Keap1 perceives stress via three sensors for the endogenous signaling molecules nitric oxide, zinc, and alkenals.

Recognition and repair of cellular damage is crucial if organisms are to survive harmful environmental conditions. In mammals, the Keap1 protein orchestrates this response, but how it perceives adverse circumstances is not fully understood. Herein, we implicate NO, Zn(2+), and alkenals, endogenously occurring chemicals whose concentrations increase during stress, in this process.

Cell homeostasis in a Leishmania major mutant overexpressing the spliced leader RNA is maintained by an increased proteolytic activity.

Although several stage-specific genes have been identified in Leishmania, the molecular mechanisms governing developmental gene regulation in this organism are still not well understood. We have previously reported an attenuation of virulence in Leishmania major and L. braziliensis carrying extra-copies of the spliced leader RNA gene.

Proteins interacting with Saccharomyces cerevisiae type 1 protein phosphatase catalytic subunit identified by single-step affinity purification and mass spectrometry.

The catalytic subunit of type 1 protein phosphatase (PP1C) interacts with a large number of polypeptides in eukaryotic cells from yeast to man and these regulatory subunits can both modulate the activity of PP1C and target it to different subcellular locations. Thus, PP1 is really a family of protein phosphatases that share a common catalytic subunit, and identifying and characterizing the PP1-associated proteins is therefore critical to understanding the cellular roles of PP1 and its ability to dephosphorylate specific substrates. Here we describe methods for affinity isolation of PP1C-containing protein complexes in the yeast Saccharomyces cerevisiae and the identification of the associated polypeptides by mass spectrometry.

Comparative analysis of the excretory-secretory proteome of the muscle larva of Trichinella pseudospiralis and Trichinella spiralis.

The nematodes Trichinella spiralis and Trichinella pseudospiralis are both intracellular parasites of skeletal muscle cells and induce profound alterations in the host cell resulting in a re-alignment of muscle-specific gene expression. While T. spiralis induces the production of a collagen capsule surrounding the host-parasite complex, T.

Laboratory studies of dissolved radiolabelled microcystin-LR in lake water.

The fate of dissolved microcystin-LR was studied in laboratory experiments using surface water taken from a eutrophic lake. Based on initial range finding, a concentration of 50 microg l(-1) dissolved 14C-microcystin-LR was selected for subsequent time-course experiments. The first was performed in May before the cyanobacterial bloom season and low increases in the radioactivity of particulate fractions occurred with an approx.

Comparative effects and metabolism of two microcystins and nodularin in the brine shrimp Artemia salina.

The toxicity and metabolism of the cyanobacterial toxins microcystin-LR (MCLR), Dhb-microcystin-HtyR and nodularin were investigated in the cysts, nauplii and adults of the brine shrimp Artemia salina. The presence of the phase II detoxication system glutathione S-transferase (sGST) in these stages was shown using different substrates. Exposure of adult A.

Novel interactions of Saccharomyces cerevisiae type 1 protein phosphatase identified by single-step affinity purification and mass spectrometry.

The catalytic subunit of Saccharomyces cerevisiae type 1 protein phosphatase (PP1(C)) is encoded by the essential gene GLC7 and is involved in regulating diverse cellular processes. To identify potential regulatory or targeting subunits of yeast PP1(C), we tagged Glc7p at its amino terminus with protein A and affinity-purified Glc7p protein complexes from yeast. The purified proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and identified by peptide mass fingerprint analysis using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry.