BACKGROUND Glutamine synthetase (GS) plays a central role in plant nitrogen assimilation, a process intimately linked to soil water availability. We previously showed that hybrid poplar (Populus tremula X alba, INRA 717-1B4) expressing ectopically a pine cytosolic glutamine synthetase gene (GS1a) display enhanced tolerance to drought. Preliminary transcriptome profiling revealed that during dro...

AMPylation is a novel post-translational modification (PTM) involving covalent attachment of an AMP moiety to threonine/tyrosine side chains of a protein. AMPylating enzymes belonging to three different families, namely Fic/Doc, GS-ATase and DrrA have been experimentally characterized. Involvement of these novel enzymes in a myriad of biological processes makes them interesting candidates for g...

We have treated rat brain synaptoneurosomes with the crosslinking agent N,N'-1,4-phenylenedimaleimide under conditions that cause extensive crosslinking of tubulin, F-actin, and the alpha and beta subunits of three major types of heterotrimeric GTP-binding regulatory proteins (G(o), Gs, Gi) present in brain membranes. The major crosslinked products are coeluted from Bio-Gel sizing columns as ve...

Guanine nucleotide-binding regulatory proteins (G proteins) are linked to a large number of surface membrane receptors and appear to regulate a variety of effector systems located both in the plasma membrane and in other parts of the cell. The mechanism of the disseminative actions of G proteins remains obscure. During an investigation of the fate of two types of G proteins, Gs and Gi, in rat a...

Metal catalyzed oxidation of specific amino acid residues has been proposed to be an important physiological mechanism of marking proteins for proteolytic degradation. After initial oxidative inactivation of dodecameric Escherichia coli glutamine synthetase (GS), the integrity of the GS active site and protein structure was assessed by monitoring ATP binding, observing a susceptibility of GS to...

In inner organs, glutamine contributes to proliferation, detoxification and establishment of a mechanical barrier, i.e., functions essential for skin, as well. However, the age-dependent and regional peculiarities of distribution of glutamine synthetase (GS), an enzyme responsible for generation of glutamine, and factors regulating its enzymatic activity in mammalian skin remain undisclosed. To...

Work from several laboratories indicates that guanine nucleotide-binding proteins (GTP-binding proteins) are required for intracellular vesicular transport. In a previous report we presented evidence indicating that one or more heterotrimeric G proteins regulate fusion between endosomes (Colombo, M. I., Mayorga, L. S., Casey, P. J., and Stahl, P. D. (1992) Science 255, 1695-1697). We now report...

Optimizing the bread-making quality properties of flour is currently one main aims bakery industry. Therefore, this study has investigated effects N fertilization and fungicide application at wheat heading on protein content (GPC), gluten composition rheological wheat. Field experiments were carried out in North-West Italy over a 3 year period, high cultivar soft winter Grain samples collected ...

Messenger RNA levels for the alpha subunit of G-proteins expressed in adipocytes of lean and obese (ob/ob) mice were compared with relative levels of the encoded proteins. Using both toxin labeling and Western blots, expression of Gs alpha, Gi alpha-1, and Gi alpha-3 was decreased by approximately 2-fold in adipocytes of obese mice, while levels of Gi alpha-2 did not differ between the phenotyp...