Characterization of a cDNA encoding a novel avian hypothalamic neuropeptide exerting an inhibitory effect on gonadotropin release

2001 ◽  
Vol 354 (2) ◽  
pp. 379-385 ◽  
Author(s):  
Honoo SATAKE ◽  
Miki HISADA ◽  
Tsuyoshi KAWADA ◽  
Hiroyuki MINAKATA ◽  
Kazuyoshi UKENA ◽  
...  
Keyword(s):  
Amino Acid ◽  
Basic Amino Acid ◽  
Inhibitory Effect ◽  
Gene Encoding ◽  
Specific Expression ◽  
Gonadotropin Secretion ◽  
Putative Gene ◽  
Gonadotropin Release ◽  
Pcr Products ◽  
Gonadotropin Inhibitory Hormone

We previously isolated a novel dodecapeptide containing a C-terminal -Arg-Phe-NH2 sequence, SIKPSAYLPLRF-NH2 (RFamide peptide), from the quail brain. This quail RFamide peptide was shown to decrease gonadotropin release from the cultured anterior pituitary and to be located at least in the quail hypothalamo-hypophysial system. We therefore designated this RFamide peptide gonadotropin inhibitory hormone (GnIH). In the present study we characterized the GnIH cDNA from the quail brain by a combination of 3′ and 5′ rapid amplification of cDNA ends (‘RACE’). The deduced GnIH precursor consisted of 173 amino acid residues, encoding one GnIH and two putative gene-related peptide (GnIH-RP-1 and GnIH-RP-2) sequences that included -LPXRF (X = L or Q) at their C-termini. All these peptide sequences were flanked by a glycine C-terminal amidation signal and a single basic amino acid on each end as an endoproteolytic site. Southern blotting analysis of reverse-transcriptase-mediated PCR products demonstrated a specific expression of the gene encoding GnIH in the diencephalon including the hypothalamus. Furthermore, mass spectrometric analyses detected the mass numbers for matured GnIH and GnIH-RP-2, revealing that both peptides are produced from the precursor in the diencephalon as an endogenous ligand. Taken together, these results lead to the conclusion that GnIH is a hypothalamic factor responsible for the negative regulation of gonadotropin secretion. Furthermore, the presence of a novel RFamide peptide family containing a C-terminal -LPXRF-NH2 sequence has been revealed.

scholarly journals Gonadotropin-Inhibitory Hormone Inhibits Gonadal Development and Maintenance by Decreasing Gonadotropin Synthesis and Release in Male Quail

Endocrinology ◽  
2006 ◽  
Vol 147 (3) ◽  
pp. 1187-1194 ◽  
Author(s):  
Takayoshi Ubuka ◽  
Kazuyoshi Ukena ◽  
Peter J. Sharp ◽  
George E. Bentley ◽  
Kazuyoshi Tsutsui
Keyword(s):  
Physiological Role ◽  
Gonadal Development ◽  
Plasma Testosterone ◽  
Dependent Manner ◽  
Inhibitory System ◽  
Continuous Administration ◽  
Gonadotropin Secretion ◽  
Avian Reproduction ◽  
Gonadotropin Release ◽  
Gonadotropin Inhibitory Hormone

Until recently, any neuropeptide that directly inhibits gonadotropin secretion had not been identified. We recently identified a novel hypothalamic dodecapeptide that directly inhibits gonadotropin release in quail and termed it gonadotropin-inhibitory hormone (GnIH). The action of GnIH on the inhibition of gonadotropin release is mediated by a novel G protein-coupled receptor in the quail pituitary. This new gonadotropin inhibitory system is considered to be a widespread property of birds and provides us with an unprecedented opportunity to study the regulation of avian reproduction from an entirely novel standpoint. To understand the physiological role(s) of GnIH in avian reproduction, we investigated GnIH actions on gonadal development and maintenance in male quail. Continuous administration of GnIH to mature birds via osmotic pumps for 2 wk decreased the expressions of gonadotropin common α and LHβ subunit mRNAs in a dose-dependent manner. Plasma LH and testosterone concentrations were also decreased dose dependently. Furthermore, administration of GnIH to mature birds induced testicular apoptosis and decreased spermatogenic activity in the testis. In immature birds, daily administration of GnIH for 2 wk suppressed normal testicular growth and rise in plasma testosterone concentrations. An inhibition of juvenile molt also occurred after GnIH administration. These results indicate that GnIH inhibits gonadal development and maintenance through the decrease in gonadotropin synthesis and release. GnIH may explain the phenomenon of photoperiod-induced gonadal regression before an observable decline in hypothalamic GnRH in quail. To our knowledge, GnIH is the first identified hypothalamic neuropeptide inhibiting reproductive function in any vertebrate class.

