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Volume 134 (2003)
- Issue 6 Pages 773-
- Issue 5 Pages 625-
- Issue 4 Pages 479-
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- Issue 2 Pages 175-
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Volume 134, Issue 5
Displaying 1-18 of 18 articles from this issue
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Tadashi Uemura, Yuko Shimada2003 Volume 134 Issue 5 Pages 625-630
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSIn many organs, epithelial cells are polarized not only along the apicobasal axis, but also along a second axis within a plane. Acquisition of the latter polarity, known as planar cell polarity (PCP) or tissue polarity, is crucial for specialized cellular functions. Genetic programming of PCP has been most thoroughly studied in Drosophila, which has allowed identification of a number of regulatory molecules that are evolutionally conserved. One group of the regulators is responsible for interpreting a hypothetical polarity cue and directing local cytoskeletal reorganization. This group includes a seven-pass transmembrane cadherin known as Flamingo (also known as Starry night), other receptors, and downstream components; and many of those molecules are redistributed to restricted subcellular compartments. Recent studies on a trio of cell-surface molecules challenge a previous hypothesis about the identity of the polarity cue and prompt a novel hypothesis about a global input. Studies on vertebrate systems support the notion that the molecular mechanisms demonstrated in Drosophila are applicable to at least two classes of polarized behaviors of vertebrate cells: sensory hair morphogenesis in the inner ear epithelium, and convergent extension movements during gastrulation.View full abstractDownload PDF (4032K) -
Kazuya Shimizu, Yoshimi Takai2003 Volume 134 Issue 5 Pages 631-636
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe nectin family comprises four Ca2+-independent immunoglobulin-like cell-cell adhesion molecules. Each nectin homophilically and heterophilically trans-interacts and causes intercellular adhesion, which organizes a variety of intercellular junctions in cooperation with, or independently of, cadherin. Nectin furthermore induces activation of Cdc42 and Rac small G proteins through c-Src, which eventually regulates formation of the cadherin-based adherens junctions through reorganization of the actin cytoskeleton, gene expression through activation of a mitogen-activated protein kinase cascade, and cell polarization through cell polarity proteins. We describe here the roles of nectin in intracellular signaling.View full abstractDownload PDF (3360K) -
Seiki Baba, Ken-ichi Takahashi, Yoshio Koyanagi, Naoki Yamamoto, Hiros ...2003 Volume 134 Issue 5 Pages 637-639
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe nucleocapsid protein of HIV-1 consists of two basic amino acid regions and two zinc fingers. We investigated the requirement of these domains for the structural conversion of a 39 mer RNA covering the dimerization initiation site by using three peptides; wild-type NCp 7, a mutant in which the two zinc fingers are mutated, and another mutant in which the two zinc fingers are deleted. The two mutants exhibited similar conversion activities to each other, which were lower than that of the wildtype, indicating that the two basic regions exhibit some activity for RNA chaperone, as we suggested before, and the zinc fingers enhance the efficiency of this activity.View full abstractDownload PDF (1305K) -
Francoise Guéraud, Denis Daveloose, Hervé Vezin, Jacques ...2003 Volume 134 Issue 5 Pages 641-653
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe effects of growth hormone on the uridine diphosphate glucuronosyltransferase functional state, biophysical membrane parameters (order parameters and rotational correlation frequency) and the composition in phospholipids were studied in male rat hepatic microsomes. Sham-operated and hypophysectomized animals were injected with two different dosages of growth hormone, mimicking either the male or female growth hormone secretion pattern. Half the animals received thyroxine and cortisol in concentrations chosen to compensate for the lack of thyroid hormones and glucocorticoids in hypophysectomized rats. Growth hormone treatment resulted in a decrease in the latency (that gives a quantification of uridine diphosphate glucuronosyltransferase functional state) of the glucuronidation activities towards various substrates (testosterone, androsterone, bilirubin and 4-nitrophenol). This decrease with growth hormone treatment was particularly evident in hypophysectomized animals that had received cortisol and thyroxine supplementation treatment. These modifications were strongly correlated with modifications in the microsomal membrane lysophospholipid content and to a lower extent with microsomal membrane fatty acid composition. The cytosolic phospholipase A2-dependent increase in the lysophospholipid content in the endoplasmic reticulum is probably a major determinant in the regulation of the functional state of glucuronoyltransferases in response to high dosage growth hormone treatment.View full abstractDownload PDF (1570K) -
