combines with actin ... Sentences with myosin 1. Noun, singular or mass These fibers, made up of myosin and actin, are positioned just inside the cell ... Troponin and tropomyosin keep the actin and myosin apart so that your muscles do not remain perpetually contracted. ... 1. myosin noun. [ˈmaɪəsən] the commonest protein in muscle; a globulin that combines with actin to form actomyosin. ...
Abstract: M45.00004 : Myosin II Dynamics during Embryo Morphogenesis. 8:36 AM-9:12 AM ... The molecular and mechanical mechanisms by which myosin drives this massive change in embryo shape are poorly understood. To ... To explore the mechanisms by which molecular-level myosin dynamics are translated into tissue-level elongation, we are using ... These studies will help elucidate how myosin-generated forces control cell movements within tissues. \textit{This work is in ...
... and each type can vary in myosin isoform composition. The fast myosin isoforms in type II fibers generate high power at the ... The protein product of MYH16 is one of the heavy chain myosins, a kind of protein that works with actin to enable muscle fibers ... In the last decade or so, some researchers have tried to get a better idea of the way that the different kinds of myosins ... The real story of myosin, jaw muscles, and ancient brains. The provocative idea that our genus arose with a deactivated muscle ...
Antibodies for proteins involved in myosin light chain binding pathways, according to their Panther/Gene Ontology ... Smooth Muscle Myosin Heavy Chain (SM-MHC) Recombinant Rabbit Monoclonal Antibody (MYH11, 2303R) ... Smooth Muscle Myosin Heavy Chain (SM-MHC) Recombinant Rabbit Monoclonal Antibody (MYH11, 2303R) ... Smooth Muscle Myosin Heavy Chain (SM-MHC) Recombinant Rabbit Monoclonal Antibody (MYH11, 2303R) ...
Recently Myosin-X has been shown to specifically localize at the tip of filopodia. Myosin-X is a member of a family of proteins ... We have found that it is unlikely that Myosin-X interacts with vesicules within filopodia. We have also found that Myosin-X ... Attachment of Myosin-X to filaments of a molecule called actin which forms a sort of conveying belt within filopodia, is ... The presence of Myosin-X at filopodia tips is strongly correlated to the attachment of filopodia to its surrounding, ...
We have found that two actin-dependent molecular motors, class 1 myosins myosin 1e and myosin 1f, are specifically localized to ... Using primary macrophages lacking both myosin 1e and myosin 1f, we found that without the actin-membrane linkage mediated by ... Membrane-cytoskeleton mechanical feedback mediated by myosin-I controls phagocytic efficiency. Sarah R. Barger, Nicholas S. ... Membrane-cytoskeleton mechanical feedback mediated by myosin-I controls phagocytic efficiency Message Subject (Your Name) has ...
Recently Myosin-X has been shown to specifically localize at the tip of filopodia. Myosin-X is a member of a family of proteins ... We have found that it is unlikely that Myosin-X interacts with vesicules within filopodia. We have also found that Myosin-X ... Attachment of Myosin-X to filaments of a molecule called actin which forms a sort of conveying belt within filopodia, is ... The presence of Myosin-X at filopodia tips is strongly correlated to the attachment of filopodia to its surrounding, ...
Blebbing, apoptotic body formation and protein release during early apoptosis are dependent on ROCK and myosin ATPase activity ... Actin-myosin-based contraction is responsible for apoptotic nuclear disintegration. J Cell Biol 2005; 168: 245-255. ... Wickman, G., Julian, L., Mardilovich, K. et al. Blebs produced by actin-myosin contraction during apoptosis release damage- ... Mills JC, Stone NL, Erhardt J, Pittman RN . Apoptotic membrane blebbing is regulated by myosin light chain phosphorylation. J ...
Hemodynamic regulation of myosin heavy chain gene expression. Studies in the transplanted rat heart. ... Hemodynamic regulation of myosin heavy chain gene expression. Studies in the transplanted rat heart. ...
