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51.
Coexistence of the genes for putrescine transport protein and ornithine decarboxylase at 16 min on Escherichia coli chromosome 总被引:9,自引:0,他引:9
K Kashiwagi T Suzuki F Suzuki T Furuchi H Kobayashi K Igarashi 《The Journal of biological chemistry》1991,266(31):20922-20927
The nucleotide sequence of one of the putrescine transport operons (pPT71), located at 16 min of the Escherichia coli chromosome, was determined. It contained the genes for an induced ornithine decarboxylase and a putrescine transport protein. The gene for the ornithine decarboxylase contained a 2,196-nucleotide open reading frame encoding a 732-amino acid protein whose calculated Mr was 82,414, and the predicted amino acid sequence from the open reading frame had 65% homology with that of a constitutive ornithine decarboxylase encoded by the gene at 64 min. The ornithine decarboxylase activity was observed in the cells carrying pPT71 cultured at pH 5.2, but not in the cells cultured at pH 7.0. The gene for the putrescine transport protein contained a 1,317-nucleotide open reading frame encoding a 439-amino acid protein whose calculated Mr was 46,494. The hydropathy profile of the putrescine transport protein revealed that it consisted of 12 putative transmembrane spanning segments linked by hydrophilic segments of variable length. The transport protein was in fact found in the membrane fraction. When the gene for the putrescine transport protein was linked to the tet promoter of the vector instead of its own promoter, the putrescine transport activity increased greatly. The results suggest that the gene expression of the operon is repressed strongly under standard conditions. 相似文献
52.
G R Grotendorst A Igarashi R Larson Y Soma M Charette 《Journal of cellular physiology》1991,149(2):235-243
We have compared the biological and biochemical properties of recombinant PDGF AA, AB, and BB using three types of fibroblastic cells: NIH/3T3, human skin fibroblast, and fetal bovine aortic smooth muscle. PDGF binding, receptor autophosphorylation, phosphatidyl inositol hydrolysis, as well as chemotactic and mitogenic responses of the cells were analyzed. PDGF-AB and PDGF-BB showed similar receptor binding, receptor autophosphorylation, and potent biological activity for all three of the cell types tested. In contrast, PDGF-AA was biologically active only for the NIH/3T3 cells in which binding sites for PDGF-AA were abundant, but was inactive for bovine aortic smooth muscle cells and human skin fibroblasts in which binding sites for PDGF-AA were absent. PDGF-AA could not induce any biochemical changes in the human skin fibroblasts or smooth muscle cells. Western blot studies with anti-Type alpha and beta PDGF receptor antibodies indicate that the NIH/3T3 cells contained both PDGF alpha and beta receptors, whereas the human skin fibroblasts and bovine smooth muscle cells contained only detectable levels of beta receptors. These results indicate that cells possessing high levels of PDGF beta receptors only are capable of responding equally well to either PDGF AB or BB. 相似文献
53.
A 1000-bp fragment of Enterococcus hirae genomic DNA was amplified by the polymerase chain reaction method, using the oligonucleotide primers designed from amino acid sequences of both amino-terminal and a tryptic fragment of the Na(+)-ATPase alpha-subunit in this organism. DNA sequencing of this product revealed that the amino acid sequence of Na(+)-ATPase alpha-subunit is highly homologous to the corresponding sequences of large (alpha) subunits of vacuolar (archaebacterial) type H(+)-ATPases, supporting our proposal [Kakinuma, Y. and Igarashi, K. (1990) FEBS Lett. 271, 97-101] that the Na(+)-ATPase of this organism belongs to the vacuolar-type ATPase. 相似文献
54.