Régis Chambert, Yannick Pereira, Marie-Francoise Petit-Glatron2003 Volume 134 Issue 5 Pages 655-660
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSYfkN isolated from the culture supernatant of Bacillus subtilis in the exponential phase of growth is a protein of 143.5 kDa that derives from a putative large precursor of 159.6 kDa processed at both the N- and C-terminal ends. Pulse-chase experiments indicated that the release occurs slowly with a half-time longer than 30min, suggesting that the event is coupled with wall turnover. YfkN exhibits 2', 3' cyclic nucleotide phosphodiesterase, 2' (or 3') nucleotidase and 5' nucleotidase activities. In vitro the protein is reduced by subtilisin digestion to a shorter polypeptide (68 kDa), displaying phosphodiesterase activity but devoid of any 5' nucleotidase activity. This proteolytic processing led us to localize the potential active sites of the various nucleotidase activities. When bacteria were grown in low phosphate medium, the exocellular production of the enzyme was enhanced, suggesting that it plays a role in phosphate metabolism. Comparison with nucleotidase databases suggests that yfkN resulted from gene fusion.View full abstractDownload PDF (3724K) -
Olin D. Liang, Khalil Bdeir, Rachel L. Matz, Triantafyllos Chavakis, K ...2003 Volume 134 Issue 5 Pages 661-666
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe glycolipid-anchored urokinase-type plasminogen activator receptor (uPAR) is engaged in various signal transduction events related to cell adhesion, migration and proliferation. In this study, using phage display and peptide array techniques, we have identified several intermolecular contact regions of uPAR. Phage-displayed uPAR fragments bound to immobilized soluble uPAR on magnetic beads, revealing that regions uPAR-(7-28) and uPAR-(60-91) in domain I, uPAR-(101-121) in domain II and uPAR-(240-260) in domain III are possible uPAR-uPAR contact sites. Using peptide array, two additional sites could be identified, uPAR-(51-59) in domain I and uPAR-(144-155) in domain II. The putative uPAR-uPAR interaction sites are different from the previously identified uPA-binding sites. Functionally, peptides uPAR-(84-95) and uPAR-(240-248) could partially inhibit differentiated human U 937 monocyte adhesion to vitronectin in the presence of uPA, indicating that these two uPAR regions might be involved not only in uPAR-uPAR but also in uPAR-vitronectin interactions. We propose that multiple uPAR-uPAR ectodomain interactions contribute considerably to the regulation of various cellular functions of uPAR.View full abstractDownload PDF (1765K) -
Takayuki Kohno, Yasuyuki Igarashi2003 Volume 134 Issue 5 Pages 667-673
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe endothelial cell-expressed sphingosine 1-phosphate receptors Edg-1/S1P1 and Edg-3/S1P3 have been implicated in various physiological events such as the regulation of angiogenesis. Since there is an excess of a ligand constitutively in blood, these receptors may have some mechanism (s) avoiding overstimulation. In this study, we found that the N-terminal ectodomains of Edg-1/S1P1 and Edg-3/S1P3 were truncated in overexpressing cells. The truncated form of Edg-1/S1P1 expressed on the cell surface had undergone complex-type oligosaccharide modification at the Golgi. A deletion mutant lacking the N-terminal processing domain of Edg-1/S1P1 accumulated in the endoplasmic reticulum, and was not expressed on the cell surface. When a basic amino acid residue was introduced at the cleavage site of Edg-1/S1P1, the molecular weight of the glycosylated protein was greater in the mutant compared to the wild type, due to the bound oligosaccharide. These results demonstrated that the structure of the N-terminal ectodomain of Edg-1/S1P1 affects both its transport to the cell surface and the N-glycosylation process. Ectodomain shedding of many membrane proteins has been implicated in various diseases. Therefore, N-terminal processing of Edg-1/S1P1 and Edg-3/S1P3 might play roles in endothelial cell functions.View full abstractDownload PDF (6530K) -
Libera Lo Presti, Erik Cabuy, Mariella Chiricolo, Fabio Dall'Olio2003 Volume 134 Issue 5 Pages 675-682
