共查询到20条相似文献,搜索用时 15 毫秒
1.
Bettina Hause Uta zur Nieden J. Lehmann C. Wasternack B. Parthier 《Plant biology (Stuttgart, Germany)》1994,107(5):333-341
The plant growth substance jasmonic acid and its methyl ester (JA-Me) induce a set of proteins (jasmonate-induced proteins, JIPs) when applied to leaf segments of barley (Hordeum vulgare L. cv. Salome). Most of these JIPs could be localized within different cell compartments by using a combination of biochemical and histochemical methods. Isolation and purification of various cell organelles of barley mesophyll cells, the separation of their proteins by one-dimensional polyacrylamide gel electrophoresis and the identification of the major abundant JIPs by Western blot analysis, as well as the immuno-gold labelling of JIPs in ultrathin sections were performed to localize JIPs intracellularly. JIP-23 was found to be in vacuoles, peroxisomes, and in the granular parts of the nucleus as well as within the cytoplasm; JIP-37 was detected in vacuoles and in the nucleoplasm; JIP-66 is a cytosolic protein. Some less abundant JIPs were also localized within different cell compartments: JIP-100 was found within the stromal fraction of chloroplasts; JIP-70 is present in the peroxisome and the nucleus; JIP-50 and JIP-6 accumulate in vacuoles. The location of JIP-66 and JIP-6 confirms their possible physiological role deduced from molecular analysis of their cDNA. 相似文献
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Tanjina Sharmin Tomomitsu Satho Keiichi Irie Mineo Watanabe Masato Hosokawa Yukihiro Hiramatsu Parimal Talukder Takahiro Okuno Shodai Tsuruda Saori Uyeda Yuki Fukmits Yukie Tamura Yukihiko Nakashima Masumi Imoto Akihisa Toda Nobuhiro Kashige Fumio Miake 《Microbiology and immunology》2013,57(4):316-322
Pyriproxyfen is a juvenile hormone mimic of vital importance for insect development with little risk to humans. This study was performed to investigate whether large doses of pyriproxyfen affect the immune response in mammals. Mice were immunized thrice with ovalbumin in 5% ethanol, with or without pyriproxyfen or alum. Large doses of pyriproxyfen (9 or 15 mM) significantly enhanced specific total IgG immune response. This enhancement was no longer present 24 hr after treatment with pyriproxyfen. These results suggest that pyriproxyfen is a safe chemical. Moreover, pyriproxyfen induced higher titers of IgG2a and enhanced tumor necrosis factor‐alpha and gamma‐interferon responses whereas alum induced IgG1 with enhanced interleukin‐4 and ‐10. These observations indicate that the mechanism of immune enhancement by pyriproxyfen may differ from that of alum. 相似文献
4.
Chromatographic, kinetic and regulatory properties of glutamine synthetase (GS) were investigated in root nodules of Alnus glutinosa L. (Gaertn) grown in a culture chamber. By DEAE Sephacel column chromatography and polyacrylamide gel electrophoresis, a major form of the enzyme was identified. Molecular weight was about 360 000 for the native protein and 43 000 for the subunits. Optimum pH was about 7.3 and Km for glutamate and ATP were 0.9 m M and 0.5 m M , respectively. By immunofluorescent techniques GS was localized in the inner cortical cells but not in vesicles of alder root nodules. 相似文献
5.
