Membrane transporters and protein traffic networks differentially affecting metal tolerance: a genomic phenotyping study in yeast

Genomic phenotyping was used to assess the role of all non-essential S. cerevisiae proteins in modulating cell viability after exposure to cadmium, nickel and other metals

Il catalogo muliebre nella Napoli del xvi secolo : un contributo di Benedetto Croce

En la literatura napolitana hi ha moltes obres literàries que lloen a les dones de Nàpols, i aquest gènere es revitalitza en contacte amb la societat aristocràtica del Vicereialme. Benedetto Croce, assistit per Giuseppe Ceci, participa activament en una sèrie de rimes, poemes, capítols i epigrames sobre el catàleg de les dones, conscients de la seva contribució a la història dels costums i la literatura del Nàpols del segle XVI. En Lodi di dame napoletane del secolo decimosesto s'analitzen que la noblesa napolitana i espanyola voldrien llegir perquè es veien reflexades en aquestes, i en el llenguatge refinat d'estil petrarquià en que estaven escrites, un espill de les seves formes elegants

Cerium oxide nanoparticles rescue α-synuclein-induced toxicity in a yeast model of Parkinson’s disease

Over the last decades, cerium oxide nanoparticles (CeO2 NPs) have gained great interest due to their potential applications, mainly in the fields of agriculture and biomedicine. Promising effects of CeO2 NPs are recently shown in some neurodegenerative diseases, but the mechanism of action of these NPs in Parkinson’s disease (PD) remains to be investigated. This issue is addressed in the present study by using a yeast model based on the heterologous expression of the human α-synuclein (α-syn), the major component of Lewy bodies, which represent a neuropathological hallmark of PD. We observed that CeO2 NPs strongly reduce α-syn-induced toxicity in a dose-dependent manner. This effect is associated with the inhibition of cytoplasmic α-syn foci accumulation, resulting in plasma membrane localization of α-syn after NP treatment. Moreover, CeO2 NPs counteract the α-syn-induced mitochondrial dysfunction and decrease reactive oxygen species (ROS) production in yeast cells. In vitro binding assay using cell lysates showed that α-syn is adsorbed on the surface of CeO2 NPs, suggesting that these NPs may act as a strong inhibitor of α-syn toxicity not only acting as a radical scavenger, but through a direct interaction with α-syn in vivo

Périgord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis

LetterInternational audienceThe Périgord black truffle ($Tuber\ melanosporum$ Vittad.) and the Piedmont white truffle dominate today's truffle market. The hypogeous fruiting body of $T.\ melanosporum$ is a gastronomic delicacy produced by an ectomycorrhizal symbiont endemic to calcareous soils in southern Europe. The worldwide demand for this truffle has fuelled intense efforts at cultivation. Identification of processes that condition and trigger fruit body and symbiosis formation, ultimately leading to efficient crop production, will be facilitated by a thorough analysis of truffle genomic traits. In the ectomycorrhizal $Laccaria\ bicolor$, the expansion of gene families may have acted as a 'symbiosis toolbox'. This feature may however reflect evolution of this particular taxon and not a general trait shared by all ectomycorrhizal species. To get a better understanding of the biology and evolution of the ectomycorrhizal symbiosis, we report here the sequence of the haploid genome of $T.\ melanosporum$, which at $\sim$125 megabases is the largest and most complex fungal genome sequenced so far. This expansion results from a proliferation of transposable elements accounting for $\sim$58% of the genome. In contrast, this genome only contains $\sim$7,500 protein-coding genes with very rare multigene families. It lacks large sets of carbohydrate cleaving enzymes, but a few of them involved in degradation of plant cell walls are induced in symbiotic tissues. The latter feature and the upregulation of genes encoding for lipases and multicopper oxidases suggest that $T.\ melanosporum$ degrades its host cell walls during colonization. Symbiosis induces an increased expression of carbohydrate and amino acid transporters in both $L.\ bicolor$ and $T.\ melanosporum$, but the comparison of genomic traits in the two ectomycorrhizal fungi showed that genetic predispositions for symbiosis $-$'the symbiosis toolbox'$-$ evolved along different ways in ascomycetes and basidiomycete

