A protein found in the thin filaments of muscle fibers. It inhibits contraction of the muscle unless its position is modified by TROPONIN.
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.
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 actin capping protein that binds to the pointed-end of ACTIN. It functions in the presence of TROPOMYOSIN to inhibit microfilament elongation.
Fibers composed of MICROFILAMENT PROTEINS, which are predominately ACTIN. They are the smallest of the cytoskeletal filaments.
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.
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.
'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.
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 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.
Contractile tissue that produces movement in animals.
A protein complex of actin and MYOSINS occurring in muscle. It is the essential contractile substance of muscle.
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.
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 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 .
The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.
One of the three polypeptide chains that make up the TROPONIN complex. It is a cardiac-specific protein that binds to TROPOMYOSIN. It is released from damaged or injured heart muscle cells (MYOCYTES, CARDIAC). Defects in the gene encoding troponin T result in FAMILIAL HYPERTROPHIC CARDIOMYOPATHY.
A protein factor that regulates the length of R-actin. It is chemically similar, but immunochemically distinguishable from actin.
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)
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.
One of the three polypeptide chains that make up the TROPONIN complex of skeletal muscle. It is a calcium-binding protein.
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
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.
One of the three polypeptide chains that make up the TROPONIN complex. It inhibits F-actin-myosin interactions.
One of two types of muscle in the body, characterized by the array of bands observed under microscope. Striated muscles can be divided into two subtypes: the CARDIAC MUSCLE and the SKELETAL MUSCLE.
A 90-kDa protein produced by macrophages that severs ACTIN filaments and forms a cap on the newly exposed filament end. Gelsolin is activated by CALCIUM ions and participates in the assembly and disassembly of actin, thereby increasing the motility of some CELLS.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
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 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.
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.
Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.
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 group of inherited congenital myopathic conditions characterized clinically by weakness, hypotonia, and prominent hypoplasia of proximal muscles including the face. Muscle biopsy reveals large numbers of rod-shaped structures beneath the muscle fiber plasma membrane. This disorder is genetically heterogeneous and may occasionally present in adults. (Adams et al., Principles of Neurology, 6th ed, p1453)
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.
The sum of the weight of all the atoms in a molecule.

Donor site competition is involved in the regulation of alternative splicing of the rat beta-tropomyosin pre-mRNA. (1/1370)

The rat beta-tropomyosin (beta-TM) gene encodes both skeletal muscle beta-TM mRNA and nonmuscle TM-1 mRNA via alternative RNA splicing. This gene contains eleven exons: exons 1-5, 8, and 9 are common to both mRNAs; exons 6 and 11 are used in fibroblasts as well as in smooth muscle, whereas exons 7 and 10 are used in skeletal muscle. Previously we demonstrated that utilization of the 3' splice site of exon 7 is blocked in nonmuscle cells. In this study, we use both in vitro and in vivo methods to investigate the regulation of the 5' splice site of exon 7 in nonmuscle cells. The 5' splice site of exon 7 is used efficiently in the absence of flanking sequences, but its utilization is suppressed almost completely when the upstream exon 6 and intron 6 are present. The suppression of the 5' splice site of exon 7 does not result from the sequences at the 3' end of intron 6 that block the use of the 3' splice site of exon 7. However, mutating two conserved nucleotides GU at the 5' splice site of exon 6 results in the efficient use of the 5' splice site of exon 7. In addition, a mutation that changes the 5' splice site of exon 7 to the consensus U1 snRNA binding site strongly stimulates the splicing of exon 7 to the downstream common exon 8. Collectively, these studies demonstrate that 5' splice site competition is responsible, in part, for the suppression of exon 7 usage in nonmuscle cells.  (+info)

Properties of non-polymerizable tropomyosin obtained by carboxypeptidase A digestion. (2/1370)

Tropomyosin digested with carboxypeptidase A [EC] (CTM) shows a lower viscosity than the undigested protein in solution. From the relation between the viscosity decrease and the amount of amino acids liberated from the carboxyl terminus during this digestion, it is inferred that loss of the tri-peptide-Thr-Ser-Ile from the C-terminus is responsible for the decrease in viscosity. The secondary structure of -TM was not affected by the digestion according to circular dichroic measurements. The viscosity of CTM did not increase in methanol-water mixtures, whereas that of tropomyosin increased markedly. These results indicate that polymerizability was lost upon the removal of a small peptide from the C-terminus without change in the secondary structure. A decrease in the viscosity of tropomyosin solutions was observed on the addition of CTM, indicating that CTM interacts with intact tropomyosin. The dependence of the viscosity decrease on the amount of CTM showed that CTM binds tropomyosin in a one-to-one ratio as a result of end-to-end interaction. Since paracrystals having a 400 A repeated band structure could be grown in the presence of Mg ions at neutral pH, side-by-side interactions in CTM molecules remain intact, even though polymerizability is lost. The disc gel electrophoretic pattern showed that troponin could bind to CTM, but no increase in viscosity due to the complex was observed in solution. That is, the C-terminal part of tropomyosin is not required for the formation of the complex. The amount of CTM bound to F-actin was less than half of that bound to undigested tropomyosin, and could be reduced to one-tenth by a washing procedure. In the presence of troponin, however, the amount recovered to the level of tropomyosin normally bound to F-actin. Therefore, it is concluded that troponin is bound in the middle of the tropomyosin molecule and strengthens the binding of tropomyosin to F-actin.  (+info)

Roles for the troponin tail domain in thin filament assembly and regulation. A deletional study of cardiac troponin T. (3/1370)

