scholarly journals Evaluation of the Biological Activity of a Growth Hormone (GH) Mutant (R77C) and Its Impact on GH Responsiveness and Stature

2007 ◽  
Vol 92 (8) ◽  
pp. 2893-2901 ◽  
Author(s):  
Vibor Petkovic ◽  
Amélie Besson ◽  
Mario Thevis ◽  
Didier Lochmatter ◽  
Andrée Eblé ◽  
...  
Keyword(s):  
Short Stature ◽  
Pubertal Development ◽  
Functional Characterization ◽  
Index Patient ◽  
Janus Kinase ◽  
Gh Receptor ◽  
Significant Difference ◽  
Microscopy Analysis ◽  
Possible Cause

Abstract Context and Objective: A single missense mutation in the GH-1 gene converting codon 77 from arginine (R) to cysteine (C) yields a mutant GH-R77C peptide, which was described as natural GH antagonist. Design, Setting, and Patients: Heterozygosity for GH-R77C/wt-GH was identified in a Syrian family. The index patient, a boy, was referred for assessment of his short stature (−2.5 sd score) and partial GH insensitivity was diagnosed. His mother and grandfather were also carrying the same mutation and showed partial GH insensitivity with modest short stature. Interventions and Results: Functional characterization of the GH-R77C was performed through studies of GH receptor binding and activation of Janus kinase 2/Stat5 pathway. No differences in the binding affinity and bioactivity between wt-GH and GH-R77C were found. Similarly, cell viability and proliferation after expression of both GH peptides in AtT-20 cells were identical. Quantitative confocal microscopy analysis revealed no significant difference in the extent of subcellular colocalization between wt-GH and GH-R77C with endoplasmic reticulum, Golgi, or secretory vesicles. Furthermore studies demonstrated a reduced capability of GH-R77C to induce GHR/GHBP gene transcription rate when compared with wt-GH. Conclusion: Reduced GH receptor/GH-binding protein expression might be a possible cause for the partial GH insensitivity with delay in growth and pubertal development found in our patients. In addition, this group of patients deserves further attention because they could represent a distinct clinical entity underlining that an altered GH peptide may also have a direct impact on GHR/GHBP gene expression causing partial GH insensitivity.

scholarly journals Growth Hormone (GH) Deficiency Type II: A Novel GH-1 Gene Mutation (GH-R178H) Affecting Secretion and Action

2010 ◽  
Vol 24 (1) ◽  
pp. 276-276
Author(s):  
Vibor Petkovic ◽  
Michela Godi ◽  
Amit V. Pandey ◽  
Didier Lochmatter ◽  
Charles R. Buchanan ◽  
...  
Keyword(s):  
Short Stature ◽  
Gh Deficiency ◽  
Functional Characterization ◽  
Provocation Test ◽  
Bone Age ◽  
Janus Kinase ◽  
Dominant Form ◽  
Gh Secretion ◽  
Gh Receptor ◽  
Igf I

ABSTRACT Context and Objective Main features of the autosomal dominant form of GH deficiency (IGHD II) include markedly reduced secretion of GH combined with low concentrations of IGF-I leading to short stature. Design, Setting, and Patients A female patient presented with short stature (height −6.0 sd score) and a delayed bone age of 2 yr at the chronological age of 5 yr. Later, at the age of 9 yr, GHD was confirmed by standard GH provocation test, which revealed subnormal concentrations of GH and a very low IGF-I. Genetic analysis of the GH-1 gene revealed the presence of a heterozygous R178H mutation. Interventions and Results AtT-20 cells coexpressing both wt-GH and GH-R178H showed a reduced GH secretion after forskolin stimulation compared with the cells expressing only wt-GH, supporting the diagnosis of IGHD II. Because reduced GH concentrations found in the circulation of our untreated patient could not totally explain her severe short stature, functional characterization of the GH-R178H performed by studies of GH receptor binding and activation of the Janus kinase-2/signal transducer and activator of transcription-5 pathway revealed a reduced binding affinity of GH-R178H for GH receptor and signaling compared with the wt-GH. Conclusion This is the first report of a patient suffering from short stature caused by a GH-1 gene alteration affecting not only GH secretion (IGHD II) but also GH binding and signaling, highlighting the necessity of functional analysis of any GH variant, even in the alleged situation of IGHD II.

