Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.3.1 (NADPH oxidase)
 11,281 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The involvement of protein phosphatases in the activation of superoxide (O2-)- generating enzyme in human neutrophils was examined using calyculin A, an inhibitor of protein phosphatase type 1 and 2A. Calyculin A inhibited the phorbol myristate acetate (PMA)- and opsonized zymosan (OZ)-activated O2- generation by human neutrophils. This inhibitory effect of calyculin A on PMA-activated O2- generation was reversed by the addition of KT5926, a specific inhibitor of myosin light chain kinase and Ca2+/calmodulin-dependent protein kinase II. These results suggest that the addition of calyculin A may cause hyperphosphorylation of some protein(s) that plays a crucial role in the PMA-dependent activation of O2- generating enzyme, and that this protein hyperphosphorylation may be evoked by a KT5926-sensitive kinase or its downstream kinase. Whereas two-dimensional analysis involving 32P revealed that calyculin A caused the hyperphosphorylation of many proteins, KT5926 mainly reduced the calyculin A-induced hyperphosphorylation of a 67 kDa protein in activated neutrophils, suggesting that the hyperphosphorylation of the 67 kDa protein might inhibit the PMA-dependent activation of NADPH oxidase. The 67 kDa cytosolic protein was moderately phosphorylated on the addition of PMA. On the other hand, in the absence of calyculin A, KT5926 inhibited both PMA-induced O2- generation and phosphorylation of the 67 kDa protein. Amino acid sequence analysis of peptides derived from the 67 kDa protein revealed that the 67 kDa protein was identical to L-plastin, an actin-bundling protein. We conclude that optimally phosphorylated L-plastin may play some crucial role in the activation of NADPH oxidase.
 ...
PMID:Possible involvement of optimally phosphorylated L-plastin in activation of superoxide-generating NADPH oxidase. 1476 71

Innate immune defense against intracellular pathogens, like Salmonella, relies heavily on the autophagy machinery of the host. This response is studied intensively in epithelial cells, the target of Salmonella during gastrointestinal infections. However, little is known of the role that autophagy plays in macrophages, the predominant carriers of this pathogen during systemic disease. Here we utilize a zebrafish embryo model to study the interaction of S. enterica serovar Typhimurium with the macroautophagy/autophagy machinery of macrophages in vivo. We show that phagocytosis of live but not heat-killed Salmonella triggers recruitment of the autophagy marker GFP-Lc3 in a variety of patterns labeling tight or spacious bacteria-containing compartments, also revealed by electron microscopy. Neutrophils display similar GFP-Lc3 associations, but genetic modulation of the neutrophil/macrophage balance and ablation experiments show that macrophages are critical for the defense response. Deficiency of atg5 reduces GFP-Lc3 recruitment and impairs host resistance, in contrast to atg13 deficiency, indicating that Lc3-Salmonella association at this stage is independent of the autophagy preinitiation complex and that macrophages target Salmonella by Lc3-associated phagocytosis (LAP). In agreement, GFP-Lc3 recruitment and host resistance are impaired by deficiency of Rubcn/Rubicon, known as a negative regulator of canonical autophagy and an inducer of LAP. We also found strict dependency on NADPH oxidase, another essential factor for LAP. Both Rubcn and NADPH oxidase are required to activate a Salmonella biosensor for reactive oxygen species inside infected macrophages. These results identify LAP as the major host protective autophagy-related pathway responsible for macrophage defense against Salmonella during systemic infection. Abbreviations: ATG: autophagy related gene; BECN1: Beclin 1; CFU: colony forming units; CYBA/P22PHOX: cytochrome b-245, alpha chain; CYBB/NOX2: cytochrome b-245 beta chain; dpf: days post fertilization; EGFP: enhanced green fluorescent protein; GFP: green fluorescent protein; hfp: hours post fertilization; hpi: hours post infection; IRF8: interferon regulatory factor 8; Lcp1/L-plastin: lymphocyte cytosolic protein 1; LAP: LC3-associated phagocytosis; MAP1LC3/LC3: microtubule-associated protein 1A/1B-light chain 3; mCherry: red fluorescent protein; mpeg1: macrophage expressed gene 1; mpx: myeloid specific peroxidase; NADPH oxidase: nicotinamide adenine dinucleotide phosphate oxidase; NCF4/P40PHOX: neutrophil cytosolic factor 4; NTR-mCherry: nitroreductase-mCherry fusion; PTU: phenylthiourea; PtdIns3K: class III phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol 3-phosphate; RB1CC1/FIP200: RB-1 inducible coiled coin 1; ROS: reactive oxygen species; RT-PCR: reverse transcriptase polymerase chain reaction; RUBCN/RUBICON: RUN and cysteine rich domain containing BECN1-interacting protein; SCV: Salmonella-containing vacuole; S. Typhimurium/S.T: Salmonella enterica serovar Typhimurium; TEM: transmission electron microscopy; Tg: transgenic; TSA: tyramide signal amplification; ULK1/2: unc-51-like autophagy activating kinase 1/2; UVRAG: UVRAG: UV radiation resistance associated; wt: wild type.
 ...
PMID:Macrophages target Salmonella by Lc3-associated phagocytosis in a systemic infection model. 3067 40