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Tropomyosin
Tropomyosin is a two-stranded alpha-helical, coiled coil protein found in many animal and fungal cells. In animals, it is an important component of the muscular system which works in conjunction with troponin to regulate muscle contraction. It is present in smooth and striated muscle tissues, which can be found in various organs and body systems, including the heart, blood vessels, respiratory system, and digestive system. In fungi, tropomyosin is found in cell walls and helps maintain the structural integrity of cells. Tropomyosin is found in other eukaryotes too, but not in plants. Overall, tropomyosin is an important protein that plays a vital role in the proper functioning of many different organisms. Tropomyosin and the actin skeleton All organisms contain organelles that provide physical integrity to their cells. These types of organelles are collectively known as the cytoskeleton, and one of the most ancient systems is based on filamentous polymers of the protein actin. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropomyosin Isoform Diversity Is Generated By The Use Of Four Genes (α,β,γ,δ) And Alternative Splicing Within At Least Three Genes
Tropomyosin is a two-stranded alpha-helical An alpha helix (or α-helix) is a sequence of amino acids in a protein that are twisted into a coil (a helix). The alpha helix is the most common structural arrangement in the secondary structure of proteins. It is also the most extreme type of l ..., coiled coil protein found in many animal and fungal cells. In animals, it is an important component of the muscular system which works in conjunction with troponin to regulate muscle contraction. It is present in smooth and striated muscle tissues, which can be found in various organs and body systems, including the heart, blood vessels, respiratory system, and digestive system. In fungi, tropomyosin is found in cell walls and helps maintain the structural integrity of cells. Tropomyosin is found in other eukaryotes too, but not in plants. Overall, tropomyosin is an important protein that plays a vital role in the proper functioning of many different organisms. Tropomyosin and the actin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropomyosin 3
Tropomyosin alpha-3 chain is a protein that in humans is encoded by the ''TPM3'' 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: protei .... This gene encodes a member of the tropomyosin family of actin-binding proteins involved in the contractile system of striated and smooth muscles and the cytoskeleton of non-muscle cells. Tropomyosins are dimers of coiled-coil proteins that polymerize end-to-end along the major groove in most actin filaments. They provide stability to the filaments and regulate access of other actin-binding proteins. In muscle cells, they regulate muscle contraction by controlling the binding of myosin heads to the actin filament. Mutations in this gene result in autosomal dominant nemaline myopathy, and oncogenes formed by chromosomal translocations involving this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TPM2
β-Tropomyosin, also known as tropomyosin beta chain is a protein that in humans is encoded by the ''TPM2'' gene. β-tropomyosin is striated muscle-specific coiled coil dimer that functions to stabilize actin filaments and regulate muscle contraction. Structure β-tropomyosin is roughly 32 kDa in molecular weight (284 amino acids), but multiple splice variants exist. Tropomysin is a flexible protein homodimer or heterodimer composed of two alpha-helical chains, which adopt a bent coiled coil conformation to wrap around the seven actin molecules in a functional unit of muscle. It is polymerized end to end along the two grooves of actin filaments and provides stability to the filaments. Tropomyosin dimers are composed of varying combinations of tropomyosin isoforms; human striated muscles express protein from the ''TPM1'' (α-tropoomyosin), ''TPM2'' (β-tropomyosin) and ''TPM3'' (γ-tropomyosin) genes, with α-tropomyosin being the predominant isoform in striated muscle. Fast s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TPM1
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) family of highly conserved, widely distributed actin-binding proteins involved in the contractile system of striated and smooth muscles and the cytoskeleton of non-muscle cells. Structure Tm is a 32.7 kDa protein composed of 284 amino acids. Tm is a flexible protein homodimer or heterodimer composed of two alpha-helical chains, which adopt a bent coiled coil conformation to wrap around the seven actin molecules in a functional unit of muscle. It is polymerized end to end along the two grooves of actin filaments and provides stability to the filaments. Human striated muscles express protein from the ''TPM1'' (α-Tm), ''TPM2'' (β-Tm) and ''TPM3'' (γ-Tm) genes, with α-Tm being the predominant isoform in striated muscle. In human cardiac muscle the ratio of α-Tm to β-Tm is roughly 5:1. Function Tm functions in association with the troponin co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TPM4
Tropomyosin alpha-4 chain is a protein that in humans is encoded by the ''TPM4'' 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: protei .... References Further reading * * * * * * * * * * * * * {{gene-19-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoskeleton
