|
Ceramide-activated Protein Phosphatase
Ceramide-activated protein phosphatases (CAPPs) are a group of enzymes that are activated by the lipid second messenger ceramide. Known CAPPs include members of the protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A) families. CAPPs are a subset of intracellular serine/threonine phosphatases. Each CAPP consists of a catalytic subunit which confers phosphatase activity and a regulatory subunit which confers substrate specificity. CAPP involvement has been implicated in glycogen metabolism, apoptotic pathways related to cancer and other cellular pathways related to Alzheimer’s disease. Structure Ceramide-activated PP2A As a member of the PP2A family, CAPPs can consist of one to three PP2A subunits (Janssens & Goris, 2001). The core enzyme consists of a conserved 34 kilodalton (kDa) catalytic subunit, C, and a conserved 65 kDa scaffold subunit, A, tightly bound to one another (Janssens & Goris, 2001). The scaffold subunit contains 15 tandem HEAT repeats which arrange ... [...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 substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), 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, 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 Ribozyme, catalytic RNA molecules, called ribozymes. Enzymes' Chemical specificity, specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceramide
Ceramides are a family of waxy lipid molecules. A ceramide is composed of N-acetyl sphingosine and a fatty acid. Ceramides are found in high concentrations within the cell membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the ... of Eukaryote, eukaryotic cells, since they are component lipids that make up sphingomyelin, one of the major lipids in the lipid bilayer. Contrary to previous assumptions that ceramides and other sphingolipids found in cell membrane were purely supporting structural elements, ceramide can participate in a variety of cellular lipid signaling, signaling: examples include regulating cell differentiation, differentiation, cell proliferation, proliferation, and programmed cell death (PCD) of Cell (biology), cells. The word ''ceramide'' comes from the Latin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Phosphatase 1
Protein phosphatase 1 (PP1) belongs to a certain class of phosphatases known as protein serine/threonine phosphatases. This type of phosphatase includes metal-dependent protein phosphatases (PPMs) and aspartate-based phosphatases. PP1 has been found to be important in the control of glycogen metabolism, muscle contraction, cell progression, neuronal activities, splicing of RNA, mitosis, cell division, apoptosis, protein synthesis, and regulation of membrane receptors and channels. Structure Each PP1 enzyme contains both a catalytic subunit and at least one regulatory subunit. The catalytic subunit consists of a 30-kD single-domain protein that can form complexes with other regulatory subunits. The catalytic subunit is highly conserved among all eukaryotes, thus suggesting a common catalytic mechanism. The catalytic subunit can form complexes with various regulatory subunits. These regulatory subunits play an important role in substrate specificity as well as compartmentaliza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Phosphatase 2A
Protein phosphatase 2A may refer to: * Protein phosphatase 2 Protein phosphatase 2 (PP2), also known as PP2A, is an enzyme that in humans is encoded by the ''PPP2CA'' gene. The PP2A heterotrimeric protein phosphatase is ubiquitously expressed, accounting for a large fraction of phosphatase activity in ..., an enzyme * (myosin-light-chain) phosphatase, an enzyme {{Short pages monitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theophylline
Theophylline, also known as 1,3-dimethylxanthine, is a phosphodiesterase inhibiting drug used in therapy for respiratory diseases such as chronic obstructive pulmonary disease (COPD) and asthma under a variety of brand names. As a member of the xanthine family, it bears structural and pharmacological similarity to theobromine and caffeine, and is readily found in nature, being present in tea (''Camellia sinensis'') and cocoa (''Theobroma cacao''). A small amount of theophylline is one of the products of caffeine metabolic processing in the liver. Medical uses The main actions of theophylline involve: * relaxing bronchial smooth muscle * increasing heart muscle contractility and efficiency (positive inotrope) * increasing heart rate (positive chronotropic) * increasing blood pressure * increasing renal blood flow * anti-inflammatory effects * central nervous system stimulatory effect mainly on the medullary respiratory center. The main therapeutic uses of theophylline are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