Gino Ruozzi. L’occhio che guarda «altrove» di Mattia Pascal

En la obra pirandelliana El fue Mattia Pascal a caracterizar el aspecto del protagonista es aquel ojo “desobediente” que Mattia en vano trata de esconder o corregir y que también resistirá a la transformación, física e identitaria. Mattia Pascal es, según una definición de Mazzacurati, un “prisionero” del espejo, prisionero del otro dentro de Mattia se refleja y después de la ceguera temporal, efecto de la operación oculística, ya no es bizco pero tiene el ojo agrandado “adivino”: ahora se pone consciente que su identidad es fruto de la relación inarmónica de dos seres en una persona. La enfermedad del protagonista también contagia la página, el mundo externo es representado como alterado:  El fue Mattia Pascal es una novela de de-formación. Justo como aquel ojo que/n In the Pirandello’s opera, Il fu Mattia Pascal that eye «disobedient» characte-rizes the appearance of the protagonist, that eye which Mattia vainly tries to hide or correct and that will withstand even the transformation, physical and identity. Mattia Pascal is, according to Mazzacurati’s definition, a «prisoner of the mirror», prisoner of the other inside him. Mattia looks in the mirror and after the temporary blindness, effect of the ophthalmologic operation, no longer cross-eyed but has a larger eye of the «prophet»: now becomes aware that his identity is the result of disharmonious relationship of two beings in one person./nThe disease of the protagonist also infects the page, the outside world is represented as distorted: Il fu Mattia Pascal is a de-formation novel. Just like that eye which does not obey the will of the protagonist, so Pirandello decides to innovate the novel’s topic and the Bildungsroman, looking away, adopting the humorous theory and removing any compact structure of the ego.Nell’opera pirandelliana Il fu Mattia Pascal a caratterizzare l’aspetto del protagonista è quell’occhio «disobbediente» che Mattia invano cerca di nascondere o correggere e che resisterà anche alla trasformazione, fisica e identitaria. Mattia Pascal è, secondo una definizione di Mazzacurati, un «prigioniero dello specchio», prigioniero dell’altro dentro di Mattia si specchia e dopo la cecità temporanea, effetto dell’operazione oculistica, non è più strabico ma ha l’occhio ingrandito del «veggente»: ora diviene consapevole che la sua identità è frutto del rapporto disarmonico di due esseri in una persona./nLa malattia del protagonista contagia anche la pagina, il mondo esterno viene rappresentato come distorto: Il fu Mattia Pascal è un romanzo di de-formazione. Proprio come quell’occhio che non obbedisce alla volontà del protagonista, così Pirandello decide di innovare la materia romanzesca e il romanzo di formazione, guardando altrove, adottando la teoria umoristica e smontando ogni concezione compatta dell’io

The role of Phytochelatin Synthase in the microalga Scenedesmus acutus M. (Sphaeropleales).

