Page last updated: 2024-10-24

NADPH oxidase complex

Definition

Target type: cellularcomponent

A enzyme complex of which the core is a heterodimer composed of a light (alpha) and heavy (beta) chain, and requires several other water-soluble proteins of cytosolic origin for activity. Functions in superoxide generation by the NADPH-dependent reduction of O2. [GOC:jl, PMID:11483596, PMID:12440767]

The NADPH oxidase complex is a multi-component enzyme system found in the plasma membrane of phagocytic cells, such as neutrophils, macrophages, and dendritic cells. This complex plays a critical role in the production of reactive oxygen species (ROS), particularly superoxide radicals (O2-), which are essential for killing invading pathogens and mediating various cellular signaling processes. The core components of the NADPH oxidase complex include:

1. **gp91phox (NOX2):** This is the catalytic subunit, a transmembrane protein that contains the FAD and heme binding sites responsible for electron transfer and superoxide generation. It is located in the plasma membrane and forms a heterodimer with p22phox.

2. **p22phox:** This transmembrane protein is associated with gp91phox and is crucial for its stability and proper assembly within the membrane.

3. **p47phox:** This cytosolic protein, along with p67phox, is recruited to the membrane upon activation. It contains SH3 domains that interact with other components of the complex and plays a role in regulating NADPH oxidase activity.

4. **p67phox:** This cytosolic protein acts as an adaptor molecule, binding to both p47phox and gp91phox. It contains a PX domain that binds to phosphoinositides, potentially facilitating membrane targeting.

5. **Rac1/Rac2:** These small GTPases are members of the Rho family and are essential for NADPH oxidase activation. They bind to p67phox and promote the assembly of the complex.

Upon activation, typically triggered by pathogens or inflammatory signals, the cytosolic components (p47phox, p67phox, and Rac1/Rac2) translocate to the membrane, assembling with the membrane-bound gp91phox/p22phox heterodimer. This assembly creates a functional NADPH oxidase complex that can transfer electrons from NADPH to molecular oxygen, generating superoxide radicals. These radicals are then converted to other ROS, such as hydrogen peroxide (H2O2), which contribute to the antimicrobial activity of phagocytes and participate in various cellular signaling pathways.'
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Proteins (3)

ProteinDefinitionTaxonomy
NADPH oxidase 4An NADPH oxidase 4 that is encoded in the genome of human. [PRO:WCB, UniProtKB:Q9NPH5]Homo sapiens (human)
Ras-related C3 botulinum toxin substrate 1A Ras-related C3 botulinum toxin substrate 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P63000]Homo sapiens (human)
Neutrophil cytosol factor 1A neutrophil cytosol factor 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P14598]Homo sapiens (human)

Compounds (42)

CompoundDefinitionClassesRoles
1-(1-naphthyl)piperazine1-(1-naphthyl)piperazine: serotonin agonist; structure given in first sourceN-arylpiperazine
ebselenebselen : A benzoselenazole that is 1,2-benzoselenazol-3-one carrying an additional phenyl substituent at position 2. Acts as a mimic of glutathione peroxidase.benzoselenazoleanti-inflammatory drug;
antibacterial agent;
anticoronaviral agent;
antifungal agent;
antineoplastic agent;
antioxidant;
apoptosis inducer;
EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor;
EC 1.13.11.34 (arachidonate 5-lipoxygenase) inhibitor;
EC 1.3.1.8 [acyl-CoA dehydrogenase (NADP(+))] inhibitor;
EC 1.8.1.12 (trypanothione-disulfide reductase) inhibitor;
EC 2.5.1.7 (UDP-N-acetylglucosamine 1-carboxyvinyltransferase) inhibitor;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor;
EC 3.1.3.25 (inositol-phosphate phosphatase) inhibitor;
EC 3.4.22.69 (SARS coronavirus main proteinase) inhibitor;
EC 3.5.4.1 (cytosine deaminase) inhibitor;
EC 5.1.3.2 (UDP-glucose 4-epimerase) inhibitor;
enzyme mimic;
ferroptosis inhibitor;
genotoxin;
hepatoprotective agent;
neuroprotective agent;
radical scavenger
fasudilfasudil : An isoquinoline substituted by a (1,4-diazepan-1-yl)sulfonyl group at position 5. It is a Rho-kinase inhibitor and its hydrochloride hydrate form is approved for the treatment of cerebral vasospasm and cerebral ischemia.

fasudil: intracellular calcium antagonist; structure in first source
isoquinolines;
N-sulfonyldiazepane
antihypertensive agent;
calcium channel blocker;
EC 2.7.11.1 (non-specific serine/threonine protein kinase) inhibitor;
geroprotector;
neuroprotective agent;
nootropic agent;
vasodilator agent
ketorolac5-benzoyl-2,3-dihydro-1H-pyrrolizine-1-carboxylic acid : A member of the class of pyrrolizines that is 2,3-dihydro-1H-pyrrolizine which is substituted at positions 1 and 5 by carboxy and benzoyl groups, respectively.

