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1.
Ada Rispoli Elena Cipollini Sandra Catania Rossella Di Giaimo Giuseppe Pulice Stineke van Houte Francesca Sparla Fabrizio Dal Piaz Davide Roncarati Paolo Trost Marialuisa Melli 《Biochimica et Biophysica Acta - Proteins and Proteomics》2013,1834(12):2591-2599
Cystatin B (CSTB) is an anti-protease frequently mutated in progressive myoclonus epilepsy (EPM1), a devastating degenerative disease. This work shows that rat CSTB is an unstable protein that undergoes structural changes following the interaction with a chaperone, either prokaryotic or eukaryotic. Both the prokaryotic DnaK and eukaryotic HSP70 promote CSTB polymerization. Denaturated CSTB is polymerized by the chaperone alone. Native CSTB monomers are more stable than denatured monomers and require Cu2 + for chaperone-dependent polymerization. Cu2 + interacts with at least two conserved histidines, at positions 72 and 95 modifying the structure of native monomeric CSTB. Subsequently, CSTB becomes unstable and readily responds to the addition of DnaK or HSP70, generating polymers. This reaction depends strictly on the presence of this divalent metal ion and on the presence of one cysteine in the protein chain. The cysteine deletion mutant does not polymerize. We propose that Cu2 + modifies the redox environment of the protein, allowing the oxidation of the cysteine residue of CSTB that triggers polymerization. These polymers are sensitive to reducing agents while polymers obtained from denatured CSTB monomers are DTT resistant. We propose that the Cu2 +/HSP70 dependent polymers are physiological and functional in eukaryotic cells. Furthermore, while monomeric CSTB has anti-protease function, it seems likely that polymeric CSTB fulfils different function(s). 相似文献
2.
Background and Aims
Tolerance and defence against herbivory are among the many mechanisms attributed to the success of invasive plants in their novel ranges. Because tolerance and defence against herbivory differ with the ontogeny of a plant, the effects of herbivore damage on plant fitness vary with ontogenetic stage and are compounded throughout a plant''s lifetime. Environmental stresses such as light and nutrient limitations can further influence the response of the plant. Much is known about the response of plants in the seedling and reproductive adult stages, but less attention has been given to the pre-reproductive juvenile stage.Methods
Juvenile plants of the North American invasive Lonicera maackii were exposed to simulated herbivory under high and low light and nitrogen availability and growth, allocation patterns and foliar defensive chemistry were measured. In a second experiment, complete nutrient availability and damage type (generalist caterpillar or simulated) were manipulated.Key Results
Juvenile plants receiving 50 % defoliation had lower total biomass and a higher root^:^shoot ratio than controls for all treatment combinations except low nitrogen/low light. Low light and defoliation increased root^:^shoot ratio. Light, fertilization and defoliation had little impact on foliar defensive chemistry. In the second experiment, there was a reduction in total biomass when caterpillar damage was applied. The root^:^shoot ratio increased under low soil fertility and was not affected by defoliation. Stem-diameter growth rates and specific leaf area did not vary by damage type or fertilization. Foliar protein increased through time, and more strongly in defoliated plants than in controls, while peroxidase activity and total flavonoids decreased with time. Overall, resource limitations were more influential than damage in the growth of juvenile L. maackii plants.Conclusions
The findings illustrate that even when resources are limited, the tolerance and defence against herbivory of a woody invasive plant in the juvenile stage may contribute to the establishment and persistence of some species in a variety of habitats. 相似文献3.
Carnevali S Petruzzelli S Longoni B Vanacore R Barale R Cipollini M Scatena F Paggiaro P Celi A Giuntini C 《American journal of physiology. Lung cellular and molecular physiology》2003,284(6):L955-L963
Cigarette smoke is a mixture of chemicals having direct and/or indirect toxic effects on different lung cells. We investigated the effect of cigarette smoke on human lung fibroblasts (HFL-1) oxidation and apoptosis. Cells were exposed to various concentrations (1, 5, and 10%) of cigarette smoke extract (CSE) for 3 h, and oxidative stress and apoptosis were assessed by fluorescence-activated cell sorting and confocal laser fluorescence microscopy. Both oxidative stress and apoptosis exhibited a dose-response relationship with CSE concentrations. Lung fibroblasts also showed marked DNA fragmentation at the Comet assay after exposure to 10% CSE. Coincubation of HLF-1 cells with N-acetylcysteine (1 mM) during CSE exposure significantly reduced oxidative stress, apoptosis, and DNA fragmentation, whereas preincubation (3 h) with the glutathione-depleting agent buthionine sulfoximine (125 microM) produced a significant increase of oxidative stress. Cigarette smoke is a potent source of oxidative stress, DNA damage, and apoptosis for HFL-1 cells, and we speculate that this could contribute to the development of pulmonary emphysema in the lungs of smokers. 相似文献
4.