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe Sda antigen is a carbohydrate determinant expressed on erythrocytes, the colonic mucosa and other tissues. This epitope, whose structure is Siaa2, 3 [GalNAcβ1, 4] Gal β1, 4 GlcNAc, is synthesized by a β1, 4 N-acetylgalactosaminyltransferase (β4 GalNAc-T) that transfers a β1, 4-linked GalNAc to the galactose residue of an α2, 3-sialylated chain. We have cloned from human colon carcinoma Caco 2 cells a cDNA whose transfection in COS cells induces a GaINAc-T active on sialylated but not on asialylated fetuin and putatively represents the human Sda β4 GalNAc-T. The cDNA predicts a 566 as protein showing 66.6% and 39% identity with mouse CT β4 GalNAc-T and human GM2/GD2 synthase, respectively, with a typical type II glycosyltransferase organization, no potential N-glycosylation sites and a 67 as cytoplasmic tail, which is probably the longest among the glycosyltransferases cloned to date. The gene maps in chromosome 17 q 23, and is composed of at least 11 exons. Exons 2-11 are homologous to exons 2-11 of the previously cloned CT β4GalNAc-T from murine cytotoxic T lymphocytes while exons 1 of the two enzymes are totally different. The mRNA is expressed at a high level in differentiated Caco 2 cells and in colonic mucosa and at a much lower level in lymphocytes and other colon cancer cell lines.View full abstractDownload PDF (4681K) -
Hiroshi Oneda, Kuniyo Inouye2003 Volume 134 Issue 5 Pages 683-690
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSBovine erythrocyte Cu, Zn-superoxide dismutase (BESOD) is a dimeric enzyme composed of identical subunits associated through unusually strong non-covalent interactions. The state of the unique tyrosyl residue (Tyr 108) of BESOD was examined, and the kinetics of subunit exchange was studied using Tyr 108 as a probe. UV absorption difference spectra demonstrate that Tyr 108 is exposed to the solvent, and that the accessibilities to ethanol, ethylene glycol, and polyethylene glycol 600 are 53.5, 52.0, and 44.6%, respectively. Tyr 108 was fully nitrated by tetranitromethane. The pKa values of the phenolic hydroxyl group of native and nitrated Tyr 108 were determined to be 11.3 and 7.9, whereas those of model compounds, L-tyrosine and 3-nitro-L-tyrosine, are 9.8 and 6.8, respectively. When the native and nitrated BESODs of an equal concentration were mixed, the hybrid dimer was formed. From the amount of hybrid dimer formed, the rate constant (k-1) of the subunit dissociation at pH 7.8, 25°C was assessed to be (4.17±0.13)×10-6 s-1. The activation energy of the subunit dissociation at pH 7.8 was determined to be 117±4 kJ•mol-1. The k-1 value remains constant at BESOD concentrations ranging from 0.62 to 6.8 μM and at pH ranging from 6.0 to 10.0, but increased remarkably with a decrease in the dielectric constant of the reaction mixture. It is suggested that hydrophobic interaction may play a significant role in the subunit interaction.View full abstractDownload PDF (980K) -
Atsuhiro Arai, Eiji Kawachi, Michihiro Hata, Mitsuo Ogura, Teruo Tanak ...2003 Volume 134 Issue 5 Pages 691-697
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSExpression of the Bacillus subtilis alkaline protease gene aprE is controlled by many positive and negative regulators at the transcriptional level. During the course of screening for organic compounds that affect the expression of a translational aprE'-_??_lacZ fusion, we found that lincomycin (Lm), erythromycin and chloramphenicol exhibited an inhibitory effect in concentrations that hardly affected cell growth. The antibiotics are known to inhibit protein synthesis by binding to ribosomes. We chose one of them, Lm, for further study. We have previously shown that aprE expression requires guanosine 3', 5'-bisdiphosphate (ppGpp) synthesized on the ribosome by the stringent factor RelA. An examination of Lm-treated cells showed that the levels of ppGpp were greatly reduced in these cells, and the inhibitory effect of the antibiotic was not seen in relA-disruption mutants. Transcriptional levels of aprE, however, were not influenced by Lm treatment as shown by using a transcriptional aprE-lacZ fusion as well as quantitative RT PCR. Furthermore, disruption of relA did not affect the expression of transcriptional aprE-lacZ. From these results, we conclude that aprE expression is controlled by the stringent control at the posttranscriptional level, and that Lm inhibits this process by inhibiting ppGpp synthesis on the ribosome.View full abstractDownload PDF (2093K) -
Rei Kikuchi-Yanoshita, Yoshitaka Taketomi, Kumiko Koga, Toshihiko Sugi ...2003 Volume 134 Issue 5 Pages 699-709
