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1.
GIP, a Petunia hybrida GA-induced cysteine-rich protein: a possible role in shoot elongation and transition to flowering 总被引:1,自引:0,他引:1
Ben-Nissan G Lee JY Borohov A Weiss D 《The Plant journal : for cell and molecular biology》2004,37(2):229-238
The Petunia hybrida GA-induced proteins (GIPs) belong to a large group of proteins identified in numerous plant species. These proteins share a similar C-terminal region containing 12 cysteine residues in conserved positions. To date, the function of these proteins remains unclear. We previously found that GIP1 expression coincides with cell elongation in stems and flowers and is induced by gibberellic acid (GA3). Transient expression of a GIP1:green fluorescent protein (GFP) fusion in tobacco bright yellow 2 (BY2) cells and immunoblot analyses suggest microsomal compartmentalization with possible endoplasmic reticulum (ER) localization. However, the polyclonal anti-GIP1 antibodies also reacted with proteins extracted from the cell wall. Three novel GIP homologs, GIP2, GIP4, and GIP5, were isolated. While GIP4, similar to GIP1, is putatively localized to the ER membrane, the cleavable hydrophobic N-terminal sequences of GIP2 and GIP5 suggest cell wall localization. GIP1 and GIP2 are expressed during cell elongation, whereas GIP4 and GIP5 are expressed during cell division; nevertheless, they all were induced by GA3. We generated transgenic petunia in which we repressed the putative cell wall protein GIP2. The transgenic plants exhibited late flowering and reduced stem elongation. These phenotypic alterations were found under low, but not moderate-high temperatures, suggesting functional redundancy under normal growth conditions. The expression pattern and cellular localization of GIP2, its regulation by GA, and the phenotype of the transgenic plants suggest a role in GA-mediated cell elongation and transition to flowering. 相似文献
2.
3.
The Sambucus nigra type-2 ribosome-inactivating protein SNA-I' exhibits in planta antiviral activity in transgenic tobacco 总被引:4,自引:0,他引:4
Transgenic tobacco (Samsun NN) plants transformed with a cDNA clone encoding SNA-I' from Sambucus nigra synthesize, and correctly process and assemble, a fully active type-2 ribosome-inactivating protein. Expression of SNA-I' under the control of the 35S cauliflower mosaic virus promoter enhances the plant's resistance against infection with tobacco mosaic virus. In contrast to type-1 ribosome-inactivating proteins, the expression of SNA-I' does not affect the growth and fertility of the transgenic plants and is not accompanied by an increased expression of pathogenesis-related proteins indicating that its antiviral activity most probably differs from that of pokeweed antiviral protein. 相似文献
4.
Willie A. M. van Emmerik Anneke M. Wagner Johanneke H. Zwiers Linus H. W. van der Plas 《Physiologia plantarum》1993,88(2):251-258
When Petunia hybrida L. cv. Rosy Morn Fertile suspension cells were inoculated in fresh medium with chloramphenicol (CAP), the activity of cytochrome C oxidase (EC 1. 9. 3. 1), and the respiration via the cytochrome pathway of isolated mitochondria decreased, while in untreated cells these parameters more than doubled in 2–3 days. However, the in vivo respiratory activity of the cytochrome pathway of CAP-treated cells showed a similar course in time as that of untreated cells, even in the presence of an uncoupler, a large rise during the first 2–3 days followed by a decline. This leads to the conclusion that the respiration via the cytochrome pathway, even when measured in the presence of an uncoupler, is not the capacity of this pathway. Furthermore, the results suggest that, although new-synthesis of proteins occurs directly after in-oculation, a large overcapacity must be present of cytochrome pathway elements (at least of those that are mitochondrial encoded). CAP had little effect on the uninhibited respiration and the cyanide-resistant, alternative pathway of the Petunia cells. However, the engagement of the alternative pathway (in the presence or absence of uncoupler) was increased in CAP-treated cells, especially after day 3 of the batch cycle, possibly as an effect of higher sugar degradation in combination with substrate phosphorylation to compensate the loss of ATP-synthesizing ability of the cytochrome pathway. It will be discussed that in general one should be careful using the term 'capacity' for the respiratory pathways. 相似文献
5.