The role of Phytochelatin Synthase in the microalga Scenedesmus acutus M. (Sphaeropleales) M. Ferrari, R. Cozza, M. Marieschi, R. Ruotolo, A. Torelli Phytochelatins (PCs) are small cysteine-rich peptides that are not genetically encoded but are synthesized by Phytochelatin Synthase (PCS) in the presence of glutathione as substrate. The constitutive expression of PCS and the presence of homologues of the PCS gene(s) in plants growing in ecosystems geographically remote from metal-contaminated sites, as well as in representatives of various kingdoms of living organisms, suggest that PCS has a wide range of different functions (Clemens et al. 2009). However, the main function of PCs in plants is to immobilize, sequester, and detoxify metal ions (Shukla et al. 2013). The effect of metals on the activity of PCS can differ not only between species, but also between different isoforms of the enzyme within a species. Although it is evident that chromium (Cr) ions can stimulate the formation of PCs in plants (Yu et al. 2018), there is no information on their presence in algae in response to Cr exposure. In this study, two strains of the green alga Scenedesmus acutus with different Cr(VI) sensitivity, namely the wild type (wt) and the chromium-tolerant strain (Cr-t), were selected as a model algal species to increase the knowledge on the role of PCs in Cr responses in microalgae. We previously reported the first evidence for a PCS gene (SaPCS) from the microalga S. acutus. More recently, we have also identified two SaPCS isoforms due to a putative alternative splicing. To define the role of PCS in Cr detoxification, we analyzed the levels of SaPCS transcription, and the abundance of PCS by using RT-qPCR and Western blot, respectively, in both strains of S. acutus after 24h culture in standard and in Cr supplemented medium (1 and 2 mg Cr (VI)/l). Given the relationship between sulfur (S) metabolism and Cr(VI) tolerance in S. acutus (Sardella et al. 2019), we also performed the same analyses in S-replete cells of both strains after medium renewal following S-starvation. The results showed a different behavior between strains in the stress response. RT-qPCR analysis revealed an increase in SaPCS transcription after Cr(VI) stress and after medium renewal following S-starvation in wt cells. Instead, the Cr-t strain induced SaPCS transcription only under S-replete conditions. Western blot analysis, performed with a polyclonal antibody raised against PCS of Arabidopsis thaliana, revealed an immunoreaction signal on two proteins with molecular weights of approximately 73 and 37 kDa. While the abundance of the 73 kDa protein did not change after the stresses studied in the two strains, the 37 kDa protein increased after S-starvation in both strains but in a significant manner only in wt. Finally, a preliminary quantification of PC production was performed, through LC Mass analysis in the two strains in preculture with or without S and under 1 mg Cr(VI)/l, which showed no modulation of PC abundance in response to Cr(VI) stress and/or S deprivation. Nevertheless, the Cr-t strain maintained PCs level significantly higher than the wt at the end of S-starvation. These observations suggest that PCS in S. acutus may not be involved in Cr(VI) detoxification, but may play a role in intracellular sulfur balance or in the cell homeostasis during stress. The PC production in the other experimental conditions (i.e. exposures longer than those studied and different Cr(VI) concentrations) should be investigated to better clarify the role of the enzyme in Cr(VI) detoxification. Letteratura citata Shukla D., Tiwari M., Tripathi E.D., Nath P., Trivedi P.K. (2013). Synthetic phytochelatins complement a phytochelatin-deficient Arabidopsis mutant and enhance the accumulation of heavy metal(loid)s. Biochem Biophy Res Commun 434:664–669 Clemens S., Peršoh D. (2009). Multi-tasking phytochelatin synthases. Plant Sci., 177, 266–271. Yu, X.Z., Ling, Q.L., Li, Y.H., Lin Y.J. (2018) mRNA Analysis of Genes Encoded with Phytochelatin Synthase (PCS) in Rice Seedlings Exposed to Chromium: The Role of Phytochelatins in Cr Detoxification. Bull Environ Contam Toxicol 101, 257–261. Sardella A., Marieschi M., Mercatali I., Zanni C., Gorbi G., Torelli A. (2019). The relationship between sulfur metabolism and tolerance of hexavalent chromium in Scenedesmus acutus (Spheropleales): Role of ATP sulfurylase. Aquatic Toxicology, 216:105320. AUTORI Michele Ferrari ([email protected]), Radiana Cozza, Department of Biology, Ecology and Earth Science, University of Calabria, Via P. Bucci, 87036 Rende (CS). Matteo Marieschi, Roberta Ruotolo, Anna Torelli, Department of Life Sciences, University of Parma, Parco Area delle Scienze 11/A, 43124 Parm