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K Anzai

Publications and source records attributed to K Anzai.

At least 109 records · Page 6Linked to original sources
PubMed1988

ID sequence-binding protein factors during development of mice.

The ID repetitive sequence has been reported to be transcribed as small RNA in both a brain-specific and a developmental stage-specific manner. Several brain-specific proteins required for transcription, along with RNA polymerase III, may be involved in controlling the gene activity throughout development. We analyzed extracts from the brains and livers of mice in an electrophoretic mobility shift assay. Of ID sequence-binding proteins, we detected a protein factor(s) that interacts specifically with the region between two promoter sequences for RNA polymerase III. This protein factor seems to be relevant to postnatal accumulation of the small RNA transcripts of ID sequences, since its time course of expression is consistent with that of the synthesis of the small RNA during development. A penta-nucleotide direct repeat (GCAAG) and its inverted complement (CTTGC) are both present in that region and may be involved in the binding site for the protein factor. The biological significance of the binding site and interacting protein factor(s) is discussed.

Aging↗
PubMed1988

Cation channels from ciliary membrane of Tetrahymena reconstituted into planar lipid bilayer. Comparison between the channels from the wild T. thermophila and from its mutant which does not show ciliary reversal.

Cation channels in ciliary membrane vesicles from wild type Tetrahymena thermophila and from its mutant which does not show ciliary reversal or avoiding reaction were reconstituted into a planar lipid bilayer. Since the mutant does not produce the regenerative Ca2+ action potential, the mutation was expected to have occurred at the Ca-channel in the ciliary membrane. In the sample from the mutant, the channel most frequently observed was selective for cations over anions. The single channel conductance shows Michaelis-Menten type dependency on the cation concentration. The maximum conductance and dissociation constants (in parenthesis) for K+, Mg2+, Ca2+, and Ba2+ were 371 pS (23.3 mM), 17 pS (0.49 mM), 18 pS (0.52 mM), and 25 pS (0.82 mM), respectively, when the anion was gluconate. The properties of the corresponding channel from the wild type are similar to those from the mutant. No essential difference was detected, which indicates that the predominant channel is not the putative Ca channel responsible for the avoiding reaction of Tetrahymena. Some other channels than the predominant channel were also observed.

Animals↗
PubMed1987

The distribution of GABA and glycine response in the mouse brain using Xenopus oocytes.

Injection of mRNA from different regions of the central nervous system (CNS) of the mouse into the Xenopus oocyte caused a difference in the relative glycine to gamma-aminobutyric acid (GABA) response of the oocyte. Glycine caused the response in oocytes injected with brainstem mRNA but hardly in oocytes injected with cerebrum mRNA and in oocytes injected with cerebellum mRNA. In contrast, GABA caused the response in oocytes injected with mRNA from each of the 3 parts of the CNS. These obvious regional differences may reflect the distribution of the receptors to each plausible neurotransmitter in the CNS.

Animals↗
PubMed1987

Brain-specific small RNA during development and ageing of mice.

The ID sequence is a repetitive sequence family of rodent species that is transcribed specifically as small RNA in the brain. The amount of brain-specific small RNA in mice was shown to increase greatly in the first month after birth and then to remain unchanged until senescence. This RNA was suggested to be involved in regulation of brain-specific gene expression during postnatal development.

Aging↗
PubMed1987

Conservation of the ID sequence and its expression as small RNA in rodent brains: analysis with cDNA for mouse brain-specific small RNA.

Two cDNA clones for mouse brain-specific small RNA were isolated, whose sequences turn out to be highly homologous to that of a genomic mouse ID-like clone isolated previously. By use of one of these cDNA clones as a probe, the copy numbers of ID-related sequences in several mammalian species were determined. The ID sequence was found to be conserved in mice, rats, hamsters and guinea pigs, but not in non-rodent species. There were about 3 orders of magnitude of difference in the copy numbers of the gene, i.e. rat 4.0 X 10(4), mouse 4.5 X 10(2), hamster 1.5 X 10(2), and guinea pig less than 50. The gene was transcribed as small RNA in the brain of rodent species. The relative concentration of small RNA in the brain was roughly proportional to the copy number of the ID sequence in mice, hamsters, and probably in guinea pigs also. On the other hand, the amount of the RNA in rat brain was much less than that expected from the large copy number of the gene. On the basis of these observations, the possibility is discussed that most of the ID sequences in the rat are pseudogenes.

Animals↗
PubMed1986

Induction of taurine responsiveness in Xenopus oocytes by messenger RNA from mouse brain.

A taurine response was induced in the surface membrane of the oocytes of Xenopus laevis by injection of the mRNA from the neonatal mouse brain, and the response was studied electrophysiologically. The permeability of mRNA-injected oocytes to chloride ions was increased by the application of taurine in a dose-dependent manner. The same oocyte also responded to GABA, but bicuculline suppressed only the GABA response. These results suggest a possibility that taurine could be a neurotransmitter of certain neurons as yet unknown in the central nervous system.