Osmotic adaptation of Escherichia coli with a negligible proton motive force in the presence of carbonyl cyanide m-chlorophenylhydrazone. 总被引:2,自引:0,他引:2
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T Ohyama S Mugikura M Nishikawa K Igarashi H Kobayashi 《Journal of bacteriology》1992,174(9):2922-2928
It has been reported that Escherichia coli is able to grow in the presence of carbonyl cyanide m-chlorophenylhydrazone (CCCP) when ATP is produced by glycolysis (N. Kinoshita et al., J. Bacteriol. 160:1074-1077, 1984). We investigated the effect of CCCP on the osmotic adaptation of E. coli growing with glucose. When E. coli growing in rich medium containing CCCP was transferred to medium containing sucrose, its growth stopped for a while and then started again. This lag time was negligible in the absence of CCCP. The same results were obtained when the osmolarity was increased by N-methylglucamine-maleic acid. In addition to adapting itself to the hyperosmotic rich medium, E. coli adapted itself to hyperosmolarity in a minimal medium containing CCCP, again with a lag time. Hyperosmotic shock decreased the internal level of potassium ion rather than causing the accumulation of external potassium ion in the presence of CCCP. The internal amount of glutamic acid increased in cells growing in hyperosmotic medium in the presence and absence of CCCP. Large elevations in levels of other amino acids were not observed in the cells adapted to hyperosmolarity. Trehalose was detected only in hyperosmosis-stressed cells in the presence and absence of CCCP. These results suggest that E. coli can adapt to changes in the environmental osmolarity with a negligible accumulation of osmolytes from the external milieu but that the accumulation may promote the adaptation. 相似文献
55.
T Yutsudo H Murai J Gonzalez T Takao Y Shimonishi Y Takeda H Igarashi Y Hinuma 《FEBS letters》1992,308(1):30-34
A new type of mitogenic factor (protein) was purified from the culture supernatant of a strain of Streptococcus pyogenes by SP-Sephadex C-25 column chromatography, preparative isoelectric focusing and reversed-phase high-performance liquid chromatography. The purified factor, showing marked mitogenic activity in rabbit peripheral blood lymphocytes, gave a single-band staining for protein on SDS-PAGE. The molecular weight of the purified mitogenic factor was determined to be 25,370, which was different from those calculated from reported amino acid sequences deduced from 4 different nucleotide sequences of 3 kinds of streptococcal pyrogenic exotoxins (two SPEAs, SPEB and SPEC). The amino acid sequence of the N-terminal region of the purified mitogenic factor was determined to be Gln-Thr-Gln-Val-Ser-Asn-Asp-Val-Val-Leu-Asn-Asp-Gly-Ala-Ser-Lys-Tyr-Leu- Asn-Glu - Ala-, which was also different from the reported N-terminal sequences deduced from the 4 different nucleotide sequences. These data indicate that this mitogenic factor is distinct from the already described streptococcal pyrogenic exotoxins. 相似文献
56.
Target epitope in the Tax protein of human T-cell leukemia virus type I recognized by class I major histocompatibility complex-restricted cytotoxic T cells.
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M Kannagi H Shida H Igarashi K Kuruma H Murai Y Aono I Maruyama M Osame T Hattori H Inoko 《Journal of virology》1992,66(5):2928-2933
A trans-acting regulatory gene product p40tax (Tax) of human T-cell leukemia virus type I (HTLV-I) is one of the main target antigens recognized by cytotoxic T lymphocytes (CTL) specific for HTLV-I. A CTL epitope within the Tax protein was identified in this report. HTLV-I-specific CD8+ CTL lines established from two HTLV-I carriers with HTLV-I-associated myelopathy or Sj?gren syndrome were previously demonstrated to kill predominantly the target cells expressing HTLV-I Tax. The CTL from two patients showed significant levels of cytotoxicity to autologous target cells pulsed with a synthetic peptide of 24 amino acids corresponding to the amino-terminal sequences of the Tax protein. Allogeneic target cells were also sensitized for CTL by this peptide when the target cells have HLA-A2. Tax-specific cytotoxicity, detected as cytolysis of the target cells infected with vaccinia virus-HTLV-I recombinant expressing Tax protein, was almost completely inhibited by competitor cells pulsed with the synthetic peptide. This indicates that a major CTL epitope is present in this peptide. Further analysis using shorter peptides revealed that the core sequence of the CTL epitope was LLFGYPVYV at positions 11 through 19. This sequence can be aligned with the HLA-A2-specific motifs reported recently. 相似文献
57.