对几株经初筛具较高抗氧化活性的疏花水柏枝的内生真菌展开研究,在体内和体外两种方法下分析了其抗氧化能力。本研究选择1,1-二苯基-2-三硝基苯肼(DPPH)法、总抗氧化能力(T-AOC)试剂盒和铁氰化钾还原力测定法来评价内生真菌的体外抗氧化活性,并对不同方法进行了比较分析;建立并优化了大肠杆菌的氧化损伤模型,并将内生真菌对其保护作用与对人神经母瘤细胞SH-SY5Y的氧化损伤保护作用进行比较,分析了不同内生真菌在体内的抗氧化活性。结果表明体内和体外的抗氧化分析方法存在一定偏差,体外分析中活性最高的菌株是SJ-12和QY-1,体内分析中对大肠杆菌抗氧化保护效果最好的菌株也是QY-1和SJ-12,但对神经细胞保护效果最好的菌株是QY-1和MG-9。综合几种方法,本实验证明了内生真菌QY-1及其发酵产物具较强的抗氧化活性,可以作为潜在的新型抗氧化剂开发利用。 相似文献
6.
The potent pro‐oxidant activity of rhododendrol–eumelanin induces cysteine depletion in B16 melanoma cells
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Shosuke Ito Masae Okura Kazumasa Wakamatsu Toshiharu Yamashita 《Pigment cell & melanoma research》2017,30(1):63-67
RS‐4‐(4‐Hydroxyphenyl)‐2‐butanol (rhododendrol, RD), a skin‐whitening agent, is known to induce leukoderma in some people. To explore the mechanism underlying this effect, we previously showed that the oxidation of RD with mushroom or human tyrosinase produces cytotoxic quinone oxidation products. We then examined the metabolism of RD in B16F1 melanoma cells in vitro and detected RD‐pheomelanin and RD‐quinone bound to non‐protein and protein thiols. In this study, we examined the changes in glutathione (GSH) and cysteine in B16 cells exposed to RD for up to 24 h. We find that the levels of cysteine, but not those of GSH, decrease during 0.5‐ to 3‐h exposure, due to oxidation to cystine. This pro‐oxidant activity was then examined using synthetic melanins. Indeed, we find that RD‐eumelanin exerts a pro‐oxidant activity as potent as Dopa‐pheomelanin. GSH, cysteine, ascorbic acid, and NADH were oxidized by RD‐eumelanin with a concomitant production of H2O2. We propose that RD‐eumelanin induces cytotoxicity through its potent pro‐oxidant activity. 相似文献
7.
《Free radical research》2013,47(8):635-642
AbstractOxidative stress plays a significant role in pathophysiology of cataracts and also known to affect the phosphatidylinositol-3-kinase/ protein kinase B (PI3K/Akt) signaling pathway. This well-documented pathway is involved in protecting against apoptosis-inducing insults, including oxidative stress. Melatonin (N-acetyl-5-methoxy-tryptamine), the major secretory product of the pineal gland, was identified as a powerful free radical scavenger and a broad-spectrum antioxidant that defends against various oxidative stress-associated diseases. This study was conducted to determine whether melatonin could prevent hydrogen peroxide (H2O2)-induced oxidative stress in human lens epithelial cells (HLECs) and to elucidate the molecular pathways involved in this protection. HLECs were subjected to various concentrations of H2O2 in the presence or absence of melatonin at different concentrations. Cell viability was monitored by a 3-(4, 5-dimethylthiazol-2yl)-2, 5-diphenyl-tetrazoliumbromide (MTT) assay, and the apoptosis rate and intracellular reactive oxygen species (ROS) levels were measured by flow cytometry using annexin V-FITC and propidium iodide (PI) staining. The expression levels of HO-1, Nrf-2, CAT, and MDA were measured using Western blot analysis. Akt activation was also evaluated by Western blot analysis. The data from our study showed that cells pretreated with melatonin can reduce H2O2-induced intracellular ROS generation and thus protect HLECs from cell apoptosis. Furthermore, we found that melatonin is a potent activator of Akt in HLECs. Our findings suggest that in addition to functioning as a direct free radical scavenger, melatonin can elicit cellular signaling pathways that are protective against oxidative stress-induced cataracts. 相似文献
8.
