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Sirtuin 3
NAD-dependent deacetylase sirtuin-3, mitochondrial also known as SIRT3 is a protein that in humans is encoded by the ''SIRT3'' gene irtuin (silent mating type information regulation 2 homolog) 3 (S. cerevisiae) SIRT3 is member of the mammalian sirtuin family of proteins, which are homologs to the yeast Sir2 protein. SIRT3 exhibits NAD+-dependent deacetylase activity. Members of the sirtuin family are characterized by a sirtuin core domain and grouped into four classes, and the protein encoded by this gene is included in class I of the sirtuin family. The human sirtuins have a range of molecular functions and have emerged as important proteins in aging, stress resistance and metabolic regulation. Yeast sirtuin proteins are known to regulate epigenetic gene silencing and suppress recombination of rDNA. In addition to protein deacetylation, studies have shown that the human sirtuins may also function as intracellular regulatory proteins with mono ADP ribosyltransferase activity. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinamide Adenine Dinucleotide
Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD and NADH (H for hydrogen), respectively. In metabolism, nicotinamide adenine dinucleotide is involved in redox reactions, carrying electrons from one reaction to another. The cofactor is, therefore, found in two forms in cells: NAD is an oxidizing agent – it accepts electrons from other molecules and becomes reduced. This reaction, also with H+, forms NADH, which can then be used as a reducing agent to donate electrons. These electron transfer reactions are the main function of NAD. However, it is also used in other cellular processes, most notably as a substrate of enzymes in adding or removing chemical groups ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NMNAT2
Nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2) is an enzyme that in humans is encoded by the ''NMNAT2'' gene. This gene product belongs to the nicotinamide-nucleotide adenylyltransferase (NMNAT) enzyme family, members of which catalyze an essential step in the nicotinamide adenine dinucleotide (NAD+ (NADP)) biosynthetic pathway. NMNAT2 is cytoplasmic (associated with the Golgi apparatus), and is predominantly expressed in the brain. Two transcript variants encoding different isoforms have been found for this gene. Loss of NMNAT2 initiates Wallerian degeneration. By contrast, NMNAT2 enhancement opposes the actions of SARM1 which would lead to axon degeneration, but this effect is not due to preventing SARM1 depletion of NAD+. Mice lacking NMNAT2 die before birth, but are completely rescued by SARM1 deletion. Activation of NMNAT2 by Sirtuin 3 (SIRT3) may be a means of inhibiting axon degeneration and dysfunction. The catechin epigallocatechin gallate Epigallocate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetyl Co-A Synthetase
Acetyl-CoA synthetase (ACS) or Acetate—CoA ligase is an enzyme () involved in metabolism of acetate. It is in the ligase class of enzymes, meaning that it catalyzes the formation of a new chemical bond between two large molecules. Reaction The two molecules joined together that make up Acetyl CoA are acetate and coenzyme A (CoA). The complete reaction with all the substrates and products included is: : ATP + Acetate + CoA AMP + Pyrophosphate + Acetyl-CoA Once acetyl-CoA is formed it can be used in the TCA cycle in aerobic respiration to produce energy and electron carriers. This is an alternate method to starting the cycle, as the more common way is producing acetyl-CoA from pyruvate through the pyruvate dehydrogenase complex. The enzyme's activity takes place in the mitochondrial matrix so that the products are in the proper place to be used in the following metabolic steps. Acetyl Co-A can also be used in fatty acid synthesis, and a common function of the synthetase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetyl-CoA
Acetyl-CoA (acetyl coenzyme A) is a molecule that participates in many biochemical reactions in protein, carbohydrate and lipid metabolism. Its main function is to deliver the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for energy production. Coenzyme A (CoASH or CoA) consists of a β-mercaptoethylamine group linked to the vitamin pantothenic acid (B5) through an amide linkage and 3'-phosphorylated ADP. The acetyl group (indicated in blue in the structural diagram on the right) of acetyl-CoA is linked to the sulfhydryl substituent of the β-mercaptoethylamine group. This thioester linkage is a "high energy" bond, which is particularly reactive. Hydrolysis of the thioester bond is exergonic (−31.5 kJ/mol). CoA is acetylated to acetyl-CoA by the breakdown of carbohydrates through glycolysis and by the breakdown of fatty acids through β-oxidation. Acetyl-CoA then enters the citric acid cycle, where the acetyl group is oxidized to carbon dioxide and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmonella Enterica
''Salmonella enterica'' (formerly ''Salmonella choleraesuis'') is a rod-headed, flagellate, facultative anaerobic, Gram-negative bacterium and a species of the genus ''Salmonella''. A number of its serovars are serious human pathogens. Epidemiology Most cases of salmonellosis are caused by food infected with ''S. enterica'', which often infects cattle and poultry, though other animals such as domestic cats and hamsters have also been shown to be sources of infection in humans. Investigations of vacuum cleaner bags have shown that households can act as a reservoir of the bacterium; this is more likely if the household has contact with an infection source (i.e., members working with cattle or in a veterinary clinic). Raw chicken eggs and goose eggs can harbor ''S. enterica'', initially in the egg whites, although most eggs are not infected. As the egg ages at room temperature, the yolk membrane begins to break down and ''S. enterica'' can spread into the yolk. Refrigeration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermogenesis
Thermogenesis is the process of heat production in organisms. It occurs in all warm-blooded animals, and also in a few species of thermogenic plants such as the Eastern skunk cabbage, the Voodoo lily ('' Sauromatum venosum''), and the giant water lilies of the genus '' Victoria''. The lodgepole pine dwarf mistletoe, '' Arceuthobium americanum'', disperses its seeds explosively through thermogenesis.Rolena A.J. deBruyn, Mark Paetkau, Kelly A. Ross, David V. Godfrey & Cynthia Ross Friedman (2015)"Thermogenesis-triggered seed dispersal in dwarf mistletoe" Types Depending on whether or not they are initiated through locomotion and intentional movement of the muscles, thermogenic processes can be classified as one of the following: * Exercise-associated thermogenesis (EAT) * Non-exercise activity thermogenesis (NEAT), energy expended for everything that is not sleeping, eating or sports-like exercise. * Diet-induced thermogenesis (DIT) Shivering One method to raise temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermogenin
Thermogenin (called uncoupling protein by its discoverers and now known as uncoupling protein 1, or UCP1) is a mitochondrial carrier protein found in brown adipose tissue (BAT). It is used to generate heat by non-shivering thermogenesis, and makes a quantitatively important contribution to countering heat loss in babies which would otherwise occur due to their high surface area-volume ratio. Mechanism UCP1 belongs to the UCP family which are transmembrane proteins that decrease the proton gradient generated in oxidative phosphorylation. They do this by increasing the permeability of the inner mitochondrial membrane, allowing protons that have been pumped into the intermembrane space to return to the mitochondrial matrix. UCP1-mediated heat generation in brown fat uncouples the respiratory chain, allowing for fast substrate oxidation with a low rate of ATP production. UCP1 is related to other mitochondrial metabolite transporters such as the adenine nucleotide translocator, a pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PPARGC1A
Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) is a protein that in humans is encoded by the ''PPARGC1A'' gene. PPARGC1A is also known as human accelerated region 20 ( HAR20). It may, therefore, have played a key role in differentiating humans from apes. PGC-1α is the master regulator of mitochondrial biogenesis. PGC-1α is also the primary regulator of liver gluconeogenesis, inducing increased gene expression for gluconeogenesis. Function PGC-1α is a super strong gene that contains two promoters, and has 4 alternative splicings. PGC-1α is a transcriptional coactivator that regulates the genes involved in energy metabolism. It is the master regulator of mitochondrial biogenesis. This protein interacts with the nuclear receptor PPAR-γ, which permits the interaction of this protein with multiple transcription factors. This protein can interact with, and regulate the activity of, cAMP response element-binding protein ( CREB) and nuclea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown Adipose Tissue
Brown adipose tissue (BAT) or brown fat makes up the adipose organ together with white adipose tissue (or white fat). Brown adipose tissue is found in almost all mammals. Classification of brown fat refers to two distinct cell populations with similar functions. The first shares a common embryological origin with muscle cells, found in larger "classic" deposits. The second develops from white adipocytes that are stimulated by the sympathetic nervous system. These adipocytes are found interspersed in white adipose tissue and are also named 'beige' or 'brite' (for "brown in white"). Brown adipose tissue is especially abundant in newborns and in hibernating mammals. It is also present and metabolically active in adult humans, but its prevalence decreases as humans age. Its primary function is thermoregulation. In addition to heat produced by shivering muscle, brown adipose tissue produces heat by non-shivering thermogenesis. The therapeutic targeting of brown fat for the treatment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Adipose Tissue
White adipose tissue or white fat is one of the two types of adipose tissue found in mammals. The other kind is brown adipose tissue. White adipose tissue is composed of monolocular adipocytes. In humans, the healthy amount of white adipose tissue varies with age, but composes between 6-25% of body weight in adult men and 14-35% in adult women. Its cells contain a single large fat droplet, which forces the nucleus to be squeezed into a thin rim at the periphery. They have receptors for insulin, sex hormones, norepinephrine, and glucocorticoids. White adipose tissue is used for energy storage. Upon release of insulin from the pancreas, white adipose cells' insulin receptors cause a dephosphorylation cascade that leads to the inactivation of hormone-sensitive lipase. It was previously thought that upon release of glucagon from the pancreas, glucagon receptors cause a phosphorylation cascade that activates hormone-sensitive lipase, causing the breakdown of the stored fat to fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondria
A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von Kölliker in 1857 in the voluntary muscles of insects. The term ''mitochondrion'' was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase coined by Philip Siekevitz in a 1957 article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). A large number of unicellular organisms, such as microsporidia, parabasalids and diplomonads, have reduced or transformed their mitochondria into other structures. One eukaryote, ''Monocercomonoides'', is known to have completely lost its mitochondria, and one multicellular organism, ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