DICTYOSTELIUM MYOSIN S1DC (MOTOR DOMAIN FRAGMENT) COMPLEXED WITH O,P-DINITROPHENYL AMINOPROPYLDIPHOSPHATE BERYLLIUM TRIFLUORIDE ... The three-dimensional structures of the truncated myosin head from Dictyostelium discoideum myosin II complexed with ... X-ray structures of the Dictyostelium discoideum myosin motor domain with six non-nucleotide analogs.. Gulick, A.M., Bauer, C.B ... DICTYOSTELIUM MYOSIN S1DC (MOTOR DOMAIN FRAGMENT) COMPLEXED WITH O,P-DINITROPHENYL AMINOPROPYLDIPHOSPHATE BERYLLIUM TRIFLUORIDE ...
Contraction shortens the sarcomere but does not change the length of the actin or myosin filaments. The myosin filaments have ... Each sarcomere consists of thick filaments of myosin, shown in purple, and thin filaments of actin, shown in orange. A ... sarcomere contracts when its actin filaments slide past its myosin filaments. ...
Recombinant Human Myosin-9 (MYH9) , partial from Cusabio. Cat Number: CSB-EP015303HUe0. USA, UK & Europe Distribution. ... Recombinant Human Myosin-9 (MYH9) , partial , CSB-EP015303HUe0 Cusabio Human Recombinants Recombinant Human Myosin-9 (MYH9) , ... Recombinant Human Myosin-9 (MYH9) , partial , CSB-EP015303HUe0 , Cusabio. Alternative Name(s): Cellular myosin heavy chain, ... Protein Families: TRAFAC class myosin-kinesin ATPase superfamily, Myosin family. Tissue Specificity: In the kidney, expressed ...
Myosin heavy chain like (Mhcl) agiert während der Embryonalentwicklung und Myogenese von Drosophila melanogaster in Redundanz ... Zellbiologische und biochemische Charakterisierung des Ustilago maydis Virulenzfaktors Mcs1(Myosin-Chitinsynthase 1) ...
ol,,li, Better understand the ,b,allosteric communication ,/b, pathway used by Myosin to convert ATP hydrolysis energy into ...
... () ... Cardiac myosin binding protein-C (cMyBP-C) is one of the proteins that make up the contractile apparatus of cardiomyocytes. ... Jacques, A.M., Copeland, O., Messer, A.E., Gallon, C.E., King, K., McKenna, W.J., Tsang, V.T. and Marston, S.B. (2008) Myosin- ... Decker, R.S., Decker, M.L., Kulikovskaya, I., Nakamura, S., Lee, D.C., Harris, K., Klocke, F.J. and Winegrad, S. (2005) Myosin- ...
... reaction was used to study the interaction between the regulatory segment and the catalytic site of smooth muscle myosin light ...
... August 23, 2023. Patrick Campbell ... This void has now been effectively filled by cardiac myosin inhibitors. These inhibitors present an entirely fresh and highly ... Some patients might choose to explore cardiac myosin inhibitors, either for a short or extended duration. Others might still ... HCPLive Cardiology: Can you reflect on the impact of the cardiac myosin inhibitor class on management of hypertrophic ...
Myosin, Protein, Proteininteraktion, Proteinregulation. Subjects:. 600 Technology, Medicine. 600 Technology, Medicine , 610 ... Ellrich, Heike (2015): Identification of lipid binding sites in myosin VI and XXI and regulation by the cargo-binding domain. ... Identification of lipid binding sites in myosin VI and XXI and regulation by the cargo-binding domain ... Identification of lipid binding sites in myosin VI and XXI and regulation by the cargo-binding domain ...
Review of Myosin Acetylation - How it Modulates Sarcomere Structure and Function ... Another level of control is applied by kinases such as myosin light-chain kinase [MLCK], myosin light chain 2 [MLC2], and cAMP- ... 240 proteins were modified on 994 lysine residues with myosin acetylated on many different lysine amino acids. In fact, myosin ... A cardiac myosin light chain kinase regulates sarcomere assembly in the vertebrate heart. J. Clin. Invest. 117, 2812-24. ...
