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H Nomiyama

Publications and source records attributed to H Nomiyama.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Function, molecular structure and gene expression regulation of LD78].

LD78 is a member of a new cytokine superfamily, consisting of at least twelve small proteins, which are involved in inflammation and cell growth. Depending on their primary structure, these cytokines can be divided into two families, one of which contains LD78 and is known as the CC family. The protein and gene structures and the physiological functions of LD78 in comparison with the other CC family members are summarized here. Furthermore, the generation mechanism of the three LD78 genes and their expression are discussed.

Amino Acid Sequence↗
PubMed1990

Chronic inhalation effects of tetrachloroethylene on hepatic and renal microsomal electron transport components and delta-aminolevulinic acid dehydratase in rats.

Hepatic and renal microsomal electron transport components and erythrocyte delta-aminolevulinate dehydratase were investigated in adult male rats exposed to 0, 50, 200 and 600 ppm tetrachloroethylene for 4 weeks. Body weight and liver weight showed a significant decrease only in the 600 ppm group. A dose-dependent decrease in erythrocyte delta-aminolevulinate dehydratase was observed at 200 and 600 ppm. Serum transaminase activity (SGPT) showed an increase in the 600 ppm group only. Hepatic and renal microsomal protein content showed an increase in all groups except in the kidneys of the 600 ppm group. Induction of hepatic cytochrome b5 activity was observed in all groups. However, hepatic cytochrome P-450 showed an induction and slight inhibition at 200 and 600 ppm respectively, without any alteration at 50 ppm. Renal microsomal cytochrome P-450 activity was induced in all groups. Induction of hepatic and renal NADPH cytochrome c reductase activity was observed at 600 ppm, but no alteration was seen at 50 and 200 ppm. These results indicate that chronic inhalation of tetrachloroethylene at higher levels alters mixed-function oxidase and heme metabolism.

Administration, Inhalation↗
PubMed1990

Structures of human genes coding for cytokine LD78 and their expression.

LD78 is a member of a newly identified superfamily of small inducible proteins involved in inflammatory responses, wound healing, and tumorigenesis. Southern blot analysis of the EcoRI-digested human genomic DNAs, using previously isolated LD78 cDNA as a probe, showed that in each individual there are 4.2- and 4.8-kilobase-pair (kb) fragments and that some have an additional 6.5-kb fragment. The 4.2-kb fragment contained genomic DNA sequences corresponding to the LD78 cDNA and was named the LD78 alpha gene. The 4.8-kb fragment contained similar sequences, showing 94% homology to the LD78 alpha gene, and was named the LD78 beta gene. The LD78 alpha gene was present in a single or a few copies per haploid genome, whereas the copy number of the LD78 beta gene and of the 6.5-kb fragment hybridizable to LD78 cDNA varied among the samples tested. Treatment of human myeloid cell lines HL-60 and U937 with phorbol 12-myristate 13-acetate (PMA) increased within 2 h cellular levels of the RNA hybridizable to LD78 cDNA. The human glioma cell line U105MG and primary culture of human fibroblasts also expressed the hybridizable RNA in response to PMA. Addition of cycloheximide had no apparent effect on this response in U937 cells and inhibited the response in fibroblasts, whereas it stimulated the response in HL-60 and U105MG cells. mRNA phenotyping experiments revealed that the LD78 alpha and LD78 beta genes were both transcribed in PMA-stimulated U937 cells.

Amino Acid Sequence↗
PubMed1989

cDNA cloning and expression of pig cytosolic aspartate aminotransferase in Escherichia coli: amino-terminal heterogeneity of expressed products and lack of its correlation with enzyme function.

A full-length cDNA encoding the pig cytosolic aspartate aminotransferase (EC 2.6.1.1) (cAspAT) was constructed from two overlapping cDNA clones. One clone (Lm pcAAT-8) isolated from a lambda gt10 pig heart cDNA library contained a 3' untranslated sequence, a poly(A) segment, and a part of the coding region for amino acid positions 127-412. Another clone (Lm pcAAT-107) isolated from a lambda gt10 primer extension library contained the coding region for amino acid positions 1-148 and a 5' untranslated sequence. Rejoining of the cDNA inserts of the two clones and recloning into pUC18 gave rise to a cDNA covering an entire coding sequence for pig cAspAT mRNA. Insertion into pKK223-3 yielded an expression plasmid, ppcAAT200. Escherichia coli JM105 cells transfected with ppcAAT200 overproduced pig cAspAT to an extent of about 3% of the total cellular soluble proteins. The expressed product was indistinguishable from the alpha subform of cAspAT isolated from pig heart in terms of specific activity, absorption spectra, molecular size, crystalline form, and immunological reactivity with anti pig cAspAT antibody. Compared with the amino-terminal sequence (Ala-Pro-Pro-) reported for pig heart cAspAT, the recombinant pig cAspAT showed heterogeneity in the amino-terminal sequence: Ala 1 (26%), Pro2 (54%), and Pro3 (19%). Construction of a mutant cAspAT with deletion of residues 1-3 and its comparison with the wild-type enzyme revealed that loss of the three amino-terminal residues does not affect the catalytic activity and structural integrity of the enzyme.