scholarly journals Structural analyses of the deduced amino acid sequences of a novel type heme–copper terminal oxidase, cytochrome aco3, from alkalophilic Bacillus YN-2000

2001 ◽  
Vol 47 (12) ◽  
pp. 1075-1081 ◽  
Author(s):  
Kimitoshi Denda ◽  
Akira Oshima ◽  
Yoshihiro Fukumori
Keyword(s):  
Amino Acid ◽  
Cytochrome C ◽  
Basic Amino Acid ◽  
Structural Features ◽  
Thermophilic Bacterium ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Bacterium Bacillus ◽  
Alkalophilic Bacillus

Cytochrome aco3 from a facultatively alkalophilic bacterium, Bacillus YN-2000, was found to be alkaline- and heat-tolerant. To better understand the structural features of Bacillus YN-2000 cytochrome aco3, the gene encoding this enzyme was cloned and sequenced. Nucleotide sequence analyses of the region neighboring the acoI (subunit I) gene revealed that the acoII (subunit II) and acoIII (subunit III) genes were concomitantly clustered upstream and downstream of the acoI gene, respectively, forming an operon with transcriptional polarity. The deduced amino acid sequence of subunit I was highly similar to that of cytochrome caa3 from thermophilic bacterium Bacillus PS3 in which the heme a3 could be replaced with heme o. Furthermore, a marked paucity of basic amino acid residues was found in the cytochrome c-binding subunit II, which might be a result of the adaptation to a highly alkaline external milieu.Key words: cytochrome c oxidase, alkalophile, thermostability, heme o, Bacilli.

scholarly journals Molecular, Antigenic, and Functional Characteristics of Ferric Enterobactin Receptor CfrA in Campylobacter jejuni

2009 ◽  
Vol 77 (12) ◽  
pp. 5437-5448 ◽  
Author(s):  
Ximin Zeng ◽  
Fuzhou Xu ◽  
Jun Lin
Keyword(s):  
Amino Acid ◽  
Campylobacter Jejuni ◽  
Growth Promotion ◽  
Stress Hormones ◽  
Critical Role ◽  
Basic Amino Acid ◽  
Inhibitory Effect ◽  
Amino Acid Identity ◽  
Pcr Analysis ◽  
Immunoblotting Analysis

ABSTRACTThe ferric enterobactin receptor CfrA not only is responsible for high-affinity iron acquisition inCampylobacter jejunibut also is essential forC. jejunicolonization in animal intestines. In this study, we determined the feasibility of targeting the iron-regulated outer membrane protein CfrA for immune protection againstCampylobactercolonization. Alignment of complete CfrA sequences from 15Campylobacterisolates showed that the levels of amino acid identity for CfrA range from 89% to 98%. Immunoblotting analysis using CfrA-specific antibodies demonstrated that CfrA was dramatically induced under iron-restricted conditions and was widespread and produced in 32Campylobacterprimary strains from various sources and from geographically diverse areas. The immunoblotting survey results were highly correlated with the results of an enterobactin growth promotion assay and a PCR analysis usingcfrA-specific primers. Inactivation of thecfrAgene also impaired norepinephrine-mediated growth promotion, suggesting that CfrA is required forC. jejunito sense intestinal stress hormones during colonization. Complementation of thecfrAmutant with a wild-typecfrAallele intransfully restored the production and function of CfrA. A growth assay using purified anti-CfrA immunoglobulin G demonstrated that specific CfrA antibodies could block the function of CfrA, which diminished ferric enterobactin-mediated growth promotion under iron-restricted conditions. The inhibitory effect of CfrA antibodies was dose dependent. Immunoblotting analysis also indicated that CfrA was expressed and immunogenic in chickens experimentally infected withC. jejuni. Amino acid substitution mutagenesis demonstrated that R327, a basic amino acid that is highly conserved in CfrA, plays a critical role in ferric enterobactin acquisition inC. jejuni.Together, these findings strongly suggest that CfrA is a promising vaccine candidate for preventing and controllingCampylobacterinfection in humans and animal reservoirs.