Home / Pharmacology / Enzymes / Kinases / Myosin Light Chain Kinases / Myosin Light Chain Kinase Inhibitors / MLCK inhibitor ... Competitive myosin light chain kinase (MLCK) inhibitor (Ki = 1 - 2.2 mM); derived from the calmodulin binding site of skeletal ... Kemp et al (1987) The calmodulin binding domain of chicken smooth muscle myosin light chain kinase contains a pseudosubstrate ... Keywords: MLCK inhibitor peptide, MLCK inhibitor peptide supplier, Myosin, light, chain, kinases, inhibitors, inhibits, MLCK, ...
The rate of cell and tissue contraction scales with the motor activity of myosin 2. ... A) Domain organization of the myosin heavy chain and myosin fragments used to study the biochemical properties of myosin. The ... there are no published values for full length myosin IIB and myosin IIC. The values for myosin IIA came from a study from the ... activates myosin motor activity, enhances the affinity of myosin for actin, and promotes myosin filament assembly (Heissler and ...
  • LIMCH1 interacted with NM-IIA, but not NM-IIB, independent of the inhibition of myosin ATPase activity with blebbistatin. (nih.gov)
  • Thus, although myosin was originally thought to be restricted to muscle cells (hence myo- (s) + -in ), there is no single "myosin" but rather a huge superfamily of genes whose protein products share the basic properties of actin binding, ATP hydrolysis (ATPase enzyme activity), and force transduction. (wn.com)
  • Blebbing, apoptotic body formation and protein release during early apoptosis are dependent on ROCK and myosin ATPase activity to drive actomyosin contraction. (nature.com)
  • In the absence of actin, myosin atpase activity is low and requires calcium ions. (biologyonline.com)
  • This protein makes up part of the sarcomere and forms macromolecular filaments composed of multiple myosin subunits. (wikipedia.org)
  • Presumably this is so the myosins may interact, via their tails, with a large number of different cargoes, while the goal in each case - to move along actin filaments - remains the same and therefore requires the same machinery in the motor. (wikipedia.org)
  • These differences in shape also determine the speed at which myosins can move along actin filaments. (wikipedia.org)
  • Mutations in the MYH7 gene lead to the production of an altered cardiac β-myosin heavy chain protein, which is thought to be less able to form thick filaments. (medlineplus.gov)
  • Attachment of Myosin-X to filaments of a molecule called actin which forms a sort of conveying belt within filopodia, is necessary for the movement of Myosin-X complexes towards the cell centre but this movement is strongly regulated by the part of Myosin-X which does not attach to actin but instead binds other molecules. (europa.eu)
  • Each sarcomere consists of thick filaments of myosin, shown in purple, and thin filaments of actin, shown in orange. (pearson.com)
  • A sarcomere contracts when its actin filaments slide past its myosin filaments. (pearson.com)
  • Contraction shortens the sarcomere but does not change the length of the actin or myosin filaments. (pearson.com)
  • The myosin filaments have heads that bind and pull actin repeatedly, shortening the sarcomere. (pearson.com)
  • The motor domain at the N-terminus of the myosin heavy chain binds actin filaments in an ATP-dependent manner. (elifesciences.org)
  • The C-terminal tail of the myosin heavy chain associates with the tails of other myosin heavy chains and promotes the assembly into bipolar filaments. (elifesciences.org)
  • The bipolar myosin filaments promote the sliding of antiparallel actin filaments relative to one another resulting in contraction of an actin network. (elifesciences.org)
  • The rational for the different myosin fragments lies in the different biochemical properties: Full-length myosin forms filaments, sediments at high speed and can be used in the in vitro motility assay. (elifesciences.org)
  • The measured FRET efficiencies were intermediate between those observed when the donor was attached to the cardiac myosin regulatory light chain in the thick filaments and troponin T in the thin filaments. (kcl.ac.uk)
  • No thick filaments of myosin were found regardless of preparative procedures, which included fixation at rest and in contraction, glycerine extraction, and storage at low pH prior to fixation. (rupress.org)
