|1a22, resolution 2.60Å ()|
HUMAN GROWTH HORMONE BOUND TO SINGLE RECEPTOR
The designed G120R mutant of human growth hormone (hGH) is an antagonist and can bind only one molecule of the growth hormone receptor. We have determined the crystal structure of the 1:1 complex between this mutant and the receptor extracellular domain (hGHbp) at 2.6 A resolution, and used it to guide a detailed survey of the structural and functional basis for hormone-receptor recognition. The overall structure of the complex is very similar to the equivalent portion of the 1:2 complex, showing that formation of the active complex does not involve major conformational changes. However, a segment involved in receptor-receptor interactions in the 1:2 complex is disordered in this structure, suggesting that its productive conformation is stabilized by receptor dimerization. The hormone binding site of the receptor comprises a central hydrophobic patch dominated by Trp104 and Trp169, surrounded by a hydrophilic periphery containing several well-ordered water molecules. Previous alanine scanning showed that the hydrophobic "hot spot" confers most of the binding energy. The new structural data, coupled with binding and kinetic analysis of further mutants, indicate that the hot spot is assembled cooperatively and that many residues contribute indirectly to binding. Several hydrophobic residues serve to orient the key tryptophan residues; kinetic analysis suggests that Pro106 locks the Trp104 main-chain into a required conformation. The electrostatic contacts of Arg43 to hGH are less important than the intramolecular packing of its alkyl chain with Trp169. The true functional epitope that directly contributes binding energy may therefore comprise as few as six side-chains, participating mostly in alkyl-aromatic stacking interactions. Outside the functional epitope, multiple mutation of residues to alanine resulted in non-additive increases in affinity: up to tenfold for a hepta-alanine mutant. Contacts in the epitope periphery can therefore attenuate the affinity of the central hot spot, perhaps reflecting a role in conferring specificity to the interaction.
Structural and functional analysis of the 1:1 growth hormone:receptor complex reveals the molecular basis for receptor affinity., Clackson T, Ultsch MH, Wells JA, de Vos AM, J Mol Biol. 1998 Apr 17;277(5):1111-28. PMID:9571026
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
[SOMA_HUMAN] Defects in GH1 are a cause of growth hormone deficiency isolated type 1A (IGHD1A) [MIM:262400]; also known as pituitary dwarfism I. IGHD1A is an autosomal recessive deficiency of GH which causes short stature. IGHD1A patients have an absence of GH with severe dwarfism and often develop anti-GH antibodies when given exogenous GH. Defects in GH1 are a cause of growth hormone deficiency isolated type 1B (IGHD1B) [MIM:612781]; also known as dwarfism of Sindh. IGHD1B is an autosomal recessive deficiency of GH which causes short stature. IGHD1B patients have low but detectable levels of GH. Dwarfism is less severe than in IGHD1A and patients usually respond well to exogenous GH. Defects in GH1 are the cause of Kowarski syndrome (KWKS) [MIM:262650]; also known as pituitary dwarfism VI. Defects in GH1 are a cause of growth hormone deficiency isolated type 2 (IGHD2) [MIM:173100]. IGHD2 is an autosomal dominant deficiency of GH which causes short stature. Clinical severity is variable. Patients have a positive response and immunologic tolerance to growth hormone therapy. [GHR_HUMAN] Defects in GHR are a cause of Laron syndrome (LARS) [MIM:262500]. A severe form of growth hormone insensitivity characterized by growth impairment, short stature, dysfunctional growth hormone receptor, and failure to generate insulin-like growth factor I in response to growth hormone. Defects in GHR may be a cause of idiopathic short stature autosomal (ISSA) [MIM:604271]. Short stature is defined by a subnormal rate of growth.
[SOMA_HUMAN] Plays an important role in growth control. Its major role in stimulating body growth is to stimulate the liver and other tissues to secrete IGF-1. It stimulates both the differentiation and proliferation of myoblasts. It also stimulates amino acid uptake and protein synthesis in muscle and other tissues. [GHR_HUMAN] Receptor for pituitary gland growth hormone involved in regulating postnatal body growth. On ligand binding, couples to the JAK2/STAT5 pathway (By similarity). The soluble form (GHBP) acts as a reservoir of growth hormone in plasma and may be a modulator/inhibitor of GH signaling. Isoform 2 up-regulates the production of GHBP and acts as a negative inhibitor of GH signaling.