Striated muscle contraction is regulated by Ca2+ binding to troponin, which has a globular domain and an elongated tail attributable to the NH2-terminal portion of the bovine cardiac troponin T (TnT) subunit. Truncation of the bovine cardiac troponin tail was investigated using recombinant TnT fragments and subunits TnI and TnC. Progressive truncation of the troponin tail caused progressively weaker binding of troponin-tropomyosin to actin and of troponin to actin-tropomyosin. A sharp drop-off in affinity occurred with NH2-terminal deletion of 119 rather than 94 residues. Deletion of 94 residues had no effect on Ca2+-activation of the myosin subfragment 1-thin filament MgATPase rate and did not eliminate cooperative effects of Ca2+ binding. Troponin tail peptide TnT1-153 strongly promoted tropomyosin binding to actin in the absence of TnI or TnC. The results show that the anchoring function of the troponin tail involves interactions with actin as well as with tropomyosin and has comparable importance in the presence or absence of Ca2+. Residues 95-153 are particularly important for anchoring, and residues 95-119 are crucial for function or local folding. Because striated muscle regulation involves switching among the conformational states of the thin filament, regulatory significance for the troponin tail may arise from its prominent contribution to the protein-protein interactions within these conformations.  (+info)

Binding of hnRNP H to an exonic splicing silencer is involved in the regulation of alternative splicing of the rat beta-tropomyosin gene. (4/1370)

In the rat beta-tropomyosin (beta-TM) gene, exons 6 and 7 are spliced alternatively in a mutually exclusive manner. Exon 6 is included in mRNA encoding nonmuscle TM-1, whereas exon 7 is used in mRNA encoding skeletal muscle beta-TM. Previously, we demonstrated that a six nucleotide mutation at the 5' end of exon 7, designated as ex-1, activated exon 7 splicing in nonmuscle cells. In this study, we show that the activating effect of this mutation is not the result of creating an exonic splicing enhancer (ESE) or disrupting a putative secondary structure. The sequence in exon 7 acts as a bona fide exonic splicing silencer (ESS), which is bound specifically by a trans-acting factor. Isolation and peptide sequencing reveal that this factor is hnRNP H, a member of the heterogeneous nuclear ribonucleoprotein (hnRNP) family. Binding of hnRNP H correlates with the ESS activity. Furthermore, addition of antibodies that specifically recognizes hnRNP H to the splicing reactions or partial depletion of hnRNP H from nuclear extract activates exon 7 splicing in vitro and this effect can be reversed by addition of purified recombinant hnRNP H. These results indicate that hnRNP H participates in exclusion of exon 7 in nonmuscle cells. The involvement of hnRNP H in the activity of an ESS may represent a prototype for the regulation of tissue- and developmental-specific alternative splicing.  (+info)

Amphidinolide B, a powerful activator of actomyosin ATPase enhances skeletal muscle contraction. (5/1370)

Amphidinolide B caused a concentration-dependent increase in the contractile force of skeletal muscle skinned fibers. The concentration-contractile response curve for external Ca2+ was shifted to the left in a parallel manner, suggesting an increase in Ca2+ sensitivity. Amphidinolide B stimulated the superprecipitation of natural actomyosin. The maximum response of natural actomyosin to Ca2+ in superprecipitation was enhanced by it. Amphidinolide B increased the ATPase activity of myofibrils and natural actomyosin. The ATPase activity of actomyosin reconstituted from actin and myosin was enhanced in a concentration-dependent manner in the presence or absence of troponin-tropomyosin complex. Ca2+-, K+-EDTA- or Mg2+-ATPase of myosin was not affected by amphidinolide B. These results suggest that amphidinolide B enhances an interaction of actin and myosin directly and increases Ca2+ sensitivity of the contractile apparatus mediated through troponin-tropomyosin system, resulting in an increase in the ATPase activity of actomyosin and thus enhances the contractile response of myofilament.  (+info)

Aldolase binding to actin-containing filaments. Formation of paracrystals. (6/1370)

Electron-microscopy observation show that when aldolase binds to F-actin or F-actin-tropomyosin, highly ordered paracrystalline structures are formed consisting of tightly packed filament bundles cross-banded at 36 nm intervals. Morphologically different paracrystalline arrays are formed between aldolase and F-actin-tropomyosin-troponin. The filament bundles are far more extensive and are characterized by a prominent cross-striation at 38nm intervals. It is suggested that this reflects an interaction between troponin and aldolase.  (+info)

Exonic splicing enhancers contribute to the use of both 3' and 5' splice site usage of rat beta-tropomyosin pre-mRNA. (7/1370)

The rat beta-tropomyosin gene encodes two tissue-specific isoforms that contain the internal, mutually exclusive exons 6 (nonmuscle/smooth muscle) and 7 (skeletal muscle). We previously demonstrated that the 3' splice site of exon 6 can be activated by introducing a 9-nt polyuridine tract at its 3' splice site, or by strengthening the 5' splice site to a U1 consensus binding site, or by joining exon 6 to the downstream common exon 8. Examination of sequences within exons 6 and 8 revealed the presence of two purine-rich motifs in exon 6 and three purine-rich motifs in exon 8 that could potentially represent exonic splicing enhancers (ESEs). In this report we carried out substitution mutagenesis of these elements and show that some of them play a critical role in the splice site usage of exon 6 in vitro and in vivo. Using UV crosslinking, we have identified SF2/ASF as one of the cellular factors that binds to these motifs. Furthermore, we show that substrates that have mutated ESEs are blocked prior to A-complex formation, supporting a role for SF2/ASF binding to the ESEs during the commitment step in splicing. Using pre-mRNA substrates containing exons 5 through 8, we show that the ESEs within exon 6 also play a role in cooperation between the 3' and 5' splice sites flanking this exon. The splicing of exon 6 to 8 (i.e., 5' splice site usage of exon 6) was enhanced with pre-mRNAs containing either the polyuridine tract in the 3' splice site or consensus sequence in the 5' splice site around exon 6. We show that the ESEs in exon 6 are required for this effect. However, the ESEs are not required when both the polyuridine and consensus splice site sequences around exon 6 were present in the same pre-mRNA. These results support and extend the exon-definition hypothesis and demonstrate that sequences at the 3' splice site can facilitate use of a downstream 5' splice site. In addition, the data support the hypothesis that ESEs can compensate for weak splice sites, such as those found in alternatively spliced exons, thereby providing a target for regulation.  (+info)

