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Syncoilin
Discovery Syncoilin is a muscle-specific atypical type III intermediate filament protein encoded in the human by the gene ''SYNC''. It was first isolated as a binding partner to α-dystrobrevin, as determined by a yeast two-hybrid assay. Later, a yeast two-hybrid method was used to demonstrate that syncoilin is a binding partner of desmin. These binding partners suggest that syncoilin acts as a mechanical "linker" between the sarcomere Z-disk (where desmin is localized) and the dystrophin-associated protein complex (where α-dystrobrevin is localized). However, the specific ''in vivo'' functions of syncoilin have not yet been determined. Through the use of Western blotting techniques, a second species of syncoilin was found. This species was 55kDa in size, whereas the original species of syncoilin was 64kDa in size. This discovery inspired scientists to use gene splicing to identify two new isoforms called SYNC2 and SYNC3. Abnormally high levels of syncoilin have been shown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dystrophin
Dystrophin is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costamere or the dystrophin-associated protein complex (DAPC). Many muscle proteins, such as α-dystrobrevin, syncoilin, synemin, sarcoglycan, dystroglycan, and sarcospan, colocalize with dystrophin at the costamere. It has a molecular weight of 427 kDa Dystrophin is coded for by the ''DMD'' gene – the largest known human gene, covering 2.4 megabases (0.08% of the human genome) at locus Xp21. The primary transcript in muscle measures about 2,100 kilobases and takes 16 hours to transcribe; the mature mRNA measures 14.0 kilobases. The 79-exon muscle transcript codes for a protein of 3685 amino acid residues. Spontaneous or inherited mutations in the dystrophin gene can cause different forms of muscular dystrophy, a disease characterized by p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermediate Filament
Intermediate filaments (IFs) are cytoskeletal structural components found in the cells of vertebrates, and many invertebrates. Homologues of the IF protein have been noted in an invertebrate, the cephalochordate ''Branchiostoma''. Intermediate filaments are composed of a family of related proteins sharing common structural and sequence features. Initially designated 'intermediate' because their average diameter (10 nm) is between those of narrower microfilaments (actin) and wider myosin filaments found in muscle cells, the diameter of intermediate filaments is now commonly compared to actin microfilaments (7 nm) and microtubules (25 nm). Animal intermediate filaments are subcategorized into six types based on similarities in amino acid sequence and protein structure. Most types are cytoplasmic, but one type, Type V is a nuclear lamin. Unlike microtubules, IF distribution in cells show no good correlation with the distribution of either mitochondria or endopla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripherin
Peripherin is a type III intermediate filament protein expressed mainly in neurons of the peripheral nervous system. It is also found in neurons of the central nervous system that have projections toward peripheral structures, such as spinal motor neurons. Its size, structure, and sequence/location of protein motifs is similar to other type III intermediate filament proteins such as desmin, vimentin and glial fibrillary acidic protein. Like these proteins, peripherin can self-assemble to form homopolymeric filamentous networks (networks formed from peripherin protein dimers), but it can also heteropolymerize with neurofilaments in several neuronal types. This protein in humans is encoded by the ''PRPH'' gene. Peripherin is thought to play a role in neurite elongation during development and axonal regeneration after injury, but its exact function is unknown. It is also associated with some of the major neuropathologies that characterize amyotropic lateral sclerosis (ALS), but despit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congenital Muscular Dystrophy
Congenital muscular dystrophies are autosomal recessively-inherited muscle diseases. They are a group of heterogeneous disorders characterized by muscle weakness which is present at birth and the different changes on muscle biopsy that ranges from myopathic to overtly dystrophic due to the age at which the biopsy takes place.update 2012 Signs and symptoms Most infants with CMD will display some progressive muscle weakness or muscle wasting (atrophy), although there can be different degrees and symptoms of severeness of progression. The weakness is indicated as ''hypotonia'', or lack of muscle tone, which can make an infant seem unstable. Children may be slow with their motor skills; such as rolling over, sitting up or walking, or may not even reach these milestones of life. Some of the rarer forms of CMD can result in significant learning disabilities. Genetics Congenital muscular dystrophies (CMDs) are autosomal recessively inherited, except in some cases of de novo ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Core Disease
Central core disease (CCD), also known as central core myopathy, is an autosomal dominantly inherited muscle disorder present from birth that negatively affects the skeletal muscles. It was first described by Shy and Magee in 1956. It is characterized by the appearance of the myofibril under the microscope. Signs and symptoms The symptoms of CCD are variable, but usually involve hypotonia (decreased muscle tone) at birth, mild delay in child development (highly variable between cases), weakness of the facial muscles, and skeletal malformations such as scoliosis and hip dislocation. CCD is usually diagnosed in infancy or childhood, but some patients remain asymptomatic until adulthood to middle age. While generally not progressive, there appears to be a growing number of people who do experience a slow clinically significant progression of symptomatology. These cases may be due to the large number of mutations of ryanodine receptor malfunction, and with continued research may be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Becker Muscular Dystrophy