Summary A petunia cell line, 1ECB, was previously isolated by the stepwise selection procedure, for resistance to methotrexate (MTX), an antimetabolite for the enzyme dihydrofolate reductase (DHFR). Using ammonium sulfate precipitates of cell lysates of cell line 1ECB and its parental cell line (WT), it was found that the mutant has an increase of 400 fold in 3H-MTX binding capacity and a decrease in the affinity for MTX binding, at two orders of magnitude, in comparison with the WT. In addition, the DHFR specific activity in the mutant increased only moderately (5- to 10-fold), this activity is extremely sensitive to MTX inhibition as compared to the WT. It is evident that the MTX resistance of line 1ECB results mainly from overproduction of an MTX-binding protein which differs from the WT DHFR by four biochemical criteria. This protein may serve as a trap for the excess amounts of MTX to which the cells are exposed. 相似文献
9.
Yusuf Scak Emine Elin Oru‐Emre Mehmet
ztürk Tuba Takn‐Tok Ayegül Karaküük‐Iyidoan 《Chirality》2019,31(8):603-615
In this study, a series of fluorine‐containing chiral hydrazide‐hydrazone derivatives [III‐XII] from ?‐cysteine ethyl ester hydrochloride was synthesized as new antioxidant and anticholinesterase agents. The antioxidant activity of these derivatives was evaluated by ABTS+· and DPPH· scavenging and CUPRAC assays and the anticholinesterase activity by the Ellman method spectrophotometrically. The results of the antioxidant assay showed that compounds V , IX , and X exhibited higher activity than BHT and α‐tocopherol used as positive standards. Among the synthesized derivatives, compound IX (IC50: 2.3 ± 1.6 μM) exhibited higher acetylcholinesterase inhibitory activity than galantamine (IC50: 4.5 ± 0.8 μM). Compounds XI (IC50: 9.6 ± 1.0 μM), IX (IC50: 12.5 ± 1.6 μM), III (IC50: 16.0 ± 1.6 μM), X (IC50: 17.2 ± 1.8 μM), VI (IC50: 20.2 ± 0.8 μM), XII (IC50: 21.5 ± 1.0 μM), and VII (IC50: 24.6 ± 0.6 μM) displayed better butyrylcholinesterase inhibitory activity than galantamine (IC50: 46.03 ± 0.14 μM). ADME‐Tox analysis was used to probe the drug‐like properties of the compounds. Molecular docking studies were also applied to understand the interactions between compounds and targets. The docking calculations were supported by the experimental data. In particular, compound IX , having better activity than galantamine against acetylcholinesterase and butyrylcholinesterase enzymes, was visualized using molecular docking. 相似文献
10.
Regulation of cell division requires the concerted function of proteins and protein complexes that properly mediate cytoskeletal
dynamics. NudC is an evolutionarily conserved protein of undetermined function that associates with microtubules and interacts
with several key regulators of mitosis, such as polo-kinase 1 (Plk1) and dynein. NudC is essential for proper mitotic progression,
and homologs have been identified in species ranging from fungi to humans. In this paper, we report the characterization of
the Caenorhabditis elegans NudC homolog, NUD-1, as a protein exhibiting molecular chaperone activity. All NudC/NUD-1 proteins share a conserved p23/HSP20
domain predicted by three-dimensional modeling [Garcia-Ranea, Mirey, Camonis, Valencia, FEBS Lett 529(2–3):162–167, 2002]. We demonstrate that nematode NUD-1 is able to prevent the aggregation of two substrate proteins, citrate synthase (CS)
and luciferase, at stoichiometric concentrations. Further, NUD-1 also protects the native state of CS from thermal inactivation
by significantly reducing the inactivation rate of this enzyme. To further determine if NUD-1/substrate complexes were productive
or simply “dead-end” unfolding intermediates, a luciferase refolding assay was utilized. Following thermal denaturation, rabbit
reticulocyte lysate and ATP were added and luciferase activity measured. In the presence of NUD-1, nearly all of the luciferase
activity was regained, indicating that unfolded intermediates complexed with NUD-1 could be refolded. These studies represent
the first functional evidence for a member of this mitotically essential protein family as having chaperone activity and facilitates
elucidation of the role such proteins play in chaperone complexes utilized in cell division. C. elegans NUD-1 is a member of an evolutionary conserved protein family of unknown function involved in the regulation of cytoskeletal
dynamics. NUD-1 and its mammalian homolog, NudC, function with the dynein motor complex to ensure proper cell division, and
knockdown or overexpression of these proteins leads to disruption of mitosis. In this paper, we show that NUD-1 possesses
ATP-independent chaperone activity comparable to that of small heat shock proteins and cochaperones and that changes in phosphorylation
state functionally alter chaperone activity in a phosphomimetic NUD-1 mutant. 相似文献
11.