Regulatory protein of vascular smooth muscle. (8/1370)

Preparations of native tropomyosin from the muscles of bovine aorta and carotid artery resensitized myosin B from either tissue. Neither preparation had any effect on desensitized myosin B from skeletal muscle but native tropomyosin from skeletal muscle could resensitize desensitized myosin B from vascular smooth muscles.  (+info)

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.

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.

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.

Tropomodulin is a protein that plays a crucial role in the regulation of actin filament length and structure in muscle and non-muscle cells. It is located at the pointed ends of the actin filaments, where it binds and caps the filament, preventing the addition or loss of actin subunits. This helps maintain the stability and integrity of the cytoskeleton. Tropomodulin also interacts with other proteins, such as troponin and tropomyosin, to regulate muscle contraction. Mutations in the tropomodulin gene have been associated with certain inherited cardiac disorders, including hypertrophic cardiomyopathy and dilated cardiomyopathy.

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.

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.

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.

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.

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.

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.

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.

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.

"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.

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.

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.

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.

Troponin T is a subunit of the troponin complex, which is a protein complex that plays a crucial role in muscle contraction. In particular, Troponin T is responsible for binding the troponin complex to tropomyosin, another protein that helps regulate muscle contraction.

In the context of medical diagnostics, Troponin T is often measured as a biomarker for heart damage. When heart muscle cells are damaged or die, such as in a myocardial infarction (heart attack), troponin T is released into the bloodstream. Therefore, measuring the levels of Troponin T in the blood can help diagnose and assess the severity of heart damage.

It's important to note that Troponin T is specific to cardiac muscle cells, which makes it a more reliable biomarker for heart damage than other markers that may also be found in skeletal muscle cells. However, it's worth noting that Troponin T levels can also be elevated in conditions other than heart attacks, such as heart failure, myocarditis, and pulmonary embolism, so clinical context is important when interpreting test results.

Actinin is a protein that belongs to the family of actin-binding proteins. It plays an important role in the organization and stability of the cytoskeleton, which is the structural framework of a cell. Specifically, actinin crosslinks actin filaments into bundles or networks, providing strength and rigidity to the cell structure. There are several isoforms of actinin, with alpha-actinin and gamma-actinin being widely studied. Alpha-actinin is found in the Z-discs of sarcomeres in muscle cells, where it helps anchor actin filaments and maintains the structural integrity of the muscle. Gamma-actinin is primarily located at cell-cell junctions and participates in cell adhesion and signaling processes.

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.

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.

Troponin C is a subunit of the troponin complex, which is a protein complex that plays a crucial role in muscle contraction. In the heart, the troponin complex is found in the myofibrils of cardiac muscle cells (cardiomyocytes). It is composed of three subunits: troponin C, troponin T, and troponin I.

Troponin C has the ability to bind calcium ions (Ca²+), which is essential for muscle contraction. When Ca²+ binds to troponin C, it causes a conformational change that leads to the exposure of binding sites on troponin I for another protein called actin. This interaction allows for the cross-bridge formation between actin and myosin, generating the force needed for muscle contraction.

In clinical settings, cardiac troponins (including troponin T and troponin I) are commonly measured in blood tests to diagnose and monitor heart damage, particularly in conditions like myocardial infarction (heart attack). However, Troponin C is not typically used as a biomarker for heart injury because it is less specific to the heart than troponin T and troponin I. Increased levels of Troponin C in the blood can be found in various conditions involving muscle damage or disease, making it less useful for diagnosing heart-specific issues.

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.

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.

Troponin I is a protein that is found in the cardiac muscle cells (myocytes) of the heart. It is a component of the troponin complex, which also includes troponin C and troponin T, that regulates the calcium-mediated interaction between actin and myosin filaments during muscle contraction.

Troponin I is specific to the cardiac muscle tissue, making it a useful biomarker for detecting damage to the heart muscle. When there is injury or damage to the heart muscle cells, such as during a heart attack (myocardial infarction), troponin I is released into the bloodstream.

Measurement of cardiac troponin I levels in the blood is used in the diagnosis and management of acute coronary syndrome (ACS) and other conditions that cause damage to the heart muscle. Elevated levels of troponin I in the blood are indicative of myocardial injury, and the degree of elevation can help determine the severity of the injury.

Striated muscle, also known as skeletal or voluntary muscle, is a type of muscle tissue that is characterized by the presence of distinct light and dark bands, or striations, when viewed under a microscope. These striations correspond to the arrangement of sarcomeres, which are the functional units of muscle fibers.

Striated muscle is under voluntary control, meaning that it is consciously activated by signals from the nervous system. It is attached to bones via tendons and is responsible for producing movements of the body. Striated muscle fibers are multinucleated, meaning that they contain many nuclei, and are composed of numerous myofibrils, which are rope-like structures that run the length of the fiber.

