|
Calcium Signalling
Calcium signaling is the use of calcium ions (Ca2+) to communicate and drive intracellular processes often as a step in signal transduction. Ca2+ is important for cellular signalling, for once it enters the cytosol of the cytoplasm it exerts allosteric regulatory effects on many enzymes and proteins. Ca2+ can act in signal transduction resulting from activation of ion channels or as a second messenger caused by indirect signal transduction pathways such as G protein-coupled receptors. Concentration regulation The resting concentration of Ca2+ in the cytoplasm is normally maintained around 100 nM. This is 20,000- to 100,000-fold lower than typical extracellular concentration. To maintain this low concentration, Ca2+ is actively pumped from the cytosol to the extracellular space, the endoplasmic reticulum (ER), and sometimes into the mitochondria. Certain proteins of the cytoplasm and organelles act as buffers by binding Ca2+. Signaling occurs when the cell is stimulated to rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Signaling Pathway
Calcium is a chemical element with the Symbol (chemistry), symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin language, Latin ''calx'' "lime (material), lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are wid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PLC Role In IP3-DAG Pathway
PLC or plc may refer to: * Public limited company, a type of public company Education * Platoon Leaders Class, of the US Marine Corps Officer Candidates School * Post Leaving Certificate, a qualification in Ireland * Presbyterian Ladies' College (other), several schools in Australia * Presidents Leadership Class at University of Colorado at Boulder, US * Professional learning community, for collaborative learning Medicine * Perlecan, a protein in humans * Peptide loading complex, an intracellular membrane protein matrix * Peter Lougheed Centre, a hospital in Calgary, Alberta, Canada * Phospholipase C, a class of membrane-associated enzymes * Pityriasis lichenoides chronica, a skin condition * Posterolateral corner, a region of the human knee Politics * Colombian Liberal Party ( es, Partido Liberal Colombiano, link=no) * Conservative Party (Spain) ( es, Partido Liberal-Conservador, link=no) * Constitutionalist Liberal Party ( es, Partido Liberal Constitucionalista, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STIM1
Stromal interaction molecule 1 is a protein that in humans is encoded by the ''STIM1'' gene. STIM1 has a single transmembrane domain, and is localized to the endoplasmic reticulum, and to a lesser extent to the plasma membrane. Even though the protein has been identified earlier, its function was unknown until recently. In 2005, it was discovered that STIM1 functions as a calcium sensor in the endoplasmic reticulum. Upon activation of the IP3 receptor, the calcium concentration in the endoplasmic reticulum decreases, which is sensed by STIM1, via its EF hand domain. STIM1 activates the "store-operated" ORAI1 calcium ion channels in the plasma membrane, via intracellular STIM1 movement, clustering under plasma membrane and protein interaction with ORAI isoforms. STIM1-mediated calcium entry is required for thrombin-induced disassembly of VE-cadherin adherens junctions. 2-Aminoethoxydiphenyl borate (2-APB) and 4-chloro-3-ethylphenol (4-CEP) cause STIM1 clustering in a cell and preven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Release Activated Channel
Calcium release-activated channels (CRAC) are specialized plasma membrane Ca2+ ion channels. When calcium ions (Ca2+) are depleted from the endoplasmic reticulum (a major store of Ca2+) of mammalian cells, the CRAC channel is activated to slowly replenish the level of calcium in the endoplasmic reticulum. The Ca2+ Release-activated Ca2+ (CRAC) Channel (CRAC-C) Family (TC# 1.A.52) is a member of the Cation Diffusion Facilitator (CDF) Superfamily. These proteins typically have between 4 and 6 transmembrane α-helical spanners (TMSs). The 4 TMS CRAC channels arose by loss of 2TMSs from 6TMS CDF carriers, an example of ' reverse' evolution'. Homology There are several proteins that belong to the CRAC-C family. A list of the currently classified members of the CRAC-C family can be found in thTransporter Classification Database This classification is based on sequence similarity which also happens to coincide with functional and structural similarities between homologues. Structure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SOC Channels
Store-operated channels (SOCs) are ion channels located in the plasma membrane of cells. These channels are most studied in regard to their role in calcium entry into the cytoplasm from extracellular milieu. There are other SOC channels selective to other ions. Calcium SOCs are especially important for the cell because they are the major source of intracellular calcium; and calcium itself is involved in a wide array of vital cellular functions. SOCs are so called because they are activated by intracellular calcium (particularly the endoplasmic reticulum (ER)) stores depletion by both physiological or pharmacological processes. See also * Calcium release activated channel Calcium release-activated channels (CRAC) are specialized plasma membrane Ca2+ ion channels. When calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that f ... References Further reading * * Cell anatomy {{ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IP3 Receptor