The disulfide bond pattern of catrocollastatin C, a disintegrin-like/cysteine-rich protein isolated from Crotalus atrox venom
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Calvete JJ Moreno-Murciano MP Sanz L Jürgens M Schrader M Raida M Benjamin DC Fox JW 《Protein science : a publication of the Protein Society》2000,9(7):1365-1373
The disulfide bond pattern of catrocollastatin-C was determined by N-terminal sequencing and mass spectrometry. The N-terminal disintegrin-like domain is a compact structure including eight disulfide bonds, seven of them in the same pattern as the disintegrin bitistatin. The protein has two extra cysteine residues (XIII and XVI) that form an additional disulfide bond that is characteristically found in the disintegrin-like domains of cellular metalloproteinases (ADAMs) and PIII snake venom Zn-metalloproteinases (SVMPs). The C-terminal cysteine-rich domain of catrocollastatin-C contains five disulfide bonds between nearest-neighbor cysteines and a long range disulfide bridge between CysV and CysX. These results provide structural evidence for a redefinition of the disintegrin-like and cysteine-rich domain boundaries. An evolutionary pathway for ADAMs, PIII, and PII SVMPs based on disulfide bond engineering is also proposed. 相似文献
12.
13.
Serge Ostrovidov Patricia Franck Josette Capiaumont Brigitte Dousset Francine Belleville 《In vitro cellular & developmental biology. Animal》1998,34(3):259-264
Summary The effect of low concentrations of hydrogen peroxide (H2O2) (5 × 10−7−9.5 × 10−7
M) on cell growth and antibody production was investigated with murine hybridoma cells (Mark 3 and anti-hPL) in culture. Cell
growth, measured by flow cytometry with morphological parameters, was significantly stimulated by H2O2 (8 × 10−7
M) but H2O2 concentration of 7 × 10−6
M and above increased cell death. H2O2 stimulation of antibody production was nonsignificant. The metabolism of cells treated with 8 × 10−7 or 1 × 10−5
M H2O2 was similar to that of the control in terms of glucose and glutamine consumption, lactate and ammonia production, and amino
acid concentrations in the medium. The concentrations of lactate dehydrogenase, a marker of cell death, in test and control
cells were similar. However, concentrations of intracellular free radicals measured by flow cytometry with dihydrorhodamine
123 (DHR 123) and dichlorofluorescein diacetate (DCFH-DA) as fluorochromes were different. The reactive oxygen species content
of cells in 8 × 10−7
M H2O2 was similar to that of the controls, but there was a sudden, marked production of superoxide anions (detected with DHR 123)
and H2O2 or peroxides (detected with DCFH-DA) by cells incubated with 1 × 10−5
M H2O2 which increased with increasing H2O2 until cell death. 相似文献
14.
Scavenging of the ABTS (2,2′-azinobis[3-ethylbenzothiazoline-6-sulphonate])-derived nitrogen-centred radical cation (ABTS?+) was used to compare the total antioxidant activities of several seasonings used in Asian cooking. The results were expressed as Trolox equivalent antioxidant capacity (TEAC). The TEAC activities of dark soy sauces were found to be exceptionally high. In evaluating the TEAC of commercial products, attention must be paid to the addition of preservatives by manufacturers to the seasonings tested. Sodium benzoate (a preservative added to several seasonings) did not react significantly with ABTS?+, but the sulphite content of certain white wines may have led to an over-estimation of their TEAC. 相似文献
15.
