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SIRT4
Sirtuin 4, also known as SIRT4, is a mitochondria, mitochondrial protein which in humans is encoded by the ''SIRT4'' gene. SIRT4 is member of the mammalian sirtuin family of proteins, which are Homology (biology)#Homology of sequences in genetics, homologs to the yeast Sir2 protein. SIRT4 exhibits NAD+-dependent protein deacetylase, deacetylase activity. Function SIRT4 is a mitochondrial ADP-ribosyltransferase that inhibits mitochondrial glutamate dehydrogenase 1 activity, thereby downregulating insulin secretion in response to amino acids. A deacetylation of malonyl-CoA decarboxylase enzyme by SIRT4 represses the enzyme activity, inhibiting Beta oxidation, fatty acid oxidation in muscle and liver cells. SIRT4 has a suppressive effect on peroxisome proliferator-activated receptor alpha (PPAR-α) which Downregulation and upregulation, downregulates fatty acid oxidation in liver cells. Acetylation, Deacetylation of ADP/ATP translocase 2 (ANT2) increases cellular ATP by dampening Un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADP/ATP Translocase 2
ADP/ATP translocase 2 is a protein that in humans is encoded by the SLC25A5 gene on the X chromosome. This protein functions as an antiporter for ADP/Adenosine triphosphate, ATP exchange between the mitochondrial matrix and cytoplasm. As a result, it plays a key role in maintaining mitochondrial membrane potential and inhibiting apoptosis and has been targeted for treating cancer. Structure The ''SLC25A5'' gene belongs to the ANT gene family, which itself belongs to the superfamily that includes genes encoding brown fat mitochondrial uncoupling proteins and mitochondrial phosphate carrier proteins. Compared to the other gene isoforms, ''SLC25A5'' possesses different motifs, including a CCACT sequence rather than the canonical CCAAT sequence upstream of the TATA box, as well as five SP1 binding sites. This gene consists of 4 exons, while its encoded protein forms a homodimer embedded in the inner mitochondrial membrane. The entire protein is composed of 300-320 amino acid resid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sirtuin
Sirtuins are a family of signaling proteins involved in metabolic regulation. They are ancient in animal evolution and appear to possess a highly conserved structure throughout all kingdoms of life. Chemically, sirtuins are a class of proteins that possess either mono- ADP-ribosyltransferase or deacylase activity, including deacetylase, desuccinylase, demalonylase, demyristoylase and depalmitoylase activity. The name Sir2 comes from the yeast gene 'silent mating-type information regulation 2', the gene responsible for cellular regulation in yeast. From ''in vitro'' studies, sirtuins were thought to be implicated in influencing cellular processes like aging, transcription, apoptosis, inflammation and stress resistance, as well as energy efficiency and alertness during low-calorie situations. As of 2018, there was no clinical evidence that sirtuins affect human aging, and a 2022 review criticized researchers who propagate this claim. Yeast Sir2 and some, but not all, sirt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malonyl-CoA Decarboxylase
Malonyl-CoA decarboxylase (), (which can also be called MCD and malonyl-CoA carboxyl-lyase) is found in bacteria and humans and has important roles in regulating fatty acid metabolism and food intake, and it is an attractive target for drug discovery. It is an enzyme associated with Malonyl-CoA decarboxylase deficiency. In humans, it is encoded by the MLYCD gene. Its main function is to catalyze the conversion of malonyl-CoA into acetyl-CoA and carbon dioxide. It is involved in fatty acid biosynthesis. To some degree, it reverses the action of Acetyl-CoA carboxylase. Structure MCD presents two isoforms which can be transcribed form one gene: a long isoform (54kDa), distributed in mitochondria, and a short isoform (49kDa) that can be found in peroxisomes and cytosol. The long isoform includes a sequence of signaling towards mitochondria in the N-terminus; whereas the short one only contains the typical sequence of peroxisomal signaling PTS1 in the C-terminus, also shared by t ... [...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'', meaning a thread-like granule, was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase popularized by Philip Siekevitz in a 1957 ''Scientific American'' article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). The multicellular animal '' Henneguya salminicola'' is known to have retained mitochondrion-related organelles despite a complete loss of their mitochondrial genome. A large number of unicellular organisms, such as microspo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxisome Proliferator-activated Receptor Alpha
Peroxisome proliferator-activated receptor alpha (PPAR-α), also known as NR1C1 (nuclear receptor subfamily 1, group C, member 1), is a nuclear receptor protein functioning as a transcription factor that in humans is encoded by the ''PPARA'' gene. Together with peroxisome proliferator-activated receptor delta and peroxisome proliferator-activated receptor gamma, PPAR-alpha is part of the subfamily of peroxisome proliferator-activated receptors. It was the first member of the PPAR family to be cloned in 1990 by Stephen Green and has been identified as the nuclear receptor for a diverse class of rodent Liver, hepatocarcinogens that causes proliferation of peroxisomes. Expression PPAR-α is primarily activated through ligand binding. Endogenous ligands include fatty acids such as arachidonic acid as well as other polyunsaturated fatty acids and various fatty acid-derived compounds such as certain members of the 15-hydroxyicosatetraenoic acid, 15-hydroxyeicosatetraenoic acid family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Expression
Gene expression is the process (including its Regulation of gene expression, regulation) by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, proteins or non-coding RNA, and ultimately affect a phenotype. These products are often proteins, but in non-protein-coding genes such as Transfer RNA, transfer RNA (tRNA) and Small nuclear RNA, small nuclear RNA (snRNA), the product is a functional List of RNAs, non-coding RNA. The process of gene expression is used by all known life—eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and viruses—to generate the macromolecule, macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, ''i.e.'' observable trait. The genetic information stored in DNA represents the genotype, whereas the phenotype results from the "interpretation" of that informati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Suppressor
