37 research outputs found

    Dirty Businesses in Italy: a case-study of illegal trafficking in hazardous waste

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    This article focuses on trafficking in hazardous and special waste in Italy during the past decade with particular attention to the role played by mafia groups and other legal and illegal actors. A number of examples of illegal management and trafficking of waste are analysed to show the techniques used and the kind of actors involved (traditional mafia-type organisations, corporate entities, legitimate enterprises and businessmen, local authorities and other official actors). It concludes that a number of factors have facilitated and/or enhanced the development and growth of the illegal waste trafficking business (such as the growing demand for clandestine and cheaper services in the sector, the low business ethic of some segments of Italian industry, the delay in implementing proper waste-management policies and legislation, and the low public awareness regarding the threat posed by eco-crimes)

    Evidence for GroES acting as a transcriptional regulator

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    Cochaperonins (cpn10) assist chaperonins (cpn60) in promoting folding and assembly of other proteins. Upon expression of Mycobacterium tuberculosis cpn10 in Escherichia coli we have purified a polypeptide which, through amino acid sequencing, was identified as the endogenous E. coli 10K-S protein. Subsequent studies showed that its expression was specifically upregulated upon cloning of different members of the cpn10 family, including GroES, the E. coli cpn10. Pulse-chase experiments demonstrated that 10K-S is but one of several proteins whose expression is modulated upon cloning of cpn10. Up-regulation of 10K-S was also observed after exposure of normal cells, but not of groES- mutants, to elevated temperatures (42 degrees C). This allowed us to define 10K-S as a heat-shock protein (hsp) whose expression is dependent on the production of another hsp, GroES. Northern blot experiments showed that enhanced expression of 10K-S was consequent to increased accumulation of transcripts and that groES- mutants were devoid even of baseline levels of transcripts both at 37 degrees C and after temperature upshift. These results show that GroES, in addition to its established role in assisting protein folding may act as a transcriptional regulator and is likely to play an important role in modulating gene expression particularly in those conditions, like the stress response, in which its production is greatly enhanced

    Heterologous expression, purification, activity and conformational studies of different forms of dianthin 30

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    Dianthin 30, a ribosome inactivating protein (RIP) from Dianthus caryophyllus, has been expressed in Escherichia coli. Heterologous expression of a deletion mutant dianthin 30 delta 255-270 resulted in the production of a protein identical to carnation mature dianthin 30, including the absence at the carboxy-terminal of a putative 16 amino acid long pro-signal peptide. The production of a form of dianthin 30, which includes the pro-signal, is described as well. Both dianthin 30 delta 255-270 and dianthin 30 expressed in E. coli are mainly localized (90%) in the soluble fraction. Dianthin 30 delta 255-270 and dianthin 30 have been purified to homogeneity and were shown to inhibit protein synthesis in vitro with an IC50 of 8 and of 11 ng/ml, respectively. Secondary structure analysis, carried out by circular dichroism spectroscopy, indicated that the naturally occurring and the recombinant forms of dianthin 30 and dianthin 30 delta 255-270 possess the same secondary structure composition, accounting for an alpha + beta type architecture. RIPs as immunotoxins in clinical trial and as mitotoxins in experimental models have been extremely efficacious. In addition, growing evidence indicates their effective use as antiviral agents, including in HIV-1 infection. These data indicate the ability to produce either chemically linked or recombinant fusion proteins with dianthin 30 and cell-binding ligands for production of new reagents for clinical and experimental use

    Molecular characterization of a thyroid tumor-specific transforming sequence formed by the fusion of ret tyrosine kinase and the regulatory subunit RI alpha of cyclic AMP-dependent protein kinase A.

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    The ret oncogene frequently has been found activated in papillary thyroid carcinomas. A previous characterization of ret activation revealed recombination of its tyrosine kinase domain and sequences derived from an uncharacterized locus (D10S170). The mechanism leading to this recombination was identified as a paracentric inversion of the long arm of chromosome 10, inv(10)(q11.2q21), with the breakpoints occurring where ret and D10S170 were mapped. To further characterize the activation of ret in papillary thyroid carcinomas, we have now isolated and sequenced a second type of ret oncogenic rearrangement not involving the D10S170 locus. The nucleotide sequence indicated that the transforming activity was created by the fusion of the ret tyrosine kinase domain with part of the RI alpha regulatory subunit of protein kinase A (PKA). This is the first example of an oncogenic activity involving a PKA gene. PKA is the main intracellular cyclic AMP receptor, and its RI alpha subunit gene is located on chromosome 17q. RI alpha-ret transcripts encode two isoforms of the chimeric protein (p76 and p81), which display constitutive tyrosine phosphorylation as well as a tyrosine kinase enzymatic activity. Under nonreducing conditions, both isoforms are found in a dimeric configuration because of both homo- and heterodimer formation. Thus, the in vivo activation of ret in human papillary thyroid carcinomas is provided by the fusion of its tyrosine kinase domain with different genes and can be mediated by different mechanisms of gene rearrangement

    High frequency of activation of tyrosine kinase oncogenes in human papillary thyroid carcinoma

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    We had previously detected a transforming oncogene, designated PTC, in 25% of 20 papillary thyroid carcinomas. In order to characterize further the transforming activity of this tumour histotype, a new panel of tumour specimens from 16 patients was analysed by using a modified calcium phosphate-DNA coprecipitation transfection protocol. Tumour DNA from 10 patients (62%) displayed a transforming activity due to activation of three different oncogenes identified in four cases as PTC, in four cases as TRK, and in two cases as N-RAS. The same structural alterations of PTC and TRK (gene rearrangements) as well as of N-RAS (point mutation) detected in the NIH3T3 transformants, were also found in the original tumour DNAs, thus indicating that their activation was not due to transfection procedures. Since both PTC, a novel rearranged form of RET, and TRK display a tyrosine protein kinase activity, it is proposed that the activation of this class of oncogenes is specifically involved in the pathogenesis of papillary thyroid cancer
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