Neuroendocrine effects of interferon alpha 2-a in healthy human subjects

The acute effects of interferon alpha-2a (3 x 10 IU im) on catecholamine and immunoreactive beta endorphin plasma levels, cortisol serum levels and lymphocyte beta 2-adrenoceptor density were evaluated in ten healthy volunteers. Interferon induced a significant increase in plasma norepinephrine; there was an increased norepinephrine standing response, too. On the contrary, epinephrine standing response was reduced by interferon. Lymphocyte beta 2-adrenoceptors decreased significantly after interferon administration; dissociation constant of binding was unchanged. Cortisol serum levels increased significantly with respect to control test, whereas immunoreactive beta endorphin did not change. These results support the hypothesis of functional relationships between neuroendocrine and immune systems; moreover they may be useful in clinical trials given the administration of interferon alpha in an increasing number of diseases.     

The cold-active lipase of Pseudomonas fragi. Heterologous expression, biochemical characterization and molecular modeling.

A recombinant lipase cloned from Pseudomonas fragi strain IFO 3458 (PFL) was found to retain significant activity at low temperature. In an attempt to elucidate the structural basis of this behaviour, a model of its three-dimensional structure was built by homology and compared with homologous mesophilic lipases, i.e. the Pseudomonas aeruginosa lipase (45% sequence identity) and Burkholderia cepacia lipase (38%). In this model, features common to all known lipases have been identified, such as the catalytic triad (S83, D238 and H260) and the oxyanion hole (L17, Q84). Structural modifications recurrent in cold-adaptation, i.e. a large amount of charged residues exposed at the protein surface, have been detected. Noteworthy is the lack of a disulphide bridge conserved in homologous Pseudomonas lipases that may contribute to increased conformational flexibility of the cold-active enzyme.     

Isozyme diversity, RFLP of the rDNA and phylogenetic affinities among cultivated Lima beans,Phaseolus lunatus (Fabaceae)

Genetic variation inPhaseolus lunatus (Lima bean) was investigated at isozyme and DNA levels. Sixty cultivated accessions, including representatives of the Mesoamerican and Andean gene pools and intermediate types, were analyzed for variability at 17 isozyme loci. Some accessions were also examined for restriction fragment length polymorphism (RFLP) at the rDNA level. These data were used to construct two dendrograms showing clear separation in two distinct groups corresponding to each of the gene pools and an intermediate one probably representing a transitional group.     

Genetic mapping and QTL analysis in European hazelnut (<Emphasis Type="Italic">Corylus avellana</Emphasis> L.)

The European hazelnut (Corylus avellana L.) is the most economically important nut species in the Betulaceae family. Despite the need for new improved hazelnut cultivars, few breeding programs are carried out because of the large plant size, the long lifecycle of the plant, and the expense and time required. To date, there are no reports of maps with quantitative trait loci (QTL) in hazelnut. Our objective in the present study was to identify QTL associated with vegetative traits to allow marker-assisted selection (MAS). An F1 progeny (275 plants) of Tonda Gentile delle Langhe × Merveille de Bollwiller obtained in 2009 was used to develop a QTL linkage map for vigour, sucker habit, and time of bud burst, after three years of observations. A set of 163 plants were analysed with 152 microsatellite markers. A map of 11 linkage groups was obtained, covering 663.1 cM, and 15 QTLs were identified and mapped for the traits examined. Of them, 10 were ‘major’ QTL, including a stably expressed region on LG_02 for leaf bud burst. At least one major QTL for each year underlies the variation in each trait and a clustering of QTL for trunk circumference and suckers/trunk circumference ratio with high inter-trait correlations was observed on LG_05, suggesting a single pleiotropic locus. This research represents an initial step in the future identification of chromosomal regions carrying genes of interest, important for breeding programs and MAS.     

