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11.
Marcio?Paulo?Pereira Felipe?Fogaroli?Corrêa Evaristo?Mauro?de?Castro Jean?Paulo?Vitor?de?Oliveira Fabricio?José?PereiraEmail author 《Protoplasma》2017,254(6):2117-2126
Previous works show the development of thicker leaves on tolerant plants growing under cadmium (Cd2+) contamination. The aim of this study was to evaluate the Cd2+ effects on the leaf meristems of the tolerant species Schinus molle. Plants were grown in nutrient solution containing 0, 10, and 50 μM of Cd2+. Anatomical analysis was performed on leaf primordia sampled at regular time intervals. Under the lowest Cd2+ level (10 μM), increased ground meristem thickness, diameter of the cells, cell elongation rate, and leaf dry mass were found. However, 50 μM of Cd2+ reduced all these variables. In addition, the ground meristem cells became larger when exposed to any Cd2+ level. The epidermis, palisade parenchyma, and vascular tissues developed earlier in Cd2+-exposed leaves. The modifications found on the ground meristem may be related to the development of thicker leaves on S. molle plants exposed to low Cd2+ levels. Furthermore, older leaves showed higher Cd2+ content when compared to the younger ones, preventing the Cd2+ toxicity to these leaves. Thus, low Cd2+ concentrations change the ground meristem structure and function reflecting on the development of thicker and enhanced leaves. 相似文献
12.
Mauro Magnani Vilberto Stocchi Marina Dachà Giorgio Fornaini 《Molecular and cellular biochemistry》1984,61(1):83-92
Summary Rabbit hexokinase (EC 2.7.1.1) has been shown to exist in reticulocytes as two distinct molecular forms, designated hexokinase Ia and Ib, but only one of these was consistently present in mature red cells. In vivo, hexokinase la and Ib show a decay rate of 3 and 8% a day, respectively, while in vitro they show a similar stability.The possibility that the proteolytic activities of the reticulocyte could be responsible for the fast decay of hexokinase was investigated. No differences were found in the decay rates of hexokinase la and Ib during in vitro reticulocyte maturation in presence or absence of proteolytic inhibitors. Contrariwise, many findings indicate the ATP-dependent proteolytic system of the reticulocyte as a possible mechanism. In fact, the decay of hexokinase and the degradation of 3H-globins are both stimulated by ATP and ubiquitin; they show similar kinetic properties and both disappear during reticulocyte maturation.The cellular localization of hexokinase la and Ib was shown to be responsible for the differences found between their decay rates.Abbreviations PMSF
phenylmethylsulfonyl fluoride
- TPCK
1-1-tosylamide-2-phenylethyl-chloromethyl ketone
- TLCK
N -p-tosyl-L-lysine chloromethyl ketone 相似文献
13.
14.
Anti-PlGF inhibits growth of VEGF(R)-inhibitor-resistant tumors without affecting healthy vessels 总被引:13,自引:0,他引:13
Fischer C Jonckx B Mazzone M Zacchigna S Loges S Pattarini L Chorianopoulos E Liesenborghs L Koch M De Mol M Autiero M Wyns S Plaisance S Moons L van Rooijen N Giacca M Stassen JM Dewerchin M Collen D Carmeliet P 《Cell》2007,131(3):463-475
Novel antiangiogenic strategies with complementary mechanisms are needed to maximize efficacy and minimize resistance to current angiogenesis inhibitors. We explored the therapeutic potential and mechanisms of alphaPlGF, an antibody against placental growth factor (PlGF), a VEGF homolog, which regulates the angiogenic switch in disease, but not in health. alphaPlGF inhibited growth and metastasis of various tumors, including those resistant to VEGF(R) inhibitors (VEGF(R)Is), and enhanced the efficacy of chemotherapy and VEGF(R)Is. alphaPlGF inhibited angiogenesis, lymphangiogenesis, and tumor cell motility. Distinct from VEGF(R)Is, alphaPlGF prevented infiltration of angiogenic macrophages and severe tumor hypoxia, and thus, did not switch on the angiogenic rescue program responsible for resistance to VEGF(R)Is. Moreover, it did not cause or enhance VEGF(R)I-related side effects. The efficacy and safety of alphaPlGF, its pleiotropic and complementary mechanism to VEGF(R)Is, and the negligible induction of an angiogenic rescue program suggest that alphaPlGF may constitute a novel approach for cancer treatment. 相似文献
15.