The myofibrils are composed of thick and thin filaments that slide past each other to cause muscle contraction. The thick filaments are made up of the protein myosin, while the thin filaments are composed of actin, tropomyosin, and troponin. When a nerve impulse arrives at the muscle fiber, it triggers the release of calcium ions from the sarcoplasmic reticulum, which bind to troponin and cause a conformational change that exposes the binding sites on actin for myosin. The myosin heads then bind to the actin filaments and pull them towards the center of the sarcomere, causing the muscle fiber to shorten and contract.

Gelsolin is a protein that plays a role in the regulation of actin, which is a major component of the cytoskeleton in cells. The gelsolin protein can bind to and sever actin filaments, as well as cap their plus ends, preventing further growth. This regulation of actin dynamics is important for various cellular processes, including cell motility, wound healing, and the immune response.

There are two forms of gelsolin in humans: plasma gelsolin, which is found in blood plasma, and cytoplasmic gelsolin, which is found in the cytoplasm of cells. Plasma gelsolin has been shown to have anti-inflammatory properties and may play a role in protecting against sepsis and other inflammatory conditions.

Mutations in the gene that encodes gelsolin can lead to various genetic disorders, including familial amyloidosis, Finnish type (FAF), which is characterized by progressive nerve damage and muscle weakness.

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.

Viscosity is a physical property of a fluid that describes its resistance to flow. In medical terms, viscosity is often discussed in relation to bodily fluids such as blood or synovial fluid (found in joints). The unit of measurement for viscosity is the poise, although it is more commonly expressed in millipascals-second (mPa.s) in SI units. Highly viscous fluids flow more slowly than less viscous fluids. Changes in the viscosity of bodily fluids can have significant implications for health and disease; for example, increased blood viscosity has been associated with cardiovascular diseases, while decreased synovial fluid viscosity can contribute to joint pain and inflammation in conditions like osteoarthritis.

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.

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.

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.

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.

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.

Nemaline myopathy is a genetic muscle disorder characterized by the presence of rod-like structures called nemalines in the muscle fibers. These rods, which are composed of accumulated protein, can be observed under a microscope in biopsied muscle tissue. The condition is typically present at birth or appears in early childhood and is often associated with muscle weakness, hypotonia (low muscle tone), and delayed motor development.

There are several types of nemaline myopathy, which vary in severity and age of onset. Some individuals with the disorder may have only mild symptoms and be able to lead relatively normal lives, while others may experience significant disability and require assistance with daily activities. The condition can also affect the heart and respiratory muscles, leading to serious complications.

Nemaline myopathy is caused by mutations in one of several genes that are involved in the formation and maintenance of muscle fibers. These genetic defects lead to abnormalities in the structure and function of the muscle fibers, resulting in the characteristic symptoms of the disorder. There is currently no cure for nemaline myopathy, but treatment is focused on managing the symptoms and improving quality of life. This may include physical therapy, assistive devices, and respiratory support, as well as medications to help manage muscle spasticity and other complications.

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.

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.