The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is composed of similar proteins in the various organisms. It is composed of three main components: microfilaments, intermediate filaments, and microtubules, and these are all capable of rapid growth and or disassembly depending on the cell's requirements. Cytoskeleton can perform many functions. Its primary function is to give the cell its shape and mechanical resistance to deformation, and through association with extracellular connective tissue and other cells it stabilizes entire tissues. The cytoskeleton can also contract, thereby deforming the cell and the cell's environment and allowing cells to migrate. Moreover, it is involved in many cell signaling pathways and in the uptake of extracellular material ( endocytosis), the segregation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-helical
An alpha helix (or α-helix) is a sequence of amino acids in a protein that are twisted into a coil (a helix). The alpha helix is the most common structural arrangement in the secondary structure of proteins. It is also the most extreme type of local structure, and it is the local structure that is most easily predicted from a sequence of amino acids. The alpha helix has a right-handed helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid that is four residues earlier in the protein sequence. Other names The alpha helix is also commonly called a: * Pauling–Corey–Branson α-helix (from the names of three scientists who described its structure) * 3.613-helix because there are 3.6 amino acids in one ring, with 13 atoms being involved in the ring formed by the hydrogen bond (starting with amidic hydrogen and ending with carbonyl oxygen) Discovery In the early 1930s, William Astbury showed that there were dras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypeptide
Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. Peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyclic peptides have an N-terminal (amine group) and C-terminal (ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Ruffling
Within molecular biology, molecular and cell biology membrane ruffling (also known as cell ruffling) is the formation of a motile cell surface that contains a meshwork of newly polymerized actin filaments. It can also be regarded as one of the earliest structural changes observed in the cell. The GTP-binding protein Rac (GTPase), Rac is the regulator of this membrane ruffling. Changes in the Polyphosphoinositide metabolism and changes in Ca2+ level of the cell may also play an important role. A number of actin-binding and organizing proteins localize to membrane ruffles and potentially target to transducing molecules. Characteristic feature of migrating cells Membrane ruffling is a characteristic feature of many actively migrating cells. When the membrane is unable to attach to the substrate, the membrane protrusion is recycled back into the cell. The ruffling of membranes is thought to be controlled by a group of enzymes known as Rho family of GTPases, Rho GTPases, specifically Rho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Weight
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (molecule), water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Promoter (genetics)
In genetics, a promoter is a sequence of DNA to which proteins bind to initiate transcription of a single RNA transcript from the DNA downstream of the promoter. The RNA transcript may encode a protein (mRNA), or can have a function in and of itself, such as tRNA or rRNA. Promoters are located near the transcription start sites of genes, upstream on the DNA (towards the 5' region of the sense strand). Promoters can be about 100–1000 base pairs long, the sequence of which is highly dependent on the gene and product of transcription, type or class of RNA polymerase recruited to the site, and species of organism. Overview For transcription to take place, the enzyme that synthesizes RNA, known as RNA polymerase, must attach to the DNA near a gene. Promoters contain specific DNA sequences such as response elements that provide a secure initial binding site for RNA polymerase and for proteins called transcription factors that recruit RNA polymerase. These transcription factor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Duplication
Gene duplication (or chromosomal duplication or gene amplification) is a major mechanism through which new genetic material is generated during molecular evolution. It can be defined as any duplication of a region of DNA that contains a gene. Gene duplications can arise as products of several types of errors in DNA replication and repair machinery as well as through fortuitous capture by selfish genetic elements. Common sources of gene duplications include ectopic recombination, retrotransposition event, aneuploidy, polyploidy, and replication slippage. Mechanisms of duplication Ectopic recombination Duplications arise from an event termed unequal crossing-over that occurs during meiosis between misaligned homologous chromosomes. The chance of it happening is a function of the degree of sharing of repetitive elements between two chromosomes. The products of this recombination are a duplication at the site of the exchange and a reciprocal deletion. Ectopic recombina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
