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Sarcospan
Sarcospan is a protein that in humans is encoded by the SSPN gene. Originally identified as Kirsten ras associated gene (KRAG), sarcospan is a 25-kDa transmembrane protein located in the dystrophin-associated protein complex of skeletal muscle cells, where it is most abundant. It contains four transmembrane spanning helices with both N- and C-terminal domains located intracellularly. Loss of SSPN expression occurs in patients with Duchenne muscular dystrophy. Dystrophin is required for proper localization of SSPN. SSPN is also an essential regulator of Akt/PKB signaling pathway, Akt signaling pathways. Without SSPN, Akt signaling pathways will be hindered and muscle regeneration will not occur. Function Sarcospan is a protein that plays a crucial role in muscle health and function. It is part of the dystrophin-associated glycoprotein complex (DGC), which is a protein complex found in muscle cells that helps to maintain the structural integrity of muscle fibers. Sarcospan interac ... [...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 (genetics), locus X chromosome, Xp21. The primary transcript in muscle measures about 2,100 kilobases and takes 16 hours to transcribe; the Mature messenger RNA, 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 form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metabolic reactions, DNA replication, Cell signaling, responding to stimuli, providing Cytoskeleton, structure to cells and Fibrous protein, organisms, and Intracellular transport, transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the Nucleic acid sequence, nucleotide sequence of their genes, and which usually results in protein folding into a specific Protein structure, 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmembrane Protein
A transmembrane protein is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequently undergo significant conformational changes to move a substance through the membrane. They are usually highly hydrophobic and aggregate and precipitate in water. They require detergents or nonpolar solvents for extraction, although some of them ( beta-barrels) can be also extracted using denaturing agents. The peptide sequence that spans the membrane, or the transmembrane segment, is largely hydrophobic and can be visualized using the hydropathy plot. Depending on the number of transmembrane segments, transmembrane proteins can be classified as single-pass membrane proteins, or as multipass membrane proteins. Some other integral membrane proteins are called monotopic, meaning that they are also permanently attached to the membrane, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dystrophin-associated Protein Complex
The dystrophin-associated protein complex, also known as the dystrophin-associated glycoprotein complex is a multiprotein complex that includes dystrophin and the dystrophin-associated proteins. It is one of the two protein complexes that make up the costamere in striated muscle cells. The other complex is the ''integrin-vinculin-talin complex''. Structure The dystrophin-associated protein complex includes dystrophin. Dystrophin binds to actin of the cytoskeleton, and also to proteins in the extracellular matrix. The dystrophin-associated protein complex also contains dystrophin-associated proteins. This includes a four subunit sarcoglycan complex, which is fixed to dystrophin in muscle cells. In the epithelia of the kidney, dystrophin may be replaced with utrophin. Aquaporin 4 may be connected to the dystrophin-associated protein complex. Function The dystrophin-associated protein complex is important for cell structure and cell signalling. It is one of two protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeletal Muscle
Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the somatic nervous system, voluntary muscular system and typically are attached by tendons to bones of a skeleton. The skeletal muscle cells are much longer than in the other types of muscle tissue, and are also known as ''muscle fibers''. The tissue of a skeletal muscle is striated muscle tissue, striated – having a striped appearance due to the arrangement of the sarcomeres. A skeletal muscle contains multiple muscle fascicle, fascicles – bundles of muscle fibers. Each individual fiber and each muscle is surrounded by a type of connective tissue layer of fascia. Muscle fibers are formed from the cell fusion, fusion of developmental myoblasts in a process known as myogenesis resulting in long multinucleated cells. In these cells, the cell nucleus, nuclei, termed ''myonuclei'', are located along the inside ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duchenne Muscular Dystrophy
