Search PubMed⌕ Search

Biomedical subjects

M Hijikata

Publications and source records attributed to M Hijikata.

At least 109 records · Page 6Linked to original sources
PubMed1990

A structural protein of hepatitis C virus expressed in E. coli facilitates accurate detection of hepatitis C virus.

A putative core protein derived from hepatitis C virus was expressed in E. coli. More than 5% of the total protein expressed in the bacteria after induction by isopropylthio-beta-D-galactoside was shown to be the expected protein. Western blotting with this E. coli lysate proved to be more efficient than ELISA with a non-structural viral protein, C100, to detect infection of hepatitis C virus in the sera of patients with non-A, non-B chronic hepatitis, hepatocellular carcinoma as well as in sera from healthy persons.

Base Sequence↗
PubMed1990

Rat peroxisomal 3-ketoacyl-CoA thiolase gene. Occurrence of two closely related but differentially regulated genes.

We isolated and analyzed the genes for rat peroxisomal 3-ketoacyl-CoA thiolase. Two active genes (termed A and B), both likely to be coding for the peroxisomal thiolase, were identified per haploid rat genome. These genes span approximately 9 and 11 kilobases, respectively, and both contain 12 exons and 11 introns, with overall similar organizations. The nucleotide sequences are highly conserved in the coding regions and in many introns. The A and B genes code for slightly different amino acid sequences, and the known cDNA sequence (Hijikata, M., Ishii, N., Kagamiyama, H., Osumi, T., and Hashimoto, T. (1987) J. Biol. Chem. 262, 8151-8158) corresponds to the B gene product. By in vitro transcription/translation, the A gene was shown to produce a thiolase precursor having a 10-residue longer amino-terminal presequence than that of the B gene product. Primer extension analysis revealed that the A gene is constitutively expressed and is not influenced by the administration of a peroxisome proliferator, whereas the B gene is markedly activated by the same treatment. Several common sequences were noted in the 5'-flanking regions of the B gene and in the genes of two other peroxisomal beta-oxidation enzymes, induced in parallel by peroxisome proliferators.

Acetyl-CoA C-Acyltransferase↗
PubMed1990

Molecular cloning of the human hepatitis C virus genome from Japanese patients with non-A, non-B hepatitis.

The nucleotide sequence of the Japanese type of hepatitis C virus (HCV-J) genome, consisting of 9413 nucleotides, was determined by analyses of cDNA clones from plasma specimens from Japanese patients with chronic hepatitis. HCV-J genome contains a long open reading frame that can encode a sequence of 3010 amino acid residues. Comparison of HCV-J with the American isolate of HCV showed 22.6% difference in nucleotide sequence and 15.1% difference in amino acid sequence. Thus HCV-J and the American isolate of HCV are probably different subtypes of HCV. The relationship of HCV-J with other animal RNA virus families and the putative organization of the HCV-J genome are discussed.

Amino Acid Sequence↗
PubMed1990

A structural protein encoded by the 5' region of the hepatitis C virus genome efficiently detects viral infection.

A structural region of the hepatitis C virus genome was molecularly cloned. A protein expressed in vitro by transcription followed by translation was precipitated immunologically by sera from patients with chronic hepatitis or hepatocellular carcinoma that were positive for antibody against the non-structural protein, C100, of hepatitis C virus, but not by sera from healthy persons. Thus, this structural protein should be useful for detection of infection with this virus.

Amino Acid Sequence↗
PubMed1990

Detection of hepatitis C virus RNA in sera and liver tissues of non-A, non-B hepatitis patients using the polymerase chain reaction.

Sera obtained from patients with non-A, non-B hepatitis were examined for the presence of hepatitis C virus (HCV) genome by using the reverse transcription-polymerase chain reaction assay, as well as for antibody to HCV (anti-HCV) by using an enzyme-linked immunosorbent assay (ELISA). We also examined the presence of HCV RNA in liver tissue obtained by surgical resection of hepatocellular carcinoma. Among 33 patients, HCV RNA was detectable in 21 (64%), and the antibody was also positive in 21 (64%). Eighteen (55%) patients were positive for both assays. The two assays gave inconsistent results in 3 patients who were positive for HCV RNA but negative for anti-HCV, and in 3 other patients who were negative for HCV RNA and positive for anti-HCV. HCV RNA was also detected in 6 out of 10 non-cancerous liver tissue specimens and in 3 out of 7 tumor tissue specimens. Using the polymerase chain reaction, the HCV genome was detected directly in many specimens obtained from patients with non-A, non-B hepatitis, suggesting the presence of replicating virus in patients positive for anti-HCV. In addition, the differing results of the two assay systems suggest that the application of both is important for evaluation of the status of HCV infection.

