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LPIN1
Lipin-1 is a protein that in humans is encoded by the ''LPIN1'' gene. Function Lipin-1 has phosphatidate phosphatase activity. The nuclear localization of Lipin 1 is regulated by the mammalian Target Of Rapamycin protein kinase and links mTORC1 activity to the regulation of Sterol regulatory element-binding proteins ( SREBP)-dependent gene transcription. Clinical significance Homozygous mutations in ''LPIN1'' gene in humans cause recurrent rhabdomyolysis and exercise-induced myalgia while carrier state may predispose for statin-induced myopathy. This gene also represents a candidate gene for human lipodystrophy, characterized by loss of body fat, fatty liver, hypertriglyceridemia, and insulin resistance Insulin resistance (IR) is a pathological condition in which cell (biology), cells fail to respond normally to the hormone insulin. Insulin is a hormone that facilitates the transport of glucose from blood into cells, thereby reducing blood gluco .... Mouse studies sugg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphatidate Phosphatase
The enzyme phosphatidate phosphatase (PAP, EC 3.1.3.4) is a key regulatory enzyme in lipid metabolism, catalyzing the conversion of phosphatidate to diacylglycerol: :a 1,2-diacylglycerol 3-phosphate + H2O \rightleftharpoons a 1,2-diacyl-''sn''-glycerol + phosphate The reverse conversion is catalyzed by the enzyme diacylglycerol kinase, which replaces the hydroxyl group on diacylgylcerol with a phosphate from ATP, generating ADP in the process. In yeast, the forward direction is Mg2+-dependent, while the reverse process is Ca2+-dependent. PAP1, a cytosolic phosphatidate phosphatase found in the lung, is also Mg^2+-dependent, but PAP2, a six-transmembrane-domain integral protein found in the plasma membrane, is not. Role in the regulation of lipid flux Phosphatidate phosphatase regulates lipid metabolism in several ways. In short, it is a key player in controlling the overall flux of triacylglycerols to phospholipids and vice versa, also exerting control through the genera ... [...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 residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MTORC1
mTORC1, also known as mammalian target of rapamycin complex 1 or mechanistic target of rapamycin complex 1, is a protein complex that functions as a nutrient/energy/redox sensor and controls protein synthesis. mTOR Complex 1 (mTORC1) is composed of the mammalian target of rapamycin, mTOR protein complex, RPTOR, regulatory-associated protein of mTOR (commonly known as raptor), mammalian lethal with SEC13 protein 8 (MLST8), AKT1S1, PRAS40 and DEPTOR. This complex embodies the classic functions of mTOR, namely as a nutrient/energy/redox sensor and controller of protein synthesis. The activity of this complex is regulated by rapamycin, insulin, growth factors, phosphatidic acid, certain amino acids and their derivatives (e.g., leucine, -leucine and β-hydroxy β-methylbutyric acid), mechanical stimuli, and oxidative stress. Recently it has been also demonstrated that cellular bicarbonate metabolism can be regulated by mTORC1 signaling. The role of mTORC1 is to activate translation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Srebp
Sterol regulatory element-binding proteins (SREBPs) are transcription factors that bind to the sterol regulatory element DNA sequence TCACNCCAC. Mammalian SREBPs are encoded by the genes ''SREBF1'' and ''SREBF2''. SREBPs belong to the basic-helix-loop-helix leucine zipper class of transcription factors. Unactivated SREBPs are attached to the nuclear envelope and endoplasmic reticulum membranes. In cells with low levels of sterols, SREBPs are cleaved to a water-soluble N-terminal domain that is translocated to the nucleus. These activated SREBPs then bind to specific sterol regulatory element DNA sequences, thus upregulating the synthesis of enzymes involved in sterol biosynthesis. Sterols in turn inhibit the cleavage of SREBPs and therefore synthesis of additional sterols is reduced through a negative feed back loop. Isoforms Mammalian genomes have two separate SREBP genes ( and ): * SREBP-1 expression produces two different isoforms, SREBP-1a and -1c. These isoforms differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipodystrophy
Lipodystrophy syndromes are a group of genetic or acquired disorders in which the body is unable to produce and maintain healthy fat tissue. The medical condition is characterized by abnormal or degenerative conditions of the body's adipose tissue. A more specific term, ''lipoatrophy ("lipo" is Greek for "fat", and "dystrophy" is Greek for "abnormal or degenerative condition")'', is used when describing the loss of fat from one area (usually the face). This condition is also characterized by a lack of circulating leptin which may lead to osteosclerosis. The absence of fat tissue is associated with insulin resistance, hypertriglyceridemia, non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome. Types Lipodystrophy can be divided into the following types: *Congenital lipodystrophy syndromes **Congenital generalized lipodystrophy (Berardinelli-Seip syndrome) **Familial partial lipodystrophy **Marfanoid–progeroid–lipodystrophy syndrome ** Chronic atypical neutrophilic d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypertriglyceridemia
Hypertriglyceridemia is the presence of high amounts of triglycerides in the blood. Triglycerides are the most abundant fatty molecule in most organisms. Hypertriglyceridemia occurs in various physiologic conditions and in various diseases, and high triglyceride levels are associated with atherosclerosis, even in the absence of hypercholesterolemia (high cholesterol levels) and predispose to cardiovascular disease. Chronically elevated serum triglyceride levels are a component of metabolic syndrome and Non-alcoholic fatty liver disease (NAFLD), both of which typically involve obesity and contribute significantly to cardiovascular mortality in industrialised countries as of 2021. Extreme triglyceride levels also increase the risk of acute pancreatitis. Hypertriglyceridemia itself is usually symptomless, although high levels may be associated with skin lesions known as ''xanthomas''. Signs and symptoms Most people with elevated triglycerides experience no symptoms. Some forms o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