About this Structure
- Clackson T, Ultsch MH, Wells JA, de Vos AM. Structural and functional analysis of the 1:1 growth hormone:receptor complex reveals the molecular basis for receptor affinity. J Mol Biol. 1998 Apr 17;277(5):1111-28. PMID:9571026 doi:10.1006/jmbi.1998.1669
- Duda KM, Brooks CL. Identification of residues outside the two binding sites that are critical for activation of the lactogenic activity of human growth hormone. J Biol Chem. 2003 Jun 20;278(25):22734-9. Epub 2003 Apr 7. PMID:12682073 doi:10.1074/jbc.M212550200
- ↑ Igarashi Y, Ogawa M, Kamijo T, Iwatani N, Nishi Y, Kohno H, Masumura T, Koga J. A new mutation causing inherited growth hormone deficiency: a compound heterozygote of a 6.7 kb deletion and a two base deletion in the third exon of the GH-1 gene. Hum Mol Genet. 1993 Jul;2(7):1073-4. PMID:8364549
- ↑ Takahashi Y, Kaji H, Okimura Y, Goji K, Abe H, Chihara K. Brief report: short stature caused by a mutant growth hormone. N Engl J Med. 1996 Feb 15;334(7):432-6. PMID:8552145 doi:http://dx.doi.org/10.1056/NEJM199602153340704
- ↑ Takahashi Y, Shirono H, Arisaka O, Takahashi K, Yagi T, Koga J, Kaji H, Okimura Y, Abe H, Tanaka T, Chihara K. Biologically inactive growth hormone caused by an amino acid substitution. J Clin Invest. 1997 Sep 1;100(5):1159-65. PMID:9276733 doi:10.1172/JCI119627
- ↑ Petkovic V, Besson A, Thevis M, Lochmatter D, Eble A, Fluck CE, Mullis PE. Evaluation of the biological activity of a growth hormone (GH) mutant (R77C) and its impact on GH responsiveness and stature. J Clin Endocrinol Metab. 2007 Aug;92(8):2893-901. Epub 2007 May 22. PMID:17519310 doi:10.1210/jc.2006-2238
- ↑ Amselem S, Duquesnoy P, Attree O, Novelli G, Bousnina S, Postel-Vinay MC, Goossens M. Laron dwarfism and mutations of the growth hormone-receptor gene. N Engl J Med. 1989 Oct 12;321(15):989-95. PMID:2779634
- ↑ Kou K, Lajara R, Rotwein P. Amino acid substitutions in the intracellular part of the growth hormone receptor in a patient with the Laron syndrome. J Clin Endocrinol Metab. 1993 Jan;76(1):54-9. PMID:8421103
- ↑ Amselem S, Duquesnoy P, Duriez B, Dastot F, Sobrier ML, Valleix S, Goossens M. Spectrum of growth hormone receptor mutations and associated haplotypes in Laron syndrome. Hum Mol Genet. 1993 Apr;2(4):355-9. PMID:8504296
- ↑ Edery M, Rozakis-Adcock M, Goujon L, Finidori J, Levi-Meyrueis C, Paly J, Djiane J, Postel-Vinay MC, Kelly PA. Lack of hormone binding in COS-7 cells expressing a mutated growth hormone receptor found in Laron dwarfism. J Clin Invest. 1993 Mar;91(3):838-44. PMID:8450064 doi:http://dx.doi.org/10.1172/JCI116304
- ↑ Duquesnoy P, Sobrier ML, Duriez B, Dastot F, Buchanan CR, Savage MO, Preece MA, Craescu CT, Blouquit Y, Goossens M, et al.. A single amino acid substitution in the exoplasmic domain of the human growth hormone (GH) receptor confers familial GH resistance (Laron syndrome) with positive GH-binding activity by abolishing receptor homodimerization. EMBO J. 1994 Mar 15;13(6):1386-95. PMID:8137822
- ↑ Sobrier ML, Dastot F, Duquesnoy P, Kandemir N, Yordam N, Goossens M, Amselem S. Nine novel growth hormone receptor gene mutations in patients with Laron syndrome. J Clin Endocrinol Metab. 1997 Feb;82(2):435-7. PMID:9024232
- ↑ Walker JL, Crock PA, Behncken SN, Rowlinson SW, Nicholson LM, Boulton TJ, Waters MJ. A novel mutation affecting the interdomain link region of the growth hormone receptor in a Vietnamese girl, and response to long-term treatment with recombinant human insulin-like growth factor-I and luteinizing hormone-releasing hormone analogue. J Clin Endocrinol Metab. 1998 Jul;83(7):2554-61. PMID:9661642
- ↑ Wojcik J, Berg MA, Esposito N, Geffner ME, Sakati N, Reiter EO, Dower S, Francke U, Postel-Vinay MC, Finidori J. Four contiguous amino acid substitutions, identified in patients with Laron syndrome, differently affect the binding affinity and intracellular trafficking of the growth hormone receptor. J Clin Endocrinol Metab. 1998 Dec;83(12):4481-9. PMID:9851797
- ↑ Enberg B, Luthman H, Segnestam K, Ritzen EM, Sundstrom M, Norstedt G. Characterisation of novel missense mutations in the GH receptor gene causing severe growth retardation. Eur J Endocrinol. 2000 Jul;143(1):71-6. PMID:10870033
- ↑ Jorge AA, Souza SC, Arnhold IJ, Mendonca BB. The first homozygous mutation (S226I) in the highly-conserved WSXWS-like motif of the GH receptor causing Laron syndrome: supression of GH secretion by GnRH analogue therapy not restored by dihydrotestosterone administration. Clin Endocrinol (Oxf). 2004 Jan;60(1):36-40. PMID:14678285
- ↑ Goddard AD, Covello R, Luoh SM, Clackson T, Attie KM, Gesundheit N, Rundle AC, Wells JA, Carlsson LM. Mutations of the growth hormone receptor in children with idiopathic short stature. The Growth Hormone Insensitivity Study Group. N Engl J Med. 1995 Oct 26;333(17):1093-8. PMID:7565946