Adult↗
PubMed1990

Frequent detection of hepatitis C virus US strain in Japanese hemophiliacs.

Hemophiliacs have been found to be at high risk of hepatitis. Hemophiliacs in Japan receive imported clotting factors as well as domestic ones. Recently we found that hepatitis C virus (HCV) could be classified into at least two types, HCV-US and HCV-J, depending on the nucleotide sequence. We analyzed the nucleotide sequences of virus RNAs from the plasma of patients with hemophilia A or B and found HCV-US in 3 of 4 Japanese hemophiliacs examined.

Adolescent↗
PubMed1990

Molecular cloning and characterization of a cDNA for a novel phorbol-12-myristate-13-acetate-responsive gene that is highly expressed in an adult T-cell leukemia cell line.

To identify gene products that might be involved in leukemogenesis of adult T-cell leukemia (ATL), we constructed a cDNA library from an ATL tumor cell line named IKD. By differential plaque hybridization using [32P]cDNAs of poly(A)+ RNA from IKD cells and a human T-lymphotropic virus type I-infected T-cell line (C91/PL) as probes and RNA blot analysis, we obtained a single cDNA clone of a gene that is highly expressed in IKD cells. Expression of this gene was also detected in fresh peripheral blood mononuclear cells of several ATL patients but not in those of healthy donors. Sequence analysis showed that the cDNA was that of a previously undescribed gene. On structural analysis of the cDNA (1,897 base pairs), a short open reading frame encoding a polypeptide of 54 amino acid residues was found. Exposure of human peripheral blood mononuclear cells, a T-cell lymphoma cell line (Jurkat), and quiescent human embryonic lung cells to phorbol-12-myristate-13-acetate resulted in rapid, transient expression of 2.0-kilobase mRNA of this gene. This induction of the gene was not inhibited by an inhibitor of protein synthesis, cycloheximide. From these findings, we suggest that this gene, named APR, is a member of the cellular immediate-early-response genes.

Amino Acid Sequence↗
PubMed1990

Sequence diversity of hepatitis C viral genomes.

The nucleotide sequences of cDNAs (275 base-pairs) in the non-structural protein 5 regions of Japanese isolates of hepatitis C virus (HCV-J) from the plasma of 11 patients with non-A, non-B hepatitis and the livers of five patients with hepatocellular carcinoma were analyzed. Approximately 14 to 17% of nucleotide sequences of the HCV-Js examined differed from that of the original isolate in the United States (HCV-US). Furthermore, 2.5 to 11% sequence diversity was found among the HCV-Js. The nucleotide sequences of the HCV-Js showed characteristic common differences from that of HCV-US, although they also showed some random substitutions. Plural HCV-J genomes were found in two of the cDNAs derived from liver specimens, and a deletion of 102 nucleotides was found in the cDNA derived from one plasma specimen. These results suggest that HCV-J is a strain different from the HCV-US and that mutation of the viral genome occurs at as high a frequency as in that of the human immunodeficiency virus.

Amino Acid Sequence↗
PubMed1987

Complete nucleotide sequence of cDNA and predicted amino acid sequence of rat acyl-CoA oxidase.

