Evidence suggesting protein tyrosine phosphorylation in plants depends on the developmental conditions

AbstractProtein tyrosine phosphorylation plays a central role in a variety of signal transduction pathways regulating animal cell growth and differentiation, but its relevance and role in plants are controversial and still largely unknown. We report here that a large number of proteins from all plant subcellular fractions are recognized by recombinant, highly specific, anti-phosphotyrosine antibodies. Protein tyrosine phosphorylation patterns vary among different adult plant tissues or somatic embryo stages and somatic embryogenesis is blocked in vivo by a cell-permeable tyrosyl-phosphorylation inhibitor, demonstrating the involvement of protein tyrosine phosphorylation in control of specific steps in plant development

Molecular cloning and characterization of a phytochelatin synthase gene, PvPCS1, from Pteris vittata L.

Pteris vittata L. is a staggeringly efficient arsenic hyperaccumulator that has been shown to be capable of accumulating up to 23,000 microg arsenic g(-1), and thus represents a species that may fully exploit the adaptive potential of plants to toxic metals. However, the molecular mechanisms of adaptation to toxic metal tolerance and hyperaccumulation remain unknown, and P. vittata genes related to metal detoxification have not yet been identified. Here, we report the isolation of a full-length cDNA sequence encoding a phytochelatin synthase (PCS) from P. vittata. The cDNA, designated PvPCS1, predicts a protein of 512 amino acids with a molecular weight of 56.9 kDa. Homology analysis of the PvPCS1 nucleotide sequence revealed that it has low identity with most known plant PCS genes except AyPCS1, and the homology is largely confined to two highly conserved regions near the 5'-end, where the similarity is as high as 85-95%. The amino acid sequence of PvPCS1 contains two Cys-Cys motifs and 12 single Cys, only 4 of which (Cys-56, Cys-90/91, and Cys-109) in the N-terminal half of the protein are conserved in other known PCS polypeptides. When expressed in Saccharomyces cerevisae, PvPCS1 mediated increased Cd tolerance. Cloning of the PCS gene from an arsenic hyperaccumulator may provide information that will help further our understanding of the genetic basis underlying toxic metal tolerance and hyperaccumulation

KDC1, a Novel Carrot Root Hair K+Channel CLONING, CHARACTERIZATION, AND EXPRESSION IN MAMMALIAN CELLS

Potassium is an essential nutrient which plays an important role in many aspects of plant growth and development. Plants have developed a number of highly specific mechanisms to take up potassium from the soil; these include the expression of K+ transporters and potassium channels in root cells. Despite the fact that root epidermal and hair cells are in direct contact with the soil, the role of these tissues in K+uptake is not well understood. Here we report the molecular cloning and functional characterization of a novel potassium channel KDC1 which forms part of a new subfamily of plant Kinchannels. Kdc1 was isolated from carrot root RNA andin situ hybridization experiments show Kdc1 to be highly expressed in root hair cells. Expressing the KDC1 protein in Chinese hamster ovary cells identified it as a voltage and pH-dependent inwardly rectifying potassium channel. An electrophysiological analysis of carrot root hair protoplasts confirmed the biophysical properties of the Kdc1 gene product (KDC1) in the heterologous expression system. KDC1 thus represents a major K+ uptake channel in carrot root hair cells

Perioperative anaphylactic risk score for risk-oriented premedication

Basing on the current knowledge, this paper is aimed to review the core characteristics of the most relevant therapeutic agents (steroids and antihistamines), administered to prevent perioperative anaphylaxis. Moreover, the Authors propose the validation of a Global Anaphylactic Risk Score, built up by recording the individual scores related to the most relevant anaphylaxis parameters (i.e. medical history, symptoms and medication for asthma, rhinitis and urticaria etc) and by adding them on all together; the score could be used in the preoperative phase to evaluate the global anaphylactic risk and to prescribe risk-oriented premedication protocols

La Provincia di Sassari: ambiente, storia, civiltà

Essere cittadino di una provincia non significa soltanto abitarvi. Significa anche lavorarvi, esercitarvi una attività che vada a vantaggio del benessere individuale e insieme del benessere della collettività. Per fare questo, per raggiungere meglio questo obiettivo, la realtà in cui si vive e si lavora bisogna conoscerla meno superficialmente di quanto normalmente non succeda. E' una constatazione che si può fare per tutti coloro che abitano in un luogo, ma che si deve fare in modo particolare quando lo strumento di conoscenza che si propone è un libro come questo