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Volume 16, Issue 1
Displaying 1-14 of 14 articles from this issue
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Tetsuya Irie, Wataru Koyama, Yôko Ikeuchi, Toku Kanaseki1991 Volume 16 Issue 1 Pages 1-16
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSLivers containing Mallory bodies (MBs, hyalin degenerative cytoplasmic inclusions) were examined using Heuser's and Van Harreveld's cryo-techniques. The tissues were collected from 1) a patient suffering from alcoholic hepatitis and 2) mice treated with griseofulvin (GF, an anti-mitotic drug). Normal mouse liver and isolated MBs from GF-treated mice were also analyzed by the same methods. Our results suggest that under the toxic influence of alcohol or GF on microtubular elements, MBs are generated by entanglement of elements of 10 nm filaments with microtubule elements. This in turn inhibits cellular transport processes. The reticular net of the ER-element which is usually observable in the normal tissue is changed into numerous small vesicles in the pathological and experimental tissues. The diameters of hepatocytes containing these vesicles were 1.5 to 2 times larger than control diameters. MBs have previously been described in thin sections as filamentous tangles. On replicas we found that they appear to be composed of pairs of filaments twisted in a roughly helical manner, each having a diameter less than 10 nm. The paired helical nature of the MB-filaments is reminiscent of other inclusion bodies, which are also composed of elements of 10 nm filaments, observable in various neurological diseases.View full abstractDownload PDF (8346K) -
Akinari Yokoya, Katsumi Kobayashi, Yasunori Miyamoto, Shozo Ishizaka1991 Volume 16 Issue 1 Pages 17-22
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSIn order to elucidate the mechanism of cell adhesion, the size of the functional site, both in the fibronectin molecule and in the mouse fibroblast cell, responsible for cell adhesion activity, was determined. The size was assumed to be equivalent to the target size, that can be determined from the X-ray inactivation dose. The target size of the cell-binding site in the fibronectin molecule was 32 kdalton. The molecular weight was much larger than that of the tripeptide, which has been reported to be the minimum peptides having a cell-binding activity. This suggests that submolecular regions in fibronectin other than the tripeptide are necessary for cell adhesion. The target size in the cell responsible for the adhesion to the fibronectin-coated surface was 4300 kdalton. The large molecular weight of the target could be explained by assuming that a complex protein system is involved in the cell-adhesion process in the cell.View full abstractDownload PDF (546K) -
Takuro Kanekura, Teruo Miyauchi, Masaaki Tashiro, Takashi Muramatsu1991 Volume 16 Issue 1 Pages 23-30
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSBasigin is a new member of the immunoglobulin super family with homology to both the immunoglobulin V domain and major histocompatibility complex class II antigen β-chain. Southern blot analysis indicated that the basigin gene was present as a single copy or as a few copies per mouse genome. Although a homologous gene was detected in the hamster and human, Southern and Northern blotting experiments indicated considerable species specificity in the basigin structure. The molecular weight of N-glycanase-treated basigin from embryonal carcinoma cells was about 32, 000 and was close to the value of basigin polypeptide inferred from the cDNA sequence; the result confirmed the open reading frame of basigin. Upon Western blotting, large amounts of basigin were detected in the mouse kidney as a glycoprotein bound to Ricinus communis agglutinin (RCA)-I and as a glycoprotein bound to concanavalin A; the molecular weight of the former was 38, 000-43, 000, and of the latter was 30, 000. Basigin of the molecular weight of 48, 000 was detected in RCA-I-binding glycoproteins of the liver, small intestine and spleen. Thus, different forms of basigin can be produced by different modes of glycosylation. Another source of heterogeneity of basigin may be differences in N-terminal sequences, since cDNA clones with different 5' coding sequences were identified.View full abstractDownload PDF (1194K) -
Binding of Viral Glycoprotein with Trypsin and Its Relation to Virulency. I. Initial Step of BindingTakako Shimamoto, Takuya Shimamoto, Yoshio Okada, Nobutoshi Yamada, Ke ...1991 Volume 16 Issue 1 Pages 31-38
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe interaction between surface proteins of some enveloped viruses and trypsin was studied by computer analysis. Prior to the cleavage of the viral protein by trypsin, hydrophobic interaction between them at the vicinity of their active sites may occur. An exposed hydrophobic portion was found there which theoretically could stimulate the interaction. This interaction would be rather non-specific: according to the analysis, trypsin could bind equally well with weakly virulent virus and virulent viruses. Following this interaction, a specific reaction between their active sites would occur. The specificity was found to be related to the virulency of the virus.View full abstractDownload PDF (395K) -
