Anionic lipid-induced conformational changes in human phagocyte flavocytochrome b precede assembly and activation of the NADPH oxidase complex

2012 ◽  
Vol 521 (1-2) ◽  
pp. 24-31 ◽  
Author(s):  
Ross M. Taylor ◽  
Marcia H. Riesselman ◽  
Connie I. Lord ◽  
Jeannie M. Gripentrog ◽  
Algirdas J. Jesaitis
Keyword(s):  
Nadph Oxidase ◽  
Conformational Changes ◽  
Anionic Lipid ◽  
Nadph Oxidase Complex ◽  
Flavocytochrome B

scholarly journals p21-activated kinase (Pak) regulates NADPH oxidase activation in human neutrophils

Blood ◽  
2005 ◽  
Vol 106 (12) ◽  
pp. 3962-3969 ◽  
Author(s):  
Kendra D. Martyn ◽  
Moon-Ju Kim ◽  
Mark T. Quinn ◽  
Mary C. Dinauer ◽  
Ulla G. Knaus
Keyword(s):  
Plasma Membrane ◽  
Nadph Oxidase ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Human Neutrophils ◽  
C Terminus ◽  
Nadph Oxidase Complex ◽  
Direct Binding ◽  
Membrane Target ◽  
P21 Activated Kinase ◽  
Flavocytochrome B

The phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase plays an instrumental role in host defense and contributes to microbicial killing by releasing highly reactive oxygen species. This multicomponent enzyme is composed of membrane and cytosolic components that assemble in the plasma membrane or phagolysosome. While the guanosine S′-triphosphatase (GTPase) Rac2 has been shown to be a critical regulator of NADPH oxidase activity and assembly, the role of its effector, p21-activated kinase (Pak), in oxidase function has not been well defined. Using HIV-1 Tat-mediated protein transduction of Pak inhibitory domain, we show here that Pak activity is indeed required for efficient superoxide generation in intact neutrophils. Furthermore, we show that Pak translocates to the plasma membrane upon N-formyl-methionyl-leucyl-phenylalanine (fMLF) stimulation and colocalizes with translocated p47phox and with p22phox, a subunit of flavocytochrome b558. Although activated Pak phosphorylated several essential serine residues in the C-terminus of p47phox, direct binding to p47phox was not observed. In contrast, active Pak bound directly to p22phox, suggesting flavocytochrome b was the oxidase-associated membrane target of this kinase and this association may facilitate further phosphorylation of p47phox in the assembling NADPH oxidase complex.

The Heme Component of the Neutrophil NADPH Oxidase Complex Is a Target for Aryliodonium Compounds†

Biochemistry ◽  
1999 ◽  
Vol 38 (12) ◽  
pp. 3694-3703 ◽  
Author(s):  
Jacques Doussiere ◽  
Jacques Gaillard ◽  
Pierre V. Vignais
Keyword(s):  
Nadph Oxidase ◽  
Nadph Oxidase Complex

scholarly journals Characterization of the NADPH Oxidase Complex in Human Myometrial and Leiomyoma Smooth Muscle Cells.

2009 ◽  
Vol 81 (Suppl_1) ◽  
pp. 295-295
Author(s):  
Fernando Mesquita ◽  
Erica Marsh ◽  
Mayandi Sivaguru ◽  
Romana Nowak
Keyword(s):  
Smooth Muscle ◽  
Nadph Oxidase ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Nadph Oxidase Complex

scholarly journals The mechanism of activation of NADPH oxidase in the cell-free system: the activation process is primarily catalytic and not through the formation of a stoichiometric complex

1999 ◽  
Vol 341 (2) ◽  
pp. 251-255 ◽  
Author(s):  
Andrew R. CROSS ◽  
Richard W. ERICKSON ◽  
John T. CURNUTTE
Keyword(s):  
Nadph Oxidase ◽  
Binding Site ◽  
Single Molecule ◽  
Active State ◽  
Stable Complex ◽  
Activation Process ◽  
Free System ◽  
Cell Free System ◽  
Flavocytochrome B ◽  
Stoichiometric Complex

It is commonly assumed that activation of the superoxide-generating NADPH oxidase requires the formation of a stable complex between flavocytochrome b-245 (the gp91phox/p22phox heterodimer) and the cytosolic cofactors p47phox, p67phox and Rac2. This association is thought to convert flavocytochrome b-245, which contains the NADPH-binding site, flavin and haem centres, from an inactive into an active state. Here we provide evidence that, in the cell-free system, this activation process does not necessarily require the formation of a stable stoichiometric complex between the phox proteins. To explain this data we propose the hypothesis that p67phox (and possibly Rac2), are capable of activating flavocytochrome b-245 in a catalytic fashion, where a single molecule of p67phox (or Rac2) is capable of activating multiple flavocytochrome b-245 molecules.