New GroEL-like chaperonin of bacteriophage OBP Pseudomonas fluorescens suppresses thermal protein aggregation in an ATP-dependent manner

2016 ◽  
Vol 473 (15) ◽  
pp. 2383-2393 ◽  
Author(s):  
Pavel I. Semenyuk ◽  
Victor N. Orlov ◽  
Olga S. Sokolova ◽  
Lidia P. Kurochkina
Keyword(s):  
Pseudomonas Fluorescens ◽  
Functional Characterization ◽  
Dependent Manner ◽  
Double Ring ◽  
Protein Inactivation ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Ring Architecture

Recently, we discovered and studied the first virus-encoded chaperonin of bacteriophage EL Pseudomonas aeruginosa, gene product (gp) 146. In the present study, we performed bioinformatics analysis of currently predicted GroEL-like proteins encoded by phage genomes in comparison with cellular and mitochondrial chaperonins. Putative phage chaperonins share a low similarity and do not form a monophyletic group; nevertheless, they are closer to bacterial chaperonins in the phylogenetic tree. Experimental investigation of putative GroEL-like chaperonin proteins has been continued by physicochemical and functional characterization of gp246 encoded by the genome of Pseudomonas fluorescens bacteriophage OBP. Unlike the more usual double-ring architecture of chaperonins, including the EL gp146, the recombinant gp246 produced by Escherichia coli cells has been purified as a single heptameric ring. It possesses ATPase activity and does not require a co-chaperonin for its function. In vitro experiments demonstrated that gp246 is able to suppress the thermal protein inactivation and aggregation in an ATP-dependent manner, thus indicating chaperonin function. Single-particle electron microscopy analysis revealed the different conformational states of OBP chaperonin, depending on the bound nucleotide.

Molecular cloning and functional characterization of duck Janus kinase 1

2020 ◽  
Vol 117 ◽  
pp. 29-36
Author(s):  
Dejian Liu ◽  
Huijun Zheng ◽  
Yaqian Li ◽  
Peng Zhou ◽  
Hui Jin ◽  
...  
Keyword(s):  
Molecular Cloning ◽  
Functional Characterization ◽  
Janus Kinase ◽  
Janus Kinase 1

scholarly journals Functional Characterization of GH-Like Homolog in Amphioxus Reveals an Ancient Origin of GH/GH Receptor System

Endocrinology ◽  
2014 ◽  
Vol 155 (12) ◽  
pp. 4818-4830 ◽  
Author(s):  
Mengyang Li ◽  
Zhan Gao ◽  
Dongrui Ji ◽  
Shicui Zhang
Keyword(s):  
Functional Characterization ◽  
Endocrine System ◽  
Pituitary Hormones ◽  
Receptor System ◽  
Subsequent Formation ◽  
Basal Chordates ◽  
Gh Receptor ◽  
Neuroendocrine Axis ◽  
Hormone Binding Domain

Amphioxus belongs to the subphylum cephalochordata, an extant representative of the most basal chordates. Despite many studies on the endocrine system of amphioxus, no evidence showed the presence of pituitary hormones. In this study, we clearly demonstrated the existence of a functional GH-like hormone in amphioxus, which is able to bind purified GH receptors, stimulate IGF-I expression, promote growth rate of fish, and rescue embryonic defects caused by a shortage of GH. We also showed the presence of a GH/prolactin-like-binding protein containing the entire hormone binding domain of GH/prolactin receptors in amphioxus, which is widely expressed among tissues, and interacts with the GH-like hormone. It is clear from these results that the GH/GH receptor-like system is present in amphioxus and, hence, in all classes of chordates. Notably, the GH-like hormone appears to be the only member of the vertebrate pituitary hormones family in amphioxus, suggesting that the hormone is the ancestral peptide that originated first in the molecular evolution of the pituitary hormones family in chordates. These data collectively suggest that a vertebrate-like neuroendocrine axis setting has already emerged in amphioxus, which lays a foundation for subsequent formation of hypothalamic-pituitary system in vertebrates.