A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell (biology), cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer. When a tumor suppressor gene is mutated, it results in a loss or reduction in its function. In combination with other genetic mutations, this could allow the cell to grow abnormally. The Loss-of-function mutation, loss of function for these genes may be even more significant in the development of human cancers, compared to the activation of oncogenes. TSGs can be grouped into the following categories: caretaker genes, gatekeeper genes, and more recently landscaper genes. Caretaker genes ensure stability of the genome via DNA repair and subsequently when mutated allow mutations to accumulate. Meanwhile, gatekeeper genes directly regulate cell growth by either inhibiting cell cycle progression or inducing apoptosis. Lastly, landscaper genes regulate growth by contributing to the surrounding e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uncoupling Protein
An uncoupling protein (UCP) is a mitochondrial inner membrane protein that is a regulated proton channel or transporter. An uncoupling protein is thus capable of dissipating the proton gradient generated by NADH-powered pumping of protons from the mitochondrial matrix to the mitochondrial intermembrane space. The energy lost in dissipating the proton gradient via UCPs is not used to do biochemical work. Instead, heat is generated. This is what links UCP to thermogenesis. However, not every type of UCPs are related to thermogenesis. Although UCP2 and UCP3 are closely related to UCP1, UCP2 and UCP3 do not affect thermoregulatory abilities of vertebrates. UCPs are positioned in the same membrane as the ATP synthase, which is also a proton channel. The two proteins thus work in parallel with one generating heat and the other generating ATP from ADP and inorganic phosphate, the last step in oxidative phosphorylation. Mitochondria respiration is coupled to ATP synthesis (ADP phosphorylati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylation
: In chemistry, acetylation is an organic esterification reaction with acetic acid. It introduces an acetyl group into a chemical compound. Such compounds are termed ''acetate esters'' or simply ''acetates''. Deacetylation is the opposite reaction, the removal of an acetyl group from a chemical compound. Acetylation/deacetylation in biology Histone deacetylases "play crucial roles in gene transcription and most likely in all eukaryotic biological processes that involve chromatin". Acetylation is one type of post-translational modification of proteins. The acetylation of the ε-amino group of lysine, which is common, converts a charged side chain to a neutral one. Acetylation/deacetylation of histones also plays a role in gene expression and cancer. These modifications are effected by enzymes called histone acetyltransferases (HATs) and histone deacetylases (HDACs). Two general mechanisms are known for deacetylation. One mechanism involves zinc binding to the acetyl o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downregulation And Upregulation
In biochemistry, in the biological context of organisms' regulation of gene expression and production of gene products, downregulation is the process by which a cell decreases the production and quantities of its cellular components, such as RNA and proteins, in response to an external stimulus. The complementary process that involves increase in quantities of cellular components is called upregulation. An example of downregulation is the cellular decrease in the expression of a specific receptor in response to its increased activation by a molecule, such as a hormone or neurotransmitter, which reduces the cell's sensitivity to the molecule. This is an example of a locally acting (negative feedback) mechanism. An example of upregulation is the response of liver cells exposed to such xenobiotic molecules as dioxin. In this situation, the cells increase their production of cytochrome P450 enzymes, which in turn increases degradation of these dioxin molecules. Downregulation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Oxidation
In biochemistry and metabolism, beta oxidation (also β-oxidation) is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA. Acetyl-CoA enters the citric acid cycle, generating NADH and FADH2, which are electron carriers used in the electron transport chain. It is named as such because the beta carbon of the fatty acid chain undergoes oxidation and is converted to a carbonyl group to start the cycle all over again. Beta-oxidation is primarily facilitated by the mitochondrial trifunctional protein, an enzyme complex associated with the inner mitochondrial membrane, although very long chain fatty acids are oxidized in peroxisomes. The overall reaction for one cycle of beta oxidation is: :C''n''-acyl-CoA + FAD + NAD''+'' + H''2''O + CoA → C''n''-2-acyl-CoA + FADH''2'' + NADH + H''+'' + acetyl-CoA Activation and membrane transport Free fatty acids cannot penetrate any bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progress In Biophysics And Molecular Biology
''Progress in Biophysics and Molecular Biology'' is a peer-reviewed scientific journal publishing review articles in the fields of biophysics and molecular biology. It was established in 1950 as ''Progress in Biophysics and Biophysical Chemistry'', obtaining its current title in 1963. It is published by Elsevier and the editors-in-chief are Denis Noble (University of Oxford), Tom Blundell (University of Cambridge), and Delphine Dean (Clemson University). According to the ''Journal Citation Reports'', the journal has a 2020 impact factor of 3.667, and a CiteScore of 5.8. History First published in 1950, under the title ''Progress in Biophysics and Biophysical Chemistry'', its original format was as a hardback book issued annually containing specialist reviews of important papers in the various different fields. Its multi-disciplinary coverage spanning biological and physical science disciplines was novel at that time, anticipating a trend that developed over the following decade ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
