Structure and regulation of the growth hormone secretagogue receptor.
Synthetic growth hormone secretagogues (GHS) stimulate growth hormone release through binding to a recently cloned specific growth hormone secretagogue receptor (GHS-R). Ghrelin, the endogenous ligand of this receptor, is part of a new endocrine pathway controlling GH secretion. However, the major physiological function of the ghrelin/GHS-R system may be related to the control of energy homeostasis. The GHS-R belongs to the family of G-protein coupled receptors. Two different receptor variants type 1a and 1b have been described which differ in their carboxyl-terminal amino acids. Both types are encoded by a single gene of approximately 4.3 kb in length through different processing. The promoter region of the human GHS-R was recently characterized. Analysis of the GHS-R may lead to new insights into the control of GH secretion and additional physiological roles of ghrelin. This review will summarize data regarding the structure of the GHS-R gene and the protein encoded, reports investigating the expression and control of the GHS-R in various tissues, and studies of the underlying transcriptional mechanisms.
Petersenn
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Division of Endocrinology, Medical Center, University of Essen, Essen, Germany. stephan.petersenn@uni-essen.de
D000595:Amino Acid Sequence; D000818:Animals; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics; D004734:Energy Metabolism / Q000502:physiology; D025461:Feedback, Physiological; D005786:Gene Expression Regulation; D005796:Genes; D054439:Ghrelin; D013006:Growth Hormone / Q000378:metabolism; D013007:Growth Hormone-Releasing Hormone / Q000502:physiology; D006706:Homeostasis; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000502:physiology; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009928:Organ Specificity; D036361:Peptide Hormones / Q000494:pharmacology / Q000502:physiology*; D011487:Protein Conformation; D020033:Protein Isoforms / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D051381:Rats; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D043562:Receptors, G-Protein-Coupled; D054440:Receptors, Ghrelin; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014714:Vertebrates / Q000235:genetics / Q000378:metabolism
D054439:Ghrelin; D036361:Peptide Hormones; D020033:Protein Isoforms; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D054440:Receptors, Ghrelin; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone