Role of apoptosis in disease.

Since the initial description of apoptosis, a number of different forms of cell death have been described. In this review we will focus on classic caspase-dependent apoptosis and its variations that contribute to diseases. Over fifty years of research have clarified molecular mechanisms involved in apoptotic signaling as well and shown that alterations of these pathways lead to human diseases.

Transcriptional regulation of the human FPR2/ALX gene: evidence of a heritable genetic variant that impairs promoter activity.

Lipoxin (LX) A(4,) a main endogenous stop-signal of inflammation, activates the G-protein-coupled receptor FPR2/ALX, which triggers potent anti-inflammatory signaling in vivo. Thus, the regulation of FPR2/ALX expression may have pathophysiological and therapeutic relevance. Here, we mapped a nucleotide sequence with strong FPR2/ALX promoter activity.

Methionine sulfoxide reductase A down-regulation in human breast cancer cells results in a more aggressive phenotype.

Breast cancer is one of the most frequent of human malignancies, and it is therefore fundamental to identify the underlying molecular mechanisms leading to cancer transformation. Among other causative agents in the development of breast cancers, an important role for reactive oxygen species (ROS) has emerged. However, most studies on the role of ROS in cancer have not reached specific conclusions, and many issues remain controversial.

An RPE cell line as a useful in vitro model for studying retinoic acid receptor beta: expression and affinity.

Retinoids mediate their biological effect by interacting with specific nuclear receptors. Of the several known RAR (retinoic acid receptor) subtypes, RAR-beta is of particular interest, since its expression is silenced in many cancers and it is believed to be a tumour suppressor. Specific ligands of RAR-beta can potentially be used in anti-cancer therapy.

Cysteine 10 is critical for the activity of Ochrobactrum anthropi glutathione transferase and its mutation to alanine causes the preferential binding of glutathione to the H-site.

The role of the evolutionarily conserved residue Cys10 in Ochrobactrum anthropi glutathione transferase (OaGST) has been examined by replacing it with an alanine. A double mutant C10A/S11A was also prepared. The effect of the replacements on the coniugating and thiotransferase activities, and on the thermal and chemical stability of the enzyme was analyzed.

Important roles of multiple Sp1 binding sites and epigenetic modifications in the regulation of the methionine sulfoxide reductase B1 (MsrB1) promoter.

Background: Methionine sulfoxide reductases (Msrs) are enzymes that catalyze the reduction of oxidized methionine residues. Most organisms that were genetically modified to lack the MsrA gene have shown shortening of their life span. Methionine sulfoxide reductases B (MsrB) proteins codified by three separate genes, named MsrB1, MsrB2, and MsrB3, are included in the Msrs system.

Role of Ser11 in the stabilization of the structure of Ochrobactrum anthropi glutathione transferase.

GSTs (glutathione transferases) are a multifunctional group of enzymes, widely distributed and involved in cellular detoxification processes. In the xenobiotic-degrading bacterium Ochrobactrum anthropi, GST is overexpressed in the presence of toxic concentrations of aromatic compounds such as 4-chlorophenol and atrazine. We have determined the crystal structure of the GST from O.

Identification and analysis of the promoter region of the human methionine sulphoxide reductase A gene.

MsrA (methionine sulphoxide reductase A) is an antioxidant repair enzyme that reduces oxidized methionine to methionine. Moreover, the oxidation of methionine residues in proteins is considered to be an important consequence of oxidative damage to cells. To understand mechanisms of human msrA gene expression and regulation, we cloned and characterized the 5' promoter region of the human msrA gene.

Expression of glutathione S-transferase and peptide methionine sulphoxide reductase in Ochrobactrum anthropi is correlated to the production of reactive oxygen species caused by aromatic substrates.

Peptide methionine sulphoxide reductase (MsrA) and glutathione S-transferases (GSTs) are considered as detoxification enzymes. In the xenobiotics-degrading bacterium Ochrobactrum anthropi the two enzymes are co-induced by toxic concentrations of aromatic substrates such as phenol and 4-chlorophenol. In aerobic organisms, degradation of aromatic substrates by mono- and dioxygenases leads to a generation of oxidative stress that causes the occurrence of reactive oxygen species (ROS).

Contribution of the two conserved tryptophan residues to the catalytic and structural properties of Proteus mirabilis glutathione S-transferase B1-1.

PmGSTB1-1 (Proteus mirabilis glutathione S-transferase B1-1) has two tryptophan residues at positions 97 and 164 in each monomer. Structural data for this bacterial enzyme indicated that Trp97 is positioned in the helix a4, whereas Trp164 is located at the bottom of the helix a6 in the xenobiotic-binding site. To elucidate the role of the two tryptophan residues they were replaced by site-directed mutagenesis.

A novel amphibian Pi-class glutathione transferase isoenzyme from Xenopus laevis: importance of phenylalanine 111 in the H-site.

Screening of a liver tumour cDNA library from Xenopus laevis resulted in the isolation of a full-length cDNA clone encoding a novel Pi-class amphibian glutathione transferase (GST) isoenzyme (designated as XlGSTP1-1). The gene encodes a protein of 212 amino acids with a calculated molecular mass of 24428 Da. The product of the gene has been overexpressed in Escherichia coli and characterized.

Proteus mirabilis glutathione S-transferase B1-1 is involved in protective mechanisms against oxidative and chemical stresses.

We investigated the effects of several xenobiotics, including antimicrobial agents and general stress factors such as starvation, heat and osmotic shock, on the modulation of expression of Proteus mirabilis glutathione S-transferase B1-1 (PmGST B1-1). The level of expression of PmGST B1-1 was established by both Western- and Northern-blot experiments. Our results show that several compounds can modulate expression of PmGST B1-1.

Liquid chromatography-electrospray mass spectrometry study of cysteine-10 S-glutathiolation in recombinant glutathione S-transferase of Ochrobactrum anthropi.

Glutathione S-transferase of Ochrobactrum anthropi (OaGST), a bacterium isolated from soils contaminated by xenobiotic pollutants, was recently purified, cloned and characterised in our laboratories. The recombinant OaGST (rOaGST), highly expressed in Escherichia coli, when purified by glutathione-affinity chromatography and then analysed by electrospray ionisation mass spectrometry (ESI-MS), has evidenced a disulphide bond with glutathione (S-glutathiolation), which was removable by reduction with 2-mercaptoethanol. Enzymatic digestion of rOaGST with endoproteinase Glu-C, followed by liquid chromatography (LC)-ESI-MS analyses of the peptide mixtures under both reducing and not reducing conditions, have shown that glutathione was covalently bound to the Cys10 residue of rOaGST.

Mu-class glutathione transferase from Xenopus laevis: molecular cloning, expression and site-directed mutagenesis.

A cDNA encoding a Mu-class glutathione transferase (XlGSTM1-1) has been isolated from a Xenopus laevis liver library, and its nucleotide sequence has been determined. XlGSTM1-1 is composed of 219 amino acid residues with a calculated molecular mass of 25359 Da. Unlike many mammalian Mu-class GSTs, XlGSTM1-1 has a narrow spectrum of substrate specificity and it is also less effective in conjugating 1-chloro-2,4-dinitrobenzene.

Glutamic acid-65 is an essential residue for catalysis in Proteus mirabilis glutathione S-transferase B1-1.

The functional role of three conserved amino acid residues in Proteus mirabilis glutathione S-transferase B1-1 (PmGST B1-1) has been investigated by site-directed mutagenesis. Crystallographic analyses indicated that Glu(65), Ser(103) and Glu(104) are in hydrogen-bonding distance of the N-terminal amino group of the gamma-glutamyl moiety of the co-substrate, GSH. Glu(65) was mutated to either aspartic acid or leucine, and Ser(103) and Glu(104) were both mutated to alanine.