Cell Signaling Technology

Product Pathways - Ca / cAMP / Lipid Signaling

Phospho-5-Lipoxygenase (Ser271) Antibody #3748

Applications Reactivity Sensitivity MW (kDa) Source
W H Transfected Only 78, 80 Rabbit

Applications Key:  W=Western Blotting
Reactivity Key:  H=Human
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

Phospho-5-Lipoxygenase (Ser271) Antibody detects transfected levels of 5-lipoxygenase protein only when phosphorylated at Ser271.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser271 of human 5-lipoxygenase protein.

Western Blotting

Western Blotting

Western blot analysis of extracts from COS cells, transfected with 5-LO wild type or 5-LO (Ser271Ala), using Phospho-5-Lipoxygenase (Ser271) Antibody. The phospho-specificity of the antibody was verified by preincubating the antibody with no peptide (upper), with 5-LO (Ser271) non-phosphopeptide (middle) or 5-LO (Ser271) phosphopeptide (lower) prior to incubating the membrane.

Western Blotting

Western Blotting

Western blot analysis of extracts from COS cells, untransfected or transfected with 5-LO wild type or 5-LO (Ser271Ala), using Phospho-5-Lipoxygenase (Ser271) Antibody (upper) and 5-Lipoxygenase (49G1) Rabbit mAb #3289 (lower). (We are thankful to Dr. Flamand from University of Michigan for providing the overexpression constructs and for his help with the antibody characterization).

Background

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.

Application References

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Companion Products

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

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