... mutations in both the γ-Tropomyosin and β-Tropomyosin genes have been identified. No mutations in the α-Tropomyosin gene have ... Although tropomyosin is sometimes included as an ABP, it is not a true ABP. The tropomyosin dimer has very low affinity for an ... muscle tropomyosin isoforms and nonmuscle tropomyosin isoforms. Muscle tropomyosin isoforms are involved in regulating ... In fungi, tropomyosin is found in cell walls and helps maintain the structural integrity of cells. Tropomyosin is found in ...
In enzymology, a tropomyosin kinase (EC is an enzyme that catalyzes the chemical reaction ATP + tropomyosin ⇌ {\ ... tropomyosin O-phosphotransferase. Other names in common use include tropomyosin kinase (phosphorylating), and STK. deBelle I, ... Montgomery K, Mak AS (1984). "In vitro phosphorylation of tropomyosin by a kinase from chicken embryo". J. Biol. Chem. 259 (9 ... Watson MH, Taneja AK, Hodges RS, Mak AS (1988). "Phosphorylation of alpha alpha- and beta beta-tropomyosin and synthetic ...
"Entrez Gene: TPM3 tropomyosin 3". Lees-Miller JP, Helfman DM (1992). "The molecular basis for tropomyosin isoform diversity". ... Tropomyosin alpha-3 chain is a protein that in humans is encoded by the TPM3 gene. This gene encodes a member of the ... Martin-Zanca D, Hughes SH, Barbacid M (1986). "A human oncogene formed by the fusion of truncated tropomyosin and protein ... Reinach FC, MacLeod AR (1986). "Tissue-specific expression of the human tropomyosin gene involved in the generation of the trk ...
... (TrkC), also known as NT-3 growth factor receptor, neurotrophic tyrosine kinase receptor type 3, ... Kue CS, Kamkaew A, Voon SH, Kiew LV, Chung LY, Burgess K, Lee HB (November 2016). "Tropomyosin Receptor Kinase C Targeted ... October 2015). "An Oncogenic NTRK Fusion in a Patient with Soft-Tissue Sarcoma with Response to the Tropomyosin-Related Kinase ... Another common feature of neurotrophins is that they produce their physiologic effects by means of the tropomyosin receptor ...
... (TrkB), also known as tyrosine receptor kinase B, or BDNF/NT-3 growth factors receptor or ... October 2015). "An Oncogenic NTRK Fusion in a Patient with Soft-Tissue Sarcoma with Response to the Tropomyosin-Related Kinase ... Ohira K, Kumanogoh H, Sahara Y, Homma KJ, Hirai H, Nakamura S, Hayashi M (February 2005). "A truncated tropomyosin-related ... Another common feature of neurotrophins is that they produce their physiologic effects by means of the tropomyosin receptor ...
Shi H, Zhu S, Qin B, Wang L, Yang J, Lu G, Dai F (December 2019). "Nerve growth factor and Tropomyosin receptor kinase A are ... Tropomyosin receptor kinase A (TrkA), also known as high affinity nerve growth factor receptor, neurotrophic tyrosine kinase ... Stoleru B, Popescu A, Tache D, Neamtu O, Emami G, Tataranu L, Buteica A, Dricu A, Purcaru S (2013). "Tropomyosin-Receptor- ... Martin-Zanca D, Hughes SH, Barbacid M (April 1986). "A human oncogene formed by the fusion of truncated tropomyosin and protein ...
... adding tropomyosin; varying light conditions; and varying temperature. The results of these studies showed that the D66 strain ...
Calponin also binds tropomyosin, tubulin, desmin, Ca2+-calmodulin, Ca2+-S100, myosin, and phospholipids. Calponin also ... Childs TJ, Watson MH, Novy RE, Lin JJ, Mak AS (1992). "Calponin and tropomyosin interactions". Biochimica et Biophysica Acta ( ... interaction with tropomyosin paracrystals". Journal of Hypertension Supplement. 6 (4): S40-3. doi:10.1097/00004872-198812040- ...
... a tropomyosin isoform encoded by the gamma-tropomyosin gene". Biochem. Biophys. Res. Commun. 201 (2): 627-34. doi:10.1006/bbrc. ... A tropomyosin-binding protein". J Biol Chem. 267 (4): 2616-21. doi:10.1016/S0021-9258(18)45926-1. PMID 1370827. Sung LA, Fan Y ... 2004). "Alterations in tropomyosin isoform expression in human transitional cell carcinoma of the urinary bladder". Int. J. ... Vera C, Lao J, Hamelberg D, Sung LA (2006). "Mapping the tropomyosin isoform 5 binding site on human erythrocyte tropomodulin: ...
Actin, desmin, myosin, and tropomyosin". Am. J. Pathol. 142 (1): 221-30. PMC 1886840. PMID 8424456. v t e (Articles with short ...
... in that skin tests confirming dust mite allergy were also positive for shellfish tropomyosin. In addition to tropomyosin, ... Tropomyosin, the major allergen in shellfish allergy, is also found in dust mites and cockroaches. Exposure to inhaled ... Tropomyosin, arginine kinase, myosin light chain and sarcoplasmic calcium-binding protein are widely present across shellfish ... The immune system overreacts to proteins found in shellfish, most commonly to tropomyosin, but often to other proteins, such as ...
Actin, desmin, myosin, and tropomyosin". Am. J. Pathol. 142 (1): 221-30. PMC 1886840. PMID 8424456. New L, Jiang Y, Zhao M, et ...
Other proteins that are known to interact with NM IIA include the actin binding protein tropomyosin 4.2 and a novel actin ... Actin, desmin, myosin, and tropomyosin". The American Journal of Pathology. 142 (1): 221-30. PMC 1886840. PMID 8424456. Lalwani ... "Load-dependent modulation of non-muscle myosin-2A function by tropomyosin 4.2". Scientific Reports. 6: 20554. Bibcode:2016NatSR ...
Actin, desmin, myosin, and tropomyosin". The American Journal of Pathology. 142 (1): 221-30. PMC 1886840. PMID 8424456. ... contraction is activated through thin filament proteins troponin and tropomyosin, whereas in NM-IIB and smooth muscle myosin, ...
McLachlan, A.D.; Stewart, Murray; Smillie, L.B. (1975). "Sequence repeats in α-tropomyosin". Journal of Molecular Biology. 98 ( ... STEWART, MURRAY; MCLACHLAN, A. D. (1975). "Fourteen actin-binding sites on tropomyosin?". Nature. 257 (5524): 331-333. Bibcode: ... such as muscle protein tropomyosin). He retired in 2006. McLachlan was elected Fellow of the Royal Society in 1989. Stone, A. J ...