Vallelian-Bindschedler Laurence Mösinger Egon Métraux Jean-Pierre Schweizer Patrick 《Plant molecular biology》1998,37(2):297-308
The primary leaves of young barley seedlings contain two major, extracellular, acid-soluble proteins of ca. 22 and 23 kDa apparent molecular mass. These proteins disappeared from the intercellular washing fluid upon stress treatments that enhanced H2O2 levels and that induced resistance to subsequent challenge by the powdery mildew fungus Erysiphe graminis f. sp. hordei. A partial peptide sequence of the 22 kDa protein was determined, and a cDNA clone was isolated. The 22 kDa protein belongs the the group of germin-like proteins (GLPs) and was designated HvGLP1. Despite its similarity to germin, i.e. oxalate oxidase, no oxalate oxidase activity of HvGLP1 could be detected. The RNA and soluble protein of HvGLP1 was highly abundant in young leaves, less abundant in older leaves and absent in roots. HvGLP1 RNA oscillated with a circadian rhythm, the minimum and maximum of RNA abundance being at the end of the dark and light periods, respectively. Heat and H2O2 treatment as well as pathogen infection caused disappearance of HvGLP1 protein from the fraction of soluble proteins of the intercellular space. HvGLP1 protein could be re-solubilized from cell walls of heat- or H2O2-treated leaves by boiling in SDS suggesting non-covalent cross linking. Although a physiological role of HvGLP1 insolubilization is still open, the protein may serve as marker for oxidative stress in cereals. 相似文献
16.
* Using pharmacological and biochemical approaches, the role of calmodulin (CaM) and the relationship between CaM and hydrogen peroxide (H(2)O(2)) in abscisic acid (ABA)-induced antioxidant defense in leaves of maize (Zea mays) plants were investigated. * Treatment with ABA or H(2)O(2) led to significant increases in the concentration of cytosolic Ca(2+) in the protoplasts of mesophyll cells and in the expression of the calmodulin 1 (CaM1) gene and the content of CaM in leaves of maize plants, and enhanced the expression of the antioxidant genes superoxide dismutase 4 (SOD4), cytosolic ascorbate peroxidase (cAPX), and glutathione reductase 1 (GR1) and the activities of the chloroplastic and cytosolic antioxidant enzymes. The up-regulation of the antioxidant enzymes was almost completely blocked by pretreatments with two CaM antagonists. * Pretreatments with CaM antagonists almost completely inhibited ABA-induced H(2)O(2) production throughout ABA treatment, but pretreatment with an inhibitor or scavenger of reactive oxygen species (ROS) did not affect the initial increase in the contents of CaM induced by ABA. * Our results suggest that Ca(2+)-CaM is involved in ABA-induced antioxidant defense, and that cross-talk between Ca(2+)-CaM and H(2)O(2) plays a pivotal role in ABA signaling. 相似文献
17.
A relation between gene dosage and UDP-glucose:flavonoid 3-O-glucosyl-transferase (UFGT) activity was found in homozygous dominant and recessive parental lines and their F1 progeny for both of the genes An1 and An2. In both F2 crosses, progeny plants could be classified as belonging to groups showing either a low or a medium to high UFGT activity. Test crosses showed that heterozygous and homozygous dominant plants were present throughout the medium- to high-active group. The dosage relation in F2 plants is most probably confounded by the segregation of modifiers. Thermal inactivation experiments indicated that structurally different UFGT enzymes are formed in homozygous dominant lines as well as in lines homozygous recessive for either An1 or An2. Lines homozygous recessive for the gene An4 contain a UFGT with a half-life time at 55° C of less than 8 min, whereas UFGTs from lines homozygous dominant for An4 show a half-life time of 25 min or above, with one exception. This relation was confirmed in the F2 progeny; heterozygotes for An4 showed an intermediate half-life time. It is concluded that An4 might be the structural gene for the enzyme; An1 and An2 are both regulatory genes. UFGT activity in flowerbuds of An4/An4 plants seems to be lower than in an4/an4 plants. Anthers of flowers of an4/an4 lines, however, are virtually devoid of UFGT activity. 相似文献
18.
