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PLA2G4A
Cytosolic phospholipase A2 is an enzyme that in humans is encoded by the ''PLA2G4A'' gene. Function This gene encodes a member of the cytosolic phospholipase A2 group IV family. The enzyme catalyzes the hydrolysis of membrane phospholipids to release arachidonic acid which is subsequently metabolized into eicosanoids. Eicosanoids, including prostaglandins and leukotrienes, are lipid-based cellular hormones that regulate hemodynamics, inflammatory responses, and other intracellular pathways. The hydrolysis reaction also produces lysophospholipids that are converted into platelet-activating factor. The enzyme is activated by increased intracellular Ca2+ levels and phosphorylation, resulting in its translocation from the cytosol and nucleus to perinuclear membrane vesicles. Interactions PLA2G4A has been shown to interact with HTATIP Histone acetyltransferase KAT5 is an enzyme that in humans is encoded by the ''KAT5'' gene. It is also commonly identified as TIP60. The pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multifocal Stenosing Ulceration Of The Small Intestine
Multifocal stenosing ulceration of the small intestine is a rare condition that is characterised by recurrent ulcers of the small intestine. Presentation The clinical features of this condition are variable. Features associated with it include: * Abdominal pain * Abdominal distension * Fatigue * Weight loss * Fever * Malaise * Joint symptoms Faecal occult blood testing is usually positive. Laboratory investigations normally show anaemia and low albumin. Cause A mutation in the cytosolic phospholipase A2-α gene (PLA2G4A) has been identified as the cause of this disease in one family.Brooke MA, Longhurst HJ, Plagnol V, Kirkby NS, Mitchell JA, Rüschendorf F, Warner TD, Kelsell DP, Macdonald TT (2012) Cryptogenic multifocal ulcerating stenosing enteritis associated with homozygous deletion mutations in cytosolic phospholipase A2-α. Gut In this family the mutation was inherited as an autosomal recessive. It is not yet known if this gene is the cause of this disease in other famil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phospholipase A2
The enzyme phospholipase A2 (EC 3.1.1.4, PLA2, systematic name phosphatidylcholine 2-acylhydrolase) catalyse the cleavage of fatty acids in position 2 of phospholipids, hydrolyzing the bond between the second fatty acid “tail” and the glycerol molecule: :phosphatidylcholine + H2O = 1-acylglycerophosphocholine + a carboxylate This particular phospholipase specifically recognizes the ''sn''2 acyl bond of phospholipids and catalytically hydrolyzes the bond, releasing arachidonic acid and lysophosphatidic acid. Upon downstream modification by cyclooxygenases or lipoxygenases, arachidonic acid is modified into active compounds called eicosanoids. Eicosanoids include prostaglandins and leukotrienes, which are categorized as anti-inflammatory and inflammatory mediators. PLA2 enzymes are commonly found in mammalian tissues as well as arachnid, insect, and snake venom. Venom from bees is largely composed of melittin, which is a stimulant of PLA2. Due to the increased presenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTATIP
Histone acetyltransferase KAT5 is an enzyme that in humans is encoded by the ''KAT5'' gene. It is also commonly identified as TIP60. The protein encoded by this gene belongs to the MYST family of histone acetyl transferases (HATs) and was originally isolated as an HIV-1 TAT-interactive protein. HATs play important roles in regulating chromatin remodeling, transcription and other nuclear processes by acetylating histone and nonhistone proteins. This protein is a histone acetylase that has a role in DNA repair and apoptosis and is thought to play an important role in signal transduction. Alternative splicing of this gene results in multiple transcript variants. Structure The structure of KAT5 includes an acetyl CoA binding domain and a zinc finger in the MYST domain, and a CHROMO domain. Excess acetyl CoA is necessary for acetylation of histones. The zinc finger domain has been shown to aid in the acetylation process as well. The CHROMO domain aids in KAT5 ability to bind chromati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perinuclear Envelope
The nuclear envelope, also known as the nuclear membrane, is made up of two lipid bilayer membranes that in eukaryotic cells surround the nucleus, which encloses the genetic material. The nuclear envelope consists of two lipid bilayer membranes: an inner nuclear membrane and an outer nuclear membrane. The space between the membranes is called the perinuclear space. It is usually about 10–50 nm wide. The outer nuclear membrane is continuous with the endoplasmic reticulum membrane. The nuclear envelope has many nuclear pores that allow materials to move between the cytosol and the nucleus. Intermediate filament proteins called lamins form a structure called the nuclear lamina on the inner aspect of the inner nuclear membrane and give structural support to the nucleus. Structure The nuclear envelope is made up of two lipid bilayer membranes, an inner nuclear membrane and an outer nuclear membrane. These membranes are connected to each other by nuclear pores. Two sets of i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorylation
In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. Protein phosphorylation often activates (or deactivates) many enzymes. Glucose Phosphorylation of sugars is often the first stage in their catabolism. Phosphorylation allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter. Phosphorylation of glucose is a key reaction in sugar metabolism. The chemical equation for the conversion of D-glucose to D-glucose-6-phosphate in the first step of glycolysis is given by :D-glucose + ATP → D-glucose-6-phosphate + ADP : ΔG° = −16.7 kJ/mol (° indicates measurement at standard condition) Hepatic cells are freely permeable to glucose, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium In Biology
Calcium ions (Ca2+) contribute to the physiology and biochemistry of organisms' cell (biology), cells. They play an important role in signal transduction pathways, where they act as a second messenger, in neurotransmitter release from neurons, in contraction of all muscle cell types, and in fertilization. Many enzymes require calcium ions as a Cofactor (biochemistry), cofactor, including several of the coagulation factors. Extracellular calcium is also important for maintaining the potential difference across excitable cell cell membrane, membranes, as well as proper bone formation. Plasma calcium levels in mammals are tightly regulated, electronic-book electronic- with bone acting as the major mineral storage site. Calcium ions, Ca2+, are released from bone into the bloodstream under controlled conditions. Calcium is transported through the bloodstream as dissolved ions or bound to proteins such as serum albumin. Parathyroid hormone secreted by the parathyroid gland regulates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysophospholipid
The lysophospholipid receptor (LPL-R) group are members of the G protein-coupled receptor family of integral membrane proteins that are important for lipid signaling. In humans, there are eight LPL receptors, each encoded by a separate gene. These LPL receptor genes are also sometimes referred to as "Edg" (an acronym for endothelial differentiation gene). Ligands The ligands for LPL-R group are the lysophospholipid extracellular signaling molecules, lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P). Origin of name The term ''lysophospholipid'' (LPL) refers to any phospholipid that is missing one of its two O- acyl chains. Thus, LPLs have a free alcohol in either the sn-1 or the sn-2 position. The prefix 'lyso-' comes from the fact that lysophospholipids were originally found to be hemolytic, however it is now used to refer generally to phospholipids missing an acyl chain. LPLs are usually the result of phospholipase A-type enzymatic activity on regular phosph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intracellular
This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions from sub-disciplines and related fields, see Glossary of genetics, Glossary of evolutionary biology, Glossary of ecology, and Glossary of scientific naming, or any of the organism-specific glossaries in :Glossaries of biology. A B C D E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair. The five cardinal signs are heat, pain, redness, swelling, and Functio laesa, loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore it is considered as a mechanism of innate immune system, innate immunity, as compared to adaptive immune system, adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytosol
The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells (intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondrion into many compartments. In the eukaryotic cell, the cytosol is surrounded by the cell membrane and is part of the cytoplasm, which also comprises the mitochondria, plastids, and other organelles (but not their internal fluids and structures); the cell nucleus is separate. The cytosol is thus a liquid matrix around the organelles. In prokaryotes, most of the chemical reactions of metabolism take place in the cytosol, while a few take place in membranes or in the periplasmic space. In eukaryotes, while many metabolic pathways still occur in the cytosol, others take place within organelles. The cytosol is a complex mixture of substances dissolved in water. Although water forms the large majority of the cytosol, its structure and prope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