Don Cipollini 《Evolutionary ecology》2010,24(1):59-68
The analysis of a suite of traits under a range of environmental conditions is necessary to fully examine costs of resistance.
I compared phenological, morphological and reproductive traits of several independent lines of a transgenic methyl jasmonate-overproducing
Arabidopsis thaliana plant (JMT plants) to that of vector controls in high and low soil nutrient environments. JMT plants constitutively express
a suite of responses normally inducible by wounding or jasmonate. JMT plants showed a marked delay in flowering time, and
were larger with more leaves at bolting than vector controls. These traits also responded more positively to increased nutrients
in JMT plants than in vector controls. At the end of the season, total seed mass and seed number was lower in JMT plants than
in vector controls overall, and these traits responded much less positively to nutrient addition in JMT plants than in vector
controls. This study revealed delayed phenology as a novel cost of resistance in Arabidopsis and that overproduction of methyl
jasmonate and associate responses can substantially constrain fitness responses to nutrients. These results establish a mechanism
whereby costs of resistance can be more apparent under high resource conditions, rather than under low resource conditions,
as is widely assumed. 相似文献
5.
Scarpato R Antonelli A Ballardin M Cipollini M Fallahi P Tomei A Traino C Barale R 《Mutation research》2006,606(1-2):21-26
The aim of our study was to assess whether or not thyroid nodularity in combination with occupational exposure to low levels of ionising radiation would be correlated with chromosome damage in peripheral lymphocytes. Conventional chromosome-aberration analysis was performed on a group of 92 hospital workers with or without thyroid nodules. On the basis of measurements of their exposure levels, the workers were classified into a low (mean total level=0.03 mSv), medium (mean total level=1.04 mSv) or high (mean total level=8.60 mSv) exposure category. Our results indicate that among workers with thyroid nodules, the high-exposed workers showed significantly higher levels of both total (2.35+/-0.34 per 100 cells) and chromosome-type aberrations (1.46+/-0.20 per 100 cells) than medium-exposed (0.98+/-0.42 and 0.68+/-0.25 per 100 cells, respectively) or low-exposed workers (1.11+/-0.29 and 0.58+/-0.17 per 100 cells, respectively). Workers without thyroid nodules had comparable frequencies of chromosome aberrations among the three exposure categories. To our knowledge, this is the first study revealing a slight, but significant increase of chromosome damage in peripheral lymphocytes from hospital workers who developed thyroid nodules under conditions of occupational exposure to radiation well below the threshold limit for the workplace. The existence of a possible association between chromosome aberrations and development of thyroid nodularity will be discussed. 相似文献
6.
Cipollini E Riccio M Di Giaimo R Dal Piaz F Pulice G Catania S Caldarelli I Dembic M Santi S Melli M 《Biochimica et biophysica acta》2008,1783(2):312-322
Progressive myoclonus epilepsy type 1 (EPM1) is a neurodegenerative disease correlating with mutations of the cystatin B gene. Cystatin B is described as a monomeric protein with antiprotease function. This work shows that, in vivo, cystatin B has a polymeric structure, highly resistant to SDS, urea, boiling and sensitive to reducing agents and alkaline pH. Hydrogen peroxide increases the polymeric structure of the protein. Mass spectrometry analysis shows that the only component of the polymers is cystatin B. EPM1 mutants of cystatin B transfected in cultured cells are also polymeric. The banding pattern generated by a cysteine-minus mutant is different from that of the wild-type protein as it contains only monomers, dimers and some very high MW bands while misses components of MW intermediate between 25 and 250 kDa. Overexpression of wild-type or EPM1 mutants of cystatin B in neuroblastoma cells generates cytoplasmic aggregates. The cysteine-minus mutant is less prone to the formation of inclusion bodies. We conclude that cystatin B in vivo has a polymeric structure sensitive to the redox environment and that overexpression of the protein generates aggregates. This work describes a protein with a physiological role characterized by highly stable polymers prone to aggregate formation in vivo. 相似文献
7.