Keizo Miyata, Yukio Kiho, Yasuhiro Hosaka1991 Volume 16 Issue 1 Pages 39-43
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe two step nature of the binding reaction between trypsin and viral glycoproteins was further investigated using two types of trypsin, bovine trypsin and Streptomyces griseus trypsin. The experimental results were explained by the van der Waals energy operating in the second step, suggesting that the conformational aspects, in addition to the electrostatic nature, of the interacting peptides are decisive in this specific process.View full abstractDownload PDF (344K) -
Yukio Kiho1991 Volume 16 Issue 1 Pages 45-48
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe problem of protein folding was studied with trypsin inhibitor by deviation analysis (1). The results showed that: i) Qualitatively, the main features of the structure, determined by this method, coincided with the structure determined by X-ray crystallography (3). This structure is, however, not topological but functional, and may elucidate the functional relations between various parts of the protein.View full abstractDownload PDF (240K) -
Yukio Kiho, Yoshio Okada, Takuya Shimamoto, Taisuke Iwai, Tsuruji Iwai1991 Volume 16 Issue 1 Pages 49-53
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe dev analysis was used to construct the functional structure of protein (3). Based on this principle, the intramolecular interaction of dev peak was investigated. Two types of peak were observed: one is the hidden peak which interacts strongly with another region of the molecule and the other is the exposed peak whose interaction was weak. Analysis was made with trypsin and its inhibitor and on the intermolecular interaction between their exposed peaks. One interaction between their exposed peaks was found to coincide with one which had been already known to be authentic between their active sites.View full abstractDownload PDF (327K) -
Naohiro Tsuyama, Masami Miura, Mayumi Kitahira, Sadahiko Ishibashi, To ...1991 Volume 16 Issue 1 Pages 55-62
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSTwo lines of immortal human fibroblasts were isolated following transfection of TIG-3 cells with plasmid DNA, pMT-10DtsA, that contained SV40 early gene with a deletion in replication origin and ts mutation in coding sequence for T-antigen. These cells continued proliferation at 34°C, over 565 population doubling level (PDL) which is far over the limited division potential of untransformed normal TIG-3 of 70-80 PDL. When the culture temperature was shifted to 40°C after 70 PDL, they ceased proliferation immediately. One of these immortal clones, SVts8, lost its ts phenotype after retransformation with wtT-antigen gene. These results indicated that the function of intact T-antigen is required for maintenance of immortal proliferation, at least in one of the SV40 transformed immortal clones.View full abstractDownload PDF (1673K) -
Osamu Yano, Hideyasu Hirano, Yuji Karasaki, Ken Higashi, Hayato Nakamu ...1991 Volume 16 Issue 1 Pages 63-71
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSWe have analyzed cellular DNA sequences at the viral genome integration site in a human fibroblast cell line VA13 immortalized by simian virus 40 (SV40). The computer analysis of the junctional cellular DNA sequences did not show any homology to the DNA sequences previously reported. This suggests that immortalization by SV40 was not induced by the destruction of any known oncogene or antioncogene at the integration site. We did not find the precise substantial sequence homology at the junctional site between the cellular DNA and SV40 DNA, indicating that the recombination mechanism involved does not require precise sequence homology and therefore, SV40 genome was probably not integrated by homologous recombination. Short direct and inverted repeats of 5 to 29 nucleotides were found in the junctional cellular and SV40 DNA.
Cellular DNA abutting SV40 DNA was found by the Northern blot analysis to be expressed in diploid human fibroblasts and SV40-transformed cells. The nature of this RNA is now under study.View full abstractDownload PDF (784K) -
Kazue Tsuji, Akemi Ueno, Toshinori Ide1991 Volume 16 Issue 1 Pages 73-80
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSG0-arrested human diploid fibroblasts, TIG-1, was stimulated to induce DNA synthesis by serum, epidermal growth factor (EGF), colchicine, colcemid, or 12-O-tetradecanoylphorbol-13-acetate (TPA). The induction of DNA synthesis was mediated by protein kinase C (PKC) when stimulated with TPA but not when stimulated with other agents. When TPA-stimulated cells were immediately treated with colcemid, induction of DNA synthesis was reduced. This reduction diminished when colcemid was added more than 6 h after TPA treatment. Conversely, when colcemid-stimulated cells were treated with TPA, induction of DNA synthesis was also reduced. This reduction was enhanced when the interval between the addition of two stimulants was extended. PKC-deprivation abolished both stimulatory and inhibitory effects of TPA on DNA synthesis. Staurosporine blocked an induction of DNA synthesis by TPA but appeared to be ineffective on the inhibitory action of TPA on DNA synthesis by colcemid. These results suggest that the inhibitory effect of TPA on the induction of DNA synthesis by colcemid is mediated by down regulation-sensitive and staurosporine-insensitive PKC.View full abstractDownload PDF (682K) -
