Lipid Rafts Keep NADPH Oxidase in the Inactive State in Human Renal Proximal Tubule Cells

Han, Weixing; Li, Hewang; Villar, Van Anthony M.; Pascua, Annabelle; Dajani, Mustafa I.; Wang, Xiaoyang; Natarajan, Aruna; Quinn, Mark T.; Felder, Robin A.; José, Pedro A.; Yu, Pingfeng

doi:10.1161/hypertensionaha.107.103275

Cited by 77 publications

(97 citation statements)

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“…1). Estimation of total proteins found in these microdomains revealed that Ͼ90% are found in non-lipid rafts, and Ͻ10% are found in lipid rafts (31). Treatment with MCD, a cholesterol-depleting reagent, resulted in the disruption of the cholesterol-enriched lipid rafts and the re-distribution of caveolin-1, D 3 R, and GRK4 to the non-lipid rafts.…”

Section: Distribution Of D 3 R and Grk4 In Membrane Microdomains-mentioning

confidence: 98%

G Protein-coupled Receptor Kinase 4 (GRK4) Regulates the Phosphorylation and Function of the Dopamine D3 Receptor

Villar

Jones

Armando

et al. 2009

Journal of Biological Chemistry

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During conditions of moderate sodium excess, the dopaminergic system sits at the fulcrum of homeostatic control of water and electrolyte balance and blood pressure (1, 2). Dopamine promotes natriuresis by inhibiting sodium chloride reabsorption in specific segments of the nephron. Dopamine exerts its action on dopamine receptors, which belong to the family of G protein-coupled receptors (GPCRs). The signal transduction that follows ligand occupation of a GPCR is tightly regulated to limit the specificity and extent of cellular response. GPCR-mediated signal transduction is rapidly dampened via receptor desensitization or the waning of the responsiveness of the receptor to agonist with time. Desensitization involves receptor phosphorylation and is carried out by either GPCR kinases (GRKs) or second messenger-activated kinases such as protein kinase A and protein kinase C. Homologous desensitization involves GRKs that selectively phosphorylate only agonist-activated receptors, whereas heterologous desensitization is carried out by second messenger-dependent kinases that indiscriminately phosphorylate agonist-activated receptors and those that have not been exposed to the agonist (7).The GRKs are serine/threonine protein kinases comprising seven isoforms that are grouped into three subfamilies. GRK1 and GRK7 belong to the rhodopsin kinase subfamily and are expressed exclusively in the retina (8 -10). GRK2 and GRK3 phosphorylate the ␤-adrenergic receptor and belong to the ␤-adrenergic receptor kinase subfamily (11), and GRK4, GRK5, and GRK6 belong to the GRK4 subfamily. GRK4 is highly enriched in the testis and, to a lesser degree, in the kidneys (12, 13). Four splice variants of human GRK4 result from the alternative splicing of exons 2 and 15 (11). GRK4-␣ is considered the full-length version, whereas GRK4-␤, -␥, and -␦ are shortened versions of . The coding region of the GRK4 gene, whose 4p16.3 locus has been linked to essential hypertension (15, 16), contains several single nucleotide polymorphisms, including R65L, A142V, and A486V, which have been linked to * This work was supported, in whole or in part, by National Institutes of Health Grants HL023081, HL074940, DK039308, HL092196, and HL068686.

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Section: Distribution Of D 3 R and Grk4 In Membrane Microdomains-mentioning

confidence: 98%

G Protein-coupled Receptor Kinase 4 (GRK4) Regulates the Phosphorylation and Function of the Dopamine D3 Receptor

Villar

Jones

Armando

et al. 2009

Journal of Biological Chemistry

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“…Moreover, co-localization of gp91 phox with the lipid raft marker GM1 in HL-60 cells has been reported (19). In addition, colocalization of both gp91 phox and p22 phox with lipid rafts has been demonstrated in hRPT cells (12).…”

Section: Discussionmentioning

confidence: 92%

“…Similarly, extraction of cholesterol by MßCD inhibited superoxide generation in HL-60 cells (19). However, cholesterol depletion increased the ROS production in hRPT and HEK-293 cells (12). MßCD, a known disruptor of lipid rafts, also reported to rescue ROS levels in yeast and protect against oxidative stress (17).…”

Section: Discussionmentioning

confidence: 98%

“…Recently, it has been reported that membrane-bound components of NADPH oxidase are present in LRs, and cytoplasmic components are recruited to raft-associated subunits upon activation and reconstitute the active complex presumably via protein-protein interactions (11). Moreover, distribution and regulation of gp91 phox and its regulatory subunits by LRs were also reported in murine microglial, bovine aortic endothelial and bovine coronary arterial endothelial cells (12). However, there are no such studies in breast cancer cells.…”

Section: Introductionmentioning

confidence: 99%

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Regulation of NADPH oxidase (Nox2) by lipid rafts in breast carcinoma cells

Malla

Raghu²,

Rao³

2010

Int J Oncol

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Abstract. Oxidative stress has emerged as an important pathogenic factor in the development of breast cancer. Cholesterol-rich membrane rafts or lipid rafts (LRs) are reported to play an important role in oxidative stress-induced signal transduction. NADPH oxidase-dependent reactive oxygen species (ROS) production is implicated in oxidative stress in human mammary epithelial cells. In the present study, we determined the expression and regulation of membranebound subunits by LRs in human breast cancer cells. We report that basal levels of gp91 phox and p22 phox are expressed in breast cancer cells. We demonstrate for the first time that disruption of LRs resulted in the downregulation of NADPH oxidase subunits in breast cancer cells. Cholesterol depletion by 10 mM methyl-ß-cyclodextrin (MßCD) translocated both gp91 phox and p22 phox out of LRs. Moreover, lipid raft disruption decreased NADPH oxidase activity (21.1±0.5% in MCF-7 and 28.9±1.0 in BT-549 cells), which was reversed by cholesterol repletion (95%). Therefore, the results suggest that the integrity of LRs plays an important role in the regulation of NADPH oxidase activity in breast cancer cells.

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“…Destruction of rafts by cholesterol depletion activates the ROS formation from Nox2 and Nox4 NADPH oxidases in human proximal tubule cells. 22 Importantly, it was observed that dopamine D1 receptor agonists also release Rac1 from lipid rafts and thereby induce an agonist-stimulated ROS production in the kidney. 21 However, it should be mentioned that overexpression studies failed to link Rac1 with Nox4 activation.…”

Section: Nadph Oxidases In Renal Hypertensionmentioning

confidence: 99%

Vascular Functions of NADPH Oxidases

Brandes

2010

Hypertension

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NADPH oxidases belong to a group of enzymes that generate reactive oxygen species (ROS) by electron transfer from NADPH to molecular oxygen. The product of this reaction is the superoxide anion (O 2 Ϫ ), which undergoes secondary reactions. O 2 Ϫ inactivates NO to yield peroxynitrite and spontaneously or under catalysis of superoxide dismutases reacts to hydrogen peroxide. NADPH oxidases, therefore, limit vascular NO availability and facilitate reactions involving ROS. 1 It is now well understood that endothelial dysfunction is largely a consequence of NADPH oxidase activation, as well as of complex secondary reactions that involve different types of ROS. Peroxynitrite oxidizes the NO synthase cofactor tetrahydrobiopterin and stimulates kinases, which both lead to uncoupling of the endothelial NO synthase. NO and O 2 Ϫ may also affect gene expression, and, in particular, NADPH oxidase-derived hydrogen peroxide has been shown to be important in this respect. In addition to the stress-mediated ROS-stimulated gene expression, hydrogen peroxide transiently or irreversibly oxidizes biological materials and, therefore, has complex effects on signaling that are still incompletely elucidated. 1 NADPH Oxidases From Past to PresentAlthough the initial work on NADPH oxidases focused on its role for gene expression and endothelial dysfunction at large, the research of recent years aimed at the identification of specific NADPH oxidase-dependent signaling pathways, the understanding of the role of the enzymes in individual disease entities, the identification of NADPH oxidase inhibitors, and finally the demonstration of a relevance of NADPH oxidases in human cardiovascular diseases. Indeed, it is now known that patients with chronic granulomatous disease, which results from loss-of-function mutations of the NADPH oxidase, have an increased vascular NO availability and reduced vascular levels of footprint markers of ROS formation. 2 This important observation provided a direct link between NADPH oxidase and endothelial function in humans. Chronic granulomatous disease, however, is too rare and too severe to study whether the advantage in endothelial function also translates into a reduced cardiovascular disease rate. Studies on polymorphisms of NADPH oxidase genes, however, failed to draw a clear picture. 3 Thus, most data in support of a relevance of NADPH oxidases for human cardiovascular disease are based on indirect treatment studies. Several highly effective cardiovascular drugs, such as statins, peroxisome proliferator-activated receptor-␥ agonists, angiotensinconverting enzyme inhibitors, and angiotensin II type 1 (AT 1 ) receptor antagonists prevent the activation or induction of NADPH oxidases and reduce the oxidative burden in patients. 4,5 The possible conclusion that NADPH oxidases are excellent cardiovascular drug targets might, however, still be premature, in particular, in light of the failures of large prospective trials testing antioxidants. 6 These studies demonstrated that, although effective in the acute se...

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Lipid Rafts Keep NADPH Oxidase in the Inactive State in Human Renal Proximal Tubule Cells

Cited by 77 publications

References 44 publications

G Protein-coupled Receptor Kinase 4 (GRK4) Regulates the Phosphorylation and Function of the Dopamine D3 Receptor

G Protein-coupled Receptor Kinase 4 (GRK4) Regulates the Phosphorylation and Function of the Dopamine D3 Receptor

Regulation of NADPH oxidase (Nox2) by lipid rafts in breast carcinoma cells

Vascular Functions of NADPH Oxidases

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