seven-transmembrane G protein-coupled receptor superfamily; This hierarchical evolutionary model represents the seven-transmembrane (7TM) receptors, often referred to as G protein-coupled receptors (GPCRs), which transmit physiological signals from the outside of the cell to the inside via G proteins. GPCRs constitute the largest known superfamily of transmembrane receptors across the three kingdoms of life that respond to a wide variety of extracellular stimuli including peptides, lipids, neurotransmitters, amino acids, hormones, and sensory stimuli such as light, smell and taste. All GPCRs share a common structural architecture comprising of seven-transmembrane (TM) alpha-helices interconnected by three extracellular and three intracellular loops. A general feature of GPCR signaling is agonist-induced conformational changes in the receptors, leading to activation of the heterotrimeric G proteins, which consist of the guanine nucleotide-binding G-alpha subunit and the dimeric G-beta-gamma subunits. The activated G proteins then bind to and activate numerous downstream effector proteins, which generate second messengers that mediate a broad range of cellular and physiological processes. However, some 7TM receptors, such as the type 1 microbial rhodopsins, do not activate G proteins. Based on sequence similarity, GPCRs can be divided into six major classes: class A (the rhodopsin-like family), class B (the Methuselah-like, adhesion and secretin-like receptor family), class C (the metabotropic glutamate receptor family), class D (the fungal mating pheromone receptors), class E (the cAMP receptor family), and class F (the frizzled/smoothened receptor family). Nearly 800 human GPCR genes have been identified and are involved essentially in all major physiological processes. Approximately 40% of clinically marketed drugs mediate their effects through modulation of GPCR function for the treatment of a variety of human diseases including bacterial infections.

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gi 81537733   1 IWIISIILAVPEAIAFDMITMNYKGEHLRICLLHPVQKTEFMRFYKSAKDWWLFS 55
Cdd:cd15976 124 IWVVSIILAVPEAIGFDMITMDYKGELLRICLLHPIQKTAFMQFYKTAKDWWLFS 178

endothelin B receptor, member of the class A family of seven-transmembrane G protein-coupled receptors; Endothelins are able to activate a number of signal transduction processes including phospholipase A2, phospholipase C, and phospholipase D, as well as cytosolic protein kinase activation. They play an important role in the regulation of the cardiovascular system and are the most potent vasoconstrictors identified, stimulating cardiac contraction, regulating the release of vasoactive substances, and stimulating mitogenesis in blood vessels. Two endothelin receptor subtypes have been isolated and identified in vertebrates, endothelin A receptor (ET-A) and endothelin B receptor (ET-B), and are members of the seven transmembrane class A G-protein coupled receptor family which activate multiple effectors via different types of G protein. Some vertebrates contain a third subtype, endothelin A receptor (ET-C). ET-A receptors are mainly located on vascular smooth muscle cells, whereas ET-B receptors are present on endothelial cells lining the vessel wall. Endothelin receptors have also been found in the brain.

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gi 81537733   1 IWIISIILAVPEAIAFDMITMNYKGEHLRICLLHPVQKTEFMRFYKSAKDWWLFS 55
Cdd:cd15976 124 IWVVSIILAVPEAIGFDMITMDYKGELLRICLLHPIQKTAFMQFYKTAKDWWLFS 178

endothelin B receptor, member of the class A family of seven-transmembrane G protein-coupled receptors; Endothelins are able to activate a number of signal transduction processes including phospholipase A2, phospholipase C, and phospholipase D, as well as cytosolic protein kinase activation. They play an important role in the regulation of the cardiovascular system and are the most potent vasoconstrictors identified, stimulating cardiac contraction, regulating the release of vasoactive substances, and stimulating mitogenesis in blood vessels. Two endothelin receptor subtypes have been isolated and identified in vertebrates, endothelin A receptor (ET-A) and endothelin B receptor (ET-B), and are members of the seven transmembrane class A G-protein coupled receptor family which activate multiple effectors via different types of G protein. Some vertebrates contain a third subtype, endothelin A receptor (ET-C). ET-A receptors are mainly located on vascular smooth muscle cells, whereas ET-B receptors are present on endothelial cells lining the vessel wall. Endothelin receptors have also been found in the brain.

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gi 81537733   1 IWIISIILAVPEAIAFDMITMNYKGEHLRICLLHPVQKTEFMRFYKSAKDWWLFS 55
Cdd:cd15976 124 IWVVSIILAVPEAIGFDMITMDYKGELLRICLLHPIQKTAFMQFYKTAKDWWLFS 178

endothelin C receptor, member of the class A family of seven-transmembrane G protein-coupled receptors; Endothelins are able to activate a number of signal transduction processes including phospholipase A2, phospholipase C, and phospholipase D, as well as cytosolic protein kinase activation. They play an important role in the regulation of the cardiovascular system and are the most potent vasoconstrictors identified, stimulating cardiac contraction, regulating the release of vasoactive substances, and stimulating mitogenesis in blood vessels. Two endothelin receptor subtypes have been isolated and identified in vertebrates, endothelin A receptor (ET-A) and endothelin B receptor (ET-B), and are members of the seven transmembrane class A G-protein coupled receptor family which activate multiple effectors via different types of G protein. Some vertebrates contain a third subtype, endothelin A receptor (ET-C). ET-A receptors are mainly located on vascular smooth muscle cells, whereas ET-B receptors are present on endothelial cells lining the vessel wall. Endothelin receptors have also been found in the brain. The ET-C receptor is specific for endothelin-3 on frog dermal melanophores; its activation causes dispersion of pigment granules.

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gi 81537733   1 IWIISIILAVPEAIAFDMITMNYKGEHLRICLLHPVQKTEFMRFYKSAKDWWLF 54
Cdd:cd15977 124 IWAVAIIVAVPEAIAFDMVEIDYRGQTLLVCMLPMEQTSSFMRFYQDVKDWWLF 177

endothelin receptors and related proteins, member of the class A family of seven-transmembrane G protein-coupled receptors; This subfamily of G-protein coupled receptors includes endothelin receptors, bombesin receptor subtype 3 (BRS-3), gastrin-releasing peptide receptor (GRPR), neuromedin B receptor (NMB-R), endothelin B receptor-like 2 (ETBR-LP-2), and GRP37. The endothelin receptors and related proteins are members of the seven transmembrane rhodopsin-like G-protein coupled receptor family (class A GPCRs) which activate multiple effectors via different types of G protein.

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gi 81537733   1 IWIISIILAVPEAIAFDMITMN-YKGEHLRICLLHPVQKteFMRFYKSAKDWWLFS 55
Cdd:cd14977 124 IWVGSVLLAVPEAVLSTVARESsLDNSSLTVCIMKPSTP--FAETYPKARSWWLFG 177