J Maimon M Mauro K C Gorray B S Schneider 《The journal of histochemistry and cytochemistry》1991,39(11):1571-1574
Antisera to guinea pig insulin are not commonly available, largely because of the short supply and limited immunogenicity of the intact hormone. To overcome these problems we have employed a novel reagent, synthetic guinea pig insulin B-chain C-terminal decapeptide, as a hapten for raising antibodies that react with intact guinea pig insulin. The decapeptide, coupled to bovine serum albumin, was successfully used as an immunogen in rabbits. The resulting anti-serum was employed for immunocytochemical staining of guinea pig insulin in pancreatic sections. The specificity of the staining was verified by both pre-absorption and pre-immune serum controls. The utility of this new antiserum for investigations of guinea pig insulin physiology is discussed. 相似文献
16.
T. Corrêa de Souza P. César Magalhães F. José Pereira E. Mauro de Castro S. Netto Parentoni 《Acta Physiologiae Plantarum》2011,33(5):1877-1885
This study was carried out to evaluate maize plants of different recurrent selection cycles of the variety (Zea mays L.—Saracura-BRS-4154) regarded to genetic gains, morphophysiology, and grain yield, achieved over the selection cycles under
intermittent flooding of the soil. This variety has the capacity to survive and produce in temporarily flooded soils and was
developed by the National Maize and Sorghum Research Center (EMBRAPA). The experiment was conducted in greenhouse by using
ten alternating selection cycles (Cycle 1–18) and BR 107 a variety known for its susceptibility to flooding. The flooding
initiated at six-leaf stage by applying 50 mm of water three times a week. At flowering, the following parameters were evaluated:
rate of leaf photosynthesis, stomatal conductance, intercellular CO2 concentration, transpiration rate, photosynthetically active leaf area, root porosity, relative chlorophyll content, grain
yield, harvest index, ear length, and interval between male and female flowering. Yield as a function of root porosity and
photosynthesis were also evaluated. An index was created in this study, in order to help the discussion of the characteristics
evaluated, it was called “Relative Tolerance Value—RTV”, only gaseous exchange measurements was not included in this index.
By the way, it was observed throughout the selection cycles an increase in all gaseous exchange parameters, being the cycle
18, the one which presented the greatest averages. RTV for leaf area showed the greatest values for cycles 7 and 18, whereas
root porosity, chlorophyll relative content, and harvest index, the greater RTV values were found in cycles 17 and 18. The
largest grain yield RTV was observed in cycle 7, followed by cycles 13, 15, and 18. Flooding resulted in longer Anthesis-Silking
Interval, especially for the first cycles. At flooding condition, grain yield was strongly related to root porosity (R
2 = 0.66). These results showed that the selection cycles of “Saracura” maize improved some morphophysiologic characters, which
favor their survival in flooded environments, also resulting in higher productivity. 相似文献
17.
