Table 1.

Nicotinamide Adenine Dinucleotide Phosphate Oxidase Isoforms, Subunits, and Expression

Enzyme	Subunits/motifs	Detected product	Activity	High-level tissue expression	Putative involvement in CNS function and disease
NOX1	p22phox (M)	O2−•	Low basal activity phosphorylation-dependent translocation of cytosolic subunits	Colon	Cell death of dopaminergic neurons in PD
	NOXO1 (C)			Vascular smooth muscle cells Endothelial cells
	NOXA1 (C)
	RAC1 (C)
	TKS4/5 (C)
	PDI
NOX2	p22phox (M)	O2−•	Low basal activity phosphorylation-dependent translocation of cytosolic subunits	Phagocytes	Synaptic connectivity
	p47phox (C)			Vascular/endothelial cells	Microglia proliferation and function
	p67phox (C)				Neural stem cell proliferation
	p40phox (C)				Neurotransmitter release
	RAC1/2 (C)
	6-Phosphogluconate dehydrogenase (6GPH)
	S100A8
	PDI
	Peroxiredoxin 6
NOX3	p22phox (M)	O2−•	Unclear	Inner ear	Otoconia formation
	NOXO1 (C)
	RAC1 (C)
NOX4	p22phox (M)	H2O2	Constitutive activity	Kidney	Neuronal expression increased after stroke
	POLDIP2 (C)			Endothelial cells
	TKS4/5 (C)			Fibroblast
	PDI			Cardiac myocytes
				Vascular smooth muscle cells
NOX5	EF-hand domains	O2−•	Intracellular Ca2+ phosphorylation	Testis	Unknown
	Calmodulin			Lymph node
	Hsp90
DUOX1	DUOXA1(M)	H2O2	Intracellular Ca2+ phosphorylation	Thyroid gland	Unknown
	DUOXA2(M)			Respiratory tract
	EF-hand domains
DUOX2	DUOXA1(M)	H2O2	Intracellular Ca2+ phosphorylation	Thyroid gland	Unknown
	DUOXA2 (M)
	EF-hand domains

C, cytosol; M, membrane.

CNS, central nervous system; DUOX, dual oxidase; NOX, nicotinamide adenine dinucleotide phosphate-dependent oxidase; PD, Parkinson disease; PDI, protein disulfide isomerase.