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Heteromer
A heteromer is something that consists of different parts; the antonym of homomeric. Examples are: Biology * Spinal neurons that pass over to the opposite side of the spinal cord. * A protein complex that contains two or more different polypeptides. Pharmacology * Ligand-gated ion channels such as the nicotinic acetylcholine receptor and GABAA receptor are composed of five subunits arranged around a central pore that opens to allow ions to pass through. There are many different subunits available that can come together in a wide variety of combinations to form different subtypes of the ion channel. Sometimes the channel can be made from only one type of subunit, such as the α7 nicotinic receptor, which is made up from five α7 subunits, and so is homomerrather than a heteromer, but more commonly several different types of subunit will come together to form a heteromeric complex (e.g., the α4β2 nicotinic receptor, which is made up from two α4 subunits and three β2 subunit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine A2A Receptor
The adenosine A2A receptor, also known as ADORA2A, is an adenosine receptor, and also denotes the human gene encoding it. Structure This protein is a member of the G protein-coupled receptor (GPCR) family which possess seven transmembrane alpha helices, as well as an extracellular N-terminus and an intracellular C-terminus. Furthermore, located in the intracellular side close to the membrane is a small alpha helix, often referred to as helix 8 (H8). The crystallographic structure of the adenosine A2A receptor reveals a ligand binding pocket distinct from that of other structurally determined GPCRs (i.e., the beta-2 adrenergic receptor and rhodopsin).; Below this primary ( orthosteric) binding pocket lies a secondary ( allosteric) binding pocket. The crystal-structure of A2A bound to the antagonist ZM241385 (PDB code: 4EIY) showed that a sodium-ion can be found in this location of the protein, thus giving it the name 'sodium-ion binding pocket'. Heteromers The actions of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPCR Oligomer
A GPCR oligomer is a protein complex that consists of a small number ( ''oligoi'' "a few", ''méros'' "part, piece, component") of G protein-coupled receptors (GPCRs). It is held together by covalent bonds or by intermolecular forces. The subunits within this complex are called protomers, while unconnected receptors are called monomers. Receptor homomers consist of identical protomers, while heteromers consist of different protomers. Receptor homodimers – which consist of two identical GPCRs – are the simplest homomeric GPCR oligomers. Receptor heterodimers – which consist of two different GPCRs – are the simplest heteromeric GPCR oligomers. The existence of receptor oligomers is a general phenomenon, whose discovery has superseded the prevailing paradigmatic concept of the function of receptors as plain monomers, and has far-reaching implications for the understanding of neurobiological diseases as well as for the development of drugs. Discovery For a long time it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinic Acetylcholine Receptor
Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral nervous system, muscle, and many other tissues of many organisms. At the neuromuscular junction they are the primary receptor in muscle for motor nerve-muscle communication that controls muscle contraction. In the peripheral nervous system: (1) they transmit outgoing signals from the presynaptic to the postsynaptic cells within the sympathetic and parasympathetic nervous system, and (2) they are the receptors found on skeletal muscle that receive acetylcholine released to signal for muscular contraction. In the immune system, nAChRs regulate inflammatory processes and signal through distinct intracellular pathways. In insects, the cholinergic system is limited to the central nervous system. The nicotinic receptors are considered cholinergi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homomeric
Something that is composed of one repeating subunit, the antonym of heteromeric. It is often used to describe proteins made up of multiple identical repeating polypeptide chains e.g. beta galactosidase β-Galactosidase (EC 3.2.1.23, lactase, beta-gal or β-gal; systematic name β-D-galactoside galactohydrolase), is a glycoside hydrolase enzyme that catalyzes hydrolysis of terminal non-reducing β-D-galactose residues in β-D-galactosides. β- .... References {{reflist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine A1 Receptor
The adenosine A1 receptor is one member of the adenosine receptor group of G protein-coupled receptors with adenosine as endogenous ligand. Biochemistry A1 receptors are implicated in sleep promotion by inhibiting wake-promoting cholinergic neurons in the basal forebrain. A1 receptors are also present in smooth muscle throughout the vascular system. The adenosine A1 receptor has been found to be ubiquitous throughout the entire body. Signalling Activation of the adenosine A1 receptor by an agonist causes binding of Gi1/2/3 or Go protein. Binding of Gi1/2/3 causes an inhibition of adenylate cyclase and, therefore, a decrease in the cAMP concentration. An increase of the inositol triphosphate/diacylglycerol concentration is caused by an activation of phospholipase C, whereas the elevated levels of arachidonic acid are mediated by DAG lipase, which cleaves DAG to form arachidonic acid. Several types of potassium channels are activated but N-, P-, and Q-type calcium channels are in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second Messenger System