  • Absence of thick myosin filaments and presence of what appear to be myosin molecules is in accord with conclusions based on X-ray diffraction (3, 12) and birefringence data (4) from living smooth muscles at rest and in contraction. (rupress.org)
  • Explanations are provided for appearances thought by others (6, 20, 21) to represent thick myosin filaments. (rupress.org)
  • The vanadate (Vi)-mediated photocleavage reaction was used to study the interaction between the regulatory segment and the catalytic site of smooth muscle myosin light chain kinase (MLCK). (go.jp)
  • In this study, we analyzed bile canaliculi dynamics, Rho kinase (ROCK)/myosin light chain kinase (MLCK) pathway implication, efflux inhibition of taurocholate [a predominant bile salt export pump (BSEP) substrate], and expression of the major canalicular and basolateral bile acid transporters. (aspetjournals.org)
  • I investigated the roles of RhoA-kinase and myosin II in semaphorin-3A-induced growth cone collapse and axon retraction. (biologists.com)
  • Formation of axonal F-actin bundles was independent of myosin II, but partially required RhoA-kinase activity. (biologists.com)
  • 1988). Kinases responsible for the phosphorylation include myosin light chain kinase (MLCK), ROCK kinase, citron kinase, myotonic dystrophy kinase-related CDC42-binding protein kinase, and Zipper-interacting protein (ZIP) kinase. (reactome.org)
  • All of these homologies were found in the known catalytic domains of these enzyme, thus enabling us to predict the location of the catalytic domain for the chicken gizzard myosin light chain kinase. (torvergata.it)
  • Myosin-Light-Chain Kinase" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (ouhsc.edu)
  • This graph shows the total number of publications written about "Myosin-Light-Chain Kinase" by people in this website by year, and whether "Myosin-Light-Chain Kinase" was a major or minor topic of these publications. (ouhsc.edu)
  • Below are the most recent publications written about "Myosin-Light-Chain Kinase" by people in Profiles. (ouhsc.edu)
  • Regulation of LPA-promoted myofibroblast contraction: role of Rho, myosin light chain kinase, and myosin light chain phosphatase. (ouhsc.edu)
  • Similar filament-forming myosin proteins were found in cardiac muscle, smooth muscle, and nonmuscle cells. (wikipedia.org)
  • The MYH7 gene provides instructions for making a protein known as the cardiac beta (β)-myosin heavy chain. (medlineplus.gov)
  • Cardiac β-myosin heavy chain is the major component of the thick filament in muscle cell structures called sarcomeres . (medlineplus.gov)
  • Cardiac myosin binding protein-C (cMyBP-C) is one of the proteins that make up the contractile apparatus of cardiomyocytes. (scirp.org)
  • Barefield, D. and Sadayappan, S. (2010) Phosphorylation and function of cardiac myosin-binding protein c in health and disease. (scirp.org)
  • Schlossarek, S., Mearini, G. and Carrier, L. (2011) Cardiac myosin-binding protein c in hypertrophic cardiomyopathy: Mechanisms and therapeutic opportunities. (scirp.org)
  • 1,2 Treatment algorithms were transformed in April 2022 with the US Food and Drug Administration approval of mavacamten (Camzyos), a cardiac myosin inhibitor from Bristol Myers Squibb, for treatment of symptomatic obstructive HCM. (hcplive.com)
  • 3 Looking at the pipeline, a next generation cardiac myosin inhibitor from Cytokinetics, called aficamten, has shown promise in phase 1 and phase 2 trials, with the company announcing the launch of the phase 3 MAPLE-HCM trial in June 2023. (hcplive.com)
  • Cardiac myosin binding protein-C (cMyBP-C) is a thick filament-associated regulatory protein frequently found mutated in patients suffering from hypertrophic cardiomyopathy (HCM). (kcl.ac.uk)
  • Notably, the ventricle expresses predominantly β-cardiac myosin while the atrium expresses mostly the α-isoform. (cam.ac.uk)
  • In several instances, such as rheumatoid arthritis, multiple sclerosis, and myocarditis, the autoimmune disease can be induced experimentally by administering self-antigen in the presence of adjuvant (col- lagen, myelin basic protein, and cardiac myosin, respec- tively) (3). (cdc.gov)
  • Myosins (/ˈmaɪəsɪn, -oʊ-/) are a superfamily of motor proteins best known for their roles in muscle contraction and in a wide range of other motility processes in eukaryotes. (wikipedia.org)
