Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.25.1 (proteasome)
 28,817 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Leishmania species are protozoan parasites that exhibit an intracellular amastigote form within mammalian macrophages and an extracellular promastigote form inside the sandfly vector. The generation of nitric oxide (NO) upon activation of macrophages is surely the principal killing effector of intracellular amastigotes but little is known about the potential action of NO against the promastigote phase during its multiplication inside the digestive tract of the sandfly vector. Therefore, we have approached this issue by using an in vitro model to study the effect of an NO donor, 3-morpholinosydnonimine (SIN-1), on the proteome and infectivity of promastigotes of Leishmania infantum. Exposure of promastigotes to SIN-1 during its logarithmic growth phase caused a dramatic effect on parasite protein expression and viability, consequently killing about 60-70% of the promastigotes. The significant changes in the proteome included the over-expression of enolase, peroxidoxin precursors, and heat-shock protein 70 (HSP70), under-expression of 20S proteasome alpha 5 unit, and phosphomannomutase and induced expression of 3-hydroxy-3-methyglutaryl-CoA (HMG-CoA) synthase and prostaglandine f2-alpha (PGD2) synthase. Interestingly, promastigotes that resisted treatment showed enhanced infectivity to J774 macrophages in comparison to the controls. This finding together with the appearance of the PGD2S and an over-expression of HSP70 isoforms in treated promastigotes led us to speculate the existence of NO-mediated programmed cell death (PCD) events as a potential mechanism of population regulation and selection of properly infecting forms that predominantly operate on the promastigote stage.
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PMID:Changes in the proteome and infectivity of Leishmania infantum induced by in vitro exposure to a nitric oxide donor. 1877 35

Within the wide range of oxidative modifications, "carbonylation" formed by the incorporation of aldehyde/keto groups, is commonly studied due to its role in cell physiology and as prospective biomarkers for numerous disorders. Despite close biochemical and physiological links between protein and lipid carbonylation, these two types of modifications are rarely addressed simultaneously in a single study. In nitrosative stress cell model we investigated levels of protein and lipid carbonylation and addressed the main modified species by combining LC-MS, biochemical, and microscopy studies. The influence of nitrosative stress on carbonylation of proteins and lipids was investigated for primary cardiomyocytes treated with SIN-1 for different time intervals. Lipid carbonylation was quantified by RPC-ESI-MS/MS. The results demonstrate dynamic generation, degradation and adduct formations of 25 different species including alkanals, alkenals, alkadienals, alkatrienals and oxo-carboxylic acids. Several new PL-bound aldehydes were present exclusively after a long incubation period. Carbonylated proteins were identified after aldehyde reactive probe derivatization, affinity enrichment and RPC-ESI-MS/MS. More than 200 proteins were identified and evaluated by systems biology to deduce the biological significance of the protein modifications. The protein carbonylation degree was verified using oxyblot and correlated with changes in 20S/26S proteasome activities. Furthermore, a new fluorescence microscopy based technique to stain carbonylated biomolecules was developed and compared with conventional DNPH-based immunocytochemistry. Subcellular localization of carbonylated species was investigated using mitochondrial and ER-specific co-localization experiments. Thus, the combination of lipidomics, proteomics, biochemical techniques, and microscopy imaging revealed a complex molecular pattern of "carbonylation stress" in the studied nitrosative stress cell model.
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PMID:Protein and lipid carbonylation in cellular model of nitrosative stress: mass spectrometry, biochemistry and microscopy study. 2646 Dec 93

Reactive oxygen and nitrogen species (ROS/RNS) play an important role in the regulation of cardiac function. Increase in ROS/RNS concentration results in lipid and protein oxidation and is often associated with onset and/or progression of many cardiovascular disorders. However, interplay between lipid and protein modifications has not been simultaneously studied in detail so far. Biomolecule carbonylation is one of the most common biomarkers of oxidative stress. Using a dynamic model of nitroxidative stress we demonstrated rapid changes in biomolecule carbonylation in rat cardiomyocytes. Levels of carbonylated species increased as early as 15min upon treatment with the peroxynitrite donor, 3-morpholinosydnonimine (SIN-1), and decreased to values close to control after 16h. Total (lipids+proteins) vs. protein-specific carbonylation showed different dynamics, with a significant increase in protein-bound carbonyls at later time points. Treatment with SIN-1 in combination with inhibitors of proteasomal and autophagy/lysosomal degradation pathways allowed confirmation of a significant role of the proteasome in the degradation of carbonylated proteins, whereas lipid carbonylation increased in the presence of autophagy/lysosomal inhibitors. Electrophilic aldehydes and ketones formed by lipid peroxidation were identified and relatively quantified using LC-MS/MS. Molecular identity of reactive species was used for data-driven analysis of their protein targets. Combination of different enrichment strategies with LC-MS/MS analysis allowed identification of more than 167 unique proteins with 332 sites modified by electrophilic lipid peroxidation products. Gene ontology analysis of modified proteins demonstrated enrichment of several functional categories including proteins involved in cytoskeleton, extracellular matrix, ion channels and their regulation. Using calcium mobilization assays, the effect of nitroxidative stress on the activity of several ion channels was further confirmed.
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PMID:Cross-talk between lipid and protein carbonylation in a dynamic cardiomyocyte model of mild nitroxidative stress. 2808 93


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