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSCoculture of mouse bone marrow-derived immature mast cells (BMMC) with Swiss 3T3 fibroblasts in the presence of stem cell factor (SCF) promotes morphological and functional maturation toward a connective tissue mast cell (CTMC)-like phenotype, which is accompanied by increased expression of several unique genes. Here we report the molecular identification of one of them, mast cell maturation-associated inducible gene (MMIG)-1. The MMIG-1 cDNA encodes a 117-kDa cytosolic protein that comprises an N-terminal PYRIN domain, a central nucleotide-binding domain, and nine C-terminal leucine-rich repeats. MMIG-1 shows >85% sequence similarity to human cryopyrin/PYPAF 1, a causal gene for familial cold urticaria and Muckle-Wells syndrome. MMIG-1 was distributed in the cytosol of CTMC-like differentiated BMMC. MMIG-1 underwent alternative splicing in the leucine-rich repeats and each variant was induced differently in BMMC during coculture. Moreover, its expression was increased in the ears of mice with experimental atopic dermatitis. Thus, MMIG-1, a likely mouse PYPAF 1 ortholog, may play a role in mast cell-directed inflammatory diseases.View full abstractDownload PDF (5047K) -
Yasushi Kaneko, Haruo Takeshita, Kouichi Mogi, Tamiko Nakajima, Toshih ...2003 Volume 134 Issue 5 Pages 711-718
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe DNase I from canine pancreas was purified 260-fold to electrophoretic homogeneity with a 35% yield using three-step column chromatography. The activity of the purified enzyme was completely inhibited by 20mM EDTA, an antibody specific to the purified enzyme and G-actin. A 1, 373-bp cDNA encoding canine DNase I was constructed from the total canine pancreatic RNA using a rapid amplification of cDNA ends method, followed by sequencing. The mature canine DNase I protein was found to consist of 262 amino acids. A survey of DNase I in 13 different canine tissues revealed the highest levels of both DNase I enzyme activity and gene expression in the pancreas; therefore, the canine DNase I is of the pancreatic type. Phylogenetic and sequence identity analyses, studies of immunological properties and the tissuedistribution patterns of DNase I indicated that the canine enzyme is more closely related to the human DNase I than to other mammalian DNases I. Therefore, canine DNase I is found to be one of the best substitutes in studies of human DNase I.View full abstractDownload PDF (1991K) -
Kyosuke Sato, Yasuzo Nishina, Kiyoshi Shiga2003 Volume 134 Issue 5 Pages 719-729
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSElectron-transferring flavoprotein (ETF), its redox partner flavoproteins, i.e., D-lactate dehydrogenase and butyryl-CoA dehydrogenase, and another well-known flavoprotein, flavodoxin, were purified from the same starting cell paste of an anaerobic bacterium, Megasphaera elsdenii. The purified ETF contained one mol FAD/mol ETF as the sole non-protein component and bound almost one mol of additional FAD. This preparation is a better subject for investigations of M. elsdenii ETF than the previously isolated ETF, which contains varying amounts of FAD and varying percentages of modified flavins such as 6-OH-FAD and 8-OH-FAD. The additionally bound FAD shows an anomalous absorption spectrum with strong absorption around 400 nm. This spectral change is not due to a chemical modification of the flavin ring because the flavin released by KBr or guanidine hydrochloride is normal FAD. It is also not due to unknown small molecules because the same spectrum appears when ETF is reconstituted from its guanidine-denatured subunits and FAD. A similar anomalous spectrum was observed for AMP-free pig ETF under acidic conditions, suggesting a common flavin environment between pig and M. elsdenii ETFs.View full abstractDownload PDF (1390K) -
Pik-Yuen Cheung, Chi-Chun Fong, Kang-To Ng, Wan-Chuen Lam, Yun-Chung L ...2003 Volume 134 Issue 5 Pages 731-738
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe interactions of two pyridoxal-5-phosphate (PLP)-dependent enzymes, alanine aminotransferase (ALT) and glutamate decarboxylase (GAD), with pyridoxal kinase (PK) were studied by fluorescence polarization as well as surface plasmon resonance techniques. The results demonstrated that PK can specifically bind to ALT and GAD. Moreover, binding profiles of both enzymes to immobilized PK were altered by excess amount of PLP. The equilibrium affinity constants for ALT in the absence and presence of PLP are 20.4×104 Wand 6.7×104M-1, and for GAD are 37×104 M-1 and 20.8×104M-1, respectively. It appears that specific interactions occur between PK and PLP-dependent enzymes, and the binding affinities of PK for PLP-dependent enzymes decrease in the presence of PLP. The results support our hypothesis that PLP transfer from PK to PLP-dependent enzymes requires a specific interaction between PK and the enzyme.View full abstractDownload PDF (2076K) -
Weon-Kyoo You, Hyun-Ji Seo, Kwang-Hoe Chung, Doo-Sik Kim2003 Volume 134 Issue 5 Pages 739-749