  • The neck domain can also serve as a binding site for myosin light chains which are distinct proteins that form part of a macromolecular complex and generally have regulatory functions. (wikipedia.org)
  • The nomenclature can therefore be somewhat confusing when attempting to compare the functions of myosin proteins within and between organisms. (wikipedia.org)
  • However, beginning in the 1970s, researchers began to discover new myosin genes in simple eukaryotes encoding proteins that acted as monomers and were therefore entitled Class I myosins. (wikipedia.org)
  • Myosins ( / ˈ m aɪ ə s ᵻ n , - oʊ - / ) comprise a family of ATP -dependent motor proteins and are best known for their role in muscle contraction and their involvement in a wide range of other motility processes in eukaryotes . (wn.com)
  • Myosin-X is a member of a family of proteins called Myosins known to shuttle other molecules within the cell and thus allow their localization at the place where they are required. (europa.eu)
  • Using a broad spectrum anti-acetyl antibody, the researchers determined that one of the acetylated proteins is myosin. (cytoskeleton.com)
  • Recently, Foster et al 10 reported that in an initial acetylome of porcine heart proteins, 240 proteins were modified on 994 lysine residues with myosin acetylated on many different lysine amino acids. (cytoskeleton.com)
  • Work done using smooth muscle myosin and mammalian non-muscle myosin have demonstrated that phosphorylation of the RLC at conserved Serine and Threonine sites ( Figure 1B , Serine-19 and Threonine-18) activates myosin motor activity, enhances the affinity of myosin for actin, and promotes myosin filament assembly ( Heissler and Sellers, 2016 ). (elifesciences.org)
  • However, it has not been biochemically demonstrated that Drosophila myosin motor activity and filament assembly is regulated by RLC phosphorylation or whether the extent of activation is similar to that of mammalian systems. (elifesciences.org)
  • Myosin II activity is stimulated by phosphorylation of MRLC. (reactome.org)
  • CaMKII-mediated phosphorylation of the myosin motor Myo1c is required for insulin-stimulated GLUT4 translocation in adipocytes. (bvsalud.org)
  • Although, the non-muscle myosin II holoenzyme (myosin) is a molecular motor that powers contraction of actin cytoskeleton networks, recent studies have questioned the importance of myosin motor activity cell and tissue shape changes. (elifesciences.org)
  • Overall, our data highlights that myosin activity is required for rapid cell contraction and tissue folding in developing Drosophila embryos. (elifesciences.org)
  • Alpha and beta myosin isoforms and human atrial and ventricular contraction. (cam.ac.uk)
  • This allowed us consider what features of contraction can and cannot be ascribed to the myosin isoforms present in the atria and ventricles. (cam.ac.uk)
  • Nonmuscle myosin II (NMM2) is an actin-based motor protein that plays a crucial role in a variety of cellular processes, including smooth muscle contraction, cell migration, polarity formation, and cytokinesis. (reactome.org)
  • He called this protein myosin. (wikipedia.org)
  • This condition is characterized by the formation of protein clumps, which contain a protein called myosin, within certain muscle fibers. (medlineplus.gov)
  • Nonmuscle myosin II (NM-II) is an important motor protein involved in cell migration. (nih.gov)
  • During embryonic morphogenesis, the myosin II motor protein generates forces that help to shape tissues, organs, and the overall body form. (aps.org)
  • The protein product of MYH16 is one of the heavy chain myosins, a kind of protein that works with actin to enable muscle fibers to contract. (johnhawks.net)
  • The protein is denoted as MyHC-M, for myosin heavy chain-masticatory. (johnhawks.net)
  • In fact, myosin is the most highly acetylated protein found to date with 49 acetylated lysine residues 10 . (cytoskeleton.com)
  • Effect of different drying methods on the myosin structure, amino acid composition, protein digestibility and volatile profile of squid fillets. (oregonstate.edu)
  • The impacts of freeze drying (FD), hot-air drying (AD), and heat pump drying (HPD) on myosin structure, amino acid composition, protein digestibility and volatile compounds of squid (Todarodes pacificus) fillets were evaluated. (oregonstate.edu)
  • NMM2 consists of two myosin heavy chains encoded by MYH9, MYH10, MYH14 (NMHC-IIA, B and C) or MYH11, two copies of MYL6 essential light chain protein, and two regulatory light chains (MRLCs), MYL9 and MYL12B. (reactome.org)