cDNA clones for rat acyl-CoA oxidase were isolated. The 3.8-kilobase mRNA sequence of the enzyme was completely covered by two overlapping clones. The composite cDNA sequence consisted of 3741 bases and contained a 1983-base open reading frame which encodes a polypeptide of 661 amino acid residues. Two species of acyl-CoA oxidase cDNA were identified. They differed in their coding nucleotide sequences, only within a small region. They contained the same number of nucleotides and can be translated in a common reading frame. They are 55% and 50% homologous in the above region at the nucleotide and the amino acid levels, respectively. Both types of cDNA were isolated from a library constructed from mRNA of a single rat, thereby suggesting the occurrence of two species of acyl-CoA oxidase in each rat. The amino terminus of the enzyme was determined to be N-acetylmethionine, which corresponds to the initiator methionine, thus confirming the absence of a terminal presequence. We reported previously that a purified preparation of the enzyme contained three polypeptide components, A, B, and C, and suggested that components B and C are produced by a proteolytic cleavage of component A (Osumi, T., Hashimoto, T., and Ui, N. (1980) J. Biochem. (Tokyo) 87, 1735-1746). We located components B and C on the amino- and the carboxyl-terminal sides of component A. Possible functional significances of several stretches of amino acids of the enzyme are discussed, based on the sequence comparison data between rat and yeast acyl-CoA oxidases.

Acyl-CoA Oxidase↗
PubMed1987

Structural organization of the gene for rat enoyl-CoA hydratase:3-hydroxyacyl-CoA dehydrogenase bifunctional enzyme.

Enoyl-CoA hydratase:3-hydroxyacyl-CoA dehydrogenase bifunctional enzyme is a monomeric protein which catalyzes the second and the third reactions of the peroxisomal beta-oxidation system. We cloned the gene for this enzyme from rat genomic libraries. The gene spans about 31 kilobases and consists of seven exons and six introns. The transcription initiation site was located 24 nucleotides upstream of the initiator methionine codon, ATG, determined by S1 nuclease mapping and primer extension analysis. The 5'-flanking region of the gene lacks typical TATA and CCAAT sequences, but contains G + C-rich sequences, including one CCGCCC ("GC" box) and two related GC hexanucleotides. Some of the structural features of the 5'-flanking region of this gene are shared by the 5'-upstream sequence of the gene for acyl-CoA oxidase, which catalyzes the first reaction of the peroxisomal beta-oxidation system and is induced coordinately with the bifunctional enzyme. Southern blot analysis of rat genomic DNA indicates that the bifunctional enzyme gene occurs once per haploid genome. The amino acid sequence of the carboxyl-terminal region of the bifunctional enzyme exhibits a significant level of homology to the sequence of pig mitochondrial 3-hydroxyacyl-CoA dehydrogenase. This region of the bifunctional enzyme is encoded mainly by the last exon (Exon VII) which codes for as much as 58% of the protein sequence. Based on the data plus our unpublished findings (N. Ishii, T. Osumi, and T. Hashimoto, unpublished data), we propose that the amino-terminal domain, which is principally encoded by Exons I-V, has enoyl-CoA hydratase activity, and the carboxyl-terminal one, which is mainly coded for by Exon VII, has a 3-hydroxyacyl-CoA dehydrogenase function.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1987

Structural analysis of cDNA for rat peroxisomal 3-ketoacyl-CoA thiolase.

cDNA clones of rat peroxisomal 3-ketoacyl-CoA thiolase were isolated. By blotting analysis using the cDNAs as probes, the mRNA for this enzyme was estimated to be about 1.9-kilobase pairs. Elevation of mRNA levels in the liver with administration of di(2-ethylhexyl)phthalate was also evident. Sequencing analysis revealed 1,272 bases of the open reading frame which encoded 424 amino acid residues. Amino acid sequence data on six tryptic peptides and the amino terminus of the purified enzyme confirmed the cDNA sequence. The precursor of peroxisomal thiolase contains at its amino terminus a peptide extension of 26 residues. The mature enzyme is composed of 398 amino acids and the molecular weight is 41,074. The presequence has a net positive charge, lacks a long stretch of hydrophobic residues, and contains a cluster of serine residues. When the primary structure of the precursor was compared to structure of known peroxisomal proteins, there was no common homologous sequence. Peroxisomal thiolase exhibits a significant sequence homology with the mitochondrial thiolase. Possible location of the transport signal of the peroxisomal thiolase is discussed. Acyl-CoA binding sites were also located on primary structures of the two thiolases. The occurrence of interrupting sequences in several clones likely originates from intron sequences.

Acetyl-CoA C-Acyltransferase↗
PubMed1987

Biosynthesis of membrane polypeptides of rat liver peroxisomes.