Tropomyosin alpha-4 chain is a protein that in humans is encoded by the TPM4 gene. GRCh38: Ensembl release 89: ENSG00000167460 ... "Entrez Gene: TPM4 tropomyosin 4". Rasmussen HH, van Damme J, Puype M, et al. (1993). "Microsequences of 145 proteins recorded ... Wilton SD, Lim L, Dorosz SD, Gunn HC, Eyre HJ, Callen DF, Laing NG (Jul 1996). "Assignment of the human alpha-tropomyosin gene ... 1986). "A muscle-type tropomyosin in human fibroblasts: evidence for expression by an alternative RNA splicing mechanism". Proc ...
Actin, desmin, myosin, and tropomyosin". Am. J. Pathol. 142 (1): 221-30. PMC 1886840. PMID 8424456. Xu XR, Huang J, Xu ZG, et ...
An accepted mechanism for this process is that ADP-bound myosin attaches to actin while thrusting tropomyosin inwards, then the ... Actin, desmin, myosin, and tropomyosin". The American Journal of Pathology. 142 (1): 221-30. PMC 1886840. PMID 8424456. Nakao K ...
Gunning P, Weinberger R, Jeffrey P (Apr 1997). "Actin and tropomyosin isoforms in morphogenesis". Anatomy and Embryology. 195 ( ...
Tropomyosin alpha-1 chain is a protein that in humans is encoded by the TPM1 gene. This gene is a member of the tropomyosin (Tm ... Perry SV (2004). "What is the role of tropomyosin in the regulation of muscle contraction?". J. Muscle Res. Cell. Motil. 24 (8 ... Cho YJ, Liu J, Hitchcock-DeGregori SE (1990). "The amino terminus of muscle tropomyosin is a major determinant for function". J ... 1988). "Evolution of tropomyosin functional domains: differential splicing and genomic constraints". J. Mol. Evol. 27 (3): 228- ...
The IT arm is anchored to tropomyosin via adjacent segments of cTnT, so it is believed to move as a unit along with tropomyosin ... Tripet B, Van Eyk JE, Hodges RS (Sep 1997). "Mapping of a second actin-tropomyosin and a second troponin C binding site within ... von der Ecken J, Müller M, Lehman W, Manstein DJ, Penczek PA, Raunser S (Mar 2015). "Structure of the F-actin-tropomyosin ... The availability of cTnI148-159 depends on the blocked-closed-open equilibrium of tropomyosin on actin, which can be impacted ...
... tropomyosin, alpha-actinin. Xin, and XIRP2. Nebulette was identified in 1995 by Moncman and Wang using primary cultures of ... depressed beating frequencies and loss of thin filament regulatory proteins troponin I and tropomyosin. Mutations in the NEBL ... "The nebulette repeat domain is necessary for proper maintenance of tropomyosin with the cardiac sarcomere". Experimental Cell ...
The helical F-actin filament found in muscles also contains a tropomyosin molecule, which is a 40 nanometre long protein that ... At times of rest, the proteins tropomyosin and troponin bind to the actin filaments, preventing the attachment of myosin. When ... During the resting phase the tropomyosin covers the actin's active sites so that the actin-myosin interaction cannot take place ... There are other protein molecules bound to the tropomyosin thread, these are the troponins that have three polymers: troponin I ...
... the actin-tropomyosin complex, and the actomyosin complex. The lab has determined the cryoEM structures of F-actin at ~2.2 Å ... "Structure of the F-actin-tropomyosin complex". Nature. Springer Science and Business Media LLC. 519 (7541): 114-117. doi: ...
Tropomyosin receptor kinase B § Agonists Andreeva, O. A.; Ivashev, M. N.; Ozimina, I. I.; Maslikova, G. V. (1998). "Diosmetin ...
Hodges RS, Sodek J, Smillie LB, Jurasek L (1973). "Tropomyosin: Amino Acid Sequence and Coiled-Coil Structure". Cold Spring ...
Ebashi, S; Kodama, A (1965). "A new protein factor promoting aggregation of tropomyosin". Journal of Biochemistry. 58 (1): 107- ...
Ono S, Ono K (March 2002). "Tropomyosin inhibits ADF/cofilin-dependent actin filament dynamics". J. Cell Biol. 156 (6): 1065-76 ...
The tropomyosin receptor kinase A receptor has five extracellular domains, and the fifth domain is sufficient in binding NGF. ... NGF can drive the expression of genes such as bcl-2 by binding to the Tropomyosin receptor kinase A, which stimulates the ... NGF binds with at least two classes of receptors: the tropomyosin receptor kinase A (TrkA) and low-affinity NGF receptor (LNGFR ... Stoleru B, Popescu A, Tache D, Neamtu O, Emami G, Tataranu L, Buteica A, Dricu A, Purcaru S (2013). "Tropomyosin-Receptor- ...
The oncogene was generated by a mutation in chromosome 1 that resulted in the fusion of the first seven exons of tropomyosin to ... Normal Trk receptors do not contain amino acid or DNA sequences related to tropomyosin. The three most common types of trk ... Stoleru B, Popescu A, Tache D, Neamtu O, Emami G, Tataranu L, Buteica A, Dricu A, Purcaru S (2013). "Tropomyosin-Receptor- ... Martin-Zanca D, Hughes SH, Barbacid M (1986). "A human oncogene formed by the fusion of truncated tropomyosin and protein ...
  • Missense mutations K15N and R21H in striated muscle tropomyosin are linked to dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM), respectively. (nih.gov)
  • We used Förster resonance energy transfer to study effects of the tropomyosin mutations on the structure and kinetics of the cardiac troponin core domain associated with the Ca 2+ -dependent regulation of cardiac thin filaments. (nih.gov)
  • Pathogenesis of most myopathies including inherited hypertrophic (HCM) and dilated (DCM) cardiomyopathies is based on modification of structural state of contractile proteins induced by point mutations, such as mutations in alpha-tropomyosin (TM). (ox.ac.uk)
  • Mutations in alpha-TM associated with HCM caused a shift of TM strands to the center of the thin filament and increased a range of tropomyosin motion and affinity of this protein to actin in the ATPase cycle. (ox.ac.uk)
