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T Nohno

Publications and source records attributed to T Nohno.

89 records · Page 5Linked to original sources
PubMed1989

Stability of CAT gene transcript depends on the 3'-end structure.

To determine the involvement of 3'-end structure of mRNA in the regulation of gene expression in eukaryotic cell, a series of pSCAT plasmids was constructed with chloramphenicol acetyltransferase (CAT) gene and the 3'-regulatory elements from various eukaryotic genes. As a result of determination of the CAT activities and the mRNA level generated from these plasmids, both results were well correlated. Furthermore, the treatment of transfected cells with phorbol ester (TPA) revealed that the polyadenylated CAT mRNAs form some genes were stabilized, in contrast, the mRNAs bearing 3'-end structure of histone or C-myc genes were not.

Chloramphenicol O-Acetyltransferase↗
PubMed1988

Cloning and sequencing of the Escherichia coli chlEN operon involved in molybdopterin biosynthesis.

The nucleotide sequence of a HinPI-HpaII restriction nuclease fragment which complemented a delta chlE strain of Escherichia coli was determined. Two open reading frames were deduced to be the structural genes for ChlE and ChlN proteins, which have molecular weights of 44,067 and 26,719, respectively. Both proteins were required for complementing a chromosomal deletion of the chlE locus. The chlE and chlN genes were transcribed from a common promoter, chlEp, located upstream of chlE. Transcriptional and translational signal sequences were recognized in this region.

Amino Acid Sequence↗
PubMed1986

Cloning and complete nucleotide sequence of the Escherichia coli glutamine permease operon (glnHPQ).

The glutamine permease operon encoding the high-affinity transport system of glutamine in Escherichia coli could be cloned in one of the mini F plasmids, but not in pBR322 or pACYC184, by selection for restoration of the Gln+ phenotype, the ability to utilize glutamine as a sole carbon source. We determined the nucleotide sequence of the glutamine permease operon, which contains the structural gene of the periplasmic glutamine-binding protein (glnH), and indispensable component of the permease activity. The N-terminal amino acid sequence and the overall amino acid composition of the purified glutamine-binding protein were in good agreement with those predicted from the nucleotide sequence, if the N-terminal 22 amino acid residues were discounted. The latter comprised two Lys residues (nos. 2 and 6) followed by 16 hydrophobic amino acid residues and was assumed to be a signal peptide for transport into the periplasmic space. There were two additional reading frames (glnP and glnQ) downstream of glnH sharing a common promoter. It was concluded that the glnP and glnQ proteins as well as the glnH protein are essential for glutamine permease activity.

Amino Acid Transport Systems, Basic↗
PubMed1986

Evaluation of effect of host immunity on growth of androgen-dependent Shionogi carcinoma 115 in the mouse.

Experiments were carried out to examine the role of the host defence mechanism in the proliferation of androgen-dependent Shionogi carcinoma 115 in the DS mouse. Stimulation of tumor growth by dexamethasone was synergistic with androgen action. Enhanced host immunity caused by bacterial infection resulted in remarkable inhibition of tumor growth. Not only androgen but also the host defence mechanism is one of the major factors that determine overall growth rate of the androgen-dependent tumor in this strain of mice.

Androgens↗
PubMed1983

Effects of thiocyanate on cytosol androgen receptor from Shionogi carcinoma 115.

The effects of KSCN and other chaotropic salts on the androgen receptor in cytosol of Shionogi carcinoma 115 were studied by means of charcoal adsorption assay and sucrose gradient centrifugation. When KSCN or NaSCN was added to the [3H]-dihydrotestosterone-cytosol mixture at the final concentration of 0.5 M, the androgen binding to the cytosol receptor was considerably inhibited. The inhibition reached maximum within 5 h at 0 degrees C and was dependent on the kind of chaotropic anion added: the potency of inhibitory effect in descending order was KSCN greater than KI greater than KBr greater than KCl. The inhibition was not observed in the estradiol-receptor interaction with KSCN or NaSCN up to 0.5 M. When 0.5 M KSCN-treated androgen-cytosol mixture was subjected to gel filtration or (NH4)2SO4 fractionation to remove the salt, a partial recovery (30-40%) in specific binding activity was observed. The binding activity of androgen receptor was unaffected by a treatment with KSCN up to 0.1 M and the androgen-receptor complex sedimented in a 5S form in 0.1-0.3 M KSCN, 0.5 M KCl or 0.5 M KBr. These results suggest that the binding activity of androgen receptor is more susceptible than that of estrogen receptor to chaotropic salts which cause impairment in intramolecular hydrophobic interactions.

Adenocarcinoma↗
PubMed1983

Apparent ineffectiveness of adriamycin for growth of androgen-dependent Shionogi carcinoma 115 in the mouse.

Although adriamycin (1 mg/kg) and 5-fluorouracil (25 mg/kg) were equally effective in inhibiting the growth of Ehrlich carcinoma, both ascites and solid forms, in the mouse, the growth of Shionogi carcinoma 115 in the male DS mouse was relatively resistant to the treatment with adriamycin as compared to 5-fluorouracil. However, direct cytotoxic activity of adriamycin in cultured Shionogi carcinoma 115 (SC 115) cells was about 1000-fold molar potent when compared with 5-fluorouracil. The apparent ineffectiveness of adriamycin against SC 115 in the DS mouse seems to be, at least in part, due to the depression of host defence mechanisms.

Animals↗
PubMed1982

Salt extractability of nuclear receptor-estrogen complex from the rat uterus.