Animals↗
PubMed1986

Isolation and sequencing of a genomic clone for mouse brain specific small RNA.

We isolated a mouse genomic clone that hybridized with small RNA present in the cytoplasm of the brain. The RNA was about 150 nucleotides long. This RNA seemed to be specific to the brain, since it was not found in the liver or kidney. The clone DNA contained a sequence homologous to 82-nucleotide "identifier" core sequence of cDNA clones of rat. The sequence contained a split promoter for RNA polymerase III and was flanked by a 12-nucleotide direct repeat (ATAAATAATTTA).

Animals↗
PubMed1986

[Present diagnostic status of scirrhous type gastric cancer--with special reference to the endoscopic diagnosis].

First, we presented an actual diagnostic situation in nowadays for gastric cancer of Borrmann 4, which is virtually the same as scirrhous gastric cancer. Among 12 patients treated by the author, all of whom were discovered late, only 3 underwent surgery. In fact, with inoperable cases in Borrmann 4, even those endoscopically found to show insufficient stretching of the gastric wall, thickening and tortuosity of folds, uneven gastric mucosa, redness and white coating, there may be negative in gastric biopsy. However, the significance of an endoscopic examination for diagnosis of scirrhous cancer is in obtaining proof of the carcinoma (especially when still operable) by gastric biopsy. Thus, one must strive not to overlook slight redness, white coating which means small erosions, but to go over gastric biopsy again and again. Next, with carcinoma presenting a leather bottle (linitis plastica type) of the stomach itself, the II c portion of the stomach consisted of fundic glands (undifferentiated carcinoma) shall become the primary focus supporting Nakamura's theory. One case of diffuse invasive cancer, mistakenly diagnosed as a II c case, and two cases of regional type, one similar to II c and the other a Borrmann 2 carcinoma of advanced carcinoma showing strongly fibrous scirrhous tendency toward infiltration, were jointly monitored.

Adenocarcinoma, Scirrhous↗
PubMed1985

Acyl migration on nucleic acid compounds related to adenosine.

Treatment of N6,N6-di-p-toluyl-2',3'-O-isopropylideneadenosine (7) with ZnBr2 in 1,4-dioxane afforded a 8,5'-O-cycloadenosine derivative 8 exclusively. Reaction of 2',3'-O-isopropylideneadenosine (1) with p-cyanobenzoyl chloride in a CH2Cl2-Et3N mixture afforded a ring-cleaved compound 11 as the main product.

Acylation↗
PubMed1983

mRNA population in the liver, kidney and brain of young and senescent mice: analysis of in vitro translation products.

Possible alterations in the population of poly(A)(+)mRNA during ageing were investigated by translation in vitro of poly(A)(+)mRNA from the liver, kidney and brain of male ddY mice of different ages. [35S]Methionine-labeled translation products were analysed by two-dimensional polyacrylamide gel electrophoresis followed by fluorography. A protein product with a molecular weight of 30 000 and isoelectric point of 6.5 was reproducibly observed only in the fluorograms of translation products of poly(A)(+)mRNA derived from the livers of senescent mice (24.5 months old). However, no age-related change was detected in the translation products of the kidney and brain. These results suggest that gene expression in liver cells changes at the level of the population of cytoplasmic poly(A)(+)mRNA during ageing.

Aging↗
PubMed1982

Purification of folding proteins of DNA from cultured mouse mammary carcinoma cells.

We described methods of preparation of folding proteins of DNA in quantity for further characterization. In principle folding proteins were first isolated as a specific DNA-protein complex from the bulk cellular proteins by centrifugation through a sucrose density gradient, followed by dissociation or by passage through a SH-Sepharose column. The overall yield was 105 micrograms of folding proteins from 1.5 x 10(9) cells. The folding protein preparation was shown to be composed of a mixture of a few kinds of SH-containing proteins, the main components being of molecular weight of 52 K and 60 K.

Animals↗
PubMed1981

A freeze-fracture study of the aggregation state of Ca2+,Mg2+-ATPase of sarcoplasmic reticulum in reconstituted vesicles at low and high temperature.