  • Among those are 30 single-residue mutations in TPM1, the gene encoding α-tropomyosin. (instem.res.in)
  • These mutations change single amino acids in slow muscle α-tropomyosin and are thought to impair the protein's ability to interact with myosin and actin within type I skeletal muscle fibers, disrupting muscle contraction. (medlineplus.gov)
  • Mutations of tropomyosin 3 (TPM3) are common and associated with type 1 myofiber hypotrophy in congenital fiber type disproportion. (medlineplus.gov)
  • NM is caused by mutations in at least nine genes: Nebulin ( NEB ), α-actin ( ACTA1 ), α-tropomyosin ( TPM3 ), β-tropomyosin ( TPM2 ), troponin T ( TNNT1 ), cofilin-2 ( CFL2 ), Kelch repeat and BTB (POZ) domain-containing 13 ( KBTBD13 ), and Kelch-like family members 40 and 41 ( KLHL40 and KLHL41 ). (biomedcentral.com)
  • We also used the GST pull-down assay to test the affinity of WT nebulin super repeats for WT α- and β-tropomyosin, and for β-tropomyosin with six patient mutations: p.Lys7del, p.Glu41Lys, p.Lys49del, p.Glu117Lys, p.Glu139del and p.Gln147Pro. (biomedcentral.com)
  • Of the tropomyosin mutations, only p.Glu41Lys showed weaker affinity for nebulin (super repeat 18). (biomedcentral.com)
  • We demonstrate for the first time the existence of direct tropomyosin-nebulin interactions in vitro , and show that nebulin interactions with actin and tropomyosin are altered by disease-causing mutations in nebulin and tropomyosin. (biomedcentral.com)
  • Mutations in this gene can alter the expression of other sarcomeric tropomyosin proteins, and cause cap disease, nemaline myopathy and distal arthrogryposis syndromes. (abbkine.com)
  • Tropomyosin, together with the troponin complex, regulates muscle contraction and, along with tropomodulin and leiomodin, controls the uniform thin-filament lengths crucial for normal sarcomere structure and function. (nih.gov)
  • Three types of troponins exist-troponin I, troponin T, and troponin C. Each subunit has a unique function: Troponin T binds the troponin components to tropomyosin, troponin I inhibits the interaction of myosin with actin, and troponin C contains the binding sites for Ca2+ that helps initiate contraction. (medscape.com)
  • This Rat Tropomyosin beta chain (TPM2) ELISA Kit employs a two-site sandwich ELISA to quantitate TPM2 in samples. (abbkine.com)
  • Rat Tropomyosin beta chain (TPM2) ELISA Kit has high sensitivity and excellent specificity for detection of Rat TPM2. (abbkine.com)
  • TPM2 isbeta-tropomyosin, a member of the actin filament binding protein family, and mainly expressed in slow, type 1 muscle fibers. (abbkine.com)
  • The TPM2 gene provides instructions for making a tropomyosin protein. (medlineplus.gov)
  • 2: Prulire G, d'Albis A, der Terrossian E. Effect of tropomyosin on the interactions of actin with actin-binding proteins isolated from pig platelets Eur J Biochem. (prlog.org)
  • Tropomyosin proteins regulate the tensing of muscle fibers (muscle contraction) by controlling the binding of two muscle proteins, myosin and actin. (medlineplus.gov)
  • In non-muscle cells, tropomyosin proteins play a role in controlling cell shape. (medlineplus.gov)
  • When tested for tropomyosin affinity, super repeats containing the p.Glu2431Lys mutation showed stronger binding than WT proteins to tropomyosin, and the super repeat containing the p.Thr7382Pro mutation showed weaker binding than WT proteins to tropomyosin. (biomedcentral.com)
  • Entrectinib is a selective tyrosine kinase inhibitor designed to inhibit the kinase activity of the tropomyosin receptor kinase (TRK) A/B/C and ROS1 proteins. (medscape.com)
  • The TPM3 gene provides instructions for making a protein called slow muscle alpha (α)-tropomyosin, which is part of the tropomyosin protein family. (medlineplus.gov)
  • A mutation in the alpha tropomyosin gene TPM3 associated with autosomal dominant nemaline myopathy. (medlineplus.gov)
  • Additional studies associating variation at these loci with change in gene expression highlighted Tropomyosin 1 ( TPM1 ) among our top-ranked candidate genes. (biomedcentral.com)
  • Genetic studies have also suggested a role for Tropomyosin 1 ( TPM1 ) in human platelet trait variation [ 6 ], though no prior studies have elucidated if or how TPM1 impacts human hematopoiesis. (biomedcentral.com)
  • Mechanistic heterogeneity in contractile properties of α-tropomyosin (TPM1) mutants associated with inherited cardiomyopathies. (instem.res.in)
  • Within mammals, four genes are responsible for generating more than 40 different tropomyosin isoforms. (wikipedia.org)
  • A vast array of tropomyosin isoforms are generated by using a combination of different genes and alternative splicing. (wikipedia.org)
  • Although functional redundancy does not exist between tropomyosin genes, these results suggest that significant redundancy exists between products from the same gene. (edu.au)
  • Tropomyosins are often categorised into two groups: muscle tropomyosin isoforms and nonmuscle tropomyosin isoforms. (wikipedia.org)
  • Muscle tropomyosin isoforms are involved in regulating interactions between actin and myosin in the muscle sarcomere and play a pivotal role in regulated muscle contraction. (wikipedia.org)
  • Nonmuscle tropomyosin isoforms function in both muscle and nonmuscle cells, and are involved in a range of cellular pathways that control and regulate the cell's cytoskeleton and other key cellular functions. (wikipedia.org)
  • The contractile system relies upon 4 actin filament isoforms and 5 tropomyosin isoforms, whereas the actin filament system of the cytoskeleton uses two actin filament isoforms and over 40 tropomyosin isoforms. (wikipedia.org)