  • No overt morphological differences were recorded for vessels dissected from KO animals, but SMTNL1 deletion was associated with loss of myosin phosphatase-targeting protein MYPT1 and increase in the myosin phosphatase inhibitor protein CPI-17. (duke.edu)
  • Myosin is a hexamer composed of two myosin heavy chains, two regulatory light chains (RLCs), and two essential light chains (ELCs) ( Figure 1A ). (elifesciences.org)
  • The light chains bind to the central neck domain of the myosin heavy chain and have structural and regulatory functions ( Heissler and Sellers, 2014 ). (elifesciences.org)
  • The top panel shows the myosin hexamer composed of two myosin heavy chains (green), two ELCs (light blue) and two RLCs (gray). (elifesciences.org)
  • Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. (ucdenver.edu)
  • An enzyme that phosphorylates myosin light chains in the presence of ATP to yield myosin-light chain phosphate and ADP, and requires calcium and CALMODULIN. (ouhsc.edu)
  • The 20-kDa light chain is phosphorylated more rapidly than any other acceptor, but light chains from other myosins and myosin itself can act as acceptors. (ouhsc.edu)
  • May be a homodimer, which associates with multiple calmodulin or myosin light chains. (lu.se)
  • Increased number of round HBVP was also seen after oIAPP stimulation, and the effect was reverted by the IAPP analogue pramlintide, Y27632, and the myosin inhibitor blebbistatin. (lu.se)
  • Collectively, these observations suggest that guidance cues cause axon retraction through the coordinated activation of myosin II and the formation of intra-axonal F-actin bundles for myosin-II-based force generation. (biologists.com)
  • The subsequent activation of focal adhesion kinases might activate or recruit myosin II. (rupress.org)
  • Armel TZ, Leinwand LA. Mutations in the beta-myosin rod cause myosin storage myopathy via multiple mechanisms. (medlineplus.gov)
  • I report that semaphorin 3A activates myosin II in growth cones and axons. (biologists.com)
  • For example, the human genome contains over 40 different myosin genes. (wikipedia.org)
  • Myosin storage myopathy is a condition that causes muscle weakness (myopathy) that does not worsen or worsens very slowly over time. (medlineplus.gov)
  • The signs and symptoms of myosin storage myopathy usually become noticeable in childhood, although they can occur later. (medlineplus.gov)
  • Myosin storage myopathy is a rare condition. (medlineplus.gov)
  • Mutations in the MYH7 gene cause myosin storage myopathy. (medlineplus.gov)
  • It is unclear how these changes lead to muscle weakness in people with myosin storage myopathy. (medlineplus.gov)
  • Tajsharghi H, Thornell LE, Lindberg C, Lindvall B, Henriksson KG, Oldfors A. Myosin storage myopathy associated with a heterozygous missense mutation in MYH7. (medlineplus.gov)
  • Newly diagnosed with Autosomal recessive myosin storage myopathy? (globalgenes.org)
  • Virtually all eukaryotic cells contain myosin isoforms. (wikipedia.org)
  • In recent years exploration of the properties of pure α- & β-myosin isoforms have been possible in solution, in isolated myocytes and myofibrils. (cam.ac.uk)
  • Myocardial performance is likely affected by the relative expression of the two myosin heavy chain (MyHC) isoforms, namely {alpha}-MyHC and ß-MyHC. (umsystem.edu)
  • Recently, molecular motor gliding assays with actin and myosin from muscle have been realized on semiconductor nanowires coated with Al2O3. (embs.org)
  • The molecular and mechanical mechanisms by which myosin drives this massive change in embryo shape are poorly understood. (aps.org)
  • To explore the mechanisms by which molecular-level myosin dynamics are translated into tissue-level elongation, we are using time-lapse confocal imaging to observe cell movements in embryos with altered myosin activity. (aps.org)
  • We have found that two actin-dependent molecular motors, class 1 myosins myosin 1e and myosin 1f, are specifically localized to Fc-receptor adhesions and required for efficient phagocytosis of antibody-opsonized targets. (biorxiv.org)
  • Structures with the characteristics of molecular myosin were identified by electron microscopy in tissue sections of vertebrate smooth muscle. (rupress.org)