Amino Acid Sequence↗
PubMed1989

Synthesis of a novel cytokine and its gene (LD78) expressions in hematopoietic fresh tumor cells and cell lines.

The gene coding for the protein LD78 was isolated from stimulated human tonsillar lymphocytes by differential hybridization. The gene product consisted of 92 amino acids with characteristics of cytokines. LD78 gene transcripts were detected in eight of eight fresh samples of cells from patients with acute nonlymphocytic leukemia (ANLL) by Northern blot analysis. ANLL cells with monocytic features gave the strongest bands. RNA transcripts were found in two of three samples of cells from patients with adult T cell leukemia (ATL), eight of nine samples from patients with acute lymphocytic leukemia (ALL) of B cell lineage, and one of the three samples from patients with T cell ALL. KG-1, HL-60, HUT 102, MT-2, and MJ cell lines expressed the LD78 gene constitutively. The LD78 protein was detected in culture supernatants and cell lysates of HUT 102, MT-2, MJ, and fresh ATL cells by Western blot analysis. This protein was not found in culture supernatants or cell lysates of monocytic leukemia cells and HL-60 cells, although LD78 transcripts were found in those cells. The discrepancy between gene and protein expression might be explained by the stability of the mRNA. Thus, the protein may be involved in the neoplastic transformation of hematopoietic cells.

Biological Factors↗
PubMed1988

Messenger RNA expressed in mouse teratocarcinoma stem cells and down-regulated by a tumor-promoting phorbol ester codes for a novel transmembrane protein.

Cloning and sequence analysis of a DNA complementary to the mRNA expressed in undifferentiated mouse F9 teratocarcinoma stem cells but disappearing rapidly after treatment with a tumor-promoting phorbol ester revealed it to be a 1.9 kilobase pairs-long cDNA encoding a protein of 323 amino acid residues. Computer-assisted analyses of the deduced amino acid sequence indicated that this protein contains a typical hydrophobic signal peptide consisting of 33 amino acid residues and six putative membrane-spanning segments. The deduced amino acid sequence, as a whole, bears no significant sequence homology to any previously described protein.

Amino Acid Sequence↗
PubMed1988

Cooperativity and hierarchical levels of functional organization in the SV40 enhancer.

We have investigated the cell-specific activity of the GT-IIC, GT-I, Sph-II, Sph-I, and octamer motifs of the SV40 enhancer in four cell lines (HeLa cells, MPC11 plasmocytoma B cells, and non-differentiated and retinoic acid-differentiated F9 embryonal carcinoma cells). Our present results reveal the existence of three classes of motifs that interact with cell-specific enhancer factors but that have no enhancer activity of their own: those (class A) that generate enhancer activity following oligomerization of tandem repeats of the motif; those (class B) that cannot enhance transcription when oligomerized as a tandem repeat but whose association with a second motif results in transcription activation after oligomerization; and those (class C) that exhibit enhancer activity when a single copy of the motif is oligomerized. Three levels of functional organization of enhancers can also be defined. The possible implications for enhancer functions are discussed.

Allosteric Regulation↗
PubMed1988

Chronic exposure to cadmium did not impair vitamin D metabolism in monkeys.

Vitamin D metabolism in primates with chronic exposure to cadmium was studied in relation to Itai-Itai disease. In a series of experiments, crab-eating monkeys were fed cadmium-contaminated rice (1.33 micrograms Cd/g) or a diet containing 3 micrograms/g cadmium chloride for 6 years. These treatments had no effect on the 1,25-dihydroxyvitamin D (1,25(OH)2D), 24,25-dihydroxyvitamin D (24,25(OH)2D), and 25-hydroxyvitamin D (25(OH)D) in the serum. This is consistent with unchanged production of 1,25(OH)2D and 24,25(OH)2D by renal mitochondria prepared from the same animals. No indication of renal dysfunction was observed. In another series of experiments, rhesus monkeys were fed a diet containing 3, 10, 30, or 100 micrograms/g cadmium for 9 years. Serum vitamin D metabolites and renal production of 24,25(OH)2D also remained unchanged. In contrast, renal 25(OH)D-1-hydroxylase (1-hydroxylase), which is responsible for the production of 1,25(OH)2D, seemed to be suppressed in the animals fed 30 or 100 micrograms/kg cadmium-contaminated diet (no statistical significance). These animals had indications of mild renal dysfunction, and there was a strong negative correlation between 1-hydroxylase and urinary concentration of either protein or beta 2-microglobulin. These data suggest a slight change in the total enzyme activity, possibly due to mild renal dysfunction. Since substrate (25(OH)D) concentration is much lower and thus rate-limiting in vivo as compared with that in vitro assay system used in this study, the slight change of enzyme activity would not have been sufficient to affect the serum level of 1,25(OH)2D. No skeletal abnormality was observed in any of these animals. In view of these data, the length of cadmium exposure and the life span of animals as well as epidemiological data published elsewhere, factors other than cadmium may also be involved in the development of Itai-Itai disease.