ketorolac : A racemate comprising equimolar amounts of (R)-(+)- and (S)-(-)-5-benzoyl-2,3-dihydro-1H-pyrrolizine-1-carboxylic acid. While only the (S)-(-) enantiomer is a COX1 and COX2 inhibitor, the (R)-(+) enantiomer exhibits potent analgesic activity. A non-steroidal anti-inflammatory drug, ketorolac is mainly used (generally as the tromethamine salt) for its potent analgesic properties in the short-term management of post-operative pain, and in eye drops to relieve the ocular itching associated with seasonal allergic conjunctivitis. It was withdrawn from the market in many countries in 1993 following association with haemorrhage and renal failure.

Ketorolac: A pyrrolizine carboxylic acid derivative structurally related to INDOMETHACIN. It is an NSAID and is used principally for its analgesic activity. (From Martindale The Extra Pharmacopoeia, 31st ed)
amino acid;
aromatic ketone;
monocarboxylic acid;
pyrrolizines;
racemate
analgesic;
cyclooxygenase 1 inhibitor;
cyclooxygenase 2 inhibitor;
non-steroidal anti-inflammatory drug
2-hydroxy-5-(2,5-dihydrobenzyl)aminobenzoic acidaromatic amine
quipazineQuipazine: A pharmacologic congener of serotonin that contracts smooth muscle and has actions similar to those of tricyclic antidepressants. It has been proposed as an oxytocic.piperazines;
pyridines
carbostyrilquinolin-2(1H)-one : A quinolone that is 1,2-dihydroquinoline substituted by an oxo group at position 2.

Quinolones: A group of derivatives of naphthyridine carboxylic acid, quinoline carboxylic acid, or NALIDIXIC ACID.
monohydroxyquinoline;
quinolone
bacterial xenobiotic metabolite
quinolineazaarene;
mancude organic heterobicyclic parent;
ortho-fused heteroarene;
quinolines
2-naphthylamine2-naphthylamine : A naphthylamine carrying the amino group at position 2.

2-Naphthylamine: A naphthalene derivative with carcinogenic action.
naphthylaminecarcinogenic agent
2-methylquinoline2-methylquinoline: RN given refers to parent cpd

methylquinoline : Any member of the class of quinolines carrying at least one methyl substituent.

quinaldine : A quinoline compound in which the quinoline skeleton is substituted at C-2 with a methyl group.
quinolines
2-aminopyrimidineaminopyrimidine : A member of the class of pyrimidines that is pyrimidine substituted by at least one amino group and its derivatives.

pyrimidin-2-amine : An aminopyrimidine carrying an amino group at position 2.
aminopyrimidine
2-aminobenzothiazolebenzothiazoles
alpha-aminopyridinealpha-aminopyridine: RN given refers to parent cpd; structure in Merck Index, 9th ed, #485

aminopyridine : Compounds containing a pyridine skeleton substituted by one or more amine groups.
8-aminoquinoline
6-aminoquinoline
1,2-Dihydroquinolin-2-imineaminoquinoline
5-aminoquinoline
staurosporineindolocarbazole alkaloid;
organic heterooctacyclic compound
apoptosis inducer;
bacterial metabolite;
EC 2.7.11.13 (protein kinase C) inhibitor;
geroprotector
4-aminoquinoline
sanguinarine chloride
1-(4-pyridyl)piperazine1-(4-pyridyl)piperazine: structure in first source
chelerythrine chloride
1-aminoisoquinoline
4-amino-2-methylquinoline4-amino-2-methylquinoline: used to induce miniature endplate potentials
perifosineammonium betaine;
phospholipid
EC 2.7.1.137 (phosphatidylinositol 3-kinase) inhibitor
ruboxistaurinruboxistaurin: inhibits protein kinase C beta; structure in first source
s 1033(trifluoromethyl)benzenes;
imidazoles;
pyridines;
pyrimidines;
secondary amino compound;
secondary carboxamide
anticoronaviral agent;
antineoplastic agent;
tyrosine kinase inhibitor
quercetin7-hydroxyflavonol;
pentahydroxyflavone
antibacterial agent;
antineoplastic agent;
antioxidant;
Aurora kinase inhibitor;
chelator;
EC 1.10.99.2 [ribosyldihydronicotinamide dehydrogenase (quinone)] inhibitor;
geroprotector;
phytoestrogen;
plant metabolite;
protein kinase inhibitor;
radical scavenger
3,7-dimethoxy-5,3',4'-trihydroxyflavone3,7-dimethoxy-5,3',4'-trihydroxyflavone: isolated from Veronia eremophila; structure given in first source

3',4',5-trihydroxy-3,7-dimethoxyflavone : A dimethoxyflavone that the 3,7-di-O-methyl derivative of quercetin.
dimethoxyflavone;
trihydroxyflavone
EC 1.3.1.22 [3-oxo-5alpha-steroid 4-dehydrogenase (NADP(+))] inhibitor;
metabolite
apigeninChamomile: Common name for several daisy-like plants (MATRICARIA; TRIPLEUROSPERMUM; ANTHEMIS; CHAMAEMELUM) native to Europe and Western Asia, now naturalized in the United States and Australia.trihydroxyflavoneantineoplastic agent;
metabolite
luteolin3'-hydroxyflavonoid;
tetrahydroxyflavone
angiogenesis inhibitor;
anti-inflammatory agent;
antineoplastic agent;
apoptosis inducer;
c-Jun N-terminal kinase inhibitor;
EC 2.3.1.85 (fatty acid synthase) inhibitor;
immunomodulator;
nephroprotective agent;
plant metabolite;
radical scavenger;
vascular endothelial growth factor receptor antagonist
kaempferol7-hydroxyflavonol;
flavonols;
tetrahydroxyflavone
antibacterial agent;
geroprotector;
human blood serum metabolite;
human urinary metabolite;
human xenobiotic metabolite;
plant metabolite
azaleatinazaleatin : A monomethoxyflavone that is quercetin in which the hydroxy group at position 5 is replaced by a methoxy group.7-hydroxyflavonol;
monomethoxyflavone;
tetrahydroxyflavone
plant metabolite
sotrastaurinsotrastaurin : A member of the class of maleimides that is maleimide which is substituted at position 3 by an indol-3-yl group and at position 4 by a quinazolin-4-yl group, which in turn is substituted at position 2 by a 4-methylpiperazin-1-yl group. It is a potent and selective inhibitor of protein kinase C and has been investigated as an immunosuppresant in renal transplant patients.

sotrastaurin: a potent protein kinase C-selective inhibitor; structure in first source
indoles;
maleimides;
N-alkylpiperazine;
N-arylpiperazine;
quinazolines
anticoronaviral agent;
EC 2.7.11.13 (protein kinase C) inhibitor;
immunosuppressive agent
gdc-0973cobimetinib : A member of the class of N-acylazetidines obtained by selective formal condensation of the carboxy group of 3,4-difluoro-2-(2-fluoro-4-iodoanilino)benzoic acid with the secondary amino group from the azetidine ring of 3-[(2S)-piperidin-2-yl]azetidin-3-ol. An inhibitor of mitogen-activated protein kinase that is used (as its fumarate salt) in combination with vemurafenib for the treatment of patients with unresectable or metastatic melanoma.

cobimetinib: has antineoplastic activity; structure in first source
aromatic amine;
difluorobenzene;
N-acylazetidine;
organoiodine compound;
piperidines;
secondary amino compound;
tertiary alcohol
antineoplastic agent;
EC 2.7.11.24 (mitogen-activated protein kinase) inhibitor
azd5438sulfonamide
nsc 23766NSC 23766 trihydrochloride : A hydrochloride resulting from the formal reaction of NSC 23766 with 3 mol eq. of hydrogen chloride. An inhibitor of the signalling G-protein known as RAC1 (Ras-related C3 botulinum toxin substrate 1).

Rac1 inhibitor : Any inhibitor of Rac1.
hydrochlorideantiviral agent;
apoptosis inducer;
EC 3.6.5.2 (small monomeric GTPase) inhibitor;
muscarinic antagonist
at13148
poziotinibHM781-36B: antitumor irreversible Pan-HER inhibitor for treatment of gastric canceracrylamides;
aromatic ether;
dichlorobenzene;
diether;
monofluorobenzenes;
N-acylpiperidine;
quinazolines;
secondary amino compound;
substituted aniline
antineoplastic agent;
apoptosis inducer;
epidermal growth factor receptor antagonist
bay 869766
gilteritinibgilteritinib : A member of the class of pyrazines that is pyrazine-2-carboxamide which is substituted by {3-methoxy-4-[4-(4-methylpiperazin-1-yl)piperidin-1-yl]phenyl}nitrilo, (oxan-4-yl)nitrilo and ethyl groups at positions 3,5 and 6, respectively. It is a potent inhibitor of FLT3 and AXL tyrosine kinase receptors (IC50 = 0.29 nM and 0.73 nM, respectively). Approved by the FDA for the treatment of acute myeloid leukemia in patients who have a FLT3 gene mutation.

gilteritinib: an FLT3/AXL protein tyrosine kinase inhibitor
aromatic amine;
monomethoxybenzene;
N-methylpiperazine;
oxanes;
piperidines;
primary carboxamide;
pyrazines;
secondary amino compound
antineoplastic agent;
apoptosis inducer;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor
glpg0634