Structure and function of the growth-hormone-releasing hormone receptor.
Growth-hormone-releasing hormone (GHRH) stimulates growth hormone (GH) secretion and GH synthesis and is also thought to cause somatotroph proliferation. Specific high-affinity binding sites for GHRH have been demonstrated on pituitary membranes using iodinated GHRH analogs. The complementary DNA encoding for the human GHRH receptor (GHRH-R) was recently cloned. The open reading frame was shown to extend 1269 bp and thus to encode a protein of 423 amino acids with a predicted molecular weight of 47 kDa. Expression is restricted to specific tissues. Analysis of the genomic structure revealed that the human GHRH-R gene spans 15 kb and consists of 13 exons. The 5'-flanking region of the human GHRH-R gene was recently characterized. Transcriptional regulation of the GHRH-R is discussed in this review. Mechanisms of signal transduction for control of GH transcription and secretion are presented. Furthermore, the role of the GHRH-R in proliferation and differentiation of the somatotrophic pituitary cell as well as in disease is examined.
Petersenn
S
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IHF Institute for Hormone and Fertility Research, University of Hamburg, Germany.
Schulte
H M
HM
D000595:Amino Acid Sequence; D005786:Gene Expression Regulation; D005938:Glucocorticoids / Q000502:physiology; D012739:Gonadal Steroid Hormones / Q000502:physiology; D013007:Growth Hormone-Releasing Hormone / Q000502:physiology*; D019382:Human Growth Hormone / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D010902:Pituitary Gland / Q000378:metabolism / Q000502:physiology; D017481:Receptors, Somatostatin / Q000737:chemistry / Q000502:physiology*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000502:physiology; D013963:Thyroid Hormones / Q000502:physiology
D005938:Glucocorticoids; D012739:Gonadal Steroid Hormones; D017481:Receptors, Somatostatin; D013963:Thyroid Hormones; D019382:Human Growth Hormone; D013007:Growth Hormone-Releasing Hormone