Investigations into Calcium-dependent Membrane Association of 15-Lipoxygenase-1

Walther, Matthias; Wiesner, Rainer; Kühn, Hartmut

doi:10.1074/jbc.m309564200

Cited by 74 publications

(37 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These observations are in agree- ment with interleukin-4 induction of 15-LOX-1 expression in fibroblasts that starts 16 h after cytokine treatment (31). Although it is unclear what mechanisms involved in oxidative stress induce changes 15-LOX-1 activity, the polycystin/lipoxygenase/␣-toxin domain present in lipoxygenases may play a role in this induction (32) and in a possible translocation to the membrane (29).…”

Section: Discussionsupporting

confidence: 76%

See 1 more Smart Citation

Selective Survival Rescue in 15-Lipoxygenase-1-deficient Retinal Pigment Epithelial Cells by the Novel Docosahexaenoic Acid-derived Mediator, Neuroprotectin D1

Calandria

Marcheselli

Mukherjee

et al. 2009

Journal of Biological Chemistry

View full text Add to dashboard Cite

The integrity of the retinal pigment epithelial (RPE) cell is essential for the survival of rod and cone photoreceptor cells. Several stressors, including reactive oxygen species, trigger apoptotic damage in RPE cells preceded by an anti-inflammatory, pro-survival response, the formation of neuroprotectin D1 (NPD1), an oxygenation product derived from the essential omega-3 fatty acid family member docosahexaenoic acid. To define the ability of NPD1 and other endogenous novel lipid mediators in cell survival, we generated a stable knockdown human RPE (ARPE-19) cell line using short hairpin RNA to target 15-lipoxygenase-1. The 15-lipoxygenase-1-deficient cells exhibited 30% of the protein expression, and 15-lipoxygenase-2 remained unchanged, as compared with an ARPE-19 cell line control established using nonspecific short hairpin RNA transfected cells. NPD1 synthesis was stimulated by tumor necrosis factor ␣/H 2 O 2 -mediated oxidative stress in nonspecific cells (controls), whereas in silenced cells, negligible amounts of NPD1, 12(S)-and 15(S)-hydroxyeicosatetraenoic acid, and lipoxin A 4 were found under these conditions. Neither control nor the deficient cells showed an increase in 15-lipoxygenase-1 protein content after 16 h of oxidative stress, suggesting that the increased activity of 15-lipoxygenase-1 is due to activation of pre-existing proteins. 15-Lipoxygenase-silenced cells also displayed an exacerbated sensitivity to oxidative stress-induced apoptosis when compared with the control cells. NPD1 selectively and potently rescued 15-lipoxygenase-silenced cells from oxidative stress-induced apoptosis. These results demonstrate that 15-lipoxygenase-1 is activated by oxidative stress in ARPE-19 cells and that NPD1 is part of an early survival signaling in RPE cells. Retinal pigment epithelial (RPE)2 cells are essential for the survival of rod and cone photoreceptors. RPE cells mediate the renewal of photoreceptor outer segments (1, 2); synthesis and secretion of neurotrophins (3); recycling of bleached visual pigments; and transport of vitamin A (4), docosahexaenoic acid (DHA), and other nutrients, and ions and fluids between photoreceptors and the choriocapillaries (5). Failure of RPE cells to accomplish their functions leads to photoreceptor damage or death and, as a consequence, decreased vision and eventually blindness. Apoptotic cell death of RPE cells takes place in retinal degenerative diseases, including retinitis pigmentosa and age-related macular degeneration; as a result, photoreceptors degenerate (6, 7).Cell fate decisions made at the ectoderm yield either neuronal progeny or RPE cells. Thus RPE cells display similarities to neuronal lineages, even when differentiated (8), that make them suitable for conversion into neurons for therapeutic purposes (9). For example, recent studies revealed mechanisms for the transdifferentiation of RPE cells that depend on the expression status of certain genes (10). These studies have created a new interest in RPE cells caused by the potential applications not on...

show abstract

Section: Discussionsupporting

confidence: 76%

“…In rabbit immune cells, translocation of reticulocyte 15-LOX-1 from the cytoplasm to cellular membranes (except nuclear ones) was shown to be promoted by calcium interactions that facilitate protein binding (29). The translocation results in increased activity in free and membrane-bound fatty acid oxygenation in that system (30).…”

Section: Discussionmentioning

confidence: 99%

Selective Survival Rescue in 15-Lipoxygenase-1-deficient Retinal Pigment Epithelial Cells by the Novel Docosahexaenoic Acid-derived Mediator, Neuroprotectin D1