Autophagy in hematopoietic stem/progenitor cells exposed to heavy metals: Biological implications and toxicological relevance

The inherent toxicity of many metal compounds, together with their widespread environmental distribution, raises concerns of potential health hazards. Little is known about the impact of these important environmental toxicants on adult stem/progenitor cells, necessary for tissue homeostasis and repair. We recently reported that autophagy is implicated in the response of hematopoietic stem/progenitor cells to toxic concentrations of hexavalent chromium (Cr[VI]) and cadmium (Cd), two well known carcinogenic heavy metal cations. Autophagy may lead to cell death if carried out too extensively, but also acts as a survival pathway in cells under stress. In stem/progenitor cells, an autophagic phenotype could mitigate metal-induced toxicity, contributing to the conservation of tissue renewal capability. Given the key role of toxic damage to adult stem/progenitor cells in cancer, it is necessary to investigate whether autophagic responses modulate the carcinogenic potential of exposure to heavy metals during stem/progenitor cell differentiation.     

Cell fractionation analysis of human CD8 glycoprotein transport between endoplasmic reticulum, intermediate compartment and Golgi complex in tissue cultured cells

We have set up an analytical cell fractionation procedure to dissect, by a non-morphological method, the anterograde transport of proteins from endoplasmic reticulum, intermediate compartment and Golgi complex in tissue cultured cells. Using this procedure after pulse-chase labelling of cells expressing human CD8 glycoprotein, we obtained results that: (1) support the view that the intermediate compartment is a distinct station in the export from the endoplasmic reticulum to the Golgi complex; and (2) strongly suggests that the O -glycosylation process starts after the intermediate compartment, presumably in the cis -Golgi complex.     

Compaction properties of an intrinsically disordered protein: Sic1 and its kinase-inhibitor domain

IDPs in their unbound state can transiently acquire secondary and tertiary structure. Describing such intrinsic structure is important to understand the transition between free and bound state, leading to supramolecular complexes with physiological interactors. IDP structure is highly dynamic and, therefore, difficult to study by conventional techniques. This work focuses on conformational analysis of the KID fragment of the Sic1 protein, an IDP with a key regulatory role in the cell-cycle of Saccharomyces cerevisiae. FT-IR spectroscopy, ESI-MS, and IM measurements are used to capture dynamic and short-lived conformational states, probing both secondary and tertiary protein structure. The results indicate that the isolated Sic1 KID retains dynamic helical structure and populates collapsed states of different compactness. A metastable, highly compact species is detected. Comparison between the fragment and the full-length protein suggests that chain length is crucial to the stabilization of compact states of this IDP. The two proteins are compared by a length-independent compaction index.     

Pea powdery mildew <Emphasis Type="Italic">er1</Emphasis> resistance is associated to loss-of-function mutations at a <Emphasis Type="Italic">MLO</Emphasis> homologous locus

The powdery mildew disease affects several crop species and is also one of the major threats for pea (Pisum sativum L.) cultivation all over the world. The recessive gene er1, first described over 60 years ago, is well known in pea breeding, as it still maintains its efficiency as a powdery mildew resistance source. Genetic and phytopathological features of er1 resistance are similar to those of barley, Arabidopsis, and tomato mlo powdery mildew resistance, which is caused by the loss of function of specific members of the MLO gene family. Here, we describe the obtainment of a novel er1 resistant line by experimental mutagenesis with the alkylating agent diethyl sulfate. This line was found to carry a single nucleotide polymorphism in the PsMLO1 gene sequence, predicted to result in premature termination of translation and a non-functional protein. A cleaved amplified polymorphic sequence (CAPS) marker was developed on the mutation site and shown to be fully co-segregating with resistance in F₂ individuals. Sequencing of PsMLO1 from three powdery mildew resistant cultivars also revealed the presence of loss-of-function mutations. Taken together, results reported in this study strongly indicate the identity between er1 and mlo resistances and are expected to be of great breeding importance for the development of resistant cultivars via marker-assisted selection.