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K Ogi

Publications and source records attributed to K Ogi.

At least 37 records · Page 2Linked to original sources
PubMed1995

Characterization of murine PACAP mRNA.

A murine PACAP precursor cDNA was isolated by screening a brain cDNA library. The amino acid sequence of the precursor was highly similar (from 81% to 93% similarity) to its rat, human, and ovine counterparts. The primary structure of murine PACAP is identical with those from sheep, humans, and rats, indicating that the mature PACAP is well conserved among mammals. Northern blot analysis revealed that the approximately 2.4 kb transcript for the PACAP precursor is expressed in murine brain. The verification that murine PACAP is identical to its human counterpart provides a rationale for physiological and pathophysiological studies of PACAP in mice.

Amino Acid Sequence↗
PubMed1994

Molecular cloning and functional expression of a human thyrotropin-releasing hormone (TRH) receptor gene.

In this study, we isolated genomic DNA fragments coding for the human thyrotropin-releasing hormone (TRH) receptor. Analysis of the nucleotide sequence revealed that the human TRH receptor gene had an exon-intron structure comprising at least two exons. A polypeptide encoded by the gene consisted of 398 amino acid residues with putative seven transmembrane domains. It showed high homology as a whole amino acid sequence with the rat and mouse TRH receptors except for considerable variation in the C-terminal region. Chromosomal mapping study indicated that the human TRH receptor gene was assigned to chromosome 8. Chinese hamster ovary (CHO) cells transfected with a DNA fragment containing the coding regions of the human TRH receptor bound with [3H]TRH. This binding was inhibited by adding unlabeled TRH in a dose-dependent fashion. Scatchard analysis indicated that the transfected CHO cells expressed a single class of high affinity binding sites at a dissociation constant (Kd) of approximately 1 nM. These results demonstrated that the isolated gene encoded a specific TRH receptor with high affinity.

Amino Acid Sequence↗
PubMed1994

Cloning and expression of a complementary DNA encoding the bovine receptor for pituitary adenylate cyclase-activating polypeptide (PACAP).

A cDNA encoding a pituitary adenylate cyclase-activating polypeptide (PACAP) receptor was cloned from a bovine brain cDNA library using a synthetic oligonucleotide probe corresponding to the partial N-terminal amino acid sequence of the PACAP receptor purified from the bovine brain. The cloned cDNA encoded a polypeptide of 513 amino acid residues with seven putative transmembrane domains. The deduced amino acid sequence exactly matched the N-terminal amino acid sequence of the purified PACAP receptor. It also shared an apparent similarity with the vasoactive intestinal peptide (VIP), secretin, growth hormone releasing hormone, calcitonin, and glucagon receptors, suggesting that the PACAP receptor is a member of the secretin receptor subfamily of the guanine nucleotide-binding regulatory protein-coupled receptor family. Northern blot analysis showed that the size of the major mRNA band which hybridized with the cDNA was about 7 kb in the bovine cerebral-cortex and hippocampus. An expression vector containing the cloned cDNA for the PACAP receptor was introduced into Chinese hamster ovary (CHO) cells. The affinity of PACAP receptors expressed on the transfected CHO cells was quite similar to that of natural PACAP receptors on the bovine brain membranes. Competitive binding experiments showed that PACAP38 displaced the binding of 125I-labeled PACAP27 to the receptors on the CHO cells more efficiently than PACAP27, while VIP was less effective. In addition, both of PACAP27 and PACAP38 elevated the levels of cAMP and inositol phosphates in the transformed CHO cells. These results indicate that the PACAP receptors encoded by the cloned cDNA are identical to the purified PACAP receptors, and that they can stimulate dual signaling cascades.

Amino Acid Sequence↗
PubMed1994

Biosynthesis of human endothelins in transformants expressing cDNAs for human prepro-endothelins.