Fabio Moda Chiara Vimercati Ilaria Campagnani Margherita Ruggerone Giorgio Giaccone Michela Morbin Lorena Zentilin Mauro Giacca Ileana Zucca Giuseppe Legname Fabrizio Tagliavini 《朊病毒》2012,6(4):383-390
Prion diseases are caused by a conformational modification of the cellular prion protein (PrPC) into disease-specific forms, termed PrPSc, that have the ability to interact with PrPC promoting its conversion to PrPSc. In vitro studies demonstrated that anti-PrP antibodies inhibit this process. In particular, the single chain variable fragment D18 antibody (scFvD18) showed high efficiency in curing chronically prion-infected cells. This molecule binds the PrPC region involved in the interaction with PrPSc thus halting further prion formation. These findings prompted us to test the efficiency of scFvD18 in vivo. A recombinant Adeno-Associated Viral vector serotype 9 was used to deliver scFvD18 to the brain of mice that were subsequently infected by intraperitoneal route with the mouse-adapted scrapie strain RML. We found that the treatment was safe, prolonged the incubation time of scrapie-infected animals and decreased the burden of total proteinase-resistant PrPSc in the brain, suggesting that scFvD18 interferes with prion replication in vivo. This approach is relevant for designing new therapeutic strategies for prion diseases and other disorders characterized by protein misfolding. 相似文献
18.
The generation of transgenic mosquitoes with a minimal fitness load is a prerequisite for the success of strategies for controlling mosquito-borne diseases using transgenic insects. It is important to assemble as much information as possible on this subject because realistic estimates of transgene fitness costs are essential for modeling and planning release strategies. Transgenic mosquitoes must have minimal fitness costs, because such costs would reduce the effectiveness of the genetic drive mechanisms that are used to introduce the transgenes into field mosquito populations. Several factors affect fitness of transgenic mosquitoes, including the potential negative effect of transgene products and insertional mutagenesis. Studies to assess fitness of transgenic mosquitoes in the field (as opposed to the laboratory) are still needed. 相似文献
19.
Perović S Schröder HC Sudek S Grebenjuk VA Batel R Stifanić M Müller IM Müller WE 《Evolution & development》2003,5(3):240-250
Sponges (Porifera) represent the evolutionary oldest multicellular animals. They are provided with the basic molecules involved in cell-cell and cell-matrix interactions. We report here the isolation and characterization of a complementary DNA from the sponge Suberites domuncula coding for the sponge homeobox gene, SUBDOIRX-a. The deduced polypeptide with a predicted Mr of 44,375 possesses the highly conserved Iroquois-homeodomain. We applied in situ hybridization to localize Iroquois in the sponge. The expression of this gene is highest in cells adjacent to the canals of the sponge in the medulla region. To study the expression of Iroquois during development, the in vitro primmorph system from S. domuncula was used. During the formation of these three-dimensional aggregates composed of proliferating cells, the expression of Iroquois depends on ferric iron and water current. An increased expression in response to water current is paralleled with the formation of canal-like pores in the primmorphs. It is suggested that Iroquois expression is involved in the formation of the aquiferous system, the canals in sponges and the canal-like structures in primmorphs. 相似文献
20.
Garcin ED Bruns CM Lloyd SJ Hosfield DJ Tiso M Gachhui R Stuehr DJ Tainer JA Getzoff ED 《The Journal of biological chemistry》2004,279(36):37918-37927
Three nitric-oxide synthase (NOS) isozymes play crucial, but distinct, roles in neurotransmission, vascular homeostasis, and host defense, by catalyzing Ca(2+)/calmodulin-triggered NO synthesis. Here, we address current questions regarding NOS activity and regulation by combining mutagenesis and biochemistry with crystal structure determination of a fully assembled, electron-supplying, neuronal NOS reductase dimer. By integrating these results, we structurally elucidate the unique mechanisms for isozyme-specific regulation of electron transfer in NOS. Our discovery of the autoinhibitory helix, its placement between domains, and striking similarities with canonical calmodulin-binding motifs, support new mechanisms for NOS inhibition. NADPH, isozyme-specific residue Arg(1400), and the C-terminal tail synergistically repress NOS activity by locking the FMN binding domain in an electron-accepting position. Our analyses suggest that calmodulin binding or C-terminal tail phosphorylation frees a large scale swinging motion of the entire FMN domain to deliver electrons to the catalytic module in the holoenzyme. 相似文献