scholarly journals Identification of a POU factor involved in regulating the neuron-specific expression of the gene encoding diapause hormone and pheromone biosynthesis-activating neuropeptide in Bombyx mori

2004 ◽  
Vol 380 (1) ◽  
pp. 255-263 ◽  
Author(s):  
Tian-Yi ZHANG ◽  
Le KANG ◽  
Zhi-Fang ZHANG ◽  
Wei-Hua XU
Keyword(s):  
Amino Acid ◽  
Bombyx Mori ◽  
Pupal Stage ◽  
Pheromone Biosynthesis ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Specific Expression ◽  
Binding Characteristics ◽  
Pheromone Biosynthesis Activating Neuropeptide ◽  
Diapause Hormone

Diapause hormone (DH) and PBAN (pheromone biosynthesis-activating neuropeptide) are two important insect neuropeptides regulating development and reproduction respectively. In the present study, we report two Bombyx mori transcription factors interacting specifically with the promoter of Bom-DH-PBAN (where Bom-DH stands for B. mori DH); we named them DHMBP-1 and -2 (DH-modulator-binding proteins 1 and 2). The developmental changes of DHMBP-1/-2 are closely correlated with that of Bom-DH-PBAN mRNA throughout the pupal stage. Competition assays indicate that DHMBP-1 from Chinese B. mori possesses binding characteristics similar to those of the POU-M1 protein from Japanese B. mori. POU-M1 cDNAs were cloned from various tissues of Chinese B. mori and were found to be distinct from the previously published POU-M1 in amino acid residues 108–136 because of insertion mutations. Owing to this difference in amino acid residues, we named this cDNA POU-M2. Even though POU-M2 differs from POU-M1 at the N-terminal, the POU domain and the binding properties of both POU-M1 and -M2 are the same. Functional analysis showed that overexpression of POU-M2 in the Bombyx cell line BmN activated the promoter of Bom-DH-PBAN, but failed to activate a promoter in which the POU-binding element was mutated. The transcriptional activity of POU-M2 is probably regulated by other factors binding to the upstream of the promoter sequence. We show that the POU-M2-binding site was able to activate the transcription of a heterologous promoter of the gene encoding B. mori larval serum protein. POU-M1 was found to exhibit the same transcriptional activities as POU-M2. Taken together, these results demonstrate that POU-M2 plays an important role in the transcriptional regulation of the Bom-DH-PBAN gene.

scholarly journals Penicillin resistance in the intestinal spirochaete Brachyspira pilosicoli associated with OXA-136 and OXA-137, two new variants of the class D β-lactamase OXA-63

2008 ◽  
Vol 57 (9) ◽  
pp. 1122-1128 ◽  
Author(s):  
Sheila M. Mortimer-Jones ◽  
Nyree D. Phillips ◽  
Tom La ◽  
Ram Naresh ◽  
David J. Hampson
Keyword(s):  
Amino Acid ◽  
Gc Content ◽  
Penicillin Resistance ◽  
Predicted Amino Acid Sequence ◽  
Gene Encoding ◽  
Brachyspira Pilosicoli ◽  
Class D ◽  
Genes Encoding ◽  
Pcr Products ◽  
Additional Amino Acid