M Itoh M Igarashi K Yamada Y Hasegawa M Seki Y Eto H Shibai 《Biochemical and biophysical research communications》1990,166(3):1479-1484
The effect of activin A on meiotic maturation was analyzed in oocytes from immature rats treated with PMSG. Activin A, which was purified as the erythroid differentiation factor, accelerated the maturation of not only follicle-enclosed oocytes and oocyte-cumulus complexes, but also denuded oocytes, as measured by an increase in the percentage of oocytes with germinal vesicle breakdown (GVBD). Oocyte maturation was not accelerated by activin A in the presence of the inhibitor of GVBD such as cyclic-AMP. These results showed activin A is a potent in vitro stimulator of oocyte maturation. 相似文献
58.
Mast cells contain spleen-type prostaglandin D synthetase 总被引:2,自引:0,他引:2
Y Urade M Ujihara Y Horiguchi M Igarashi A Nagata K Ikai O Hayaishi 《The Journal of biological chemistry》1990,265(1):371-375
Prostaglandin D synthetase activity in the cytosol (100,000 x g, 1-h supernatant) fraction of peritoneal mast cells of adult rats (105.0 nmol/min/mg protein) was the highest among such activities in various rat tissues and cells. As judged by the absolute requirement for glutathione for the reaction (Km = 300 microM), the Km value for prostaglandin H2 (200 microM), and insensitivity of the activity to 1 mM 1-chloro-2,4-dinitrobenzene, the enzyme in mast cells was similar to rat spleen prostaglandin D synthetase and differed from rat brain prostaglandin D synthetase or glutathione S-transferase, all of which catalyze the isomerase reaction from prostaglandin H2 to prostaglandin D2. In immunotitration analyses, the activity in mast cells showed a titration curve exactly identical with that of the purified spleen-type enzyme and almost completely absorbed by an excess amount of antibody against this enzyme, but it remained unchanged after incubation with antibodies against the brain-type enzyme and glutathione S-transferase isozymes thus far purified. In Western blot after two-dimensional electrophoresis of crude extracts of mast cells, a single immunoreactive spot was observed with antibody against the spleen-type enzyme at the same position as that of the purified enzyme (Mr = 26,000, pI = 5.2). Furthermore, the immunoreactive protein obtained from mast cells showed the same peptide fingerprints as those of the purified spleen-type enzyme, after partial digestion with Staphylococcus aureus V8 protease or trypsin. In immunoperoxidase staining, the immunoreactivity of the spleen-type enzyme was found in the cytosol of tissue mast cells in various organs such as thymus, intestine, stomach, and skin of adult rats. These findings indicate that prostaglandin D2 is produced by the spleen-type synthetase in mast cells of various tissues. 相似文献
59.
Species specificity of the radioreceptor assay (RRA) for rat FSH, in which pregnant mare serum gonadotropin (PMSG)-treated immature rat ovary was employed as the receptor, was compared with that of NIAMDD rat FSH radioimmunoassay (RIA). In the RIA system, pituitary preparations from mammals only showed significant crossreaction. Their inhibition curves, however, were not always parallel to the standard curve. On the other hand, in the RRA system, the pituitary preparations from mammals, avians, lizard and amphibians competitively inhibited the binding of radioactive rat FSH to the ovarian receptor. Only the pituitary preparation from dog salmon failed to show any crossreaction in the RRA system. These results indicated that this RRA system would be useful for the measurement of FSH or gonadotropins of the pituitaries from mammals to amphibians. 相似文献
60.
M Kitada K Igarashi S Hirose H Kitagawa 《Biochemical and biophysical research communications》1979,87(2):388-394
Both NADPH- and ascorbic acid-dependent lipid peroxidations were inhibited by spermine, the degree of inhibition being greater with the former peroxidation. The effective concentration of spermine required for inhibition was higher when larger amounts of microsomes were used. However, the activities of NADPH-cytochrome c reductase and NADPH-peroxidase were not influenced by spermine. These results suggest that spermine inhibits lipid peroxidation by binding to phospholipids in the microsomes. 相似文献