Éva Margittai

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AIMS The endoplasmic reticulum (ER) is involved in many functions, including protein folding, redox homeostasis, and Ca(2+) storage and signaling. To perform these multiple tasks, the ER is composed of distinct, specialized subregions, amongst which mitochondrial-associated ER membranes (MAM) emerge as key signaling hubs. How these multiple functions are(More)
The redox state of the intraluminal pyridine nucleotide pool was investigated in rat liver microsomal vesicles. The vesicles showed cortisone reductase activity in the absence of added reductants, which was dependent on the integrity of the membrane. The intraluminal pyridine nucleotide pool could be oxidized by the addition of cortisone or metyrapone but(More)
The endoplasmic reticulum (ER) is central for many essential cellular activities, such as folding, assembly and quality control of secretory and membrane proteins, disulfide bond formation, glycosylation, lipid biosynthesis, Ca(2+) storage and signaling. In addition, this multifunctional organelle integrates many adaptive and/or maladaptive signaling cues(More)
Stress is the imbalance of homeostasis, which can be sensed even at the subcellular level. The stress-sensing capability of various organelles including the endoplasmic reticulum (ER) has been described. It has become evident that acute or prolonged ER stress plays an important role in many human diseases; especially those involving organs/tissues(More)
The aim of the present study was the investigation of the occurrence of NADPH-generating pathways in the endoplasmic reticulum others then hexose-6-phosphate dehydrogenase. A significant isocitrate and a moderate malate-dependent NADP+ reduction were observed in endoplasmic reticulum-derived rat liver microsomes. The isocitrate-dependent activity was very(More)
It has been recently reported that tea flavanols, including epigallocatechin gallate (EGCG), efficiently inhibit glucosidase II in liver microsomes. Since glucosidase II plays a central role in glycoprotein processing and quality control in the endoplasmic reticulum we investigated the possible contribution of endoplasmic reticulum stress and unfolded(More)
Oxidative protein folding in the luminal compartment of the endoplasmic reticulum is thought to be mediated by a proteinaceous electron relay system composed by PDI and ER oxidoreductin 1 (Ero1), transferring electrons from the cysteinyl residues of substrate proteins to oxygen. However, recent observations revealed that Ero1 isoforms are dispensable.(More)
Polyunsaturated fatty acids are susceptible to peroxidation and they yield various degradation products, including the main α,β-unsaturated hydroxyalkenal, 4-hydroxy-2,3-trans-nonenal (HNE) in oxidative stress. Due to its high reactivity, HNE interacts with various macromolecules of the cell, and this general toxicity clearly contributes to a wide variety(More)
Beyond its general role as antioxidant, specific functions of ascorbate are compartmentalized within the eukaryotic cell. The list of organelle-specific functions of ascorbate has been recently expanded with the epigenetic role exerted as a cofactor for DNA and histone demethylases in the nucleus. Compartmentation necessitates the transport through(More)
Toxic endogenous or exogenous compounds can be inactivated by various conjugation reactions. Glucuronidation (i.e. conjugation with glucuronate) is especially important due to the large number of drugs and chemical carcinogens that are detoxified through this pathway. Stable and harmless glucuronides can be reactivated by enzymatic hydrolysis thus(More)