I studied the influence of gibberellic acid (GA3) treatment in a field population of common bean on plant tolerance to leaf removal. Individual bean seedlings were treated
with a foliar application of 10 μM GA3 on day 7 and day 14 after emergence, which led to a significant increase in height in GA3-treated plants. Twenty-eight days after emergence, either zero, one, two, or three leaflets from each trifoliate leaf were
removed from each of 20 GA3-treated and 20 control plants. All pods were harvested from each plant after plants became senescent 6 weeks later. Multivariate
analyses revealed that leaf removal produced significant reductions in several yield components in both GA3-treated and control plants, although the effects were not pronounced until at least two leaflets from each trifoliate leaf
(67% of the total leaf area) were removed. However, GA3-treated plants suffered greater reductions in total pod wall mass and total seed number than control plants after 33 and
67% leaf area removal. These results indicate that GA3 treatment may have altered the assimilatory capacity or resource allocation pattern of treated plants in such a way as to
decrease their ability to tolerate leaf removal, a negative consequence of the hormonal alteration of traits important to
plant compensation for biotic stressors.
Received December 6, 1996; accepted March 5, 1997 相似文献
8.
9.
Jonathan M. Adams Wei Fang Ragan M. Callaway Don Cipollini Elizabeth Newell 《Biological invasions》2009,11(4):1005-1016
Acer platanoides (Norway maple) is a widespread native tree species in Europe. It has been introduced to North America where it has often
established dense stands in both secondary woodlands and relatively undisturbed mature woodlands. In Europe A. platanoides is also extending its original range, but generally seems to exist at much lower densities. One explanation for the ‘aggressiveness’
of invasive plants such as A. platanoides is that they have left behind pests and diseases which limit their population densities in their native lands (the enemy
release hypothesis or ERH). To assess the ERH for Norway maple, a large network of collaborators assessed leaf herbivory rates
in populations throughout Europe and North America. We found significantly lower total leaf herbivory (1.6% ± 0.19, n = 21 vs. 7.4% ± 1.94, n = 34) and lower fungal damage (1.0% ± 0.35, n = 13 vs. 3.7% ± 0.85, n = 34) in North America than in Europe over a 2 year period, which is consistent with the predictions of the Enemy Release
Hypothesis. Across years, the average total leaf herbivory was significantly correlated with average annual temperature of
the site (P < 0.05), although this was mostly due to sites in Europe (P < 0.001), and not sites in North America (P > 0.05). Furthermore, only populations in Europe showed very high levels of herbivory (e.g., nine sites had total leaf herbivory
ranging from 10.0 to 51.2% in at least 1 year) or leaf fungal damage (only one site in North America showed high levels of
fungal damage in 1 year), suggesting the possibility of more frequent episodic outbreaks in the native range. Leaf herbivory
and fungal damage are only two aspects of consumer pressure and we do not know whether the differences reported here are enough
to actually elicit release from top-down population control, but such large scale biogeographic differences in herbivory contribute
towards understanding exotic invasions.
Jonathan M. Adams and Wei Fang—equally contributed as first authors.
A list of the participating members of the Transatlantic Acer platanoides Invasion Network is given in the Appendix 3. 相似文献
10.
Alliaria petiolata is a European biennial herb that invades North American forests and has direct negative effects on associated flora and fauna. In some places, A. petiolata has invaded the habitat of Pieris virginiensis, a rare, univoltine butterfly that normally uses native spring ephemeral crucifer hosts. There are occasional observations of P. virginiensis laying eggs on A. petiolata, but the frequency and effects of these “mistake oviposition events” are not yet known. We investigated P. virginiensis oviposition preference through field observations in three locations (NY, OH, PA), and also through laboratory experiments measuring egg deposition of adult females on either a native or invasive crucifer. In addition, we examined neonate larval performance through no-choice feeding assays on both A. petiolata leaves and cabbage leaves painted with A. petiolata leaf extracts. We found that P. virginiensis lays significantly more eggs on the exotic A. petiolata than on its native host Cardamine diphylla in both field and laboratory experiments. Caterpillars fed either A. petiolata leaf tissue or its ethanol extract did not survive to pupation, and most died after only a few days. Continual invasion and persistence of A. petiolata in P. virginiensis habitats may lead to genetic bottlenecking and possibly local extinctions without human intervention. 相似文献