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Tachykinin
Tachykinin peptides are one of the largest families of neuropeptides, found from amphibians to mammals. They were so named due to their ability to rapidly induce contraction of gut tissue. The tachykinin family is characterized by a common C-terminal sequence, Phe-X- Gly- Leu- Met-NH2, where X is either an Aromatic or an Aliphatic amino acid. The genes that produce tachykinins encode precursor proteins called preprotachykinins, which are chopped apart into smaller peptides by posttranslational proteolytic processing. The genes also code for multiple splice forms that are made up of different sets of peptides. Tachykinins excite neurons, evoke behavioral responses, are potent vasodilators, and contract (directly or indirectly) many smooth muscles. Tachykinins are from ten to twelve residues long. The two human tachykinin genes are called TAC1 and TAC3 for historical reasons, and are equivalent to Tac1 and Tac2 of the mouse, respectively. TAC1 encodes neurokinin A (formerly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurokinin A
Neurokinin A (NKA), formerly known as Substance K, is a neurologically active peptide translated from the pre-protachykinin gene. Neurokinin A has many excitatory effects on mammalian nervous systems and is also influential on the mammalian inflammatory and pain responses. Introduction Neurokinin A (formally known as substance K) is a member of the tachykinin family of neuropeptide neurotransmitters. Tachykinins are important contributors to nociceptive processing, satiety, and smooth muscle contraction. Tachykinins are known to be highly excitatory neurotransmitters in major central neural systems. Neurokinin A is ubiquitous in both the central and peripheral mammalian nervous systems, and seems to be involved in reactions to pain and the inflammatory responses. It is produced from the same preprotachykinin A gene as the neuropeptide substance P. Both substance P and neurokinin A are encoded by the same mRNA, which when alternatively spliced can be translated into either com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tachykinin
Tachykinin peptides are one of the largest families of neuropeptides, found from amphibians to mammals. They were so named due to their ability to rapidly induce contraction of gut tissue. The tachykinin family is characterized by a common C-terminal sequence, Phe-X- Gly- Leu- Met-NH2, where X is either an Aromatic or an Aliphatic amino acid. The genes that produce tachykinins encode precursor proteins called preprotachykinins, which are chopped apart into smaller peptides by posttranslational proteolytic processing. The genes also code for multiple splice forms that are made up of different sets of peptides. Tachykinins excite neurons, evoke behavioral responses, are potent vasodilators, and contract (directly or indirectly) many smooth muscles. Tachykinins are from ten to twelve residues long. The two human tachykinin genes are called TAC1 and TAC3 for historical reasons, and are equivalent to Tac1 and Tac2 of the mouse, respectively. TAC1 encodes neurokinin A (formerly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substance P
Substance P (SP) is an undecapeptide (a peptide composed of a chain of 11 amino acid residues) and a type of neuropeptide, belonging to the tachykinin family of neuropeptides. It acts as a neurotransmitter and a neuromodulator. Substance P and the closely related neurokinin A (NKA) are produced from a polyprotein precursor after alternative splicing of the preprotachykinin A gene. The deduced amino acid sequence of substance P is as follows: * Arg Pro Lys Pro Gln Gln Phe Phe Gly Leu Met (RPKPQQFFGLM) with an amide group at the C-terminus. Substance P is released from the terminals of specific sensory nerves. It is found in the brain and spinal cord and is associated with inflammatory processes and pain. Discovery The original discovery of Substance P (SP) was in 1931 by Ulf von Euler and John H. Gaddum as a tissue extract that caused intestinal contraction ''in vitro''. Its tissue distribution and biologic actions were further investigated over the follow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TAC3
Tachykinin-3 is a protein that in humans is encoded by the ''TAC3'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. 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: protei .... See also * Neurokinin B * Tachykinin receptor 3 References Further reading * * * * * * * * * * * * * * * {{gene-12-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurokinin B
Neurokinin B (NKB) belongs in the family of tachykinin peptides. Neurokinin B is implicated in a variety of human functions and pathways such as the secretion of gonadotropin-releasing hormone. Additionally, NKB is associated with pregnancy in females and maturation in young adults. Reproductive function is highly dependent on levels of both neurokinin B and also the G-protein coupled receptor ligand kisspeptin. The first NKB studies done attempted to resolve why high levels of the peptide may be implicated in pre-eclampsia during pregnancy. NKB, kisspeptin, and dynorphin together are found in the arcuate nucleus (ARC) known as the KNDy subpopulation. This subpopulation is targeted by many steroid hormones and works to form a network that feeds back to GnRH pulse generator. Synthesis Neurokinin B is found in humans as a ten-peptide chain (decapeptide) attached to a terminal amide group. The peptide formula is H-Asp-Met-His-Asp-Phe-Phe-Val-Gly-Leu-Met-NH2 (DMHDFFVGLM-NH2). Neuro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide
Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. Peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyclic peptides have an N-terminal (amine group) and C-terminal (carboxyl g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TAC1
Preprotachykinin-1, (abbreviated PPT-1, PPT-I, or PPT-A), is a precursor protein that in humans is encoded by the ''TAC1'' gene. Isoforms and derivatives The protein has four isoforms—alpha-, beta-, gamma-, and delta-PPT—which can variably undergo post-translational modification to produce neurokinin A (formerly known as substance K) and substance P. Alpha- and delta-PPT can only be modified to substance P, whereas beta- and gamma-PPT can produce both substance P and neurokinin A. Neurokinin A can also be further modified to produce neuropeptide K (also known as neurokinin K) and neuropeptide gamma. These hormones are thought to function as neurotransmitters which interact with nerve receptors and smooth muscle cells. They are known to induce behavioral responses and function as vasodilators and secretagogues. Alternative splicing of exons 4 and/or 6 produces four known products of undetermined significance. Human basal ganglia The nature and distribution of PPT-1 ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuropeptide
Neuropeptides are chemical messengers made up of small chains of amino acids that are synthesized and released by neurons. Neuropeptides typically bind to G protein-coupled receptors (GPCRs) to modulate neural activity and other tissues like the gut, muscles, and heart. Neuropeptides are synthesized from large precursor proteins which are cleaved and post-translationally processed then packaged into large dense core vesicles. Neuropeptides are often co-released with other neuropeptides and neurotransmitters in a single neuron, yielding a multitude of effects. Once released, neuropeptides can diffuse widely to affect a broad range of targets. Neuropeptides are extremely ancient and highly diverse chemical messengers. Placozoa, Placozoans such as ''Trichoplax'', extremely basal animals which do not possess neurons, use peptides for cell-to-cell communication in a way similar to the neuropeptides of higher animals. Examples Peptide signals play a role in information processing t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasodilator
Vasodilation, also known as vasorelaxation, is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. Blood vessel walls are composed of endothelial tissue and a basal membrane lining the lumen of the vessel, concentric smooth muscle layers on top of endothelial tissue, and an adventitia over the smooth muscle layers. Relaxation of the smooth muscle layer allows the blood vessel to dilate, as it is held in a semi-constricted state by sympathetic nervous system activity. Vasodilation is the opposite of vasoconstriction, which is the narrowing of blood vessels. When blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance and increase in cardiac output. Vascular resistance is the amount of force circulating blood must overcome in order to allow perfusion of body tissues. Narrow vessels create more vascular resistan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G Protein-coupled
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily related proteins that are cell surface receptors that detect molecules outside the cell and activate cellular responses. They are coupled with G proteins. They pass through the cell membrane seven times in the form of six loops (three extracellular loops interacting with ligand molecules, three intracellular loops interacting with G proteins, an N-terminal extracellular region and a C-terminal intracellular region) of amino acid residues, which is why they are sometimes referred to as seven-transmembrane receptors. Text was copied from this source, which is available under Attribution 2.5 Generic (CC BY 2.5) licence/ref> Ligands can bind either to the extracellular N-terminus and loops (e.g. glutamate receptors) or to the binding site withi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammalian
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three Evolution of mammalian auditory ossicles, middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors Genetic divergence, diverged in the Carboniferous Period over 300 million years ago. Around 6,640 Neontology#Extant taxon, extant species of mammals have been described and divided into 27 Order (biology), orders. The study of mammals is called mammalogy. The largest orders of mammals, by number of species, are the rodents, bats, and eulipotyphlans (including hedgehogs, Mole (animal), moles and shrews). The next three are the primates (including humans, monkeys and lemurs), the Artiodactyl, even-toed ungulates (including pigs, camels, and whales), and the Carnivora (including Felidae, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