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSA novel hemorrhagic metalloprotease, halysase, isolated from the snake venom of Gloydius halys induces apoptosis in endothelial cells. The purified metalloprotease is a monomeric glycoprotein with an isoelectric point of 4. 8. Analysis of the cDNA sequence encoding halysase revealed that the enzyme consists of multifunctional domains including a proprotein domain, a protease domain, a disintegrin-like domain and a cysteine-rich domain. The metalloprotease has a DECD sequence in the disintegrin-like domain instead of the typical RGD sequence. Halysase strongly inhibits proliferation of human umbilical vein endothelial cells in a dose-dependent manner as well as adhesion of the cells to extracellular matrix proteins. The enzyme specifically hydrolyzes not only extracellular matrix proteins such as fibronectin, vitronectin, and type IV collagen, but also integrins α1β1 and α5α1. The apoptosis of endothelial cells induced by halysase is closely associated with activation of caspase-3 and decreased level of Bcl-XL/Bax. Apohalysase, which lacks metalloprotease activity, is also able to induce the apoptosis. Several lines of experimental evidence suggest that the protease domain and the disintegrin-like domain of halysase cooperatively contribute to the induction of endothelial cell apoptosis.View full abstractDownload PDF (7557K) -
Masayuki Arakawa, Masataka Shiozuka, Yuki Nakayama, Takahiko Hara, Mas ...2003 Volume 134 Issue 5 Pages 751-758
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe ability of aminoglycoside antibiotics to promote read-through of nonsense muta diseases. However, the toxicity of aminoglycoside antibiotics may result in severe side effects during long-term treatment. In this paper, we report that negamycin, a dipeptide antibiotic, also restores dystrophin expression in skeletal and cardiac muscles of the mdx mouse, an animal model of Duchenne muscular dystrophy (DMD) with a nonsense mutation in the dystrophin gene, and in cultured mdx myotubes. Dystrophin expression was confirmed by immunohistochemistry and immunoblotting. We also compared the toxicity of negamycin and gentamicin, and found negamycin to be less toxic. Furthermore, we demonstrate that negamycin binds to a partial sequence of the eukaryotic rRNA-decoding A-site. We conclude that negamycin is a promising new therapeutic candidate for DMD and other genetic diseases caused by nonsense mutations.View full abstractDownload PDF (3305K) -
Xianfeng Zhang, Masami Yamada, Naoto Mabuchi, Hisatoshi Shida2003 Volume 134 Issue 5 Pages 759-764
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSWe studied the cellular requirements for the translocation of CRM 1 (exportin 1) between the nucleus and the cytoplasm. CRM 1 import requires neither ATP, Ran, Ran-dependent GTP hydrolysis, nor a particular temperature. CRM 1 and importin β compete with each other during their import. Thus, CRM 1 is able to enter the nucleus in a manner similar to importinβ. In contrast, the in vivo export of CRM 1 involves ATP-consuming step (s).View full abstractDownload PDF (3469K) -
Melinda J. Maver, Anthonv J. Michapl2003 Volume 134 Issue 5 Pages 765-772
Published: 2003
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSIt was reported recently that overexpression of human ornithine decarboxylase (ODC) cDNA in transgenic rice plants resulted in increased steady-state concentration of polyamines, i.e., enough biosynthetic control is invested at this step to enable adjustment of polyamine levels. To investigate critically whether constitutive overexpression of ODC is sufficient to control steady-state polyamine levels, we expressed an ODC cDNA from Datura stramonium in transgenic tobacco plants. Transgenic progeny of self-fertilised primary transformants exhibited increases in ODC activity of 25-fold in leaves and 5-fold in Rower buds. However, the increase in putrescine levels was only 1.5- to 2.1-fold in leaves and 1.1- to 1.3-fold in Rower buds. Emphatically, no changes to spermidine or spermine steady-state levels or to soluble or insoluble hydroxycinnamic acid-conjugated polyamines were observed. Ornithine feeding to cell suspension cultures derived from the transgenic plants indicated that putrescine accumulation was limited in part by ornithine availability. These results demonstrate that a large increase in the capacity of the tobacco plants to decarboxylate ornithine does not result in a comparable increase in the level of free or conjugated polyamines. Plant polyamine homeostatic mechanisms efficiently accommodate increased ODC activity, suggesting that polyamine biosynthetic control is invested at multiple interdependent steps.View full abstractDownload PDF (4887K)
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