Duchenne muscular dystrophy (DMD) is a severe type of muscular dystrophy predominantly affecting boys. The onset of muscle weakness typically begins around age four, with rapid progression. Initially, muscle loss occurs in the thighs and pelvis, extending to the arms, which can lead to difficulties in standing up. By the age of 12, most individuals with Duchenne muscular dystrophy are unable to walk. Affected muscles may appear larger due to an increase in fat content, and scoliosis is common. Some individuals may experience intellectual disability, and females carrying a single copy of the mutated gene may show mild symptoms. Duchenne muscular dystrophy is caused by mutations or deletions in any of the 79 exons encoding the large dystrophin protein, which is essential for maintaining the muscle fibers' cell membrane integrity. The disorder follows an X-linked recessive inheritance pattern, with approximately two-thirds of cases inherited from the mother and one-third res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akt/PKB Signaling Pathway
The Akt signaling pathway or PI3K-Akt signaling pathway is a signal transduction pathway that promotes survival and growth in response to extracellular signals. Key proteins involved are PI3K (phosphatidylinositol 3-kinase) and Akt (protein kinase B). Initial stimulation by one of the growth factors causes activation of a cell surface receptor and phosphorylation of PI3K. Activated PI3K then phosphorylates lipids on the plasma membrane, forming second messenger phosphatidylinositol (3,4,5)-trisphosphate (PIP3). Akt, a serine/threonine-specific protein kinase, serine/threonine kinase, is recruited to the membrane by interaction with these phosphoinositide docking sites, so that it can be fully activated. Activated Akt mediates downstream responses, including cell survival, growth, cell proliferation, proliferation, cell migration and angiogenesis, by phosphorylating a range of intracellular proteins. The pathway is present in all cells of higher eukaryotes and is highly conserved. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syntrophin, Alpha 1
Alpha-1-syntrophin is a protein that in humans is encoded by the ''SNTA1'' gene. Alpha-1 syntrophin is a signal transducing adaptor protein and serves as a scaffold for various signaling molecules. Alpha-1 syntrophin contains a PDZ domain, two Pleckstrin homology domain and a 'syntrophin unique' domain. Function Dystrophin is a large, rod-like cytoskeletal protein found at the inner surface of muscle fibers. Dystrophin is missing in Duchenne Muscular Dystrophy patients and is present in reduced amounts in Becker Muscular Dystrophy patients. The protein encoded by this gene is a peripheral membrane protein found associated with dystrophin and dystrophin-related proteins. This gene is a member of the syntrophin gene family, which contains at least two other structurally related genes. The PDZ domain of syntrophin-α1(SNTA1), the most abundant isoform in the heart, has been reported to bind to the C-terminal domain of murine cardiac voltage-gated sodium channels (SkM2) causing a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dystroglycan
Dystroglycan is a protein that in humans is encoded by the ''DAG1'' gene. Dystroglycan is one of the dystrophin-associated glycoproteins, which is encoded by a 5.5 kb transcript in ''Homo sapiens'' on chromosome 3. There are two exons that are separated by a large intron. The spliced exons code for a protein product that is finally cleaved into two non-covalently associated subunits, lpha(N-terminal) and eta(C-terminal). Function In skeletal muscle the dystroglycan complex works as a transmembrane linkage between the extracellular matrix and the cytoskeleton. lphadystroglycan is extracellular and binds to merosin lpha2 laminin in the basement membrane, while etadystroglycan is a transmembrane protein and binds to dystrophin, which is a large rod-like cytoskeletal protein, absent in Duchenne muscular dystrophy patients. Dystrophin binds to intracellular actin cables. In this way, the dystroglycan complex, which links the extracellular matrix to the intracellular actin c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarcolemma
The sarcolemma (''sarco'' (from ''sarx'') from Greek; flesh, and ''lemma'' from Greek; sheath), also called the myolemma, is the cell membrane surrounding a skeletal muscle fibre or a cardiomyocyte. It consists of a lipid bilayer and a thin outer coat of polysaccharide material ( glycocalyx) that contacts the basement membrane. The basement membrane contains numerous thin collagen fibrils and specialized proteins such as laminin that provide a scaffold to which the muscle fibre can adhere. Through transmembrane proteins in the plasma membrane, the actin skeleton inside the cell is connected to the basement membrane and the cell's exterior. At each end of the muscle fibre, the surface layer of the sarcolemma fuses with a tendon fibre, and the tendon fibres, in turn, collect into bundles to form the muscle tendons that adhere to bones. The sarcolemma generally maintains the same function in muscle cells as the plasma membrane does in other eukaryote cells. It acts as a barrie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