scholarly journals Alpha-Gal Syndrome: Involvement of Amblyomma americanum α-D-galactosidase and α-1,4 Galactosyltransferase enzymes in α-gal metabolism

2021 ◽  
Author(s):  
Surendra Raj Sharma ◽  
Gary Crispell ◽  
Ahmed Mohamed ◽  
Cameron Cox ◽  
Joshua Lange ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Functional Characterization ◽  
Basophil Activation Test ◽  
Amblyomma Americanum ◽  
Delayed Type Hypersensitivity ◽  
Galactose Metabolism ◽  
Significant Difference ◽  
Ige Mediated

AbstractAlpha-Gal Syndrome (AGS) is an IgE-mediated delayed-type hypersensitivity reaction to the oligosaccharide galactose-⍰-1,3-galactose (α-gal) injected into humans from the lone star tick (Amblyomma americanum) bite. This study aims at the functional characterization of two tick enzymes, α-D-galactosidase (ADGal) and α-1,4 galactosyltransferase (β-1,4GalT) in α-gal metabolism. The ADGal enzyme cleaves terminal α-galactose moieties from glycoproteins and glycolipids, whereas β-1,4GalT transfers α-galactose to a β1,4 terminal linkage acceptor sugars: GlcNAc, Glc, and Xyl in various processes of glycoconjugate synthesis. An RNA interference approach was utilized to silence ADGal and β-1,4GalT in Am. americanum to examine their functional role in α-gal metabolism and AGS onset. Silencing of ADGal led to the significant down regulation of genes involved in galactose metabolism and transport in Am. americanum. Immunoblot and N-glycan analysis of the Am. americanum salivary glands showed a significant reduction in ⍰-gal levels in silenced tissues. However, there was no significant difference in the level of ⍰-gal in β-1,4GalT silenced tick salivary glands. A basophil-activation test showed a decrease in the frequency of activated basophil by ADGal silenced salivary glands. These results provide an insight into the role of α-D galactosidase & β-1,4GalT in tick biology and the probable involvement in the onset of AGS.

scholarly journals Functional Characterization of Truncated Growth Hormone (GH) Receptor-(1–277) Causing Partial GH Insensitivity Syndrome with High GH-Binding Protein1

1999 ◽  
Vol 84 (3) ◽  
pp. 1011-1016
Author(s):  
Keiji Iida ◽  
Yutaka Takahashi ◽  
Hidesuke Kaji ◽  
Michiko Okazaki Takahashi ◽  
Yasuhiko Okimura ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Functional Characterization ◽  
Gh Receptor

scholarly journals Identification and Functional Characterization of Two Novel NPR2 Mutations in Japanese Patients With Short Stature

2014 ◽  
Vol 99 (4) ◽  
pp. E713-E718 ◽  
Author(s):  
Naoko Amano ◽  
Tokuo Mukai ◽  
Yoshiya Ito ◽  
Satoshi Narumi ◽  
Toshiaki Tanaka ◽  
...  
Keyword(s):  
Short Stature ◽  
Functional Characterization ◽  
Japanese Patients

scholarly journals GH mutant (R77C) in a pedigree presenting with the delay of growth and pubertal development: structural analysis of the mutant and evaluation of the biological activity

2007 ◽  
Vol 157 (suppl_1) ◽  
pp. S67-S74 ◽  
Author(s):  
Vibor Petkovic ◽  
Mario Thevis ◽  
Didier Lochmatter ◽  
Amélie Besson ◽  
Andrée Eblé ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Short Stature ◽  
Receptor Gene ◽  
Final Height ◽  
Pubertal Development ◽  
Functional Characterization ◽  
Family Members ◽  
Antagonistic Effect ◽  
Care Needs ◽  
Igf I

