The AP-1 site is essential for the promoter activity of NOX1/NADPH oxidase, a vascular superoxide-producing enzyme: Possible involvement of the ERK1/2-JunB pathway.
NADPH oxidase is a major source of the superoxide produced in cardiovascular tissues. The expression of NOX1, a catalytic subunit of NADPH oxidase, is induced by various vasoactive factors, including angiotensin II, prostaglandin (PG) F(2alpha), and platelet-derived growth factor (PDGF). It was reported previously that the inducible expression of NOX1 is governed by the activating transcription factor-1 (ATF-1)-myocyte enhancer factor 2B (MEF2B) cascade downstream of phosphoinositide 3 (PI3) kinase. It was also reported that extracellular signal-regulated kinase (ERK) 1/2 is involved in the expression of NOX1. To further clarify the factors involved in NOX1 induction downstream of ERK1/2, the promoter region of the NOX1 gene was analyzed. A consensus activator protein-1 (AP-1) site was found at -98/-92 in the 5'-flanking region of the rat NOX1 gene. The introduction of mutations at this site abolished PGF(2alpha)-induced transcriptional activation in a luciferase assay. Electrophoresis mobility shift assays demonstrated that PGF(2alpha) and PDGF augmented the binding of JunB to this sequence. PD98059, an inhibitor of MAPK/ERK kinase, suppressed the expression of JunB induced by PGF(2alpha) or PDGF. These results suggest that the ERK1/2-JunB pathway is a key regulator of the inducible expression of the NOX1 gene in vascular smooth muscle cells.
Cevik
Muhammer Ozgur
MO
Department of Pharmacology, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan.
Katsuyama
Masato
M
Kanda
Sayaka
S
Kaneko
Tetsuo
T
Iwata
Kazumi
K
Ibi
Masakazu
M
Matsuno
Kuniharu
K
Kakehi
Tomoko
T
Cui
Wenhao
W
Sasaki
Mika
M
Yabe-Nishimura
Chihiro
C
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D016384:Consensus Sequence; D015237:Dinoprost / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000201:enzymology*; D009154:Mutation; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics*; D000074624:NADPH Oxidase 1; D011401:Promoter Regions, Genetic; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D051381:Rats; D013481:Superoxides / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects; D015533:Transcriptional Activation
D047428:Protein Kinase Inhibitors; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D013481:Superoxides; D015237:Dinoprost; D009247:NADH, NADPH Oxidoreductases; D000074624:NADPH Oxidase 1; C000614712:NOX1 protein, rat; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3