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Protein Filament
In biology, a protein filament is a long chain of protein monomers, such as those found in hair, muscle, or in flagella. Protein filaments form together to make the cytoskeleton of the cell. They are often bundled together to provide support, strength, and rigidity to the cell. When the filaments are packed up together, they are able to form three different cellular parts. The three major classes of protein filaments that make up the cytoskeleton include: actin filaments, microtubules and intermediate filaments. Cellular types Microfilaments Compared to the other parts of the cytoskeletons, the microfilaments contain the thinnest filaments, with a diameter of approximately 7 nm. Microfilaments are part of the cytoskeleton that are composed of protein called actin. Two strands of actin intertwined together form a filamentous structure allowing for the movement of motor proteins. Microfilaments can either occur in the monomeric G-actin or filamentous F-actin. Microfilament ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microfilaments
Microfilaments, also called actin filaments, are protein filaments in the cytoplasm of eukaryotic cells that form part of the cytoskeleton. They are primarily composed of polymers of actin, but are modified by and interact with numerous other proteins in the cell. Microfilaments are usually about 7 nm in diameter and made up of two strands of actin. Microfilament functions include cytokinesis, amoeboid movement, cell motility, changes in cell shape, endocytosis and exocytosis, cell contractility, and mechanical stability. Microfilaments are flexible and relatively strong, resisting buckling by multi-piconewton compressive forces and filament fracture by nanonewton tensile forces. In inducing cell motility, one end of the actin filament elongates while the other end contracts, presumably by myosin II molecular motors. Additionally, they function as part of actomyosin-driven contractile molecular motors, wherein the thin filaments serve as tensile platforms for myosin's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actin Microfilament
Microfilaments, also called actin filaments, are protein filaments in the cytoplasm of eukaryotic cells that form part of the cytoskeleton. They are primarily composed of polymers of actin, but are modified by and interact with numerous other proteins in the cell. Microfilaments are usually about 7 nm in diameter and made up of two strands of actin. Microfilament functions include cytokinesis, amoeboid movement, cell motility, changes in cell shape, endocytosis and exocytosis, cell contractility, and mechanical stability. Microfilaments are flexible and relatively strong, resisting buckling by multi-piconewton compressive forces and filament fracture by nanonewton tensile forces. In inducing cell motility, one end of the actin filament elongates while the other end contracts, presumably by myosin II molecular motors. Additionally, they function as part of actomyosin-driven contractile molecular motors, wherein the thin filaments serve as tensile platforms for myosin's ATP-depen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colchicine
Colchicine is a medication used to prevent and treat gout, to treat familial Mediterranean fever and Behçet's disease, and to reduce the risk of myocardial infarction. The American College of Rheumatology recommends colchicine, nonsteroidal anti-inflammatory drugs (NSAIDs) or steroids in the treatment of gout. Other uses for colchicine include the management of pericarditis. Colchicine is taken by mouth. The injectable route of administration for colchicine can be toxic. In 2008, the US Food and Drug Administration removed all injectable colchicine from the US market. Colchicine has a narrow therapeutic index, so overdosing is a significant risk. Common side effects of colchicine include gastrointestinal upset, particularly at high doses. Severe side effects may include pancytopenia (low blood cell counts) and rhabdomyolysis (damage to skeletal muscle), and the medication can be deadly in overdose. Whether colchicine is safe for use during pregnancy is unclear, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrite
A dendrite (from Ancient Greek language, Greek δένδρον ''déndron'', "tree") or dendron is a branched cytoplasmic process that extends from a nerve cell that propagates the neurotransmission, electrochemical stimulation received from other neural cells to the cell body, or soma (biology), soma, of the neuron from which the dendrites project. Electrical stimulation is transmitted onto dendrites by upstream neurons (usually via their axons) via synapses which are located at various points throughout the dendritic tree. Dendrites play a critical role in integrating these synaptic inputs and in determining the extent to which action potentials are produced by the neuron. Structure and function Dendrites are one of two types of cytoplasmic processes that extrude from the cell body of a neuron, the other type being an axon. Axons can be distinguished from dendrites by several features including shape, length, and function. Dendrites often taper off in shape and are shorter, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axon
An axon (from Greek ἄξων ''áxōn'', axis) or nerve fiber (or nerve fibre: see American and British English spelling differences#-re, -er, spelling differences) is a long, slender cellular extensions, projection of a nerve cell, or neuron, in Vertebrate, vertebrates, that typically conducts electrical impulses known as action potentials away from the Soma (biology), nerve cell body. The function of the axon is to transmit information to different neurons, muscles, and glands. In certain sensory neurons (pseudounipolar neurons), such as those for touch and warmth, the axons are called afferent nerve fibers and the electrical impulse travels along these from the peripheral nervous system, periphery to the cell body and from the cell body to the spinal cord along another branch of the same axon. Axon dysfunction can be the cause of many inherited and acquired neurological disorders that affect both the Peripheral nervous system, peripheral and Central nervous system, central ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtubule Organizing Center