Penicillin resistance mediated by β-lactamase activity has been reported previously in the anaerobic intestinal spirochaete Brachyspira pilosicoli, and a novel class D β-lactamase (OXA-63) hydrolysing oxacillin was described recently in a resistant human strain from France. In the current study, 18 B. pilosicoli strains from Australia and Papua New Guinea were tested for ampicillin and oxacillin susceptibility, and investigated for the presence of the class D β-lactamase gene bla OXA-63 using PCR. PCR products were amplified from seven human and four porcine strains that were penicillin resistant, but not from seven penicillin-sensitive strains. Sequence analysis of the whole gene amplified from seven of the resistant strains from humans and pigs revealed only minor nucleotide differences among them, but there were significant differences compared with bla OXA-63. The predicted amino acid sequence of the enzyme from all seven strains had the same key structural motifs as the previously reported OXA-63, but two variants with 94–95 % identity with OXA-63 were identified. OXA-136 had an additional amino acid and 12 other consistent amino acid substitutions compared with OXA-63. OXA-137 had the same differences compared with OXA-63 as OXA-136, but had an additional amino acid substitution at position 16. No structures consistent with integrons or transposons were found in the nucleotide sequences in the vicinity of bla OXA-136 in partially sequenced B. pilosicoli strain 95/1000, and the GC content (25.2 mol%) of the gene was similar to that of the whole genome. The gene encoding OXA-136 from B. pilosicoli strain Cof-10 conferred penicillin resistance on Escherichia coli. This study shows that penicillin resistance in human and porcine B. pilosicoli strains from Australia is associated with the production of two variants of OXA-63, and that susceptible strains lack the genes encoding OXA-63 or the variants.

scholarly journals Gonadotropin-inhibitory hormone in Gambel's white-crowned sparrow (Zonotrichia leucophrys gambelii): cDNA identification, transcript localization and functional effects in laboratory and field experiments

2004 ◽  
Vol 182 (1) ◽  
pp. 33-42 ◽  
Author(s):  
T Osugi ◽  
K Ukena ◽  
GE Bentley ◽  
S O'Brien ◽  
IT Moore ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cellular Localization ◽  
Field Experiments ◽  
Bird Species ◽  
Free Living ◽  
Zonotrichia Leucophrys ◽  
Gonadotropin Release ◽  
Zonotrichia Leucophrys Gambelii ◽  
Gonadotropin Inhibitory Hormone ◽  
Seasonally Breeding

The neuropeptide control of gonadotropin secretion is primarily through the stimulatory action of the hypothalamic decapeptide, GnRH. We recently identified a novel hypothalamic dodecapeptide with a C-terminal LeuPro-Leu-Arg-Phe-NH2 sequence in the domestic bird, Japanese quail (Coturnix japonica). This novel peptide inhibited gonadotropin release in vitro from the quail anterior pituitary; thus it was named gonadotropin-inhibitory hormone (GnIH). GnIH may be an important factor regulating reproductive activity not only in domesticated birds but also in wild, seasonally breeding birds. Thus, we tested synthetic quail GnIH in seasonally breeding wild bird species. In an in vivo experiment, chicken gonadotropin-releasing hormone-I (cGnRH-I) alone or a cGnRH-I/quail GnIH cocktail was injected i.v. into non-breeding song sparrows (Melospiza melodia). Quail GnIH rapidly (within 2 min) attenuated the GnRH-induced rise in plasma LH. Furthermore, we tested the effects of quail GnIH in castrated, photostimulated Gambel's white-crowned sparrows (Zonotrichia leucophrys gambelii), using quail GnIH or saline for injection. Again, quail GnIH rapidly reduced plasma LH (within 3 min) compared with controls. To characterize fully the action of GnIH in wild birds, the identification of their endogenous GnIH is essential. Therefore, in the present study a cDNA encoding GnIH in the brain of Gambel's white-crowned sparrow was cloned by a combination of 3' and 5' rapid amplification of cDNA ends and compared with the quail GnIH cDNA previously identified. The deduced sparrow GnIH precursor consisted of 173 amino acid residues, encoding one sparrow GnIH and two sparrow GnIH-related peptides (sparrow GnIH-RP-1 and GnIH-RP-2) that included Leu-Pro-Xaa-Arg-Phe-NH2 (Xaa=Leu or Gln) at their C-termini. All these peptide sequences were flanked by a glycine C-terminal amidation signal and a single basic amino acid on each end as an endoproteolytic site. Although the homology of sparrow and quail GnIH precursors was approximately 66%, the C-terminal structures of GnIH, GnIH-RP-1 and GnIH-RP-2 were all identical in two species. In situ hybridization revealed the cellular localization of sparrow GnIH mRNA in the paraventricular nucleus (PVN) of the hypothalamus. Immunohistochemical analysis also showed that sparrow GnIH-like immunoreactive cell bodies and terminals were localized in the PVN and median eminence respectively. Thus, only the sparrow PVN expresses GnIH, which appears to be a hypothalamic inhibitory factor for LH release, as evident from our field injections of GnIH into free-living breeding white-crowned sparrows. Sparrow GnIH rapidly (within 2 min) reduced plasma LH when injected into free-living Gambel's white-crowned sparrows on their breeding grounds in northern Alaska. Taken together, our results indicate that, despite amino acid sequence differences, quail GnIH and sparrow GnIH have similar inhibitory effects on the reproductive axis in wild sparrow species. Thus, GnIH appears to be a modulator of gonadotropin release.

