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SETMAR
Histone-lysine N-methyltransferase SETMAR is an enzyme that in humans is encoded by the ''SETMAR'' gene. Function SETMAR contains a SET domain that confers its histone methyltransferase activity, on Lys-4 and Lys-36 of Histone H3, both of which are specific tags for epigenetic activation. It has been identified as a repair protein as it mediates dimethylation at Lys-36 at double-strand break locations, a signal enhancing NHEJ repair. Anthropoid primates, including humans, have a version of the protein fused to a Mariner/Tc1 transposase. This fusion region provides the DNA-binding abilities for the protein as well as some nuclease activity. The transposase activity is lost due to the presence of several inactivating mutations, including the D610N mutation. However, the domesticated transposase domain retains its ability to bind to the mariner repeat elements in the genome. SETMAR has been found to affect the expression and splicing of genes close to or containing mariner repeat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mariner/Tc1
Tc1/mariner is a class and superfamily of interspersed repeats DNA (Class II) transposons. The elements of this class are found in all animals, including humans. They can also be found in protists and bacteria. The class is named after its two best-studied members, the Tc1 transposon of ''Caenorhabditis elegans'' and the mariner transposon of ''Drosophila''. Structure The transposon consists of a transposase gene, flanked by two terminal inverted repeats (TIR). Two short tandem site duplications (TSD) are present on both sides of the insert. Transposition happens when two transposases recognize and bind to TIR sequences, join together and promote DNA double-strand cleavage. The DNA-transposase complex then inserts its DNA cargo at specific DNA motifs elsewhere in the genome, creating short TSDs upon integration. In the IS630/Tc1/mariner system, the motif used is a "TA" dinucleotide, duplicated on both ends after insertion. When the transposase gene is not carried by the tran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histone Methyltransferase
Histone methyltransferases (HMT) are histone-modifying enzymes (e.g., histone-lysine N-methyltransferases and histone-arginine N-methyltransferases), that catalyze the transfer of one, two, or three methyl groups to lysine and arginine residues of histone proteins. The attachment of methyl groups occurs predominantly at specific lysine or arginine residues on histones H3 and H4. Two major types of histone methyltranferases exist, lysine-specific (which can be SET (Su(var)3-9, Enhancer of Zeste, Trithorax) domain containing or non-SET domain containing) and arginine-specific. In both types of histone methyltransferases, S-Adenosyl methionine (SAM) serves as a cofactor and methyl donor group. The genomic DNA of eukaryotes associates with histones to form chromatin. The level of chromatin compaction depends heavily on histone methylation and other post-translational modifications of histones. Histone methylation is a principal epigenetic modification of chromatin that determines ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucose Tolerance Test
The glucose tolerance test (GTT, not to be confused with GGT test) is a medical test in which glucose is given and blood samples taken afterward to determine how quickly it is cleared from the blood. The test is usually used to test for diabetes, insulin resistance, impaired beta cell function, and sometimes reactive hypoglycemia and acromegaly, or rarer disorders of carbohydrate metabolism. In the most commonly performed version of the test, an ''oral glucose tolerance test'' (OGTT), a standard dose of glucose is ingested by mouth and blood levels are checked two hours later. Many variations of the GTT have been devised over the years for various purposes, with different standard doses of glucose, different routes of administration, different intervals and durations of sampling, and various substances measured in addition to blood glucose. History The glucose tolerance test was first described in 1923 by Jerome W. Conn. The test was based on the previous work in 1913 by A. T. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Model Organism
A model organism (often shortened to model) is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Model organisms are widely used to research human disease when human experimentation would be unfeasible or unethical. This strategy is made possible by the common descent of all living organisms, and the conservation of metabolic and developmental pathways and genetic material over the course of evolution. Studying model organisms can be informative, but care must be taken when generalizing from one organism to another. In researching human disease, model organisms allow for better understanding the disease process without the added risk of harming an actual human. The species chosen will usually meet a determined taxonomic equivalency to humans, so as to react to disease or its treatment in a way that resembles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrobacter
''Citrobacter'' is a genus of Gram-negative coliform bacteria in the family Enterobacteriaceae. The species ''C. amalonaticus'', ''C. koseri'', and ''C. freundii'' can use citrate as a sole carbon source. ''Citrobacter'' species are differentiated by their ability to convert tryptophan to indole (''C. koseri'' is the only citrobacter to be commonly indole-positive), ferment lactose (''C. koseri'' is a lactose fermentor), and use malonate. ''Citrobacter'' shows the ability to accumulate uranium by building phosphate complexes. Clinical significance These bacteria can be found almost everywhere in soil, water, wastewater, etc. They can also be found in the human intestine. They are rarely the source of illnesses, except for infections of the GI Tract, urinary tract and infant meningitis and sepsis. ''Citrobacter freundii'' strains have inducible ''ampC'' genes encoding resistance to ampicillin and first-generation cephalosporins. In addition, isolates of ''Citrobacter'' may be r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmonella
''Salmonella'' is a genus of rod-shaped (bacillus) Gram-negative bacteria of the family Enterobacteriaceae. The two species of ''Salmonella'' are ''Salmonella enterica'' and ''Salmonella bongori''. ''S. enterica'' is the type species and is further divided into six subspecies that include over 2,600 serotypes. ''Salmonella'' was named after Daniel Elmer Salmon (1850–1914), an American veterinary surgeon. ''Salmonella'' species are non-spore-forming, predominantly motile enterobacteria with cell diameters between about 0.7 and 1.5 μm, lengths from 2 to 5 μm, and peritrichous flagella (all around the cell body, allowing them to move). They are chemotrophs, obtaining their energy from oxidation and reduction reactions, using organic sources. They are also facultative anaerobes, capable of generating ATP with oxygen ("aerobically") when it is available, or using other electron acceptors or fermentation ("anaerobically") when oxygen is not available. ''Salmonella'' spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micronucleus Test
A micronucleus test is a test used in toxicological screening for potential genotoxic compounds. The assay is now recognized as one of the most successful and reliable assays for genotoxic carcinogens, i.e., carcinogens that act by causing genetic damage and is recommended by the OECD guideline for the testing of chemicals. There are two major versions of this test, one ''in vivo'' and the other ''in vitro''. The ''in vivo'' test normally uses mouse bone marrow or mouse peripheral blood. When a bone marrow erythroblast develops into a polychromatic erythrocyte, the main nucleus is extruded; any micronucleus that has been formed may remain behind in the otherwise anucleated cytoplasm. Visualisation of micronuclei is facilitated in these cells because they lack a main nucleus. An increase in the frequency of micronucleated polychromatic erythrocytes in treated animals is an indication of induced chromosome damage. Micronuclei were first used to quantify chromosomal damage by H.J. Ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripheral Blood Lymphocyte
Peripheral blood lymphocytes (PBL) are mature lymphocytes that circulate in the blood, rather than localising to organs (such as the spleen or lymph nodes). They comprise T cells, NK cells and B cells B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted o .... References Lymphocytes {{lymphatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haematology
Hematology ( always spelled haematology in British English) is the branch of medicine concerned with the study of the cause, prognosis, treatment, and prevention of diseases related to blood. It involves treating diseases that affect the production of blood and its components, such as blood cells, hemoglobin, blood proteins, bone marrow, platelets, blood vessels, spleen, and the mechanism of coagulation. Such diseases might include hemophilia, blood clots (thrombus), other bleeding disorders, and blood cancers such as leukemia, multiple myeloma, and lymphoma. The laboratory analysis of blood is frequently performed by a medical technologist or medical laboratory scientist. Specialization Physicians specialized in hematology are known as hematologists or haematologists. Their routine work mainly includes the care and treatment of patients with hematological diseases, although some may also work at the hematology laboratory viewing blood films and bone marrow slides under the mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunoglobulin
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can ''tag'' a microbe or an infected cell for attack by other parts of the immune system, or can neutralize it directly (for example, by blocking a part of a virus that is essential for its invasion). To allow the immune system to recognize millions of different antigens, the antigen-binding sites at both tips of the antibody come in an equally wide variety. In contrast, the remainder of the antibody is relatively constant. It only occurs in a few vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Plasma
Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the intravascular part of extracellular fluid (all body fluid outside cells). It is mostly water (up to 95% by volume), and contains important dissolved proteins (6–8%; e.g., serum albumins, globulins, and fibrinogen), glucose, clotting factors, electrolytes (, , , , , etc.), hormones, carbon dioxide (plasma being the main medium for excretory product transportation), and oxygen. It plays a vital role in an intravascular osmotic effect that keeps electrolyte concentration balanced and protects the body from infection and other blood-related disorders. Blood plasma is separated from the blood by spinning a vessel of fresh blood containing an anticoagulant in a centrifuge until the blood cells fall to the bottom of the tube. The blood plasma is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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