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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] |
Cell Membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to ions a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concentration
In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: '' mass concentration'', ''molar concentration'', ''number concentration'', and ''volume concentration''. The concentration can refer to any kind of chemical mixture, but most frequently refers to solutes and solvents in solutions. The molar (amount) concentration has variants, such as normal concentration and osmotic concentration. Etymology The term concentration comes from the word concentrate, from the French , from con– + center, meaning “to put at the center”. Qualitative description Often in informal, non-technical language, concentration is described in a qualitative way, through the use of adjectives such as "dilute" for solutions of relatively low concentration and "concentrated" for solutions of relatively high concentration. To concentrate a solution, one must add more solute (for example, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Families
A protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be confused with family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar three-dimensional structures, functions, and significant sequence similarity. The most important of these is sequence similarity (usually amino-acid sequence), since it is the strictest indicator of homology and therefore the clearest indicator of common ancestry. A fairly well developed framework exists for evaluating the significance of similarity between a group of sequences using sequence alignment methods. Proteins that do not share a common ancestor are very unlikely to show statistically significant sequence similarity, making sequence alignment a powerful tool for identifying the members of protein familie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRPC1
Transient receptor potential canonical 1 (TRPC1) is a protein that in humans is encoded by the ''TRPC1'' gene. Function TRPC1 is an ion channel located on the plasma membrane of numerous human and animal cell types. It is a nonspecific cation channel, which means that both sodium and calcium ions can pass through it. TRPC1 is thought to mediate calcium entry in response to depletion of endoplasmic calcium stores or activation of receptors coupled to the phospholipase C system. In HEK293 cells the unitary current-voltage relationship of endogenous TRPC1 channels is almost linear, with a slope conductance of about 17 pS. The extrapolated reversal potential of TRPC1 channels is +30 mV. The TRPC1 protein is widely expressed throughout the mammalian brain and has a similar corticolimbic expression pattern as TRPC4 and TRPC5. The highest density of TRPC1 protein is found in the lateral septum, an area with dense TRPC4 expression, and hippocampus and prefrontal cortex, areas with de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STIM2
Stromal interaction molecule 2 (STIM2) is a protein that in humans is encoded by the ''STIM2'' gene. This gene is a member of the stromal interaction molecule (STIM) family which comprises only two members together with its homologue STIM1, and likely arose from a common ancestral gene. They encode type 1 transmembrane proteins that are located in the sarco/endoplasmic reticulum ( SR / ER) into the cell. Alternative translation initiation from an AUG and a non-AUG (UUG) start site results in the production of two different STIM2 isoforms. Both members of the STIM family were identified in 2005 as free-calcium (Ca2+) sensors which participate in a mechanism of Ca2+ entry into the cell referred to as store-operated Ca2+ entry (SOCE). Many cellular processes and signaling pathways are started by previous release of Ca2+ stored in subcellular organelles, which needs of a continuous refilling. SOCE is considered the mechanism of store refilling and an essential mechanism of Ca2+ s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anant Parekh
Anant B. Parekh is professor of Physiology at the University of Oxford and a Fellow of Merton College, Oxford.Anant Parekh's Education Parekh was a student at Hymers College and University College, Oxford. He was awarded a Doctor of Philosophy degree by the University of Oxford in 1991 for research on smooth muscle supervised by Alison Brading. He carried out postdoctoral research at the Max Planck Institute for biophysical Chemistry (Goettingen) in the laboratory of Nobel Laureate Erwin Neher, working with Walter Stuehmer and then Reinhold Penner. Career and research Parekh's research investigates the physiology of Calcium signalling and Calcium release activated channels (CRACs). He investigates how cells communicate with one another, with an emphasis on how the ubiquitous intracellular signalling messenger calcium controls biological functions such as secretion, energy production and gene expression. Parekh's research investigates how aberrant calcium signals can cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Transduction
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellular response. Proteins responsible for detecting stimuli are generally termed receptors, although in some cases the term sensor is used. The changes elicited by ligand binding (or signal sensing) in a receptor give rise to a biochemical cascade, which is a chain of biochemical events known as a signaling pathway. When signaling pathways interact with one another they form networks, which allow cellular responses to be coordinated, often by combinatorial signaling events. At the molecular level, such responses include changes in the transcription or translation of genes, and post-translational and conformational changes in proteins, as well as changes in their location. These molecular events are the basic mechanisms controlling cell growth, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drosophila Melanogaster
''Drosophila melanogaster'' is a species of fly (the taxonomic order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly" or "pomace fly". Starting with Charles W. Woodworth's 1901 proposal of the use of this species as a model organism, ''D. melanogaster'' continues to be widely used for biological research in genetics, physiology, microbial pathogenesis, and life history evolution. As of 2017, five Nobel Prizes have been awarded to drosophilists for their work using the insect. ''D. melanogaster'' is typically used in research owing to its rapid life cycle, relatively simple genetics with only four pairs of chromosomes, and large number of offspring per generation. It was originally an African species, with all non-African lineages having a common origin. Its geographic range includes all continents, including islands. ''D. melanogaster'' is a common pest in homes, restaurants, and othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TMEM66
SARAF is a protein that in humans is encoded by the ''SARAF'' gene, formerly known as TMEM66 (transmembrane protein 66). Function SARAF (TMEM66) is a negative regulator of the store-operated calcium channel (SOCE) into cells. SARAF is an endoplasmic reticulum (ER) membrane resident protein that associates with STIM1, to facilitate the inactivation of SOCE. SARAF plays a key role in shaping cytoplasmic 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 forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ... signals and determining the content of the major intracellular Ca2+ stores in the cell. By doing so it is likely to be important in protecting cells from calcium overfilling. References Further reading * * * * * * * * {{gene-8-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmembrane Protein
A transmembrane protein (TP) 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-span (or bitopic) or multi-span (polytopic). Some other integral membrane proteins are called monotopic, meaning that they are also permanently attached to the membrane, but do not pass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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 ''calx'' "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 widely used in many industries: in foods and pharma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