The microtubule-organizing center (MTOC) is a structure found in eukaryotic cells from which microtubules emerge. MTOCs have two main functions: the organization of eukaryotic flagella and cilia and the organization of the mitotic and meiotic spindle apparatus, which separate the chromosomes during cell division. The MTOC is a major site of microtubule nucleation and can be visualized in cells by immunohistochemical detection of γ-tubulin. The morphological characteristics of MTOCs vary between the different phyla and kingdoms. In animals, the two most important types of MTOCs are 1) the basal bodies associated with cilia and flagella and 2) the centrosome associated with spindle formation. Organization Microtubule-organizing centers function as the site where microtubule formation begins, as well as a location where free-ends of microtubules attract to. Within the cells, microtubule-organizing centers can take on many different forms. An array of microtubules can arrange the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellum
A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many protists with flagella are known as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium '' Helicobacter pylori'', for example, uses its flagella to propel itself through the stomach to reach the mucous lining where it may colonise the epithelium and potentially cause gastritis, and ulcers – a risk factor for stomach cancer. In some swarming bacteria, the flagellum can also function as a sensory organelle, being sensitive to wetness outside the cell. Across the three domains of Bacteria, Archaea, and Eukaryota, the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word means " whip" to describe its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cilium
The cilium (: cilia; ; in Medieval Latin and in anatomy, ''cilium'') is a short hair-like membrane protrusion from many types of eukaryotic cell. (Cilia are absent in bacteria and archaea.) The cilium has the shape of a slender threadlike projection that extends from the surface of the much larger cell body. Eukaryotic flagella found on sperm cells and many protozoans have a similar structure to motile cilia that enables swimming through liquids; they are longer than cilia and have a different undulating motion. There are two major classes of cilia: ''motile'' and ''non-motile'' cilia, each with two subtypes, giving four types in all. A cell will typically have one primary cilium or many motile cilia. The structure of the cilium core, called the axoneme, determines the cilium class. Most motile cilia have a central pair of single microtubules surrounded by nine pairs of double microtubules called a 9+2 axoneme. Most non-motile cilia have a 9+0 axoneme that lacks the centr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasm
The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are the cytosol (a gel-like substance), the cell's internal sub-structures, and various cytoplasmic inclusions. In eukaryotes the cytoplasm also includes the nucleus, and other membrane-bound organelles.The cytoplasm is about 80% water and is usually colorless. The submicroscopic ground cell substance, or cytoplasmic matrix, that remains after the exclusion of the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, a highly complex, polyphasic system in which all resolvable cytoplasmic elements are suspended, including the larger organelles such as the ribosomes, mitochondria, plant plasti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtubule
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nanometer, nm and have an inner diameter between 11 and 15 nm. They are formed by the polymerization of a Protein dimer, dimer of two globular proteins, Tubulin#Eukaryotic, alpha and beta tubulin into #Structure, protofilaments that can then associate laterally to form a hollow tube, the microtubule. The most common form of a microtubule consists of 13 protofilaments in the tubular arrangement. Microtubules play an important role in a number of cellular processes. They are involved in maintaining the structure of the cell and, together with microfilaments and intermediate filaments, they form the cytoskeleton. They also make up the internal structure of cilia and flagella. They provide platforms for intracellular transport and are involved in a variety of cellular processes, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titin
Titin (; also called connectin) is a protein that in humans is encoded by the ''TTN'' gene. The protein, which is over 1 μm in length, functions as a molecular spring that is responsible for the passive elasticity of muscle. It comprises 244 individually folded protein domains connected by unstructured peptide sequences. These domains unfold when the protein is stretched and refold when the tension is removed. Titin is important in the contraction of striated muscle tissues. It connects the Z disc to the M line in the sarcomere. The protein contributes to force transmission at the Z disc and resting tension in the I band region. It limits the range of motion of the sarcomere in tension, thus contributing to the passive stiffness of muscle. Variations in the sequence of titin between different types of striated muscle ( cardiac or skeletal) have been correlated with differences in the mechanical properties of these muscles. Titin is the third most abundant protein in m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nebulin
Nebulin is an actin-binding protein which is localized to the thin filament of the sarcomeres in skeletal muscle. Nebulin in humans is coded for by the gene ''NEB''. It is a very large protein (600–900 kDa) and binds as many as 200 actin monomers. Because its length is proportional to thin filament length, it is believed that nebulin acts as a thin filament "ruler" and regulates thin filament length during sarcomere assembly. Other functions of nebulin, such as a role in cell signaling, remain uncertain. Nebulin has also been shown to regulate actin-myosin interactions by inhibiting ATPase activity in a calcium-calmodulin sensitive manner. Mutations in nebulin cause some cases of the autosomal recessive disorder nemaline myopathy. A smaller member of the nebulin protein family, termed nebulette, is expressed in cardiac muscle. Structure The structure of the SH3 domain of nebulin was determined by protein nuclear magnetic resonance spectroscopy.; The SH3 domain from n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