Since it was possible for Ca2+,Mg2+-ATPase of sarcoplasmic reticulum (SR) to change its aggregation state in the membrane depending on temperature, and since the change could be the cause of the break in the Arrhenius plot of Ca2+,Mg2+-ATPase activity, the aggregation state of Ca2+,Mg2+-ATPase at 0 degrees C in the membrane was compared with that at 35 degrees C by freeze-fracture electron microscopy. These temperatures are below and above the break in the Arrhenius plot (about 18 degrees C), respectively. Two kinds of samples were used; fragmented SR vesicles and egg PC-ATPase vesicles, a reconstituted preparation from purified Ca2+,Mg2+-ATPase and egg yolk phosphatidylcholine (egg PC). For both the appearance of particles in the fracture faces of the samples fixed at 0 degrees C was similar to that at 35 degrees C, and phase separation between protein and lipid was not observed even at 0 degrees C. The size of the particles was measured and histograms of the sizes at 0 degrees C and 35 degrees C were made. The histogram at 0 degrees C was similar to that at 35 degrees C with a peak at 7.1 nm, which is 1-2 nm smaller than the value reported so far. The number of the particles per unit area of the membrane was also counted. The value at 0 degrees C was similar to that at 35 degrees C. These results indicate that Ca2+,Mg2+-ATPase of SR exists in the same aggregation state (estimated as oligomer based on the values obtained in this experiment) between 0 degrees C and 35 degrees C. Based on the results of this study we think that the break in the Arrhenius plot of Ca2+,Mg2+-ATPase activity in SR is not caused by the change in the aggregation state of Ca2+,Mg2+-ATPase.

Animals↗
PubMed1981

Effects of ADP and AMPPNP on the hydrogen-deuterium exchange kinetics in Ca2+, Mg2+-ATpase of sarcoplasmic reticulum.

The kinetics of the hydrogen-deuterium exchange reaction in sarcoplasmic reticulum (SR) membranes isolated from rabbit skeletal muscle was followed by infrared absorption measurements. The exchange rate in SR was much lower than that in the soluble proteins reported so far. When adenylyl-imidophosphate (AMPPNP, an TP analog) was present, the exchange rate was lower than that in free SR and it was the lowest when ADP was present. The effect of the nucleotides on the exchange rate reflects the conformational change of the Ca2+, Mg2+-ATpase of SR membranes on binding the nucleotides. The structure of e Ca2+, Mg2+-ATPase is more restricted in the following order: SR + ADP greater than SR + AMPPNP greater than free SR.

Adenosine Diphosphate↗
PubMed1978

Supercoiled DNA folded by nonhistone proteins in cultured mouse carcinoma cells.

Upon gentle lysis of exponentially growing mouse carcinoma cells FM3A by sodium dodecyl sulfate, DNA was released as a "DNA-protein complex" in a folded conformation. No histones could be detected in the DNA-protein complex. The proteins bound to DNA were found to be composed of several kinds of nonhistone proteins with a molecular weight range of 50,000 to 60,000; they appear to play a key role in stabilizing and maintaining the compact and folded structure of the complex. Removal of the proteins by Pronase or 2-mercaptoethanol produced a more relaxed structure sedimenting about half as fast as the original complex in a neutral sucrose gradient. DNA in the folded complex is supercoiled, as indicated by the characteristic biphasic response of its sedimentation rate to increasing concentration of various intercalating agents, actinomycin D, ethidium bromide and acriflavine, with which the cells were treated before lysis. Pronase- or 2-mercaptoethanol-treated relaxed DNA still possessed the characteristic of closed-circular structure as judged from its response to intercalating agents. Nicking with gamma-ray or 4NQO broke these superhelical turns and relaxed the folded complex to slower sedimenting forms equivalent to the relaxed DNA obtained on treatment with Pronase or 2-mercaptoethanol. Viscometric observations of DNA-protein complex were consistent with the above results. A tentative model for the structure of this DNA-protein complex is proposed in which supercoiled DNA is folded into loops by several kinds of nonhistone proteins. Autoradiographic examination of the complex appeared to support this model.

4-Nitroquinoline-1-oxide↗
PubMed1978

Temperature-induced change in the Ca2+-dependent ATPase activity and in the state of the ATPase protein of sarcoplasmic reticulum membrane.

The temperature dependence of the Ca2+-dependent ATPase activity and of the conformational fluctuation of the ATPase molecule has been measured for four kinds of preparations: fragmented sarcoplasmic reticulum, MacLennan's enzyme (purified ATPase preparation), and DOL and egg PC-ATPase (purified ATPase preparations in which lipids are replaced with dioleoyllecithin and egg yolk lecithin, respectively). It has been found that Arrhenius plots of the Ca2+-dependent ATPase activity show a break at about 18 degrees C for all the preparations. Hydrogen--deuterium exchange kinetics of the peptide NH protons were used to measure the conformational fluctuation of the protein molecules. Van't Hoff plots of the conformational fluctuation amplitude of a region near the surface of the ATPase molecule also show a break at about 18 degrees C for all the preparations. It is concluded that the break at around 18 degrees C is not related to a gel-liquid crystalline transition of lipids but to a change in the conformation of the ATPase molecule existing in fluid lipids.

Adenosine Triphosphatases↗