  • To investigate these mechanisms, we generated a collection of transgenic flies expressing variants of myosin II with altered motor function and regulation. (aps.org)
  • Citations to Hemodynamic regulation of myosin heavy chain gene expression. (jci.org)
  • Hemodynamic regulation of myosin heavy chain gene expression. (jci.org)
  • Synthetic peptide corresponding to Human heavy chain Myosin/MYH3 aa 100-200 conjugated to keyhole limpet haemocyanin. (abcam.com)
  • A ) Domain organization of the myosin heavy chain and myosin fragments used to study the biochemical properties of myosin. (elifesciences.org)
  • The myosin motor domain, the light chain binding neck and the tail domain of the heavy chain are indicated. (elifesciences.org)
  • Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. (ucdenver.edu)
  • Korfage, JAM 2004, ' Myosin heavy chain composition of the human jaw muscles ', PhD, University of Amsterdam. (vu.nl)
  • Both young and old rats displayed an increase in developmental myosin heavy chain (MHCdev+) labeling in the exposed muscle, indicating muscle regeneration. (cdc.gov)
  • Depletion of LIMCH1 attenuated myosin regulatory light chain (MRLC) diphosphorylation in HeLa cells, which was restored by reexpression of small interfering RNA-resistant LIMCH1. (nih.gov)
  • Most myosin molecules are composed of a head, neck, and tail domain. (wikipedia.org)
  • The tail domain generally mediates interaction with cargo molecules and/or other myosin subunits. (wikipedia.org)
  • Multiple myosin II molecules generate force in skeletal muscle through a power stroke mechanism fuelled by the energy released from ATP hydrolysis. (wikipedia.org)
  • It is thus possible that Myosin-X shuttles molecules from the tip to the centre of the cell thus un-abling filopodia to communicate with the rest of the cell about what is detected in its environment. (europa.eu)
  • To elucidate the role Myosin-X plays in filopodia, we have started a study of its movements within filopodia in relation to other molecules or to small vesicles. (europa.eu)
  • This allows us to consider the extent to which the atrial vs ventricular mechanical characteristics are defined by the myosin isoform expressed, and how the isoform properties are matched to their physiological roles. (cam.ac.uk)
  • The head domain binds the filamentous actin, and uses ATP hydrolysis to generate force and to "walk" along the filament towards the barbed (+) end (with the exception of myosin VI, which moves towards the pointed (-) end). (wikipedia.org)
  • These studies will help elucidate how myosin-generated forces control cell movements within tissues. (aps.org)
  • Following the discovery in 1973 of enzymes with myosin-like function in Acanthamoeba castellanii, a global range of divergent myosin genes have been discovered throughout the realm of eukaryotes. (wikipedia.org)
  • The wide variety of myosin genes found throughout the eukaryotic phyla were named according to different schemes as they were discovered. (wikipedia.org)
  • Following the discovery by Pollard and Korn (1973) of enzymes with myosin-like function in Acanthamoeba castellanii , a large number of divergent myosin genes have been discovered throughout eukaryotes. (wn.com)
  • These new myosins were collectively termed "unconventional myosins" and have been found in many tissues other than muscle. (wikipedia.org)
  • The unconventional myosins also have divergent tail domains, suggesting unique functions. (wikipedia.org)
  • The unconventional myosin Myo1c has been implicated in insulin -regulated GLUT4 translocation to the plasma membrane in adipocytes . (bvsalud.org)
  • Using primary macrophages lacking both myosin 1e and myosin 1f, we found that without the actin-membrane linkage mediated by these myosins, the organization of individual adhesions is compromised, leading to excessive actin polymerization, slower adhesion turnover, and deficient phagocytic internalization. (biorxiv.org)
  • The structure and function of myosin is globally conserved across species, to the extent that rabbit muscle myosin II will bind to actin from an amoeba. (wikipedia.org)
  • Skeletal muscle myosin, the most conspicuous of the myosin superfamily due to its abundance in muscle fibers, was the first to be discovered. (wikipedia.org)
  • Here we identify non-muscle myosin-2C (NM2C) as a component of the terminal web. (vanderbilt.edu)
  • Analysis of the amino acid sequences of different myosins shows great variability among the tail domains, but strong conservation of head domain sequences. (wikipedia.org)