The role of pyruvate and autocrine polypeptide factors (APF) secreted by cytotoxic IL-2-dependent CTLL-2 cells in cell defense from oxidative stress was investigated. The addition of a conditioned medium (CM) containing pyruvate and APF into CTLL-2 cell cultures significantly increased the cell survival under oxidative stress conditions induced by hydrogen peroxide (H2O2). The kinetics of (H2O2) removal from cell cultures with added CM has been registered. It has been shown that, at the beginning of oxidative stress (less than 15 min), H2O2 was mostly removed by means of its reaction with pyruvate contained in CM. Pyruvate content in CM was estimated as 138 ± 7 μM. Gel filtration on a column with Bio-Gel P-10 was used to eliminate pyruvate from CM. Gel filtration resulted in three CM fractions (A, B, and C) corresponding to three chromatogram peaks. Pyruvate was not detected in any fraction. The fraction A was the first to be eluted from the column and contained the largest molecules. In the cell survival test, fraction B had the highest protective ability for CTLL-2 cells under oxidative stress. Fraction A supported cell survival to a lesser degree and fraction C did not show any protective abilities. Fraction B added to cells under oxidative stress kept intracellular ATP content at a significantly higher level then in control cells. Moreover, it was found that APF from fraction B was able to react with H2O2 directly and inactivate it in the absence of cells. APF from fraction A did not have such properties. 相似文献
19.
The ubiquitin/proteasome pathway: friend or foe in zinc-, cadmium-, and H2O2-induced neuronal oxidative stress 总被引:3,自引:0,他引:3
One of the hallmarks of neurodegeneration is the accumulation of ubiquitinated proteins in intraneuronal inclusions in the cytosol, endosomes/lysosomes and nuclei of affected cells. The relationship between inclusion production and cell viability is not well understood. On the one hand inclusions may be beneficial and result from an attempt of the cell to isolate a subclass of ubiquitinated proteins that are not effectively degraded. On the other hand, the inclusions may impede normal cell function contributing to cell death. To address this issue we treated mouse neuronal HT4 cells with three toxic agents cadmium, zinc and H2O2, and investigated their effects on glutathione homeostasis, on accumulation of ubiquitinated proteins and on cell viability. The three treatments induce oxidative stress manifested by decreases in glutathione (GSH) and/or increases in protein mixed disulfides (PrSSG). After an overnight recovery period in the absence of treatment, GSH and PrSSG were restored to almost normal levels. However, the levels of ubiquitinated proteins were significantly increased, and cell viability was sharply reduced. These results suggest that the ubiquitin-proteasome pathway is recruited for removal of proteins that are oxidatively modified. However, if the ubiquitinated proteins are not efficiently degraded, they accumulate in the cell and contribute to a decrease in cell viability. 相似文献
20.
The structure of a sulfated galactan from Porphyra haitanensis and its in vivo antioxidant activity 总被引:18,自引:0,他引:18
The sulfated galactan fraction F1 isolated from the red seaweed, Porphyra haitanensis, showed typical porphyran structure. It has a linear backbone of alternating 3-linked beta-D-galactosyl units and 4-linked alpha-L-galactosyl 6-sulfate and 3,6-anhydro-alpha-L-galactosyl units. The L-residues are mainly composed of alpha-L-galactosyl 6-sulfate units, and the 3,6-anhydrogalactosyl units are minor. Partial methylation occurred at the C-6 position of the D-galactosyl units and at the C-2 position of the 3,6-anhydro-alpha-L-galactosyl units. Intraperitoneal administration of F1 significantly decreased the lipid peroxidation in aging mice. F1 treatment increased the total antioxidant capacity and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in aging mice. The results indicated that F1 had significant in vivo antioxidant activity. 相似文献