To understand the biosynthesis of the human ET family, three kinds of cloned cDNA for human prepro-endothelin-1 (prepro-ET-1), prepro-ET-2, and prepro-ET-3 were stably expressed in Chinese hamster ovary cells (CHO-K1). Immunoreactive (ir-) ET polypeptides in the culture media of the transformants were purified by reverse-phase high-performance liquid chromatography (HPLC) coupled with sandwich-type enzyme immunoassay (EIA). Amino acid sequencing and FAB mass spectrometry of the purified ir-ET polypeptides revealed the presence of human big ET-1 (1-38), big ET-2 (1-38), and big ET-3 (1-41)NH2 as intermediate forms. These results directly revealed the biosynthetic pathways of three human ETs at the peptide level.

Amino Acid Sequence↗
PubMed1993

Molecular cloning and functional expression of a cDNA encoding a human pituitary adenylate cyclase activating polypeptide receptor.

A functional cDNA clone for a human pituitary adenylate cyclase activating polypeptide (PACAP) receptor was isolated from a human pituitary cDNA library. The cDNA encoded a polypeptide consisting of 525 amino acids with putative seven hydrophobic domains. Chinese hamster ovary (CHO)-K1 cells transfected with the cDNA specifically bound PACAP and mediated PACAP-triggered intracellular accumulation of cAMP, indicating that this cDNA encoded a functional human PACAP Type I receptor. This receptor was structurally related to the vasoactive intestinal peptide (VIP), secretin, calcitonin and parathyroid hormone receptors and is much more homologous to a rat PACAP receptor. Northern blot analysis revealed that PACAP receptor mRNAs were expressed mainly in the brain and widely distributed in the central nervous system.

Amino Acid Sequence↗
PubMed1993

Molecular cloning and functional expression of rat cDNAs encoding the receptor for pituitary adenylate cyclase activating polypeptide (PACAP).

Two types of cDNA encoding PACAP receptors were isolated from the rat brain cDNA library by homology screening with a cDNA probe for VIP receptor. Nucleotide sequence analysis indicated that these two types of receptor mRNA were generated by alternative splicing mechanisms. These two cloned cDNAs were introduced into CHO cells respectively. Resultant transformants showed specific binding to [125I]PACAP27 which was displaced by unlabeled PACAP27 but not by VIP. Thus, these receptors are two subtypes of Type I PACAP receptor (Type I-A and Type I-B). The amino acid sequences of rat PACAP receptors deduced by the cDNAs showed a remarkable similarity with rat receptors for VIP, secretin, glucagon, and GHRH. A 6.5 kb significant hybridizing signal of the PACAP receptor mRNA was detected in the rat brain, and slight signal was also detected in the lung and the liver.

Alternative Splicing↗
PubMed1992

Expression of human pituitary adenylate cyclase activating polypeptide (PACAP) cDNA in CHO cells and characterization of the products.

cDNA encoding human PACAP precursor was expressed in non-neuroendocrine Chinese hamster ovary cells, CHO-K1, The cells were transfected with expression vector (pTS705) containing the human PACAP cDNA by electroporation. A cell line which produced more than 80 ng/ml of immunoreactive PACAP (ir-PACAP) into the conditioned medium was established. RP-HPLC analysis of culture medium of this established cell line exhibited the presence of two types of PACAP, i.e. PACAP38 and PACAP27. At the same time, it was also revealed that immunoreactive PACAP-related peptide (ir-PRP) was secreted into the cultured medium. The ir-PACAPs were confirmed to ahve biological activities such as induction of cAMP and neurite outgrowth in rat pheochromocytoma PC12h cells.

Adenylyl Cyclases↗
PubMed1992

Structure of the human pituitary adenylate cyclase activating polypeptide (PACAP) gene.

The human gene encoding pituitary adenylate cyclase activating polypeptide (PACAP) was isolated and its nucleotide sequence was determined. By comparison with a human PACAP cDNA, the exon/intron organization of PACAP gene was determined. The last exon encoded the longer form of PACAP, PACAP38 and 3'-untranslated sequences, suggesting that the shorter form of PACAP, PACAP27 is not generated by alternative splicing mechanisms. The 5'-flanking region of the PACAP gene contains several sequence motifs homologous to CRE, TRE, and GHF-1. On the basis of DNA isolated from mouse A9 microcell hybrid clone containing a single human chromosome, the PACAP gene was assigned to human chromosome 18. Furthermore, we determined the locus of the gene to be 18p11 by the chromosomal in situ hybridization technique.

Amino Acid Sequence↗
PubMed1991

Expression of endothelin-2 (ET-2) gene in a human renal adenocarcinoma cell line: purification and cDNA cloning of ET-2.

It has been found that human renal adenocarcinoma ACHN cells synthesize and secrete immunoreactive endothelin (ir-ET) in the culture medium. Partial characterization of this material with reverse-phase high-performance liquid chromatography (RP-HPLC) suggested that ACHN cells synthesized only human endothelin-2 (ET-2). Isolation and characterization of this ir-ET-2 has revealed that this peptide has almost the same amino acid sequence and molecular weight as that of human ET-2 deduced from the nucleotide sequence of cloned human ET-2 gene. To delineate the precise structure of human ET-2 precursor, ET-2 cDNAs were cloned from a cDNA library constructed with mRNA derived from the ACHN cells, and the nucleotide and deduced amino acid sequences were determined. The ET-2 cDNA that has the longest open reading frame encodes prepro-ET-2 protein, consisting of 178 amino acid residues. The ET-like sequence found in the prepro-ET-1 and -ET-3 was also conserved in this prepro-ET-2. The Northern blot analysis of mRNA revealed that the transcript of the human ET-2 gene was 1.4 kb.

Adenocarcinoma↗
PubMed1990

Molecular cloning and characterization of cDNA for the precursor of rat pituitary adenylate cyclase activating polypeptide (PACAP).

We have isolated and cloned a cDNA for rat pituitary adenylate cyclase activating polypeptide (PACAP) precursor protein from the brain. The nucleotide and the deduced amino acid sequences revealed that the rat PACAP cDNA encoded a 175 amino acid protein highly homologous to the ovine and human PACAP precursors. The rat PACAP precursor protein included a putative signal peptide at the amino-terminus, a PACAP-related peptide (PRP) of 29 amino acid residues and the rat PACAP of 38 amino acid residues flanked by basic processing sites, and a carboxy-teminus amidation signal for PACAP. Furthermore, the amino acid sequence of the rat PACAP was completely identical to that of the ovine and human PACAP. Northern blot analysis of rat brain RNA revealed an approximately 3.0 kb transcript for the PACAP precursor in rat brain.

Amino Acid Sequence↗
PubMed1990

Specific expression of human endothelin-2 (ET-2) gene in a renal adenocarcinoma cell line. Molecular cloning of cDNA encoding the precursor of ET-2 and its characterization.

Analysis of culture medium of human renal adenocarcinoma cells ACHN by RP-HPLC suggested that the cells specifically secreted human endothelin-2 (ET-2). cDNAs encoding human ET-2 precursor were cloned from a cDNA library constructed with mRNA derived from the ACHN cells, and the nucleotide and deduced amino acid sequences were determined. The ET-2 cDNA was revealed to contain 1.3 kb and encode prepro-ET-2 protein consisting of 178 amino acid residues. The ET-like sequences found in the prepro-ET-1 and -ET-3 was conserved in this prepro-ET-2. The Northern blot analysis of mRNA suggested that the transcript of ET-2 gene was 1.4 kb. This is the first direct evidence that human ET-2 gene was expressed specifically in tumor cells.

Adenocarcinoma↗
PubMed1990

One of the endothelin gene family, endothelin 3 gene, is expressed in the placenta.