Calandria

Marcheselli

Mukherjee

et al. 2009

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Based on the sequence identity to the membrane-targeting domain of gangrene ␣-toxin and site-directed mutagenesis experiments, Ca 2ϩ -binding amino acids have been identified in its N-terminal domain. Calcium has also been shown to promote the binding of 15S-LOX1 to membranes; however, this interaction does not appear to require specific Ca 2ϩ -binding amino acids (7). The structure of 8R-LOX reveals clearly defined calcium-binding sites in its C2-like domain, and the chelating residues are conserved in both 5-LOX and gangrene ␣-toxin.…”

Section: Discussionmentioning

confidence: 97%

“…The fold of the ␤-barrel domain resembles that of a "C2" module, calcium-dependent membrane-targeting domains found in many protein kinases and phospholipases (3), and is equivalent in topology to the C2-like membrane-binding domain of gangrene ␣-toxin (4). Similarly, the ␤-barrel domains of LOXs have also been shown to mediate membrane binding (5)(6)(7).…”

Section: Lipoxygenases (Loxs)mentioning

confidence: 99%

Insights from the X-ray Crystal Structure of Coral 8R-Lipoxygenase

Oldham

Brash

Newcomer

2005

Journal of Biological Chemistry

View full text Add to dashboard Cite

Lipoxygenases (LOXs) catalyze the regio-and stereospecific dioxygenation of polyunsaturated membrane-embedded fatty acids. We report here the 3.2 Å resolution structure of 8R-LOX from the Caribbean sea whip coral Plexaura homomalla, a LOX isozyme with calcium dependence and the uncommon R chiral stereospecificity. Structural and spectroscopic analyses demonstrated calcium binding in a C2-like membrane-binding domain, illuminating the function of similar amino acids in calcium-activated mammalian 5-LOX, the key enzyme in the pathway to the pro-inflammatory leukotrienes. Mutation of Ca 2؉ -ligating amino acids in 8R-LOX resulted not only in a diminished capacity to bind membranes, as monitored by fluorescence resonance energy transfer, but also in an associated loss of Ca 2؉ -regulated enzyme activity. Moreover, a structural basis for R chiral specificity is also revealed; creation of a small oxygen pocket next to Gly 428 (Ala in all S-LOX isozymes) promoted C-8 oxygenation with R chirality on the activated fatty acid substrate.

show abstract

“…Surface exposed hydrophobic amino acids (bride residues) surround the entrance into the substrate-binding pocket. Most of these amino acids have been implicated in membrane binding of the enzyme as indicated by site-directed mutagenesis [120].…”

Section: Oxidation Hypothesis Of Atherosclerosismentioning

confidence: 99%

The role of lipoxygenase-isoforms in atherogenesis

Kühn¹,

Römisch²,

Belkner³

2005

Mol. Nutr. Food Res.

View full text Add to dashboard Cite

Lipoxygenases (LOXs) form a heterogeneous family of lipid-peroxidizing enzymes, and several LOX-isoforms (12/15-LOX, 5-LOX) have been implicated in atherogenesis. However, the precise role of these enzymes is still a matter of discussion. 12/15-LOXs are capable of oxidizing lipoproteins (low-density lipoprotein (LDL), high-density lipoprotein (HDL)) to atherogenic forms, and functional inactivation of this enzyme in murine atherosclerosis models slows down lesion formation. In contrast, rabbits that overexpress this enzyme were protected from lesion formation when fed a lipid-rich diet. To contribute to this discussion, we recently investigated the impact of 12/15-LOX overexpression on in vitro foam cell formation. When 12/15-LOX-transfected J774 cells were incubated in culture with modified LDL, we found that intracellular lipid deposition was reduced in the transfected cells when compared with the corresponding control transfectants. This paper briefly summarizes the current status of knowledge on the biological activity of different LOX-isoforms in atherogenesis and will also provide novel experimental data characterizing the role of 12/15-LOX in cellular LDL modification and for in vitro foam cell formation.

show abstract

Investigations into Calcium-dependent Membrane Association of 15-Lipoxygenase-1

Cited by 74 publications

References 42 publications

Selective Survival Rescue in 15-Lipoxygenase-1-deficient Retinal Pigment Epithelial Cells by the Novel Docosahexaenoic Acid-derived Mediator, Neuroprotectin D1

Selective Survival Rescue in 15-Lipoxygenase-1-deficient Retinal Pigment Epithelial Cells by the Novel Docosahexaenoic Acid-derived Mediator, Neuroprotectin D1

Insights from the X-ray Crystal Structure of Coral 8R-Lipoxygenase

The role of lipoxygenase-isoforms in atherogenesis

Contact Info

Product

Resources

About