Inhibitory effect of gurmarin on palatal taste responses to amino acids in the rat

2000 ◽  
Vol 278 (6) ◽  
pp. R1513-R1517 ◽  
Author(s):  
Shuitsu Harada ◽  
Yasuo Kasahara
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basic Amino Acid ◽  
Inhibitory Effect ◽  
Taste Buds ◽  
Gymnema Sylvestre ◽  
Inhibitory Effects ◽  
Quinine Hydrochloride ◽  
Saccharin Sodium ◽  
Greater Superficial Petrosal Nerve

Gurmarin (10 μg/ml), a protein extracted from Gymnema sylvestre, depressed significantly (40–50%) the phasic taste responses to sugars (sucrose, fructose, lactose, and maltose) and saccharin sodium recorded from the greater superficial petrosal nerve (GSP) innervating palatal taste buds in the rat. However, no significant effect of gurmarin was observed for taste responses to NaCl, HCl, and quinine hydrochloride. Phasic responses tod-amino acids that taste sweet to humans (His, Asn, Phe, Gln) were also depressed, but gurmarin treatment was without significant effect on taste responses to d-Trp andd-Ala, six l-amino acids (His, Asn, Phe, Gln, Trp, and Ala), and two basic amino acid HCl salts (Arg and Lys). With the exception of d-Trp, these inhibitory effects of gurmarin on GSP taste responses were related to the rat's preference for these substances.

Stimulation of gonadotropin release by a non-GnRH peptide sequence of the GnRH precursor

Science ◽  
1986 ◽  
Vol 232 (4746) ◽  
pp. 68-70 ◽  
Author(s):  
RP Millar ◽  
PJ Wormald ◽  
RC Milton
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basic Amino Acid ◽  
Prolactin Secretion ◽  
Biologically Active ◽  
Peptide Sequence ◽  
Pituitary Cells ◽  
Amino Acid Residues ◽  
Amino Acid Peptide ◽  
Gonadotropin Release

The human gonadotropin-releasing hormone (GnRH) precursor comprises the GnRH sequence followed by an extension of 59 amino acids. Basic amino acid residues in the carboxyl terminal extension may represent sites of processing to biologically active peptides. A synthetic peptide comprising the first 13 amino acids (H X Asp-Ala-Glu-Asn-Leu-Ile-Asp-Ser-Phe-Gln-Glu-Ile-Val X OH) of the 59-amino acid peptide was found to stimulate the release of gonadotropic hormones from human and baboon anterior pituitary cells in culture. The peptide did not affect thyrotropin or prolactin secretion. A GnRH antagonist did not inhibit gonadotropin stimulation by the peptide, and the peptide did not compete with GnRH for GnRH pituitary receptors, indicating that the action of the peptide is independent of the GnRH receptor. The GnRH precursor contains two distinct peptide sequences capable of stimulating gonadotropin release from human and baboon pituitary cells.

scholarly journals Molecular Basis for the Activation of Gonadotropin-Inhibitory Hormone Gene Transcription by Corticosterone