The biosynthesis of three major peroxisomal membrane polypeptides of rat liver was investigated. Total hepatic RNA extracted by the guanidinium/CsCl method from three control and three di(2-ethylhexyl)phthalate (a peroxisomal proliferator)-fed rats was translated in vitro in a rabbit reticulocyte lysate protein-synthesizing system. Translation products were immunoprecipitated by the antibodies against peroxisomal membrane polypeptides, subjected to sodium dodecyl sulfate/polyacrylamide gel electrophoresis, and analyzed by fluorography. The in vitro translation products of 70, 26, and 22 kDa peroxisomal membrane polypeptides were apparently of the same size as the respective mature polypeptides. The ratio of translatable mRNA levels for the 70, 26, and 22 kDa polypeptides in di(2-ethylhexyl)phthalate-fed rats to those in control rats were 5.4, 11.4, and 2.7, respectively. The synthesis of these three polypeptides with the free polysome fraction from di(2-ethylhexyl)phthalate-fed rats was more active than that with the membrane-bound polysome fraction, whereas the synthesis of albumin with the free polysome fraction was 27% of that with the membrane-bound polysome fraction. These results indicate that the peroxisomal major membrane polypeptides are synthesized on free polysomes and transported to peroxisomal membrane without any apparent proteolytic processing, and that the induction of these polypeptides by administration of a peroxisomal proliferator corresponds well to the induction of the peroxisomal beta-oxidation enzymes. The data also support the idea that peroxisomes are organized from pre-existing peroxisomes.

Animals↗
PubMed1986

Complete nucleotide sequence of cDNA and deduced amino acid sequence of rat liver catalase.

We have isolated five cDNA clones for rat liver catalase (hydrogen peroxide:hydrogen peroxide oxidoreductase, EC 1.11.1.6). These clones overlapped with each other and covered the entire length of the mRNA, which had been estimated to be 2.4 kilobases long by blot hybridization analysis of electrophoretically fractionated RNA. Nucleotide sequencing was carried out on these five clones and the composite nucleotide sequence of catalase cDNA was determined. The 5' noncoding region contained 83 bases and was followed by 1581 bases of an open reading frame that encoded 527 amino acids. The 3' noncoding region was 831 bases long and contained long repeats of the unit AC. The amino acid sequence deduced from the nucleotide sequence of the cDNAs showed about 90% homology with the reported primary structure of bovine liver catalase. The molecular weight of rat liver catalase was calculated to be 59,758 from the predicted amino acid sequence. The amino acid residues in contact with the heme group are completely identical for bovine liver and rat liver catalases. The amino acid sequence at the COOH terminus was confirmed by the results of carboxypeptidase P treatment of the protein purified from rat liver in the presence of leupeptin. Rat liver catalase has no cleavable signal peptide for translocation of the enzyme into peroxisomes.

Amino Acid Sequence↗
PubMed1985

Molecular cloning and nucleotide sequence of the cDNA for rat peroxisomal enoyl-CoA: hydratase-3-hydroxyacyl-CoA dehydrogenase bifunctional enzyme.

For the studies on the mechanism of induction of peroxisomal beta-oxidation enzymes and biogenesis of the organelle, we have isolated cDNA clones for rat peroxisomal enoyl-CoA: hydratase-3-hydroxyacyl-CoA dehydrogenase bifunctional enzyme. On blotting experiments with liver RNA, the cDNAs hybridized to a 3.0-kilobase RNA which was increased 5-7-fold by the administration of di-(2-ethylhexyl)phthalate to rats. Nucleotide sequencing was carried out for four cloned cDNAs and one obtained by a primer extension method. By overlapping these sequences with each other, we identified 20 nucleotides of 5'-noncoding, 2,166 nucleotides of coding, and 910 nucleotides of 3'-noncoding regions. The deduced amino acid sequence of the enzyme is composed of 722 residues, and the composition agrees with that of the protein data. The sequence was confirmed by the amino acid compositions and sequence analyses of some of the tryptic peptides. The molecular weight of the mature enzyme is calculated to be 78,511 from the predicted amino acid sequence. The enzyme has no terminal peptide extension as a signal for translocation into peroxisomes.

3-Hydroxyacyl CoA Dehydrogenases↗