A cDNA encoding human endothelin 3 (ET-3) precursor was cloned from a cDNA library from the placenta, and its nucleotide and deduced amino acid sequences were determined. This ET-3 cDNA was found to contain 2.3 kb pairs and encode prepro-ET-3 protein consisting of 224 amino acid residues. The putative big-ET-3 seems to consist of 42 amino acid residues. Two of the intron insertion sites were determined with information from nucleotide sequences of the cloned genomic ET-3 gene. This is the first direct evidence that the ET-3 gene is transcribed and expressed in the placenta.

Amino Acid Sequence↗
PubMed1990

A novel peptide which stimulates adenylate cyclase: molecular cloning and characterization of the ovine and human cDNAs.

A novel neuropeptide which remarkably stimulates adenylate cyclase in rat anterior pituitary cell cultures has been recently isolated from ovine hypothalami by A. Arimura and his collaborators (Biochem.Biophys.Res.Commun.164, 567-574(1989)). This peptide was designated as PACAP38(Pituitary Adenylate Cyclase Activating Polypeptide with 38 residues). In an attempt to investigate physiological implications of PACAP38, we have succeeded in cloning the cDNAs encoding the precursor of PACAP38 from ovine hypothalamus and human testis. An ovine cDNA encodes a protein of 176 amino acids in which PACAP38 is proceeded by a putative signal peptide and a "pro"-region (107 amino acids), and followed by a Gly-Arg-Arg sequence for proteolytic processing and amidation. Deduced amino-acid sequence of human PACAP38 was completely identical to that of the ovine isolated peptide. Cloning of PACAP38 cDNAs confirms the expression of the corresponding mRNAs and the presence of this neuropeptide in ovine hypothalamus and also in human testis.

Adenylyl Cyclases↗
PubMed1990

[An epidemiological study on relationship between life style and colorectal cancer].

In Kumamoto prefecture, 2,359 cases were diagnosed as colorectal cancer and operated in 5 years from 1983 to 1987. Their records were analysed to determine the annual incidences in the cecum, ascending, transverse, descending, sigmoid colon and rectum. The female age-adjusted mortality from cancer of the cecum and ascending colon was slightly surpassed that of the male's. While the incidences of colonic and rectal cancer were 21.0 per 100,000 in 1983, they have increased to 26.0 per 100,000 in 1987. As for the crude mortality, it was 11.5 per 100,000 in 1983 and 13.5 per 100,000 in 1987 respectively. Increasing of the incidence was greatest in people over 50 years of age.

Adult↗
PubMed1989

Synthesis of human endothelin-1 precursors in Escherichia coli.

Endothelin, the most potent vasoconstrictor found in nature, is thought to be important in the regulation of blood pressure and/or local blood distribution. Human placenta cDNA fragment encoding preproendothelin-1 (preproET-1) and its carboxyl terminal mature precursor (C-matured precursor) was expressed in E. coli. These products were characterized by both enzyme immunoassay and Western blot analysis.

Blotting, Western↗
PubMed1989

[Electron microscopic observation of the soft tissue in the gubernacular canal. 3. Changes in the components with aging].

In the present study, we observed the epithelial remnants in the gubernacular canal of a 3-month-old crab-eating monkey by transmission electron microscopy, and compared our findings with those in a 1-year-old one. The following results were obtained: 1. The basal lamina of the epithelial remnants of the 3-month-old monkey was more clearly seen than that of the older animal, and it had a brush-like appearance probably due to relatively high forming activity. 2. No marked difference was observed among the cellular components between the two ages. The tonofilaments which were fibrous in ordinary epithelial cells already showed some aggregation and granular appearance in the 3-month material. 3. In most parts of the 3-month-old material, only a small number of atrophied cells were observed; however in the epithelial remnants located near the gingival epithelium, we observed cells containing swollen mitochondria which probably occurred due to the degeneration of the cells. 4. The density of collagen fibers around the dental germ was relatively low, whereas in the area close to the gingiva, the density of fibers was very high. 5. In the present study, no components exactly derived from the remnants of epithelial cells were observed within the extracellular spaces of the connective tissue.

Aging↗