scholarly journals Role of l-amino acid oxidase isolated from Calloselasma rhodostoma venom on neutrophil NADPH oxidase complex activation

Toxicon ◽  
2018 ◽  
Vol 145 ◽  
pp. 48-55 ◽  
Author(s):  
Mauro Valentino Paloschi ◽  
Charles Nunes Boeno ◽  
Jéssica Amaral Lopes ◽  
André Eduardo dos Santos da Rosa ◽  
Weverson Luciano Pires ◽  
...  
Keyword(s):  
Amino Acid ◽  
Nadph Oxidase ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Nadph Oxidase Complex ◽  
Calloselasma Rhodostoma

The Ku70 autoantigen interacts with p40phox in B lymphocytes

1999 ◽  
Vol 112 (4) ◽  
pp. 503-513
Author(s):  
N. Grandvaux ◽  
S. Grizot ◽  
P.V. Vignais ◽  
M.C. Dagher
Keyword(s):  
Nadph Oxidase ◽  
B Lymphocytes ◽  
B Lymphocyte ◽  
Cell Extract ◽  
Dependent Protein ◽  
Terminal Amino ◽  
Flavocytochrome B ◽  
Lymphocyte Cell ◽  
Two Hybrid

Ku70, a regulatory component of the DNA-dependent protein kinase, was identified by a yeast two-hybrid screen of a B lymphocyte cDNA library as a partner of p40phox, a regulatory component of the O2--producing NADPH oxidase. Truncated constructs of p40phox and Ku70 were used to map the interacting sites. The 186 C-terminal amino acids (aa) of Ku70 were found to interact with two distinct regions of p40phox, the central core region (aa 50–260) and the C-terminal extremity (aa 260–339). In complementary experiments, it was observed that Ku70 binds to immobilized recombinant p40phox fusion protein and that p40phox and Ku70 from a B lymphocyte cell extract comigrate in successive chromatographies on Q Separose, Superose 12 and hydroxylapatite columns. Moreover, we report that Ku70 and p40phox colocalize in B lymphocytes and in transfected Cos-7 cells. We also show that the two NADPH oxidase activating factors, p47phox and p67phox are substrates for DNA-PK in vitro and that they are present together with p40phox in the nucleus of B cells. These results may help solve the paradox that the phox protein triad, p40phox, p47phox and p67phox, is expressed equally in B lymphocytes and neutrophils, whereas the redox component of the NADPH oxidase, a flavocytochrome b, which is well expressed in neutrophils, is barely detectable in B lymphocytes.

Exaggerated vasomotor response to ANG II in rats with fetal programming of hypertension associated with exposure to a low-protein diet during gestation

2006 ◽  
Vol 291 (4) ◽  
pp. R1060-R1068 ◽  
Author(s):  
C. Yzydorczyk ◽  
F. Gobeil ◽  
G. Cambonie ◽  
I. Lahaie ◽  
N. L. O. Lê ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Renin Angiotensin System ◽  
Underlying Mechanism ◽  
Maximal Response ◽  
Ang Ii ◽  
Vasomotor Response ◽  
Enhanced Chemiluminescence ◽  
Low Protein ◽  
Diphenylene Iodonium ◽  
Nadph Oxidase Complex

The renin-angiotensin system plays a key role in the initiation and maintenance of elevated blood pressure associated with altered intrauterine milieu. The current studies were undertaken to verify whether vascular response to ANG II is increased in adult offspring of low-protein fed dams (LP) compared with control (CTRL) and if so, to examine underlying mechanism(s). ANG II-induced contraction of carotid rings was increased in LP (Emax, the maximum asymptote of the curve, relative to maximal response to KCl 80 mM: 230 ± 3% LP vs. 201 ± 2% CTRL, P < 0.05). In both groups, contraction to ANG II was mediated solely by AT1R. Responses to thromboxane A2 analog U-46619 and to KCl 80 mM under step increases in tension were similar between groups. Endothelium depletion enhanced contraction to ANG II in both groups, more so in LP. Blockade of endothelin formation had no effect on response to ANG II, and ANG-(1–7) did not elicit vasomotor response in either group. Superoxide dismutase (SOD) analog Tempol normalized LP without modifying CTRL response to ANG II. Basal levels of superoxide (aortic segments, lucigenin-enhanced chemiluminescence and fluorescent dye hydroethidine) were higher in LP. ANG II further increased superoxide production in LP only, and this was inhibited by coincubation with diphenylene iodonium or apocynin (inhibitor of NADPH oxidase complex). AT1R expression in carotid arteries was increased in LP, whereas SOD expression was unchanged. In conclusion, vasoconstriction to ANG II is exaggerated in this model of developmental programming of hypertension, secondary to enhanced vascular production of superoxide anion by NADPH oxidase with concomitant increase of AT1R expression.

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