  • The importance of acetylation has recently been elevated by the utilization of histone deacetylase (HDAC) inhibitors in pre-clinical research and the treatment of hypertrophic heart disease 6,7 , as well as the discovery of several critical acetylated forms of myosin amino acids that need to be modified in order for the sarcomere to function correctly 8,9 . (cytoskeleton.com)
  • We have found that it is unlikely that Myosin-X interacts with vesicules within filopodia. (europa.eu)
  • Myosin II interacts with F-actin to generate contractile forces that result in axon retraction. (biologists.com)
  • The power stroke occurs at the release of phosphate from the myosin molecule after the ATP hydrolysis while myosin is tightly bound to actin. (wikipedia.org)
  • Using biophysical approaches, we found that these myosin variants also have decreased turnover dynamics within cells. (aps.org)
  • This work identifies a novel role for class 1 myosins in coordinated adhesion turnover during phagocytosis and supports a model for a membrane-tension based feedback mechanism for phagocytic cup closure. (biorxiv.org)
  • These results indicate that HBVP, in an in vitro model of microvasculature, respond morphologically to vasoconstrictors, dilators, and myosin inhibitors. (lu.se)
  • Myosin II pulls growth cones in the right direction, as shown by Stephen Turney and Paul Bridgman (Washington University, St. Louis, MO).Growing neurons in the developing embryo are directed by guidance cues such as laminin-1 (LN1), which steer the extension of neurite growth cones. (rupress.org)
  • Bridgman had previously noticed that neuronal growth cones contain high levels of myosin II. (rupress.org)
  • The contractile forces generated by myosin activity orient cell movements along a common axis, promoting local cell rearrangements that contribute to global tissue elongation. (aps.org)
  • We found that variants that are predicted to have increased myosin activity cause defects in tissue elongation. (aps.org)
  • Here, combining the biochemical analysis of enzymatic and motile properties for purified myosin mutants with in vivo measurements of apical constriction for the same mutants, we show that in vivo constriction rate scales with myosin motor activity. (elifesciences.org)
  • The defect in the myosin motor activity in these mutants is evident in developing Drosophila embryos where tissue recoil following laser ablation is decreased compared to wild-type tissue. (elifesciences.org)
  • But when myosin II activity was inhibited, the neurites ignored the change in substrate and grew over polyornithine. (rupress.org)
  • Myosin II activity is required for axon retraction but not growth cone collapse. (biologists.com)
  • Based on these findings, we conclude that deletion of SMTNL1 contributes to enhancement of pressure-induced contractility of mesenteric resistance vessels by influencing the activity of myosin phosphatase. (duke.edu)
  • how can myosin II drive axon retraction if the major source of the required substratum for force generation, growth cone F-actin, has been depleted? (biologists.com)
  • ATP hydrolysis within the myosin will cause it to bind to actin again to repeat the cycle. (wikipedia.org)
  • Science: enzyme) An enzyme that catalyses the hydrolysis of myosin aTP in the presence of actin to form myosin aDP and orthophosphate. (biologyonline.com)
  • Scholars@Duke publication: Smoothelin-like 1 deletion enhances myogenic reactivity of mesenteric arteries with alterations in PKC and myosin phosphatase signaling. (duke.edu)
  • Our findings answer a decades old question on the function of terminal web myosin and hold broad implications for understanding apical morphogenesis in diverse epithelial systems. (vanderbilt.edu)
  • Given the prominence of myosin as a target for acetylation in cardiomyocytes, further biochemical and functional studies were undertaken. (cytoskeleton.com)
  • On polyornithine, both myosin II and focal complexes are randomly distributed. (rupress.org)
  • On LN1, however, myosin IIB concentrated in the transitional domain of the growth cone-intermingled with or just behind the new front of focal complexes. (rupress.org)
  • We are utilizing computational approaches to quantify the dynamics and directionality of myosin localization and cell rearrangements. (aps.org)