Becker muscular dystrophy is an X-linked recessive inherited disorder characterized by slowly progressing muscle weakness of the legs and pelvis. It is a type of dystrophinopathy. This is caused by mutations in the dystrophin gene, which encodes the protein dystrophin. Becker muscular dystrophy is related to Duchenne muscular dystrophy in that both result from a mutation in the dystrophin gene, but has a milder course. Signs and symptoms Some symptoms consistent with Becker muscular dystrophy are: Individuals with this disorder typically experience progressive muscle weakness of the leg and pelvis muscles, which is associated with a loss of muscle mass (wasting). Muscle weakness also occurs in the arms, neck, and other areas, but not as noticeably severe as in the lower half of the body. Calf muscles initially enlarge during the ages of 5-15 (an attempt by the body to compensate for loss of muscle strength), but the enlarged muscle tissue is eventually replaced by fat and connect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duchenne Muscular Dystrophy
Duchenne muscular dystrophy (DMD) is a severe type of muscular dystrophy that primarily affects boys. Muscle weakness usually begins around the age of four, and worsens quickly. Muscle loss typically occurs first in the thighs and pelvis followed by the arms. This can result in trouble standing up. Most are unable to walk by the age of 12. Affected muscles may look larger due to increased fat content. Scoliosis is also common. Some may have intellectual disability. Females with a single copy of the defective gene may show mild symptoms. The disorder is X-linked recessive. About two thirds of cases are inherited from a person's mother, while one third of cases are due to a new mutation. It is caused by a mutation in the gene for the protein dystrophin. Dystrophin is important to maintain the muscle fiber's cell membrane. Genetic testing can often make the diagnosis at birth. Those affected also have a high level of creatine kinase in their blood. Although there is no know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Isoform
A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene or gene family and are the result of genetic differences. While many perform the same or similar biological roles, some isoforms have unique functions. A set of protein isoforms may be formed from alternative splicings, variable promoter usage, or other post-transcriptional modifications of a single gene; post-translational modifications are generally not considered. (For that, see Proteoforms.) Through RNA splicing mechanisms, mRNA has the ability to select different protein-coding segments ( exons) of a gene, or even different parts of exons from RNA to form different mRNA sequences. Each unique sequence produces a specific form of a protein. The discovery of isoforms could explain the discrepancy between the small number of protein coding regions genes revealed by the human genome project and the large diversity of proteins seen in an organism: different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripheral Nervous System
The peripheral nervous system (PNS) is one of two components that make up the nervous system of bilateral animals, with the other part being the central nervous system (CNS). The PNS consists of nerves and ganglia, which lie outside the brain and the spinal cord. The main function of the PNS is to connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body. Unlike the CNS, the PNS is not protected by the vertebral column and skull, or by the blood–brain barrier, which leaves it exposed to toxins. The peripheral nervous system can be divided into the somatic nervous system and the autonomic nervous system. In the somatic nervous system, the cranial nerves are part of the PNS with the exception of the optic nerve (cranial nerve II), along with the retina. The second cranial nerve is not a true peripheral nerve but a tract of the diencephalon. Cranial nerve ganglia, as with all ganglia, are part of the P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Nervous System
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts. It is a structure composed of nervous tissue positioned along the rostral (nose end) to caudal (tail end) axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain (precursor structures exist in onychophorans, gastropods and lancelets). The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals. Overview In vertebrates, the brain and spinal cord are both enclosed in the meninges. The meninges provide a barrier to chemicals dissolv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuromuscular Junction
A neuromuscular junction (or myoneural junction) is a chemical synapse between a motor neuron and a muscle fiber. It allows the motor neuron to transmit a signal to the muscle fiber, causing muscle contraction. Muscles require innervation to function—and even just to maintain muscle tone, avoiding atrophy. In the neuromuscular system nerves from the central nervous system and the peripheral nervous system are linked and work together with muscles. Synaptic transmission at the neuromuscular junction begins when an action potential reaches the presynaptic terminal of a motor neuron, which activates voltage-gated calcium channels to allow calcium ions to enter the neuron. Calcium ions bind to sensor proteins (synaptotagmins) on synaptic vesicles, triggering vesicle fusion with the cell membrane and subsequent neurotransmitter release from the motor neuron into the synaptic cleft. In vertebrates, motor neurons release acetylcholine (ACh), a small molecule neurotransmitter, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DTNA
Dystrobrevin alpha is a protein that in humans is encoded by the ''DTNA'' gene. Function The protein encoded by this gene belongs to the dystrobrevin subfamily and the dystrophin family. This protein is a component of the dystrophin-associated protein complex (DPC). The DPC consists of dystrophin and several integral and peripheral membrane proteins, including dystroglycans, sarcoglycans, syntrophins and alpha- and beta-dystrobrevin. The DPC localizes to the sarcolemma and its disruption is associated with various forms of muscular dystrophy. This protein may be involved in the formation and stability of synapses as well as the clustering of nicotinic acetylcholine receptors. Multiple alternatively spliced transcript variants encoding different isoforms have been identified. Clinical significance Mutations in ''DTNA'' are associated with Ménière's disease. Interactions Dystrobrevin has been shown to interact Advocates for Informed Choice, dba interACT or interACT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