Mauro Magnani Giordano Serafini Rita Crinelli Antonella Antonelli Manuela Malatesta Giancarlo Gazzanelli 《Molecular and cellular biochemistry》1993,122(2):123-132
Hexokinase in mammalian brain is particulate and usually considered to be bound to the outer mitochondrial membrane. Investigation of rabbit brain mitochondria prepared either by differential centrifugation and discontinuous density gradient centrifugation has provided evidence that this particulate fraction also contains endoplasmic vesicles and synaptosomes. Solubilization of the bound hexokinase by different combinations of detergents and metabolites has proved the existence of different hexokinase binding sites. Electron microscopic examination of hexokinase location by immuno-gold labelling techniques confirmed, that hexokinase is indeed predominantly bound to mitochondria but that a significant proportion is also bound to non-mitochondrial membranes. Attempts to quantify this distribution were unsuccessful since different figures were obtained using anti-hexokinase IgG affinity purified on immobilized native or denatured hexokinase. Binding studies of the purified rabbit brain mitochondrial hexokinase to rabbit liver mitochondria and microsomes confirmed that in addition to a binding site on mitochondria there is another binding site on microsomes. The N-terminal sequence of hexokinase has been shown to be important for mitochondria binding and also for microsome binding. These results suggest that the intracellular localization of hexokinase in rabbit brain is not exclusively mitochondrial and that the metabolic role of this enzyme should be reconsidered by including a binding site on the endoplasmic reticulum. 相似文献
6.
Chemiluminescence energy transfer: a new technique applicable to the study of ligand--ligand interactions in living systems 总被引:1,自引:0,他引:1
Chemiluminescent molecules can be readily detected in the range 10(-15) to 10(-18) mol, and potentially at least down to 10(-20) mol reacting/s. The chemiluminescent compound aminobutylethylisoluminol (ABEI) and its isothiocyanate derivative have been synthesized. The ABEI was coupled to rabbit immunoglobulin and cyclic AMP. These labeled antigens were stable for at least 9 months and were used to establish chemiluminescent immunoassays. When these chemiluminescent-labeled antigens bound to their respective fluorescein-labeled antibodies, a wavelength shift towards the green was detected in the chemiluminescence. This was due to chemiluminescence energy transfer and used to establish an homogenous immunoassay which could measure these antigens in biological samples at least as sensitively as conventional radioimmunoassays. 相似文献
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The receptors for aggregated immunoglobulin G (IgG) (an Fc receptor) and for ristocetin-von Willebrand factor on human platelets were studied by means of various modifications of the platelet surface. The expression of these receptors was measured by the agglutination of platelets to ristocetin in the presence of von Willebrand factor, which is part of the factor VIII complex, and by the binding of aggregated IgG coupled to 3H-labelled diazobenzen. Treatment of platelets with chymotrypsin, trypsin, papain and pronase which removed protein and glycoprotein from the platelet under conditions where the release reaction was inhibited caused loss of the expression of the receptor for ristocetin-von Willebrand factor and an enhancement of that for aggregated IgG. Induction of membrane changes with ADP and of the release reaction with the ionophore A23187 abolished agglutination to ristocetin-von Willebrand factor but did not alter the receptor for aggregated IgG. Possible contributions of unspecific membrane changes, produced by protease treatment of platelets, to the modification of receptor expression were eliminated by the use of formaldehyde-treated platelets. Trypsin, papain and pronase destroyed the ability of these platelets to agglutinate to ristocetin-von Willebrand factor but produced no change in the binding of aggregated IgG. Therefore, the receptor for ristocetin-von Willebrand factor is truly sensitive to proteolysis while the Fc receptor is not, but is partially masked by protease-sensitive material. 相似文献
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Thomas Southworth Andrew Higham Umme Kolsum Jian Li Thomas Scott Josiah Dungwa Sriram Sridhar Tuyet-Hang Pham Paul Newbold Dave Singh 《Journal of cellular and molecular medicine》2021,25(4):2203-2212