  • Depending on the promoter and initial exon used, tropomyosin isoforms can be categorized as either high-molecular-weight (HMW, 284 amino acids) or low-molecular-weight (LMW, 248). (wikipedia.org)
  • Geeves, M.A., Hitchcock-DeGregori, S.E. and Gunning, P.W. (2015) A Systematic Nomenclature for Mammalian Tropomyosin Isoforms. (scirp.org)
  • Houle, F., Poirier, A., Dumaresq, J. and Huot, J. (2007) DAP Kinase Mediates the Phosphorylation of Tropomyosin-1 Downstream of the ERK Pathway, Which Regulates the Formation of Stress Fibers in Response to Oxidative Stress. (scirp.org)
  • Receptor tropomyosin-related kinase B (TRKB) has been identified as a key player mediating antidepressant drug (AD) induced effects, and it's a potential target for NO since it displays multiple potential sites for nitration. (helsinki.fi)
  • We aimed to elucidate the potential diagnostic utility of pan-tropomyosin receptor kinase (Trk) immunohistochemistry and its relationship with the fusion gene subtype in SASC. (elsevierpure.com)
  • ImmunoPrecise's Unique Proprietary Bispecific Antibodies Link Cells Expressing Tumor-Associated Antigen Tropomyosin Receptor Kinase B (TrkB) with CD3-Positive T Cells, Immune System Cells that Respond by Recognizing and Eliminating Cancer Cells. (ipatherapeutics.com)
  • Thus, this study aimed to investigate the effects of gamma irradiation on tropomyosin allergen, proximate composition, and mineral elements in Macrobrachium rosenbergii. (upm.edu.my)
  • The findings provide a new information that food irradiation may affect the tropomyosin allergen, proximate composition and mineral elements of the prawn. (upm.edu.my)
  • A smaller protein with properties similar to those of myosin is tropomyosin. (britannica.com)
  • To establish α-tropomyosin (Tm)'s structure-function relationships in cooperative regulation of muscle contraction, thin filaments were reconstituted with a variety of Tm mutants (Δ2Tm, Δ3Tm, Δ6Tm, P2sTm, P3sTm, P2P3sTm, P1P5Tm, and wtTm), and force and sliding velocity of the thin filament were studied using an in vitro motility assay. (elsevierpure.com)
  • One example is the tropomyosin (Tm) overlap region of the thin filament that is crucial for the function of the cardiac sarcomere. (arizona.edu)
  • In vivo biological analysis of cold plasma on allergenicity reduction of tropomyosin in shrimp. (bvsalud.org)
  • Abnormal tropomyosin function in ATPase cycle in hypertrophic and dilated cardiomyopathies]. (ox.ac.uk)
  • By focusing on the stabilizing protein tropomyosin Cdc8, bundling protein fimbrin Fim1, and severing protein coffin Adf1, we examined how their pairwise and collective interactions with actin filaments regulate their activity and segregation to functionally diverse F-actin networks. (elifesciences.org)
  • Slow muscle α-tropomyosin helps regulate muscle contraction in type I skeletal muscle fibers. (medlineplus.gov)
  • Zerradi, M. , Houle, F. and Huot, J. (2015) Regulation of Breast Cancer Progression by Phosphorylation of the Tumor Suppressor Tropomyosin-1 Alpha. (scirp.org)
  • Gunning, P., O'Neill, G. and Hardeman, E. (2008) Tropomyosin-Based Regulation of the Actin Cytoskeleton in Time and Space. (scirp.org)
  • Simoneau, B., Houle, F. and Huot, J. (2012) Regulation of Endothelial Permeability and Transendothelial Migration of Cancer Cells by Tropomyosin-1 Phosphorylation. (scirp.org)
  • NDLI: The excimer fluorescence of pyrene-labeled tropomyosin. (iitkgp.ac.in)
  • [ 4 ] In both fish and shellfish, the major allergens (Gal c 1 and tropomyosin, respectively) are resistant to boiling. (medscape.com)
  • Molecular basis of mRNA transport by a kinesin-1-atypical tropomyosin complex. (embl.org)
  • Super repeats containing the deletion p.Val3924_Asn3929del showed similar affinity for actin and tropomyosin as that seen with WT super repeats. (biomedcentral.com)
  • In fungi, tropomyosin is found in cell walls and helps maintain the structural integrity of cells. (wikipedia.org)
  • The structural and allergenic modifications of tropomyosin Tod p1 (TMTp1) in fresh squids induced by high hydrostatic pressure (HHP) were investigated. (oregonstate.edu)
  • Background: Tropomyosin 1 alpha chain (Tm1) is an actin-binding protein that regulates the endothelial cell response to oxidative stress following its phosphorylation at Serine 283 (S283). (scirp.org)
  • Perry, S.V. (2001) Vertebrate Tropomyosin: Distribution, Properties and Function. (scirp.org)
  • In vivo biological regulations of the allergenicity of tropomyosin (TM) treated by cold plasma (CP) were investigated by in vivo mouse model. (bvsalud.org)
  • Overall, tropomyosin is an important protein that plays a vital role in the proper functioning of many different organisms. (wikipedia.org)
  • Tropomyosin from Porcine Muscle is a high quality Tropomyosin from porcine muscle. (prlog.org)
  • Slow muscle α-tropomyosin is found in skeletal muscles, which are the muscles used for movement. (medlineplus.gov)
  • Slow muscle α-tropomyosin is found only in type I fibers. (medlineplus.gov)
  • Tropomyosin is a two-stranded alpha-helical, coiled coil protein found in many animal and fungal cells. (wikipedia.org)
  • Allergenic response to squid (Todarodes pacificus) tropomyosin Tod p1 structure modifications induced by high hydrostatic pressure. (oregonstate.edu)
  • This graph shows the total number of publications written about "Tropomyosin" by people in this website by year, and whether "Tropomyosin" was a major or minor topic of these publications. (wakehealth.edu)
  • Tropomyosin is found in other eukaryotes too, but not in plants. (wikipedia.org)
  • The results showed that band density of tropomyosin irradiated at 10 and 15 kGy is markedly decreased. (upm.edu.my)