Animals↗
PubMed1987

Tissue metal shifts by a single exposure to metals in rats.

Intraperitoneal pretreatment with a large dose of Cd, Zn, Hg, Mn or Ag remarkably depressed the lethal effects of X-ray. The CHX pretreatment before metal challenge depressed the lethal effects of X-ray more remarkably. Therefore, metal-binding protein may not play an important role in protective effects of metal pretreatment on the lethal effects of X-ray, but quantum mechanical characters of metals may do so.

Animals↗
PubMed1987

Cell-specific activity of the constituent elements of the simian virus 40 enhancer.

We have compared the activation of transcription from the early promoter of simian virus 40 brought about by the enhancer during transient expression in several cell lines. The enhancer stimulated RNA synthesis approximately 400-, 100-, 100-, and 300-fold in human HeLa cells, the mouse plasmacytoma B cells MPC11, and the nondifferentiated and retinoic acid-differentiated mouse embryonal carcinoma F9 cells, respectively. The contribution to enhancer activity of its multiple constituent motifs has been investigated in the different cell types using the pA series of recombinants mutated throughout the enhancer. A comparison of the activity of these recombinants in the four cell lines indicates that the activity of the various enhancer motifs is cell specific. The activity of a given motif in a given cell line correlates well with the known presence in this cell line of a protein(s) that binds specifically to that motif in vitro.

Animals↗
PubMed1986

Cloning and sequence analysis of mRNA for mouse aspartate aminotransferase isoenzymes.

The nucleotide sequences of mRNAs for the mouse mitochondrial and cytosolic aspartate aminotransferase isoenzymes (mAspAT and cAspAT) (EC 2.6.1.1) were determined from complementary DNAs. The mAspAT mRNA comprises minimally 2460 nucleotides and codes for a polypeptide of 430 amino acid residues corresponding to the precursor form of the mAspAT (pre-mAspAT). The cAspAT mRNA comprises minimally 2086 nucleotides and codes for a polypeptide of 413 amino acid residues. The region coding for the mature mAspAT and that for the cAspAT show about 53% overall homology. The former shares 49% and the latter 48% of homology, respectively, with that of the Escherichia coli aspC gene, which has been shown to code for the E. coli AspAT (Kuramitsu, S., Okuno, S., Ogawa, T., Ogawa, H., and Kagamiyama, H. (1985) J. Biochem. (Tokyo) 97, 1259-1262). When the deduced amino acid sequence of the mouse pre-mAspAT was compared with that of the pig pre-mAspAT polypeptide, we found that they share a 94% homology and that the mouse pre-mAspAT yields a presequence consisting of 29 amino acid residues and a mature mAspAT, consisting of 401 amino acid residues. These numbers and the amino acid residues present at the putative cleavage site are all in complete agreement in these two species. The deduced amino acid sequence of the mouse cAspAT shares 91% homology with that of the pig cAspAT. Comparisons of the nucleotide and deduced amino acid sequences between the mouse and E. coli AspATs suggest that the mammalian mAspAT gene is more closely related to the E. coli aspC gene than is the mammalian cAspAT gene.

Amino Acid Sequence↗
PubMed1986

Amplification of human argininosuccinate synthetase pseudogenes.

The human genome contains multiple pseudogenes for an argininosuccinate synthetase (AS) gene. To elucidate the molecular mechanisms of generation and dispersion, complete nucleotide sequences of four different AS pseudogenes, psi AS-Y, psi AS-A1, psi AS-A2 and psi AS-A3, have been determined. A comparison of these sequences with those of three reported AS pseudogenes, psi AS-1, psi AS-3 and psi AS-7 revealed that two pairs, psi AS-Y/psi AS-7 and psi AS-A3/psi AS-1, are highly homologous but not identical, thereby suggesting that one of the pairs is generated by a duplication of the other member of the pairs. The psi AS-Y, which is probably located on chromosome Y, and the partially sequenced psi AS-7 are both interrupted by an Alu element at exactly the same site in their 3'-end regions. These two Alu elements are located in an opposite orientation relative to the direction of transcription of the pseudogene, and their possible role on pseudogene dispersion was examined. The psi AS-A1 is also accompanied by an Alu element at its 3' end. In this case, the orientation of the Alu element is the same as that of the pseudogene. The psi AS-A1 and the Alu element are flanked with direct repeats, as if they had been inserted into a chromosomal site, as a single unit.

Argininosuccinate Synthase↗
PubMed1986

Critical concentration of 'unbound' cadmium in the rabbit renal cortex.

Critical concentration of 'unbound' cadmium in the rabbit renal cortex was around 13 micrograms Cd/g, which was far lower than the critical concentration of 'total' cadmium in the renal cortex, 200-300 micrograms Cd/g, and a little lower than the critical concentration of non-MT-Cd in the renal cortex, 35-60 micrograms Cd/g, respectively. The above result may suggest that it is necessary to identify the chemical form of 'active' cadmium in the renal cortex.

Amino Acids↗