Phospho-5-Lipoxygenase (Ser663

3749:

Western Blotting

Phospho-5-Lipoxygenase (Ser663) Antibody detects overexpressed phospho-5-lipoxygenase protein only when phosphorylated at Ser663.

Antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser663 of human 5-lipoxygenase protein.

Western Blotting

Western blot analysis of extracts from COS cells, transfected with 5-LO wild type or GFP 5-LO (Ser663Ala), using Phospho-5-Lipoxygenase (Ser663) Antibody. The phospho-specificity of the antibody was verified by preincubating the antibody with no peptide (left), with 5-LO (Ser663) non-phosphopeptide (middle) or 5-LO (Ser663) phosphopeptide (right) prior to incubating the membrane.

Western blot analysis of extracts from COS cells, untransfected, or transfected with either 5-LO wild type or GFP 5-LO (Ser663Ala), using Phospho-5-Lipoxygenase (Ser663) Antibody (upper) and 5-Lipoxygenase (C49G1) Rabbit mAb #3289 (lower). (We are thankful to Dr. Flamand from University of Michigan for providing the overexpression constructs and for his help in characterizing this antibody).

5-Lipoxygenase (5-LO, ALOX5) is an important catalytic enzyme responsible for the biosynthesis of leukotriene LTA₄ from arachidonic acid (1,2). Leukotriene synthesis also requires 5-lipoxygenase-activating protein (FLAP, ALOX5AP), a nuclear membrane-bound protein that binds arachidonic acid and is thought to activate 5-LO. A number of related leukotrienes (i.e. B₄ , C₄ , D₄ ) are derived from LTA₄ and together these lipid mediators function in immune reaction regulation. 5-LO is primarily expressed in polymorphonuclear leukocytes, peripheral blood monocytes, macrophages, and mast cells (1,3). Overexpression of 5-LO protein is seen in certain cancer cells and is associated with poor diagnosis (1,4). Depending upon the cell type, 5-LO is localized to either the cytosol or the nucleus of quiescent cells (5). Following stimulation, 5-LO translocates to the nucleus and associates with FLAP to catalyze LTA₄ synthesis (2,3). Phosphorylation of specific residues can regulate 5-LO enzymatic activity. Phosphorylation of 5-LO at Ser523 by PKA family kinases inhibits oxygenase activity (6,7) while MAPKAP2 and ERK family kinase phosphorylation at Ser271 and Ser663 stimulates 5-LO enzymatic activity in vivo (8,9).

1. Woods, J.W. et al. (1995) J Clin Invest 95, 2035-46.
2. Evans, J.F. et al. (2008) Trends Pharmacol Sci 29, 72-8.
3. Radmark, O. et al. (2007) Trends Biochem Sci 32, 332-41.
4. Chen, X. et al. (2006) Curr Cancer Drug Targets 6, 613-22.
5. Werz, O. (2002) Curr Drug Targets Inflamm Allergy 1, 23-44.
6. Luo, M. et al. (2004) J Biol Chem 279, 41512-20.
7. Luo, M. et al. (2005) J Biol Chem 280, 40609-16.
8. Werz, O. et al. (2002) FASEB J 16, 1441-3.
9. Werz, O. et al. (2002) J Biol Chem 277, 14793-800.

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• 3289 5-Lipoxygenase (C49G1) Rabbit mAb
• 3748 Phospho-5-Lipoxygenase (Ser271) Antibody
• 7003 20X LumiGLO^® Reagent and 20X Peroxide
• 7071 Phototope^® -HRP Western Blot Detection System, Anti-rabbit IgG, HRP-linked Antibody
• 7074 Anti-rabbit IgG, HRP-linked Antibody
• 7720 Prestained Protein Marker, Broad Range (Premixed Format)
• 7727 Biotinylated Protein Ladder Detection Pack

For Research Use Only. Not For Use In Diagnostic Procedures.