A heterozygous missense mutation in the GH-1 gene converting codon 77 from arginine (R) to cysteine (C), which was previously reported to have some GH antagonistic effect, was identified in a Syrian family. The index patient, a boy, was referred for assessment of his short stature (−2.5 SDS) at the age of 6 years. His mother and grandfather were also carrying the same mutation, but did not differ in adult height from the other unaffected family members. Hormonal examination in all affected subjects revealed increased basal GH, low IGF-I concentrations, and subnormal IGF-I response in generation test leading to the diagnosis of partial GH insensitivity. However, GH receptor gene (GHR) sequencing demonstrated no abnormalities. As other family members carrying the GH-R77C form showed similar alterations at the hormonal level, but presented with normal final height, no GH therapy was given to the boy, but he was followed through his pubertal development which was delayed. At the age of 20 years he reached his final height, which was normal within his parental target height. Functional characterization of the GH-R77C, assessed through activation of Jak2/Stat5 pathway, revealed no differences in the bioactivity between wild-type-GH (wt-GH) and GH-R77C. Detailed structural analysis indicated that the structure of GH-R77C, in terms of disulfide bond formation, is almost identical to that of the wt-GH despite the introduced mutation (Cys77). Previous studies from our group demonstrated a reduced capability of GH-R77C to induce GHR/GH-binding protein (GHBP) gene transcription rate when compared with wt-GH. Therefore, reduced GHR/GHBP expression might well be the possible cause for the partial GH insensitivity found in our patients. In addition, this group of patients deserve further attention because they could represent a distinct clinical entity underlining that an altered GH peptide may also have a direct impact on GHR/GHBP gene expression causing partial GH insensitivity. This might be responsible for the delay of growth and pubertal development. Finally, we clearly demonstrate that GH-R77C is not invariably associated with short stature, but that great care needs to be taken in ascribing growth failure to various heterozygous mutations affecting the GH–IGF axis and that careful functional studies are mandatory.

scholarly journals Functional characterization of mango seed starch (Mangifera indica l.)

2021 ◽  
Vol 10 (3) ◽  
pp. e30310310118
Author(s):  
Joiciana Cardoso Arruda de Souza ◽  
Jéssica Franco Freitas Macena ◽  
Ivo Henrique Pinto Andrade ◽  
Geany Peruch Camilloto ◽  
Renato Souza Cruz
Keyword(s):  
Mangifera Indica ◽  
Functional Characterization ◽  
Extraction Yield ◽  
Starch Granules ◽  
Texture Profile ◽  
Significant Difference ◽  
Fruit Processing ◽  
Mango Seed ◽  
Average Size

Mango agribusiness is an expanding activity in Brazil and produces a large volume of waste that are not reused. Mango seeds are one of the residues from fruit processing, and are a potential starch source. In the food industry, starch is used as a functional ingredient, allowing the preservation of important characteristics of foods. The objectives of this study were to extract starch from mango seed, and to characterize it in terms of its physicochemical, technological and rheological properties. Starch extraction involved washing, cutting, and milling the mango seeds. The extraction yield was 53.89% and the starch granules presented spherical to irregular ellipsoidal shapes with superficial grooves and average size of 20 µm. It had an initial paste temperature of 75.3 °C and a maximum viscosity of 706 BU at 88.1 ºC. The rate of syneresis, 1.51%, was considered low, which indicates a starch with good stability at low temperatures. In the texture profile it was found that there was a significant difference (p ≤ 0.05) in the texture profile of gels with sodium chloride, sucrose and citric acid added. The gel with emulsifier showed no significant difference in any of the parameters analyzed (hardness, cohesiveness and gumminess). The properties of the starch indicated great potential for use in food products.

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