In chronic obstructive pulmonary disease (COPD), the effects of inhaled corticosteroids are predicted by blood eosinophil counts. We previously briefly reported increased immunoglobulin (Ig)A and IgM levels in bronchoalveolar lavage (BAL) of COPD patients with higher (eosinophilhigh) compared to lower (eosinophillow) blood eosinophils (>250/μL versus < 150/μL), suggesting differences in adaptive immune function. An inverse relationship exists between eosinophil counts and airway pathogenic bacteria levels. The mechanistic reasons for these associations between eosinophils, corticosteroids and pathogenic bacteria are unclear. IgA, IgM and IgG levels were assessed in BAL, bronchial biopsies and epithelium collected from eosinophilhigh (n = 20) and eosinophillow (n = 21) patients. Bronchial B-cell numbers were measured by immunohistochemistry. B-cell activity was assessed in bronchial samples and following exposure to BAL from eosinophilhigh and eosinophillow patients. BAL levels of non-typeable Haemophilus influenza (NTHi)-specific immunoglobulins were quantified. Results showed airway expression of IgA, IgG1 and IgM were lower in eosinophillow compared to eosinophilhigh patients, with lower levels of NTHi-specific IgA and IgM. Bronchial B-cell numbers were similar in both groups, but B-cell activity was lower in eosinophillow patients. In conclusion, COPD eosinophillow patients show differences in adaptive immune function compared to COPD eosinophilhigh patients. These differences may cause different microbiomes in these COPD phenotypes. 相似文献
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Glaezel Angelique Torres-Barredo Hotaka Atarashi Akinobu Kajikawa Aiko Hirata Akihito Endo 《Bioscience, biotechnology, and biochemistry》2018,82(5):916-925
Sirtuin has been associated in prolonging lifespan of different model organisms. It has been shown to have an enzymatic activity of NAD+-dependent protein deacetylation targeting acetylated proteins. To determine targets and possible roles of sirtuin (LpSirA) in the Lactobacillus paracasei BL23, deletion (ΔsirA), sirtuin overexpressor (highsirA) and GFP fusion (highsirA-Venus) strains were generated, and microscopic localization and cell length analysis were done. Microscopic analysis revealed localization of LpSirA at cell division plates, at cell poles and all throughout the cell length in a spiral manner. Cell length analysis revealed that 46.9% of the ΔsirA cells were observed to be shorter (<2 μm), whereas 12.6% of the highsirA cells were observed to be longer (>4 μm) in comparison with the wild-type with only 17.1% short cells and 5.3% long cells. Our results suggest that sirtuin may have an essential role in cell division and cell shape regulation. 相似文献
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Di Pietro R Mariggiò MA Guarnieri S Sancilio S Giardinelli A Di Silvestre S Consoli A Zauli G Pandolfi A 《Journal of cellular biochemistry》2006,97(4):782-794
We have recently demonstrated that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) increases endothelial nitric oxide synthase (eNOS) phosphorylation, NOS activity, and nitric oxide (NO) synthesis in cultured human umbilical vein endothelial cells (HUVEC), without inducing apoptotic cell death. Although an important factor that regulates eNOS activity is its localization within the cells, little is known about the role of TRAIL in the regulation of eNOS trafficking among cellular compartments and the cytoskeleton involvement in this machinery. Then, we did both quantitative and semi-quantitative evaluations with biochemical assays and immune fluorescence microscopy in the presence of specific inhibitors of NOS activity as well as of cytoskeletal microtubule structures. In our cellular model, TRAIL treatment not only increased NO levels but also caused a time-dependent NO migration of fluorescent spots from the plasma membrane to the inner part of the cells. In unstimulated cells, most of the eNOS was localized at the cell membranes. However, within 10 min following addition of TRAIL, nearly all the cells showed an increased cytoplasm localization of eNOS which appeared co-localized with the Golgi apparatus at a higher extent than in unstimulated cells. These effects were associated to an increased formation of trans-cytoplasm stress fibers with no significant changes of the microtubule network. Conversely, microtubule disruption and Golgi scattering induced with Nocodazole treatment inhibited TRAIL-increased NOS activity, indicating that, on cultured HUVEC, TRAIL ability to affect NO production by regulating eNOS sub-cellular distribution is mediated by cytoskeleton and Golgi complex modifications. 相似文献
11.