Estrogen receptors in the nuclei of rat uterus were determined 1 or 6 h after the injection of [3H]estradiol. Ratio of 0.4 M KCl-extractable to -resistant receptor-estradiol complex was constant during this time interval. Three consecutive extractions took out about 95% of receptor-estradiol complex either 1 or 6 h after injection. Extraction with KCl before the exchange assay reduced the amount of salt-resistant nuclear receptor-estradiol complex. However, when exchange incubation with [3H] estradiol was done before KCl extraction, salt-resistant receptor-estradiol complex was significantly increased, even after three consecutive extractions.

Animals↗
PubMed1982

Stimulatory effects of dexamethasone and indomethacin on growth of androgen-dependent Shionogi carcinoma 115 in the mouse.

The effects of dexamethasone and indomethacin on the growth of androgen-dependent Shionogi carcinoma 115 were studied. When castrated male DS mice were treated with dexamethasone for 2 weeks at daily doses of 1-5 mg/kg starting from 3 days before tumor inoculation, the tumor weight as well as the transplantability was significantly increased. The tumor grown in dexamethasone-treated mice had morphological, biochemical and biological characteristics similar to those of the original Shionogi carcinoma 115. Indomethacin at daily doses of 2-10 mg/kg also stimulated the tumor growth in castrated DS mice, but the effect was less pronounced than that of dexamethasone. In allogeneic male ICR mice, dexamethasone promoted tumor growth, but indomethacin had no effect. These results suggest that tumor growth in the mouse is stimulated not only by androgens but also by glucocorticoids through the suppression of immune responses of the host and direct action on the tumor cells.

Androgens↗
PubMed1981

Binding kinetics and physical properties of androgen receptor in androgen-dependent Shionogi mammary carcinoma 115.

The characteristics of the androgen receptor in the cytoplasmic fraction of Shionogi carcinoma 115 were studied in vitro by means of charcoal adsorption assay, sucrose density gradient centrifugation, and polyacrylamide gel electrophoresis. The equilibrium dissociation constant for [3H]dihydrotestosterone (Kd = (2-5) X 10(-11) M) was estimated from independently determined rates of association and dissociation, and was lower by one order of magnitude than the value obtained by saturation analysis (Kd = (2-8) X 10(-10) M). Evaluation of the effect of temperature on receptor binding of androgen allowed the estimation of several thermodynamic parameters, including activation energies of association (4 kcal/mol) and dissociation (14 kcal/mol), the apparent free energy (-13 kcal/mol), enthalpy (-9 kcal/mol), and entropy (+14 cal/mol per K). The receptor was greatly stabilized when bound with androgen. The results indicate how the lability of the unbound receptor and slow rate of dihydrotestosterone-receptor interaction can influence the estimation of dissociation constants by usual saturation analysis. The sedimentation coefficient of androgen receptor in freshly prepared cytosol was 6S, and became 7S after storage for 2 months at -80 degrees C. The 7S conversion of the receptor was reversed by treatment with heparin. In all cases, a single 5S peak was obtained in the presence of 0.5 M KCl. On electrophoresis in heparin-containing polyacrylamide gel, protein-bound radioactive androgen migrated as a single peak (Rf = 0.5 in 5% gel). Differences in reported values for the sedimentation coefficient of androgen receptor in cytosol of Shionogi carcinoma 115 appear to be derived from aggregation of the receptor protein during the assay procedure.

Animals↗
PubMed1979

Trans-4-hydroxy-3-methoxycinnamic acid (ferulic acid) inhibits the effect of androgens on the rat prostate.

Trans-4-hydroxy-3-methoxycinnamic acid (ferulic acid, FA) antagonized the effect of exogenous androgens on the ventral prostate (VP) in castrated rats as well as the effect of endogenous androgens in intact rats. FA, however, had no effect on the seminal vesicles (SV) and levator ani muscle (LAM), nor oestrogenic effect in female rats and mice. FA did not antagonize the receptor binding of testosterone nor inhibit the conversion of testosterone into 5 alpha-dihydrotestosterone (DHT).

Amino Acids↗
PubMed1977

Natriuresis of fasting in intact and adrenalectomized rats.

Experiments were carried out in an attempt to elucidate the mechanism of fasting-induced natriuresis in conscious rats. Female animals were given low sodium diet and saline in a fixed concentration for at least three days, and deprived of food thereafter. The sodium balance significantly shifted to negative independently of potassium supply in intact rats. Such was also observed in the dexamethasone-replaced, adrenalectomized rats and was not affected by further administration of aldosterone. In addition, the diuretic effect of insulin in fasted intact rats was not evident in the fed diabetic rats in which diabetes had been induced by streptozotocin. Such findings suggested participation of factors other than insulin. The natriuresis of fasting in intact rats appears to involve two factors, one of which is independent of the sodium intake level. Dependence on the sodium intake level may be derived from alteration of the solute diuresis-like effect of drinking saline w hen animals are fasted. These results suggest that neither aldosterone nor insulin is a major causal factor involved in fasting-induced natriuresis.

Adrenalectomy↗
PubMedDate not supplied

Effects of estrogens and antiestrogens on androgen-dependent growth of Shionogi carcinoma 115: role of estrogen receptor.

Experiments were performed to observe the role of estrogen receptor in the proliferation of androgen-dependent mouse tumor, Shionogi carcinoma 115. Estradiol and diethylstilbestrol inhibited tumor growth as well as the weight gain of seminal vesicles and prostate glands in intact male mice. Tamoxifen decreased the tumor weight in intact males. Both nitromifene given to intact mice and tamoxifen given to castrated androgenized mice decreased the weight of seminal vesicles, but increased tumor weight. Estradiol was bound to the androgen receptor of the tumor cytosol with relatively high affinity, whereas diethylstilbestrol, tamoxifen and nitromifene were not. These were effective competitors in the estrogen receptor present in the tumor cytosol. These results suggest that the estrogen receptor system in Shionogi carcinoma 115 inhibits the proliferation of tumor cells.

Animals↗