Inositol trisphosphate receptor (InsP3R) is a membrane glycoprotein complex acting as a Ca2+ channel activated by inositol trisphosphate (InsP3). InsP3R is very diverse among organisms, and is necessary for the control of cellular and physiological processes including cell division, cell proliferation, apoptosis, fertilization, development, behavior, learning and memory. Inositol triphosphate receptor represents a dominant second messenger leading to the release of Ca2+ from intracellular store sites. There is strong evidence suggesting that the InsP3R plays an important role in the conversion of external stimuli to intracellular Ca2+ signals characterized by complex patterns relative to both space and time, such as Ca2+ waves and oscillations. Discovery The InsP3 receptor was first purified from rat cerebellum by neuroscientists Surachai Supattapone and Solomon Snyder at Johns Hopkins University School of Medicine. The cDNA of the InsP3 receptor was first cloned in the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Kinase C
In cell biology, Protein kinase C, commonly abbreviated to PKC (EC 2.7.11.13), is a family of protein kinase enzymes that are involved in controlling the function of other proteins through the phosphorylation of hydroxyl groups of serine and threonine amino acid residues on these proteins, or a member of this family. PKC enzymes in turn are activated by signals such as increases in the concentration of diacylglycerol (DAG) or calcium ions (Ca2+). Hence PKC enzymes play important roles in several signal transduction cascades. In biochemistry, the PKC family consists of fifteen isozymes in humans. They are divided into three subfamilies, based on their second messenger requirements: conventional (or classical), novel, and atypical. Conventional (c)PKCs contain the isoforms α, βI, βII, and γ. These require Ca2+, DAG, and a phospholipid such as phosphatidylserine for activation. Novel (n)PKCs include the δ, ε, η, and θ isoforms, and require DAG, but do not require Ca2+ for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diacylglycerol
A diglyceride, or diacylglycerol (DAG), is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages. Two possible forms exist, 1,2-diacylglycerols and 1,3-diacylglycerols. DAGs can act as surfactants and are commonly used as emulsifiers in processed foods. DAG-enriched oil (particularly 1,3-DAG) has been investigated extensively as a fat substitute due to its ability to suppress the accumulation of body fat; with total annual sales of approximately USD 200 million in Japan since its introduction in the late 1990s till 2009. Production Diglycerides are a minor component of many seed oils and are normally present at ~1–6%; or in the case of cottonseed oil as much as 10%. Industrial production is primarily achieved by a glycerolysis reaction between triglycerides and glycerol. The raw materials for this may be either vegetable oils or animal fats. Food additive Diglycerides, generally in a mix with monoglycerides (E471), a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inositol Trisphosphate
Inositol trisphosphate or inositol 1,4,5-trisphosphate abbreviated InsP3 or Ins3P or IP3 is an inositol phosphate signaling molecule. It is made by hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2), a phospholipid that is located in the plasma membrane, by phospholipase C (PLC). Together with diacylglycerol (DAG), IP3 is a second messenger molecule used in signal transduction in biological cells. While DAG stays inside the membrane, IP3 is soluble and diffuses through the cell, where it binds to its receptor, which is a calcium channel located in the endoplasmic reticulum. When IP3 binds its receptor, calcium is released into the cytosol, thereby activating various calcium regulated intracellular signals. Properties Chemical formula and molecular weight IP3 is an organic molecule with a molecular mass of 420.10 g/mol. Its empirical formula is C6H15O15P3. It is composed of an inositol ring with three phosphate groups bound at the 1, 4, and 5 carbon positions, and three h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PIP2
Phosphatidylinositol 4,5-bisphosphate or PtdIns(4,5)''P''2, also known simply as PIP2 or PI(4,5)P2, is a minor phospholipid component of cell membranes. PtdIns(4,5)''P''2 is enriched at the plasma membrane where it is a substrate for a number of important signaling proteins. PIP2 also forms lipid clusters that sort proteins. PIP2 is formed primarily by the type I phosphatidylinositol 4-phosphate 5-kinases from PI(4)P. In metazoans, PIP2 can also be formed by type II phosphatidylinositol 5-phosphate 4-kinases from PI(5)P. The fatty acids of PIP2 are variable in different species and tissues, but the most common fatty acids are stearic in position 1 and arachidonic in 2. Signaling pathways PIP2 is a part of many cellular signaling pathways, including PIP2 cycle, PI3K signalling, and PI5P metabolism. Recently, it has been found in the nucleus with unknown function. Functions Cytoskeleton dynamics near membranes PIP2 regulates the organization, polymerization, and branc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the substance and w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Tyrosine Kinase
Receptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase proteins. Receptor tyrosine kinases have been shown not only to be key regulators of normal cellular processes but also to have a critical role in the development and progression of many types of cancer. Mutations in receptor tyrosine kinases lead to activation of a series of signalling cascades which have numerous effects on protein expression. Receptor tyrosine kinases are part of the larger family of protein tyrosine kinases, encompassing the receptor tyrosine kinase proteins which contain a transmembrane domain, as well as the non-receptor tyrosine kinases which do not possess transmembrane domains. History The first RTKs to be discovered were EGF and NGF in the 1960s, but the classification of receptor tyrosine kinases was not d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