Endocrinology ◽  
2014 ◽  
Vol 155 (5) ◽  
pp. 1817-1826 ◽  
Author(s):  
You Lee Son ◽  
Takayoshi Ubuka ◽  
Misato Narihiro ◽  
Yujiro Fukuda ◽  
Itaru Hasunuma ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Transcriptional Activation ◽  
Molecular Basis ◽  
Neuronal Cell ◽  
Reproductive Function ◽  
Inhibitory Effect ◽  
Coding Region ◽  
Gonadotropin Secretion ◽  
High Concentrations ◽  
Gonadotropin Inhibitory Hormone

The inhibitory effect of stress on reproductive function is potentially mediated by high concentrations of circulating glucocorticoids (GCs) acting via the GC receptor (GR). Gonadotropin-inhibitory hormone (GnIH) is a hypothalamic neuropeptide that inhibits gonadotropin secretion. GnIH may mediate stress-induced reproductive dysfunction. However, it is not yet known whether GC-bound GR is directly involved in GnIH transcription. Here, we demonstrated the localization of GR mRNA in GnIH neurons in the paraventricular nucleus of quail, suggesting that GC can directly regulate GnIH transcription. We next showed that 24 hours of treatment with corticosterone (CORT) increase GnIH mRNA expression in the quail diencephalon. We further investigated the mechanism of activation of GnIH transcription by CORT using a GnIH-expressing neuronal cell line, rHypoE-23, derived from rat hypothalamus. We found the expression of GR mRNA in rHypoE-23 cells and increased GnIH mRNA expression by 24 hours of CORT treatment. We finally characterized the promoter activity of rat GnIH gene stimulated by CORT. Through DNA deletion analysis, we identified a CORT-responsive region at 2000–1501 bp upstream of GnIH precursor coding region. This region included 2 GC response elements (GREs) at −1665 and −1530 bp. Mutation of −1530 GRE abolished CORT responsiveness. We also found CORT-stimulated GR recruitment at the GnIH promoter region containing the −1530 GRE. These results provide a putative molecular basis for transcriptional activation of GnIH under stress by demonstrating that CORT directly induces GnIH transcription by recruitment of GR to its promoter.

Ghrelin action on GnRH neurons and pituitary gonadotropes might be mediated by GnIH-GPR147 system

2016 ◽  
Vol 25 (2) ◽  
Author(s):  
Onder Celik ◽  
Nilufer Celik ◽  
Suleyman Aydin ◽  
Banu Kumbak Aygun ◽  
Esra Tustas Haberal ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Wide Distribution ◽  
Gonadotropin Secretion ◽  
Ghrelin Receptor ◽  
Gnrh Neurons ◽  
The Status ◽  
Potential Impact ◽  
Gonadotropin Inhibitory Hormone ◽  
Reproductive Events ◽  
G Protein Coupled

AbstractAcylated ghrelin (AG) effect on GnRH secretion is mediated, at least in part, by GH secreta-gogue receptor (GHS-R) which is present in the GnRH neurons. As the acylation is mandatory for binding to GHS-R, unacylated isoform of ghrelin (UAG) action on gonadotropin secretion is likely to be mediated by other receptors or mediators that have not been identified yet. UAG, therefore, may act partially via a GHS-R-independent mechanism and inhibitory impact of UAG on GnRH neurons may be executed via modulation of other neuronal networks. Ghrelin and gonadotropin inhibitory hormone (GnIH), two agonistic peptides, have been known as important regulators of reproductive events. Potential impact of ghrelin on the activity of GnIH neurons is not exactly known. Both GnIH and ghrelin are potent stimulators of food intake and inhibitors of gonadotropin release. By binding G-protein coupled GnIH receptor (GnIH-R), GPR147, which is located in the human gonadotropes and GnRh neurons, GnIH exerts an inhibitory effect on both GnRH neurons and the gonadotropes. The GnIH-GPR147 system receives information regarding the status of energy reservoir of body from circulating peptides and then transfers them to the kisspeptin-GnIH-GnRH network. Due to wide distribution of this network in brain GnIH neurons may project on ghrelin neurons in the arcuate nucleus and contribute to the regulation of UAG’s central effects or vice versa. Together, the unidentified ghrelin receptor in the hypothalamus and hypophysis may be GnIH-R. Therefore, it is reasonable that ghrelin may act on both hypothalamus and hypophysis via GnIH-GPR147 system to block gonadotropin synthesis and secretion.

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