Second messengers are intracellular signaling molecules released by the cell in response to exposure to extracellular signaling molecules—the first messengers. (Intercellular signals, a non-local form or cell signaling, encompassing both first messengers and second messengers, are classified as autocrine, juxtacrine, paracrine, and endocrine depending on the range of the signal.) Second messengers trigger physiological changes at cellular level such as proliferation, differentiation, migration, survival, apoptosis and depolarization. They are one of the triggers of intracellular signal transduction cascades. Examples of second messenger molecules include cyclic AMP, cyclic GMP, inositol triphosphate, diacylglycerol, and calcium. First messengers are extracellular factors, often hormones or neurotransmitters, such as epinephrine, growth hormone, and serotonin. Because peptide hormones and neurotransmitters typically are biochemically hydrophilic molecules, these first messenger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannabinoid Receptor 1
Cannabinoid receptor type 1 (CB1), also known as cannabinoid receptor 1, is a G protein-coupled cannabinoid receptor that in humans is encoded by the ''CNR1'' gene. The human CB1 receptor is expressed in the peripheral nervous system and central nervous system. It is activated by: endocannabinoids, a group of retrograde neurotransmitters that include anandamide and 2-arachidonoylglycerol (2-AG); plant phytocannabinoids, such as the compound THC which is an active ingredient of the psychoactive drug cannabis; and, synthetic analogs of THC. CB1 is antagonized by the phytocannabinoid tetrahydrocannabivarin (THCV). The primary endogenous agonist of the human CB1 receptor is anandamide. Structure The CB1 receptor shares the structure characteristic of all G-protein-coupled receptors, possessing seven transmembrane domains connected by three extracellular and three intracellular loops, an extracellular N-terminal tail, and an intracellular C-terminal tail. The receptor may exist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Journal Of Pharmacology
The ''British Journal of Pharmacology'' is a biweekly peer-reviewed medical journal covering all aspects of experimental pharmacology. It is published for the British Pharmacological Society by Wiley-Blackwell. It was established in 1946 as the ''British Journal of Pharmacology and Chemotherapy''. The journal obtained its current title in 1968. The current editor-in-chief is Amrita Ahluwalia. Previous editors-in-chief include Ian McGrath, Humphrey Rang, Alan North, Phil Moore, Bill Large, and Tony Birmingham. A sister journal, also published for the British Pharmacological Society by Wiley-Blackwell is the '' British Journal of Clinical Pharmacology''. The journal publishes research papers, review articles, commentaries and correspondence in all fields of pharmacology. It also publishes themed issues, as well as supplements. ''The Concise Guide to PHARMACOLOGY'' The ''Concise Guide to PHARMACOLOGY'' is a supplement of the ''British Journal of Pharmacology'', replacing the "Guide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabotropic Glutamate Receptor 5
Metabotropic glutamate receptor 5 is an excitatory Gq-coupled G protein-coupled receptor predominantly expressed on the postsynaptic sites of neurons. In humans, it is encoded by the ''GRM5'' gene. Function The amino acid L-glutamate is the major excitatory neurotransmitter in the central nervous system and activates both ionotropic and metabotropic glutamate receptors. Glutamatergic neurotransmission is involved in most aspects of normal brain function and can be perturbed in many neuropathologic conditions. The metabotropic glutamate receptors are a family of G protein-coupled receptors, that have been divided into 3 groups on the basis of sequence homology, putative signal transduction mechanisms, and pharmacological properties. Group I includes GRM1 and GRM5 and these receptors have been shown to activate phospholipase C. Group II includes GRM2 and GRM3 while Group III includes GRM4, GRM6, GRM7, and GRM8. Group II and III receptors are linked to the inhibition of the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine Receptor D3
Dopamine receptor D3 is a protein that in humans is encoded by the ''DRD3'' gene. This gene encodes the D3 subtype of the dopamine receptor. The D3 subtype inhibits adenylyl cyclase through inhibitory G-proteins. This receptor is expressed in phylogenetically older regions of the brain, suggesting that this receptor plays a role in cognitive and emotional functions. It is a target for drugs which treat schizophrenia, drug addiction, and Parkinson's disease. Alternative splicing of this gene results in multiple transcript variants that would encode different isoforms, although some variants may be subject to nonsense-mediated decay (NMD). Function Alpha-synuclein (α-Syn) aggregation via Lewy bodies inclusion, a pathogenic signature exclusively present in PD patients, is decreased by D3 agonists while DA content is elevated by inhibiting DA reuptake and breakdown. The regulation of α-Syn aggregation and clearance enhances brain-derived neurotrophic factor (BDNF) secretion, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine Receptor D1
Dopamine receptor D1, also known as DRD1. It is one of the two types of D1-like receptor family - receptors D1 and D5. It is a protein that in humans is encoded by the DRD1 gene. Tissue distribution D1 receptors are the most abundant kind of dopamine receptor in the central nervous system. Northern blot and in situ hybridization show that the mRNA expression of DRD1 is highest in the dorsal striatum ( caudate and putamen) and ventral striatum (nucleus accumbens and olfactory tubercle). Lower levels occur in the basolateral amygdala, cerebral cortex, septum, thalamus, and hypothalamus. Function D1 receptors regulate the memory, learning, and the growth of neurons, also is used in the reward system and locomotor activity, mediating some behaviors and modulating dopamine receptor D2-mediated events. They play a role in addiction by facilitating the gene expression changes that occur in the nucleus accumbens during addiction. They are Gs/a coupled and can stimulate neuron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