Ronan Jambou Ahmed Zahraoui Birgitta Olofsson Armand Tavitian Ginette Jaureguiberry 《Biology of the cell / under the auspices of the European Cell Biology Organization》1996,88(3):113-121
Summary— During its erythrocytic life cycle Plasmodium falciparum exchanges compounds with host cells through phagocytosis and exocytosis. In eucaryotic cells, small GTP-binding proteins of the Ras superfamily appear to be involved in different steps of membrane trafficking and in intracellular signals. In this paper, we investigate the Rab4, Rab6 and Ras-related proteins in P falciparum infected red cells. We report that P falciparum Rab and Ras-related proteins could be distinguished from their counterparts by iso-electrofocusing and immunoblotting. The localization of P falciparum Rab 4 and Rab 6 was studied by immunogold electron microscopy on ultrathin frozen sections of infected red blood cells. Rab4 parasite-relate protein was found associated with the membranes of early endosome-like structures near the parasite plasma membrane. Rab6-related protein was associated with the Golgi/trans Golgi network, as already suggested by immunofluorescence microscopy studies and Ras-related protein was cytoplasmic and plasma membrane-associated. These results are in accordance with their mammalian counterparts and support the implication of Rab-related proteins in vesicular trafficking in Plasmodium. 相似文献
12.
A dense complex has been isolated from bacteria infected with gene V amber mutant f 1 bacteriophage. The major protein in this complex is the f 1 bacteriophage-specific gene II protein. Other proteins in the complex include the f 1 bacteriophage coat protein and proteins which migrate on sodium dodecyl sulfate/polyacrylamide gel electrophoresis with the f1 bacteriophage-specific gene III, gene IV and X protein. A protein of approximately 20,000 Mr is also present in the complex. Examination of bacteria infected with gene V mutant f1 bacteriophage revealed the complex as a densely staining amorphous body which appears to be associated with the cytoplasmic membrane. Bacteria infected with f1 bacteriophage that contain amber mutations in genes other than gene V do not contain this complex. 相似文献
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Nieva C Spindler-Barth M Spindler KD 《Archives of insect biochemistry and physiology》2008,68(1):40-48
Initially, nuclear import of the ecdysteroid receptor (EcR) in vertebrate cells (CHO-K1 and COS-7) does not afford a heterodimerization partner. Later on, EcR is retained in the nucleus only in the presence of a heterodimerization partner. Ultraspiracle (Usp) is more efficient compared to its vertebrate orthologue RXR and leads to an exclusively nuclear localization of EcR even in the absence of ligand. The DNA binding domain of the heterodimerization partner is important for retainment of EcR in the nucleus as shown by Usp4 (Usp(R130C)), which has lost its DNA binding capability. The C-terminal end of Usp (Usp(Delta205-508)) encompassing the C-terminal part of the D-domain and the E- and F-domains are essential for retainment of EcR in the nucleus. Nuclear localization is further influenced by cell-specific factors, since hormone and heterodimerization stabilizes the EcR protein in a cell-specific way. 相似文献
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Summary Intracellular K activities, (K)
c
, in rabbit gallbladder were determined using conventional and ion-selective microelectrodes. (K)
c
averaged 73mm and was 1.5 times that predicted for an equilibrium distribution of the ion across both apical and basolateral membranes. Thus, K must be actively transported into the cell, and the responsible mechanism is almost certainly the Na–K exchange pump in the basolateral membrane.Measurements of the bidirectional transepithelial fluxes of42K indicate that K is secreted into the mucosal solution at a rate of 0.8 eq/cm2 hr; this value is only 6% of the rate of transcellular Na absorption by this epithelium.Calculation of the conductance of the basolateral membrane,G
s, reveals that it is too low to account for the maintenance of the steady-state (K)
c
by a 3 Na2 K pump mechanism at the basolateral membrane if K exit across that barrier is entirely electrodiffusional.Our results together with those of others strongly suggest that a significant fraction of downhill K exit from the cell across the basolateral membrane is nonconductive and coupled to the movement of some other ion, perhaps Cl. 相似文献
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Shigeru Sugiyama Yusuke Nomura Taiichi Sakamoto Tomoya Kitatani Asako Kobayashi Shin Miyakawa Yoshinori Takahashi Hiroaki Adachi Kazufumi Takano Satoshi Murakami Tsuyoshi Inoue Yusuke Mori Yoshikazu Nakamura Hiroyoshi Matsumura 《Acta Crystallographica. Section F, Structural Biology Communications》2008,64(10):942-944
Aptamers, which are folded DNA or RNA molecules, bind to target molecules with high affinity and specificity. An RNA aptamer specific for the Fc fragment of human immunoglobulin G (IgG) has recently been identified and it has been demonstrated that an optimized 24‐nucleotide RNA aptamer binds to the Fc fragment of human IgG and not to other species. In order to clarify the structural basis of the high specificity of the RNA aptamer, it was crystallized in complex with the Fc fragment of human IgG1. Preliminary X‐ray diffraction studies revealed that the crystals belonged to the orthorhombic space group P21212, with unit‐cell parameters a = 83.7, b = 107.2, c = 79.0 Å. A data set has been collected to 2.2 Å resolution. 相似文献
18.