Tsuyoshi Takasuka, Mihoko Sakayama, Emiko Miyake, Sadahiko Ishibashi, ...1991 Volume 16 Issue 1 Pages 81-85
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESStsJT16 is a cell cycle temperature-sensitive (ts) mutant from a Fischer rat cell line. When it is growth-stimulated from G0 phase it enters S phase at the permissive temperature (34°C) but not at the nonpermissive temperature (40°C). It induces a nuclear labile protein, p70, when it is stimulated from G0 phase at 34°C, but not at 40°C. In growing cell cycle it progresses through the S, G2 and M phases at both temperatures but fails to pass through G1 phase at 40°C. Here we described that p70 was synthesized neither in the randomly growing cycle nor in the G1 phase synchronously progressing from M phase. The cells synchronized at early G1 phase by culturing in serum-free medium for 7.5 h from G1/S boundary induced c-fos and c-myc following serum addition, but under the same condition p70 was not synthesized. These results indicate that the synthesis of p70 is not required for progression of the G1 phase of the growing cycle and can be used as an exclusive marker of G0-S transition.View full abstractDownload PDF (678K) -
Nobuaki Yanai, Takeshi Satoh, Masuo Obinata1991 Volume 16 Issue 1 Pages 87-93
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSThe spleen is an erythropoietic organ in mouse. To reconstruct a microenvironment essential for erythropoiesis in vitro, the stroma (MSS31) cell line had been established from newborn mouse spleens. MSS31 cells exhibited properties of endothelial cells: (a) the cells showed the activity to uptake acetylated low-density lipoprotein (Ac-LDL) and (b) the cells can form a capillarylike structure by a phenotypic modulation in collagen matrices. MSS31 cells selectively supported the proliferation and differentiation of the erythroid progenitor cells by direct cell-to-cell contact in a semisolid medium in the presence of erythropoietin. These layers also supported erythrocyte maturation and enucleation of erythroblasts. This suggests that spleen endothelial cells are a new type of stromal cell with erythropoietic stimulation activity and may have a critical function in the hemopoietic inductive microenvironment of the mouse spleen.View full abstractDownload PDF (3327K) -
Sunil C. Kaul, Gulshan R. Sapra1991 Volume 16 Issue 1 Pages 95-103
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSFine structural observations on heat shocked cells of S. mytilus reveal that cell organelles undergo structural alterations. Mitochondria show distorted shapes with disorganized cristae and vacuolar spaces. Pulse heat shock results in dilated rough endoplasmic reticulum, abundant polysomes as well as smooth endoplasmic reticulum. Heat shocked cells show membrane bound bodies containing osmiophilic cores. In macronuclei, dense chromatin breaks up into discrete bodies accompanied by the appearance of bundles of fine filaments and clustering of nuclear pores. The most prominent changes are noticed in nucleoli. Within 15 min of heat shock, nucleoli show hypertrophy and fine fibrillar zone which gradually replaces the granular zone by 120 min giving the nucleoli ring shaped configuration. In S phase cells, macronuclei show the arrested replication band in which the diffused zone (the site of DNA replication) is absent.View full abstractDownload PDF (4157K) -
Hideyo Yasuda, Masayuki Kamijo, Reiko Honda, Mayumi Nakamura, Fumio Ha ...1991 Volume 16 Issue 1 Pages 105-112
Published: 1991
Released on J-STAGE: March 27, 2006
JOURNAL FREE ACCESSA mouse temperature-sensitive mutant for cell growth, tsFT210, was characterized. More than 90 % of the mutant cells were arrested at the G2 phase at the nonpermissive temperature (39°C). In this mutant, the activity of cdc2 kinase did not increase at the nonpermissive temperature (39°C) but did increase at the permissive temperature (33°C) at the G2/M phase in the cell cycle. The in vitro activity of cdc2 kinase of tsFT210 was more thermolabile than that of wild-type cells. The amount of cdc2 kinase in tsFT210 cells decreased when the cells were incubated at 39 °C, but that in wild-type cells did not. Using the polymerase chain reaction (PCR), a point mutation in cDNA of cdc2 kinase was found in tsFT210, and as a result, the proline of wild-type cdc2 kinase at the 272 amino acid residues from N-terminal methionine changed to serine. During preparation of this paper, the detection of two mutation sites of this mutant was reported (Th'ng, J. P. H., Wright, P. S., Hamaguchi, J., Lee, M. G., Norbury, C. J., Nurse, P., and Bradbury, E. M. (1990). Cell, 63: 313-324); one was the same site as reported here, the other was A-to-G change in the 154th base from base A in initial ATG, and this caused the change of isoleucine to valine in the PSTAIR region of cdc2 kinase. This mutation in the PSTAIR region was not detected by us. The probable reason for this discrepancy was in that Th'ng and his group sequenced a cDNA cloned from the amplified cDNAs by PCR, and did not directly sequenc the amplified cDNA as we did.View full abstractDownload PDF (914K)
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