Detection of disease-specific augmentation of abnormal immunoglobulin G in sera of patients with rheumatoid arthritis 总被引:3,自引:0,他引:3
Tang W Matsumoto A Shikata K Takeuchi F Konishi T Nakata M Mizuochi T 《Glycoconjugate journal》1998,15(9):929-934
Galactose-free immunoglobulin G (IgG), which is known to be higher in the sera of patients with rheumatoid arthritis, was prepared from IgG of healthy volunteers using enzymes. Its reactivity to lectins was analyzed. The galactose-free IgG showed no reactivity to Ricinus communis agglutinin 120 but displayed greater reactivity to concanavalin A and Lens culinaris lectin than did intact human IgG. Then, IgG in serum samples was bound to protein A immobilized on a nitrocellulose membrane, and its reactivity to biotinylated concanavalin A was measured with streptavidin-conjugated horseradish peroxidase. When the reactivity to concanavalin A of IgG in sera from healthy individuals and patients with rheumatoid arthritis (RA), osteoarthritis, systemic lupus erythematosus, or hepatic disease was compared, higher levels were shown in patients with RA, notably in 60% of the seronegative patients and 80% of the early phase patients. Therefore, it was suggested that augmentation of the abnormal IgG in sera was highly specific to patients with RA and that this novel serum test could be very useful for an accurate diagnosis of this disease. 相似文献
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The folylpolyglutamate synthetase (FPGS) activities of Neurospora crassa, wild type (FGSC 853) and two polyglutamate-deficient mutants, met-6,35809 (FGSC 1330) and mac, 65108 (FGSC 3609), were examined after growth in defined media. Extracts of the wild type produced H4PteGlu6 (60 %), H4PteGlu3 (35 %) and H4PteGlu2 (15 %). Met-6 extracts formed H4PteGlu2 but lacked the ability to utilize H4PteGlu4 or H4PteGlu5. The mac mutant failed to catalyse glutamate addition to H4PteGlu but H4PteGlu2 was an effective substrate for tri- and hexaglutamate synthesis. These polyglutamates were also formed by reaction systems containing mixtures of met-6 and mac protein or heterokaryon protein derived from mycelial fusions of met-6 and mac. Extract fractionations and heat treatments provided evidence for more than one FPGS activity in the wild type. A mitochondrial FPGS catalysed the H4PteGlu2 → H4PteGlu3 reaction but a cytosolic fraction synthesized di-, tri- and hexaglutamates when incubated with H4PteGlu and glutamate. The latter system contained a temperature-sensitive diglutamate-forming activity and a relatively stable H4PteGlu2 → H4PteGlu6 activity. Polyglutamate synthesis in N. crassa appears to involve more than one step, H4PteGlu → H4PteGlu2 followed by H4PteGlu2 → H4PteGlu6, in addition to the mitochondrial activity. These partial activities are lacking in mac and met-6 respectively. Consequently, these mutants are unable to form the folylhexaglutamates that predominate the folate pool of the wild type. 相似文献
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Allelism of genes determining two IgG1 allotypes in cattle 总被引:1,自引:0,他引:1